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Any Transport over MPLS

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Any Transport over MPLS

Table Of Contents

Any Transport over MPLS

Contents

Prerequisites for Any Transport over MPLS

Restrictions for Any Transport over MPLS

Information About Any Transport over MPLS

How AToM Transports Layer 2 Packets

AToM Configuration Commands Prior to Cisco IOS Release 12.0(25)S

Benefits of AToM

MPLS Traffic Engineering Fast Reroute

Maximum Transmission Unit Guidelines for Estimating Packet Size

Estimating Packet Size: Example

mpls mtu Command Changes

Frame Relay over MPLS and DTE, DCE, and NNI Connections

Local Management Interface and Frame Relay over MPLS

QoS Features Supported with AToM

How to Configure Any Transport over MPLS

Configuring the Pseudowire Class

Configuring ATM AAL5 over MPLS on PVCs

Restrictions

Examples

Configuring ATM AAL5 over MPLS in VC Class Configuration Mode

Restriction

Examples

Configuring OAM Cell Emulation for ATM AAL5 over MPLS

Configuring OAM Cell Emulation for ATM AAL5 over MPLS on PVCs

Examples

Configuring OAM Cell Emulation for ATM AAL5 over MPLS in VC Class Configuration Mode

Examples

Configuring ATM Cell Relay over MPLS in VC Mode

Example

Configuring ATM Cell Relay over MPLS in VC Mode Using VC Class Configuration Mode

Examples

Configuring ATM Cell Relay over MPLS in PVP Mode

Examples

Configuring ATM Cell Relay over MPLS in Port Mode

Examples

Troubleshooting Tips

Configuring ATM Single Cell Relay over MPLS

Configuring ATM Packed Cell Relay over MPLS

Restrictions

Configuring ATM Packed Cell Relay over MPLS in VC Mode

Examples

Configuring ATM Packed Cell Relay over MPLS in VC Mode Using VC Class Configuration Mode

Examples

Configuring ATM Packed Cell Relay over MPLS in VP Mode

Examples

Configuring ATM Packed Cell Relay over MPLS in Port Mode

Examples

Configuring Ethernet over MPLS in VLAN Mode

Configuring Ethernet over MPLS in Port Mode

Examples

Configuring Ethernet over MPLS with VLAN ID Rewrite

Configuring Ethernet over MPLS with VLAN ID Rewrite for the Cisco 12000 Series Routers for
Cisco IOS Releases 12.0(29)S and Earlier Releases

Configuring Ethernet over MPLS with VLAN ID Rewrite for the Cisco 12000 Series Routers for
Cisco IOS Releases 12.0(30)S and Later Releases

Configuring Ethernet over MPLS with MTU Values in xconnect Configuration Mode

Restrictions

Configuring Frame Relay over MPLS with DLCI-to-DLCI Connections

Configuring Frame Relay over MPLS with Port-to-Port Connections

Configuring HDLC and PPP over MPLS

Restrictions

Configuring Tunnel Selection

Examples

Troubleshooting Tips

Setting Experimental Bits with AToM

Restrictions

Setting the Frame Relay Discard Eligibility Bit on the Cisco 7200 and 7500 Series Routers

Matching the Frame Relay DE Bit on the Cisco 7200 and 7500 Series Routers

Examples

Configuration Examples for Any Transport over MPLS

ATM over MPLS: Example

Ethernet over MPLS with MPLS Traffic Engineering Fast Reroute: Example

Configuring MTU Values in xconnect Configuration Mode for AToM: Example

Configuring MTU Values in xconnect Configuration Mode for L2VPN Interworking: Example

Additional References

Related Documents

Standards

MIBs

RFCs

Technical Assistance

Command Reference

cell-packing

encapsulation (Any Transport over MPLS)

oam-ac emulation-enable

Feature Information for Any Transport over MPLS


Any Transport over MPLS


First Published: January 1, 2001
Last Updated: July 13, 2007

Any Transport over MPLS (AToM) transports data link layer (Layer 2) packets over a Multiprotocol Label Switching (MPLS) backbone. AToM enables service providers to connect customer sites with existing Layer 2 networks by using a single, integrated, packet-based network infrastructure—a Cisco MPLS network. Instead of using separate networks with network management environments, service providers can deliver Layer 2 connections over an MPLS backbone. AToM provides a common framework to encapsulate and transport supported Layer 2 traffic types over an MPLS network core.

AToM supports the following like-to-like transport types:

ATM Adaptation Layer Type-5 (AAL5) over MPLS

ATM Cell Relay over MPLS

Ethernet over MPLS (VLAN and port modes)

Frame Relay over MPLS

PPP over MPLS

High-Level Data Link Control (HDLC) over MPLS

Finding Feature Information in This Module

Your Cisco IOS software release may not support all of the features documented in this module. To reach links to specific feature documentation in this module and to see a list of the releases in which each feature is supported, use the "Feature Information for Any Transport over MPLS" section.

Finding Support Information for Platforms and Cisco IOS and Catalyst OS Software Images

Use Cisco Feature Navigator to find information about platform support and Cisco IOS and Catalyst OS software image support. To access Cisco Feature Navigator, go to http://www.cisco.com/go/cfn. An account on Cisco.com is not required.

Contents

Prerequisites for Any Transport over MPLS

Restrictions for Any Transport over MPLS

Information About Any Transport over MPLS

How to Configure Any Transport over MPLS

Configuration Examples for Any Transport over MPLS

Additional References

Command Reference

Feature Information for Any Transport over MPLS

Prerequisites for Any Transport over MPLS

Before configuring AToM, ensure that the network is configured as follows:

Configure IP routing in the core so that the provider edge (PE) routers can reach each other via IP.

Configure MPLS in the core so that a label-switched path (LSP) exists between the PE routers.

Enable Cisco Express Forwarding or distributed Cisco Express Forwarding before configuring any Layer 2 circuits.

Configure a loopback interface for originating and terminating Layer 2 traffic. Make sure the PE routers can access the other router's loopback interface. Note that the loopback interface is not needed in all cases. For example, tunnel selection does not need a loopback interface when AToM is directly mapped to a traffic engineering (TE) tunnel.

AToM is supported on the Cisco 7200 and 7500 series routers. For details on supported hardware, see the following documents:

Cross-Platform Release Notes for Cisco IOS Release 12.0S

Cross-Platform Release Notes for Cisco IOS Release 12.4T, Part 2: Platform-Specific Information

AToM is supported on the Cisco 7600 routers. For details on supported shared port adapters and line cards, see the following documents:

Supported Hardware for Cisco 7600 Series Routers with Release 12.2SR

Release Notes for Cisco IOS Release 12.2SR for the Cisco 7600 Series Routers

The Cisco 7600 router has platform-specific instructions for configuring some AToM features. Platform-specific configuration information is included in the following documents:

The "Configuring PFC3BXL and PFC3B Mode Multiprotocol Label Switching" module of the Cisco 7600 Series Cisco IOS Software Configuration Guide, Release 12.2SR

The "Configuring Multiprotocol Label Switching on the Optical Services Modules" module of the OSM Configuration Note, Release 12.2SR

The "Configuring Multiprotocol Label Switching on FlexWAN and Enhanced FlexWAN Modules" module of the Cisco 7600 Series Router Module Configuration Notes

The "Configuring Any Transport over MPLS on a SIP" section of the Cisco 7600 Series Router SIP, SSC, and SPA Software Configuration Guide

The "Configuring AToM VP Cell Mode Relay Support" section of the Cisco 7600 Series Router SIP, SSC, and SPA Software Configuration Guide

The Release Notes for Cisco IOS Release 12.2SR for the Cisco 7600 Series Routers

AToM is supported on the Cisco 10000 series routers. For details on supported hardware, see the "Configuring Any Transport over MPLS" section of the Cisco 10000 Series Router Broadband Aggregation, Leased-Line, and MPLS Configuration Guide.

The Cisco 10000 series router has platform-specific instructions for configuring some AToM features. Platform-specific configuration information is contained in the "Configuring Any Transport over MPLS" section of the Cisco 10000 Series Router Broadband Aggregation, Leased-Line, and MPLS Configuration Guide.

AToM is supported on the Cisco12000 series routers. For information about hardware requirements, see the Cross-Platform Release Notes for Cisco IOS Release 12.0S.

Restrictions for Any Transport over MPLS

The following general restrictions pertain to all transport types under AToM:

Address format: Configure the Label Distribution Protocol (LDP) router ID on all PE routers to be a loopback address with a /32 mask. Otherwise, some configurations might not function properly.

Layer 2 virtual private networks (L2VPN) features (AToM and Layer 2 Tunnel Protocol Version 3 (L2TPv3)) are not supported on an ATM interface.

Distributed Cisco Express Forwarding is the only forwarding model supported on the Cisco 12000 series routers and is enabled by default. Disabling distributed Cisco Express Forwarding on the Cisco 12000 series routers disables forwarding.

Distributed Cisco Express Forwarding mode is supported on the Cisco 7500 series routers for Frame Relay, HDLC, and PPP. In distributed Cisco Express Forwarding mode, the switching process occurs on the Versatile Interface Processors (VIPs) that support switching. When distributed Cisco Express Forwarding is enabled, VIP port adapters maintain identical copies of the Forwarding Information Base (FIB) and adjacency tables. The port adapters perform the express forwarding between port adapters, relieving the Route Switch Processor (RSP) from performing the switching. Distributed Cisco Express Forwarding uses an interprocess communications (IPC) mechanism to ensure synchronization of FIBs and adjacency tables between the RSP and port adapters.

The following restrictions pertain to ATM Cell Relay over MPLS:

For ATM Cell Relay over MPLS, if you have TE tunnels running between the PE routers, you must enable LDP on the tunnel interfaces.

Configuring ATM Relay over MPLS with the Cisco 12000 Series Router engine 2 8-port OC-3 STM-1 ATM line card: In Cisco IOS Release 12.0(25)S, there were special instructions for configuring ATM cell relay on the Cisco 12000 series router with an engine 2 8-port OC-3 STM-1 ATM line card. The special configuration instructions are no longer needed. You no longer need to use the atm mode cell-relay command.

In Cisco IOS Release 12.0(25)S, when you configured the Cisco 12000 series 8-port OC-3 STM-1 ATM line card for ATM Cell Relay over MPLS, two ports were reserved. That is no longer true. Only one port is reserved now.

In addition, in Cisco IOS Release 12.0(25)S, if you configured an 8-port OC-3 STM-1 ATM port for ATM AAL5 over MPLS and then configured ATM single cell relay over MPLS on that port, the VCs and VPs for AAL5 on the port and its corresponding port were removed. Starting in Cisco IOS Release 12.0(26)S, this behavior no longer occurs. ATM AAL5 over MPLS and ATM single cell relay over MPLS are supported on the same port. The Cisco 12000 series 8-port OC-3 STM-1 ATM line cards now support, by default, the ATM single cell relay over MPLS feature in both VP and VC modes and ATM AAL5 over MPLS on the same port.

The F4 end-to-end OAM cells are transparently transported along with the ATM cells. When a permanent virtual path (PVP) or PVC is down on one PE router, the label associated with that PVP or PVC is withdrawn. Subsequently, the peer PE router detects the label withdrawal and sends an F4 AIS/RDI signal to its corresponding CE router. The PVP or PVC on the peer PE router remains in the up state.

The following restrictions pertain to the Ethernet over MPLS feature:

Ethernet over MPLS supports VLAN packets that conform to the IEEE 802.1Q standard. The 802.1Q specification establishes a standard method for inserting VLAN membership information into Ethernet frames. The Inter-Switch Link (ISL) protocol is not supported between the PE and CE routers.

The AToM control word is supported. However, if the peer PE does not support a control word, the control word is disabled. This negotiation is done by LDP label binding.

Ethernet packets with hardware-level cyclic redundancy check (CRC) errors, framing errors, and runt packets are discarded on input.

In Cisco IOS Release 12.2(25)S, the behavior of the mpls mtu command changed. If the interface MTU is less than 1524 bytes, you can set the maximum MPLS MTU to 24 bytes more than the interface MTU. For example, if the interface MTU is set to 1510 bytes, then you can set the maximum MPLS MTU to 1534 bytes (1510 + 24).


Caution Although you can set the MPLS MTU to a value greater than the interface MTU, set the MPLS MTU less than or equal to the interface MTU to prevent data corruption, dropped packets, and high CPU rates..

If the interface MTU is greater than or equal to 1524 bytes, then you can set the maximum MPLS MTU as high as the interface MTU. For example, if the interface MTU is set to 1600 bytes, then you can set the MPLS MTU to a maximum of 1600 bytes. If you set the MPLS MTU higher than the interface MTU, traffic is dropped.

For interfaces that do not allow you to configure the interface MTU value and the interface MTU is 1500 bytes, the MPLS MTU range is 64 to 1524 bytes.

If you upgrade to Cisco IOS Release 12.2(25)S from an earlier release and you have an MPLS MTU setting that does not conform to these guidelines, the command is rejected. See the "Maximum Transmission Unit Guidelines for Estimating Packet Size" section for more information.

The following restrictions pertain to the Frame Relay over MPLS feature:

Frame Relay traffic shaping is not supported with AToM switched VCs.

If you configure Frame Relay over MPLS on the Cisco 12000 series router and the core-facing interface is an engine 4 or 4+ line card and the edge-facing interface is an engine 0 or 2 line card, then the BECN, FECN, control word (CW), and DE bit information is stripped from the PVC.

Information About Any Transport over MPLS

To configure AToM, you must understand the following concepts:

How AToM Transports Layer 2 Packets

AToM Configuration Commands Prior to Cisco IOS Release 12.0(25)S

Benefits of AToM

MPLS Traffic Engineering Fast Reroute

Maximum Transmission Unit Guidelines for Estimating Packet Size

Frame Relay over MPLS and DTE, DCE, and NNI Connections

QoS Features Supported with AToM

How AToM Transports Layer 2 Packets

AToM encapsulates Layer 2 frames at the ingress PE and sends them to a corresponding PE at the other end of a pseudowire, which is a connection between the two PE routers. The egress PE removes the encapsulation and sends out the Layer 2 frame.

The successful transmission of the Layer 2 frames between PE routers is due to the configuration of the PE routers. You set up the connection, called a pseudowire, between the routers. You specify the following information on each PE router:

The type of Layer 2 data that will be transported across the pseudowire, such as Ethernet, Frame Relay, or ATM

The IP address of the loopback interface of the peer PE router, which enables the PE routers to communicate

A unique combination of peer PE IP address and VC ID that identifies the pseudowire

The following example shows the basic configuration steps on a PE router that enable the transport of Layer 2 packets. Each transport type has slightly different steps.

Step 1 defines the interface or subinterface on the PE router:

Router# interface interface-type interface-number

Step 2 specifies the encapsulation type for the interface, such as dot1q:

Router(config-if)# encapsulation encapsulation-type

Step 3 does the following:

Makes a connection to the peer PE router by specifying the LDP router ID of the peer PE router.

Specifies a 32-bit unique identifier, called the VC ID, which is shared between the two PE routers.

The combination of the peer router ID and the VC ID must be unique on the router. Two circuits cannot use the same combination of peer router ID and VC ID.

Specifies the tunneling method used to encapsulate data in the pseudowire. AToM uses MPLS as the tunneling method.

Router(config-if)# xconnect peer-router-id vcid encapsulation mpls

As an alternative, you can set up a pseudowire class to specify the tunneling method and other characteristics. See the "Configuring the Pseudowire Class" section for more information.

AToM Configuration Commands Prior to Cisco IOS Release 12.0(25)S

In releases of AToM previous to Cisco IOS 12.0(25)S, the command used to configure AToM circuits was mpls l2 transport route. This command has been replaced with the xconnect command.

No enhancements will be made to the mpls l2transport route command. Enhancements will be made to either the xconnect command or pseudowire-class command. Therefore, Cisco recommends that you use the xconnect command to configure AToM circuits.

Configurations from releases previous to Cisco IOS 12.0(25)S that use the mpls l2transport route command are still supported.

Benefits of AToM

The following list explains some of the benefits of enabling Layer 2 packets to be sent in the MPLS network:

The AToM product set accommodates many types of Layer 2 packets, including Ethernet and Frame Relay, across multiple Cisco router platforms, such as the Cisco 7200 and 7500 series routers. This enables the service provider to transport all types of traffic over the backbone and accommodate all types of customers.

AToM adheres to the standards developed for transporting Layer 2 packets over MPLS. (See the "Standards" section for the specific standards that AToM follows.) This benefits the service provider that wants to incorporate industry-standard methodologies in the network. Other Layer 2 solutions are proprietary, which can limit the service provider's ability to expand the network and can force the service provider to use only one vendor's equipment.

Upgrading to AToM is transparent to the customer. Because the service provider network is separate from the customer network, the service provider can upgrade to AToM without disruption of service to the customer. The customers assume that they are using a traditional Layer 2 backbone.

MPLS Traffic Engineering Fast Reroute

AToM can use MPLS traffic engineering (TE) tunnels with fast reroute (FRR) support. AToM VCs can be rerouted around a failed link or node at the same time as MPLS and IP prefixes.

Enabling fast reroute on AToM does not require any special commands; you can use standard fast reroute commands. At the ingress PE, an AToM tunnel is protected by fast reroute when it is routed to an FRR-protected TE tunnel. Both link and node protection are supported for AToM VCs at the ingress PE. For more information on configuring MPLS TE fast reroute, see the following document:

MPLS Traffic Engineering (TE)—Link and Node Protection, with RSVP Hellos Support


Note The AToM VC independence feature was introduced in Cisco IOS Release 12.0(31)S and enables the Cisco 12000 series router to perform fast reroute in fewer than 50 milliseconds, regardless of the number of VCs configured. In previous releases, the fast reroute time depended on the number of VCs inside the protected TE tunnel.


For the Cisco 12000 series routers, fast reroute uses three or more labels, depending on where the TE tunnel ends:

If the TE tunnel is from a PE router to a PE router, three labels are used.

If the TE tunnel is from a PE router to the core router, four labels are used.

Engine 0 ATM line cards support three or more labels, although performance degrades. Engine 2 Gigabit Ethernet line cards and engine 3 line cards support three or more labels and can work with the fast reroute feature.

You can issue the debug mpls l2transport fast-reroute command to debug fast reroute with AToM.


Note This command does not display output on platforms where AToM fast reroute is implemented in the forwarding code. The command does display output on Cisco 10720 Internet router line cards and
Cisco 12000 series line cards. This command does not display output for the Cisco 7500 (both Route Processor (RP) and VIP) series routers, Cisco 7200 series routers, and Cisco 12000 series RP.


In the following example, the primary link is disabled, which causes the backup tunnel (Tunnel 1) to become the primary path. In the following example, bolded output show the status of the tunnel:

Router# execute-on slot 3 debug mpls l2transport fast-reroute

========= Line Card (Slot 3) =========
AToM fast reroute debugging is on
SLOT 3:Sep 16 17:58:56.346: AToM SMGR: Processing TFIB FRR event for 10.4.0.1
SLOT 3:Sep 16 17:58:56.346: AToM SMGR: Finished processing TFIB FRR event for 10.4.0.1
SLOT 3:Sep 16 17:58:56.346: AToM SMGR: Processing TFIB FRR event for Tunnel41
SLOT 3:Sep 16 17:58:56.346: AToM SMGR: Finished processing TFIB FRR event for Tunnel41
Sep 16 17:58:58.342: %LINK-3-UPDOWN: Interface POS0/0, changed state to down
Sep 16 17:58:58.342: %OSPF-5-ADJCHG: Process 1, Nbr 10.0.0.1 on POS0/0 from FULL to DOWN, 
Neighbor Down: Interface down or detached
Sep 16 17:58:59.342: %LINEPROTO-5-UPDOWN: Line protocol on Interface POS0/0, changed state 
to down

Maximum Transmission Unit Guidelines for Estimating Packet Size

The following calculation helps you determine the size of the packets traveling through the core network. You set the maximum transmission unit (MTU) on the core-facing interfaces of the P and PE routers to accommodate packets of this size. The MTU should be greater than or equal to the total bytes of the items in the following equation:

Core MTU >= (Edge MTU + Transport header + AToM header + (MPLS label stack * MPLS label size))

The following sections describe the variables used in the equation.

Edge MTU

The edge MTU is the MTU for the customer-facing interfaces.

Transport Header

The Transport header depends on the transport type. Table 1 lists the specific sizes of the headers.

Table 1 Header Size of Packets 

Transport Type
Packet Size

AAL5

0-32 bytes

Ethernet VLAN

18 bytes

Ethernet Port

14 bytes

Frame Relay DLCI

2 bytes for Cisco encapsulation, 8 bytes for Internet Engineering Task Force (IETF) encapsulation

HDLC

4 bytes

PPP

4 bytes


AToM Header

The AToM header is 4 bytes (control word). The control word is optional for Ethernet, PPP, HDLC, and cell relay transport types. However, the control word is required for Frame Relay and ATM AAL5 transport types.

MPLS Label Stack

The MPLS label stack size depends on the configuration of the core MPLS network:

AToM uses one MPLS label to identify the AToM VCs (VC label). Therefore, the minimum MPLS label stack is one for directly connected AToM PEs, which are PE routers that do not have a P router between them.

If LDP is used in the MPLS network, the label stack size is two (the LDP label and the VC label).

If a TE tunnel instead of LDP is used between PE routers in the MPLS network, the label stack size is two (the TE label and the VC label).

If a TE tunnel and LDP are used in the MPLS network (for example, a TE tunnel between P routers or between P and PE routers, with LDP on the tunnel), the label stack is three (TE label, LDP label, VC label).

If you use MPLS fast reroute in the MPLS network, you add a label to the stack. The maximum MPLS label stack in this case is four (FRR label, TE label, LDP label, VC label).

If AToM is used by the customer carrier in an MPLS VPN Carrier Supporting Carrier environment, you add a label to the stack. The maximum MPLS label stack in the provider carrier network is five (FRR label, TE label, LDP label, VPN label, VC label).

If an AToM tunnel spans different service providers that exchange MPLS labels using IPv4 Border Gateway Protocol (BGP) (RFC 3107), you add a label to the stack. The maximum MPLS label stack is five (FRR label, TE label, Border Gateway Protocol (BGP) label, LDP label, VC label).

Other circumstances can increase the MPLS label stack size. Therefore, analyze the complete data path between the AToM tunnel endpoints and determine the maximum MPLS label stack size for your network. Then multiply the label stack size by the size of the MPLS label.

Estimating Packet Size: Example

Thee size of packets is estimate in the following example, which uses the following assumptions:

The edge MTU is 1500 bytes.

The transport type is Ethernet VLAN, which designates 18 bytes for the transport header.

The AToM header is 0, because the control word is not used.

The MPLS label stack is 2, because LDP is used. The MPLS label is 4 bytes.

Edge MTU + Transport header + AToM header + (MPLS label stack * MPLS label) = Core MTU
1500     + 18                    + 0      + (2                * 4         ) = 1526

You must configure the P and PE routers in the core to accept packets of 1526 bytes.

Once you determine the MTU size to set on your P and PE routers, you can issue the mtu command on the routers to set the MTU size. The following example specifies an MTU of 1526 bytes:

Router(config-if)# mtu 1526

mpls mtu Command Changes

Some interfaces (such as FastEthernet) require the mpls mtu command to change the MTU size.
In Cisco IOS Release 12.2(25)S, the behavior of the mpls mtu command changed.

If the interface MTU is ferwer than 1524 bytes, you can set the maximum MPLS MTU to 24 bytes more than the interface MTU. For example, if the interface MTU is set to 1510 bytes, then you can set the maximum MPLS MTU to 1534 bytes (1510 + 24).


Caution Although you can set the MPLS MTU to a value greater than the interface MTU, set the MPLS MTU less than or equal to the interface MTU to prevent data corruption, dropped packets, and high CPU rates.

If the interface MTU is greater than or equal to 1524 bytes, then you can set the maximum MPLS MTU as high as the interface MTU. For example, if the interface MTU is set to 1600 bytes, then you can set the MPLS MTU to a maximum of 1600 bytes. If you set the MPLS MTU higher than the interface MTU, traffic is dropped.

For interfaces that do not allow you to configure the interface MTU value and the interface MTU is
1500 bytes, the MPLS MTU range is 64 to 1524 bytes.

If you upgrade to Cisco IOS Release 12.2(25)S and you have an MPLS MTU setting that does not conform to these guidelines, the command is rejected.

For Cisco IOS Release 12.2(27)SBC, 12.2(33)SRA, 12.4(11)T, 12.2(33)SXH, and later releases, you cannot set the MPLS MTU greater than the interface MTU. This eliminates problems, such as dropped packets, data corruption, and high CPU rates. See the MPLS MTU Command Changes document for more information.

Frame Relay over MPLS and DTE, DCE, and NNI Connections

You can configure an interface as a DTE device or a DCE switch, or as a switch connected to a switch with network-to-network interface (NNI) connections. Use the following command in interface configuration mode:

frame-relay intf-type [dce | dte | nni]

The keywords are explained in Table 2.

Table 2 frame-relay intf-type Command Keywords

Keyword
Description

dce

Enables the router or access server to function as a switch connected to a router.

dte

Enables the router or access server to function as a DTE device. DTE is the default.

nni

Enables the router or access server to function as a switch connected to a switch.


Local Management Interface and Frame Relay over MPLS

Local Management Interface (LMI) is a protocol that communicates status information about PVCs. When a PVC is added, deleted, or changed, the LMI notifies the endpoint of the status change. LMI also provides a polling mechanism that verifies that a link is up.

How LMI Works

To determine the PVC status, LMI checks that a PVC is available from the reporting device to the Frame Relay end-user device. If a PVC is available, LMI reports that the status is "Active," which means that all interfaces, line protocols, and core segments are operational between the reporting device and the Frame Relay end-user device. If any of those components is not available, the LMI reports a status of "Inactive."


Note Only the DCE and NNI interface types can report LMI status.


Figure 1 is a sample topology that helps illustrate how LMI works.

Figure 1 Sample Topology

In Figure 1, note the following:

CE1 and PE1 and PE2 and CE2 are Frame Relay LMI peers.

CE1 and CE2 can be Frame Relay switches or end-user devices.

Each Frame Relay PVC comprises multiple segments.

The DLCI value is local to each segment and is changed as traffic is switched from segment to segment. Two Frame Relay PVC segments exist in Figure 1; one is between PE1 and CE1 and the other is between PE2 and CE2.

The LMI protocol behavior depends on whether you have DLCI-to-DLCI or port-to-port connections.

DLCI-to-DLCI Connections

If you have DLCI-to-DLCI connections, LMI runs locally on the Frame Relay ports between the PE and CE devices:

CE1 sends an active status to PE1 if the PVC for CE1 is available. If CE1 is a switch, LMI checks that the PVC is available from CE1 to the user device attached to CE1.

PE1 sends an active status to CE1 if the following conditions are met:

A PVC for PE1 is available.

PE1 received an MPLS label from the remote PE router.

An MPLS tunnel label exists between PE1 and the remote PE.

For DTE or DCE configurations, the following LMI behavior exists: The Frame Relay device accessing the network (DTE) does not report PVC status. Only the network device (DCE) or NNI can report status. Therefore, if a problem exists on the DTE side, the DCE is not aware of the problem.

Port-to-Port Connections

If you have port-to-port connections, the PE routers do not participate in the LMI status-checking procedures. LMI operates between the CE routers only. The CE routers must be configured as DCE-DTE or NNI-NNI.

For information about LMI, including configuration instructions, see the "Configuring the LMI" section of the Configuring Frame Relay document.

QoS Features Supported with AToM

For information about configuring QoS features on the Cisco 12000 series routers, see the following feature module:

Any Transport over MPLS (AToM): Layer 2 QoS for the Cisco 12000 Series Router (Quality of Service)

The following tables list the QoS features supported by AToM on the Cisco 7200 and 7500 series routers:

Table 3, QoS Features Supported with Ethernet over MPLS on the Cisco 7200 and 7500 Series Routers

Table 4, QoS Features Supported with Frame Relay over MPLS on the Cisco 7200 and 7500 Series Routers

Table 5, QoS Features Supported with ATM Cell Relay and AAL5 over MPLS on the Cisco 7200 and 7500 Series Routers

Table 3 QoS Features Supported with Ethernet over MPLS on the Cisco 7200 and 7500 Series Routers 

QoS Feature
Ethernet over MPLS

Service policy

Can be applied to:

Interface (input and output)

Subinterface (input and output)

Classification

Supports the following commands:

match cos (on interfaces and subinterfaces)

match mpls experimental (on interfaces and subinterfaces)

match qos-group (on interfaces) (output policy)

Marking

Supports the following commands:

set cos (output policy)

set discard-class (input policy)

set mpls experimental (input policy) (on interfaces and subinterfaces)

set qos-group (input policy)

Policing

Supports the following:

Single-rate policing

Two-rate policing

Color-aware policing

Multiple-action policing

Queueing and shaping

Supports the following:

Distributed Low Latency Queueing (dLLQ)

Distributed Weighted Random Early Detection (dWRED)

Byte-based WRED


Table 4 QoS Features Supported with Frame Relay over MPLS on the Cisco 7200 and 7500 Series Routers 

QoS Feature
Frame Relay over MPLS

Service policy

Can be applied to:

Interface (input and output)

PVC (input and output)

Classification

Supports the following commands:

match fr-de (on interfaces and VCs)

match fr-dlci (on interfaces)

match qos-group

Marking

Supports the following commands:

frame-relay congestion management (output)

set discard-class

set fr-de (output policy)

set fr-fecn-becn (output)

set mpls experimental

set qos-group

threshold ecn (output)

Policing

Supports the following:

Single-rate policing

Two-rate policing

Color-aware policing

Multiple-action policing

Queueing and shaping

Supports the following:

dLLQ

dWRED

Distributed traffic shaping

Distributed class-based weighted fair queueing (dCBWFQ)

Byte-based WRED

random-detect discard-class-based command


Table 5 QoS Features Supported with ATM Cell Relay and AAL5 over MPLS on the Cisco 7200 and 7500 Series Routers

QoS Feature
ATM Cell Relay and AAL5 over MPLS

Service policy

Can be applied to:

Interface (input and output)

Subinterface (input and output)

PVC (input and output)

Classification

Supports the following commands:

match mpls experimental (on VCs)

match qos-group (output)

Marking

Supports the following commands:

random-detect discard-class-based (input)

set clp (output) (on interfaces, subinterfaces, and VCs)

set discard-class (input)

set mpls experimental (input) (on interfaces, subinterfaces, and VCs)

set qos-group (input)

Policing

Supports the following:

Single-rate policing

Two-rate policing

Color-aware policing

Multiple-action policing

Queueing and shaping

Supports the following:

dLLQ

dWRED

dCBWFQ

Byte-based WRED

random-detect discard-class-based command

Class-based shaping support on ATM PVCs


How to Configure Any Transport over MPLS

This section explains how to perform a basic AToM configuration and includes the following procedures:

Configuring the Pseudowire Class (required)

Configuring ATM AAL5 over MPLS on PVCs (optional)

Configuring ATM AAL5 over MPLS in VC Class Configuration Mode (optional)

Configuring OAM Cell Emulation for ATM AAL5 over MPLS (optional)

Configuring OAM Cell Emulation for ATM AAL5 over MPLS on PVCs (optional)

Configuring OAM Cell Emulation for ATM AAL5 over MPLS in VC Class Configuration Mode (optional)

Configuring ATM Cell Relay over MPLS in VC Mode (optional)

Configuring ATM Cell Relay over MPLS in VC Mode Using VC Class Configuration Mode (optional)

Configuring ATM Cell Relay over MPLS in PVP Mode (optional)

Configuring ATM Cell Relay over MPLS in Port Mode (optional)

Configuring ATM Single Cell Relay over MPLS (optional)

Configuring ATM Packed Cell Relay over MPLS (optional)

Configuring Ethernet over MPLS in VLAN Mode (optional)

Configuring Ethernet over MPLS in Port Mode (optional)

Configuring Ethernet over MPLS with VLAN ID Rewrite (optional)

Configuring Ethernet over MPLS with MTU Values in xconnect Configuration Mode (optional)

Configuring Frame Relay over MPLS with DLCI-to-DLCI Connections, page 55 (optional)

Configuring Frame Relay over MPLS with Port-to-Port Connections (optional)

Configuring HDLC and PPP over MPLS (optional)

Configuring Tunnel Selection (optional)

Setting Experimental Bits with AToM (optional)

Setting the Frame Relay Discard Eligibility Bit on the Cisco 7200 and 7500 Series Routers (optional)

Matching the Frame Relay DE Bit on the Cisco 7200 and 7500 Series Routers (optional)

Configuring the Pseudowire Class

The successful transmission of the Layer 2 frames between PE routers is due to the configuration of the PE routers. You set up the connection, called a pseudowire, between the routers.


Note In simple configurations, this task is optional. You do not need to specify a pseudowire class if you specify the tunneling method as part of the xconnect command.


The pseudowire-class configuration group specifies the following characteristics of the tunneling mechanism:

Encapsulation type

Control protocol

Payload-specific options

For more information about the pseudowire-class command, see the following feature module:

Layer 2 Tunnel Protocol Version 3

You must specify the encapsulation mpls command as part of the pseudowire class or as part of the xconnect command for the AToM VCs to work properly. If you omit the encapsulation mpls command as part of the xconnect command, you receive the following error:

% Incomplete command.

Once you specify the encapsulation mpls command, you cannot remove it using the no encapsulation mpls command. Nor can you change the command's setting using the encapsulation l2tpv3 command. Those methods result in the following error message:

Encapsulation changes are not allowed on an existing pw-class.

To remove the command, you must delete the pseudowire with the no pseudowire-class command. To change the type of encapsulation, remove the pseudowire with the no pseudowire-class command and reestablish the pseudowire and specify the new encapsulation type.

SUMMARY STEPS

1. enable

2. configure terminal

3. pseudowire-class name

4. encapsulation mpls

DETAILED STEPS

 
Command or Action
Purpose

Step 1 

enable

Example:

Router> enable

Enables privileged EXEC mode.

Enter your password if prompted.

Step 2 

configure terminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3 

pseudowire-class name

Example:

Router(config)# pseudowire-class atom

Establishes a pseudowire class with a name that you specify and enters pseudowire class configuration mode.

Step 4 

encapsulation mpls

Example:

Router(config-pw)# encapsulation mpls

Specifies the tunneling encapsulation.

Configuring ATM AAL5 over MPLS on PVCs

ATM AAL5 over MPLS for permanent virtual circuits encapsulates ATM AAL5 service data unit (SDUs) in MPLS packets and forwards them across the MPLS network. Each ATM AAL5 SDU is transported as a single packet.

Restrictions

AAL5 over MPLS is supported only in SDU mode.

SUMMARY STEPS

1. enable

2. configure terminal

3. interface typeslot/port

4. pvc [name] vpi/vci l2transport

5. encapsulation aal5

6. xconnect peer-router-id vcid encapsulation mpls

7. exit

8. exit

9. exit

10. show mpls l2transport vc

DETAILED STEPS

 
Command or Action
Purpose

Step 1 

enable

Example:

Router> enable

Enables privileged EXEC mode.

Enter your password if prompted.

Step 2 

configure terminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3 

interface typeslot/port

Example:

Router(config)# interface atm1/0

Specifies the interface by type, slot, and port number, and enters interface configuration mode.

Step 4 

pvc [name] vpi/vci l2transport

Example:

Router(config-if)# pvc 1/200 l2transport

Creates or assigns a name to an ATM PVC and enters L2transport configuration mode.

The l2transport keyword indicates that the PVC is a switched PVC instead of a terminated PVC.

Step 5 

encapsulation aal5

Example:

Router(config-if-atm-l2trans-pvc)# encapsulation aal5

Specifies ATM AAL5 encapsulation for the PVC. Make sure you specify the same encapsulation type on the PE and customer edge (CE) routers.

Step 6 

xconnect peer-router-id vcid encapsulation mpls

Example:

Router(config-if-atm-l2trans-pvc)# xconnect 10.13.13.13 100 encapsulation mpls

Binds the attachment circuit to a pseudowire VC.

Step 7 

exit

Example:

Router(config-if-atm-l2trans-pvc)# exit

Exits L2transport configuration mode.

Step 8 

exit

Example:

Router(config-if)# exit

Exits interface configuration mode.

Step 9 

exit

Example:

Router(config)# exit

Exits global configuration mode.

Step 10 

show mpls l2transport vc

Example:

Router# show mpls l2transport vc

Displays output that shows ATM AAL5 over MPLS is configured on a PVC.

Examples

The following example enables ATM AAL5 over MPLS on an ATM PVC:

enable
 configure terminal
 interface atm1/0
 pvc 1/200 l2transport
 encapsulation aal5
 xconnect 10.13.13.13 100 encapsulation mpls

The following is example output from the show mpls l2transport vc, which shows that ATM AAL5 over MPLS is configured on a PVC:

Router# show mpls l2transport vc

Local intf   Local circuit          Dest address      VC ID      Status
---------    -------------          ------------      -----      ------
ATM1/0       ATM AAL5 1/100         10.4.4.4           100        UP

Configuring ATM AAL5 over MPLS in VC Class Configuration Mode

You can create a VC class that specifies the AAL5 encapsulation and then attach the encapsulation type to an interface, subinterface, or PVC. The following task creates a VC class and attaches it to a main interface.

Restriction

AAL5 over MPLS is supported only in SDU mode.

SUMMARY STEPS

1. enable

2. configure terminal

3. vc-class atm vc-class-name

4. encapsulation layer-type

5. exit

6. interface typeslot/port

7. class-int vc-class-name

8. pvc [name] vpi/vci l2transport

9. xconnect peer-router-id vcid encapsulation mpls

10. exit

11. exit

12. exit

13. show atm class-links

DETAILED STEPS

 
Command or Action
Purpose

Step 1 

enable

Example:

Router> enable

Enables privileged EXEC mode.

Enter your password if prompted.

Step 2 

configure terminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3 

vc-class atm vc-class-name

Example:

Router(config)# vc-class atm aal5class

Creates a VC class and enters VC class configuration mode.

Step 4 

encapsulation layer-type

Example:

Router(config-vc-class)# encapsulation aal5

Configures the AAL and encapsulation type.

Step 5 

exit

Example:

Router(config-vc-class)# exit

Exits VC class configuration mode.

Step 6 

interface typeslot/port

Example:

Router(config)# interface atm1/0

Specifies the interface by type, slot, and port number, and enters interface configuration mode.

Step 7 

class-int vc-class-name

Example:

Router(config-if)# class-int aal5class

Applies a VC class to the ATM main interface or subinterface.

Note You can also apply a VC class to a PVC.

Step 8 

pvc [name] vpi/vci l2transport

Example:

Router(config-if)# pvc 1/200 l2transport

Creates or assigns a name to an ATM PVC and enters L2transport VC configuration mode.

The l2transport keyword indicates that the PVC is a switched PVC instead of a terminated PVC.

Step 9 

xconnect peer-router-id vcid encapsulation mpls

Example:

Router(config-if-atm-l2trans-pvc)# xconnect 10.13.13.13 100 encapsulation mpls

Binds the attachment circuit to a pseudowire VC.

Step 10 

exit

Example:

Router(config-if-atm-l2trans-pvc)# exit

Exits L2transport configuration mode.

Step 11 

exit

Example:

Router(config-if)# exit

Exits interface configuration mode.

Step 12 

exit

Example:

Router(config)# exit

Exits global configuration mode.

Step 13 

show atm class-links

Example:

Router# show atm class-links

Displays the type of encapsulation and that the VC class was applied to an interface.

Examples

The following example configures ATM AAL5 over MPLS in VC class configuration mode. The VC class is then applied to an interface.

enable
configure terminal
vc-class atm aal5class
encapsulation aal5
interface atm1/0
class-int aal5class
pvc 1/200 l2transport
xconnect 10.13.13.13 100 encapsulation mpls

The following example configures ATM AAL5 over MPLS in VC class configuration mode. The VC class is then applied to a PVC.

enable
configure terminal
vc-class atm aal5class
encapsulation aal5
interface atm1/0
pvc 1/200 l2transport
class-vc aal5class
xconnect 10.13.13.13 100 encapsulation mpls

In the following example, the command output of the show atm class-links command verifies that ATM AAL5 over MPLS is configured as part of a VC class. The command output shows the type of encapsulation and that the VC class was applied to an interface.

Router# show atm class-links 1/100

Displaying vc-class inheritance for ATM1/0.0, vc 1/100:
no broadcast - Not configured - using default
encapsulation aal5 - VC-class configured on main interface

Configuring OAM Cell Emulation for ATM AAL5 over MPLS

If a PE router does not support the transport of Operation, Administration, and Maintenance (OAM) cells across a label switched path (LSP), you can use OAM cell emulation to locally terminate or loop back the OAM cells. You configure OAM cell emulation on both PE routers, which emulates a VC by forming two unidirectional LSPs. You use the oam-ac emulation-enable and oam-pvc manage commands on both PE routers to enable OAM cell emulation.

After you enable OAM cell emulation on a router, you can configure and manage the ATM VC in the same manner as you would a terminated VC. A VC that has been configured with OAM cell emulation can send loopback cells at configured intervals toward the local CE router. The endpoint can be either of the following:

End-to-end loopback, which sends OAM cells to the local CE router.

Segment loopback, which responds to OAM cells to a device along the path between the PE and CE routers.

The OAM cells include the following cells:

Alarm indication signal (AIS)

Remote defect indication (RDI)

These cells identify and report defects along a VC. When a physical link or interface failure occurs, intermediate nodes insert OAM AIS cells into all the downstream devices affected by the failure. When a router receives an AIS cell, it marks the ATM VC down and sends an RDI cell to let the remote end know about the failure.

This section contains two tasks:

Configuring OAM Cell Emulation for ATM AAL5 over MPLS on PVCs

Configuring OAM Cell Emulation for ATM AAL5 over MPLS in VC Class Configuration Mode

Configuring OAM Cell Emulation for ATM AAL5 over MPLS on PVCs

Perform this task to configure OAM cell emulation for ATM AAL5 over MPLS on a PVC.


Note For AAL5 over MPLS, you can configure the oam-pvc manage command only after you issue the oam-ac emulation-enable command.


SUMMARY STEPS

1. enable

2. configure terminal

3. interface typeslot/port

4. pvc [name] vpi/vci l2transport

5. encapsulation aal5

6. xconnect peer-router-id vcid encapsulation mpls

7. oam-ac emulation-enable [ais-rate]

8. oam-pvc manage [frequency]

9. exit

10. exit

11. exit

12. show atm pvc

DETAILED STEPS

 
Command or Action
Purpose

Step 1 

enable

Example:

Router> enable

Enables privileged EXEC mode.

Enter your password if prompted.

Step 2 

configure terminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3 

interface typeslot/port

Example:

Router(config)# interface atm1/0

Specifies the interface by type, slot, and port number, and enters interface configuration mode.

Step 4 

pvc [name] vpi/vci l2transport

Example:

Router(config-if)# pvc 1/200 l2transport

Creates or assigns a name to an ATM PVC and enters L2transport VC configuration mode.

The l2transport keyword indicates that the PVC is a switched PVC instead of a terminated PVC.

Step 5 

encapsulation aal5

Example:

Router(config-if-atm-l2trans-pvc)# encapsulation aal5

Specifies ATM AAL5 encapsulation for the PVC. Make sure you specify the same encapsulation type on the PE and CE routers.

Step 6 

xconnect peer-router-id vcid encapsulation mpls

Example:

Router(config-if-atm-l2trans-pvc)# xconnect 10.13.13.13 100 encapsulation mpls

Binds the attachment circuit to a pseudowire VC.

Step 7 

oam-ac emulation-enable [ais-rate]

Example:

Router(config-if-atm-l2trans-pvc)# oam-ac emulation-enable 30

Enables OAM cell emulation for AAL5 over MPLS. The ais-rate argument lets you specify the rate at which AIS cells are sent. The default is one cell every second. The range is 0 to 60 seconds.

Step 8 

oam-pvc manage [frequency]

Example:

Router(config-if-atm-l2trans-pvc)# oam-pvc manage

Enables the PVC to generate end-to-end OAM loopback cells that verify connectivity on the virtual circuit.

The optional frequency argument is the interval between transmission of loopback cells and ranges from 0 to
600 seconds. The default value is 10 seconds.

Step 9 

exit

Example:

Router(config-if-atm-l2trans-pvc)# exit

Exits L2transport configuration mode.

Step 10 

exit

Example:

Router(config-if)# exit

Exits interface configuration mode.

Step 11 

exit

Example:

Router(config)# exit

Exits global configuration mode.

Step 12 

show atm pvc

Example:

Router# show atm pvc

Displays output that shows OAM cell emulation is enabled on the ATM PVC.

Examples

The following example enables OAM cell emulation on an ATM PVC:

interface ATM 1/0/0
pvc 1/200 l2transport
encapsulation aal5
xconnect 10.13.13.13 100 encapsulation mpls 
oam-ac emulation-enable
oam-pvc manage

The following example sets the rate at which an AIS cell is sent every 30 seconds:

interface ATM 1/0/0
pvc 1/200 l2transport
encapsulation aal5
xconnect 10.13.13.13 100 encapsulation mpls 
oam-ac emulation-enable 30
oam-pvc manage

The output of the show atm pvc command in the following example shows that OAM cell emulation is enabled on the ATM PVC:

Router# show atm pvc 5/500

ATM4/1/0.200: VCD: 6, VPI: 5, VCI: 500                    
UBR, PeakRate: 1                                         
AAL5-LLC/SNAP, etype:0x0, Flags: 0x34000C20, VCmode: 0x0 
OAM Cell Emulation: enabled, F5 End2end AIS Xmit frequency: 1 second(s) 
OAM frequency: 0 second(s), OAM retry frequency: 1 second(s)
OAM up retry count: 3, OAM down retry count: 5
OAM Loopback status: OAM Disabled
OAM VC state: Not ManagedVerified
ILMI VC state: Not Managed
InPkts: 564, OutPkts: 560, InBytes: 19792, OutBytes: 19680
InPRoc: 0, OutPRoc: 0
InFast: 4, OutFast: 0, InAS: 560, OutAS: 560
InPktDrops: 0, OutPktDrops: 0
CrcErrors: 0, SarTimeOuts: 0, OverSizedSDUs: 0
Out CLP=1 Pkts: 0
OAM cells received: 26
F5 InEndloop: 0, F5 InSegloop: 0, F5 InAIS: 0, F5 InRDI: 26
OAM cells sent: 77
F5 OutEndloop: 0, F5 OutSegloop: 0, F5 OutAIS: 77, F5 OutRDI: 0 
OAM cell drops: 0
Status: UP

Configuring OAM Cell Emulation for ATM AAL5 over MPLS in VC Class Configuration Mode

The following steps explain how to configure OAM cell emulation as part of a VC class. You can then apply the VC class to an interface, a subinterface, or a VC. When you configure OAM cell emulation in VC class configuration mode and then apply the VC class to an interface, the settings in the VC class apply to all the VCs on the interface, unless you specify a different OAM cell emulation value at a lower level, such as the subinterface or VC level. For example, you can create a VC class that specifies OAM cell emulation and sets the rate of AIS cells to every 30 seconds. You can apply the VC class to an interface. Then, for one PVC, you can enable OAM cell emulation and set the rate of AIS cells to every 15 seconds. All the PVCs on the interface use the cell rate of 30 seconds, except for the one PVC that was set to 15 seconds.

Perform this task to enable OAM cell emulation as part of a VC class and apply it to an interface.


Note For AAL5 over MPLS, you can configure the oam-pvc manage command only after you issue the oam-ac emulation-enable command.


SUMMARY STEPS

1. enable

2. configure terminal

3. vc-class atm name

4. encapsulation layer-type

5. oam-ac emulation-enable [ais-rate]

6. oam-pvc manage [frequency]

7. exit

8. interface typeslot/port

9. class-int vc-class-name

10. pvc [name] vpi/vci l2transport

11. xconnect peer-router-id vcid encapsulation mpls

DETAILED STEPS

 
Command or Action
Purpose

Step 1 

enable

Example:

Router> enable

Enables privileged EXEC mode.

Enter your password if prompted.

Step 2 

configure terminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3 

vc-class atm name

Example:

Router(config)# vc-class atm oamclass

Creates a VC class and enters VC class configuration mode.

Step 4 

encapsulation layer-type

Example:

Router(config-vc-class)# encapsulation aal5

Configures the AAL and encapsulation type.

Step 5 

oam-ac emulation-enable [ais-rate]

Example:

Router(config-vc-class)# oam-ac emulation-enable 30

Enables OAM cell emulation for AAL5 over MPLS. The ais-rate argument lets you specify the rate at which AIS cells are sent. The default is one cell every second. The range is 0 to 60 seconds.

Step 6 

oam-pvc manage [frequency]

Example:

Router(config-vc-class)# oam-pvc manage

Enables the PVC to generate end-to-end OAM loopback cells that verify connectivity on the virtual circuit.

The optional frequency argument is the interval between transmission of loopback cells and ranges from 0 to
600 seconds. The default value is 10 seconds.

Step 7 

exit

Example:

Router(config-vc-class)# exit

Exits VC class configuration mode.

Step 8 

interface typeslot/port

Example:

Router(config)# interface atm1/0

Specifies the interface by type, slot, and port number, and enters interface configuration mode.

Step 9 

class-int vc-class-name

Example:

Router(config-if)# class-int oamclass

Applies a VC class to the ATM main interface or subinterface.

Note You can also apply a VC class to a PVC.

Step 10 

pvc [name] vpi/vci l2transport

Example:

Router(config-if)# pvc 1/200 l2transport

Creates or assigns a name to an ATM PVC and enters L2transport VC configuration mode.

The l2transport keyword indicates that the PVC is a switched PVC instead of a terminated PVC.

Step 11 

xconnect peer-router-id vcid encapsulation mpls

Example:

Router(config-if-atm-l2trans-pvc)# xconnect 10.13.13.13 100 encapsulation mpls

Binds the attachment circuit to a pseudowire VC.

Examples

The following example configures OAM cell emulation for ATM AAL5 over MPLS in VC class configuration mode. The VC class is then applied to an interface.

enable
configure terminal
vc-class atm oamclass
encapsulation aal5
oam-ac emulation-enable 30
oam-pvc manage
interface atm1/0
class-int oamclass
pvc 1/200 l2transport
xconnect 10.13.13.13 100 encapsulation mpls

The following example configures OAM cell emulation for ATM AAL5 over MPLS in VC class configuration mode. The VC class is then applied to a PVC.

enable
configure terminal
vc-class atm oamclass
encapsulation aal5
oam-ac emulation-enable 30
oam-pvc manage
interface atm1/0
pvc 1/200 l2transport
class-vc oamclass
xconnect 10.13.13.13 100 encapsulation mpls

The following example configures OAM cell emulation for ATM AAL5 over MPLS in VC class configuration mode. The VC class is then applied to an interface. One PVC is configured with OAM cell emulation at an AIS rate of 10. That PVC uses the AIS rate of 10 instead of 30.

enable
configure terminal
vc-class atm oamclass
encapsulation aal5
oam-ac emulation-enable 30
oam-pvc manage
interface atm1/0
class-int oamclass
pvc 1/200 l2transport
oam-ac emulation-enable 10
xconnect 10.13.13.13 100 encapsulation mpls

Configuring ATM Cell Relay over MPLS in VC Mode

Perform this task to configure ATM cell relay on the permanent virtual circuits.

SUMMARY STEPS

1. enable

2. configure terminal

3. interface atmslot/port

4. pvc vpi/vci l2transport

5. encapsulation aal0

6. xconnect peer-router-id vcid encapsulation mpls

7. exit

8. exit

9. exit

10. show atm vc

DETAILED STEPS

 
Command or Action
Purpose

Step 1 

enable

Example:

Router> enable

Enables privileged EXEC mode.

Enter your password if prompted.

Step 2 

configure terminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3 

interface atmslot/port

Example:

Router(config)# interface atm1/0

Specifies an ATM interface and enters interface configuration mode.

Step 4 

pvc vpi/vci l2transport

Example:

Router(config-if)# pvc 0/100 l2transport

Assigns a virtual path identifier (VPI) and virtual circuit identifier (VCI) and enters L2transport VC configuration mode.

The l2transport keyword indicates that the PVC is a switched PVC instead of a terminated PVC.

Step 5 

encapsulation aal0

Example:

Router(config-if-atm-l2trans-pvc)# encapsulation aal0

For ATM cell relay, specifies raw cell encapsulation for the interface. Make sure you specify the same encapsulation type on the PE and CE routers.

Step 6 

xconnect peer-router-id vcid encapsulation mpls

Example:

Router(config-if-atm-l2trans-pvc)# xconnect 10.13.13.13 100 encapsulation mpls

Binds the attachment circuit to a pseudowire VC.

Step 7 

exit

Example:

Router(config-if-atm-l2trans-pvc)# exit

Exits L2transport configuration mode.

Step 8 

exit

Example:

Router(config-if)# exit

Exits interface configuration mode.

Step 9 

exit

Example:

Router(config)# exit

Exits global configuration mode.

Step 10 

show atm vc

Example:

Router# show atm vc

Verifies that OAM cell emulation is enabled on the ATM VC.

Example

The output of the following show atm vc command shows that the interface is configured for VC mode cell relay:

Router# show atm vc 7

ATM3/0: VCD: 7, VPI: 23, VCI: 100
UBR, PeakRate: 149760
AAL0-Cell Relay, etype:0x10, Flags: 0x10000C2D, VCmode: 0x0
OAM Cell Emulation: not configured
InBytes: 0, OutBytes: 0
Status: UP

Configuring ATM Cell Relay over MPLS in VC Mode Using VC Class Configuration Mode

You can create a VC class that specifies the ATM cell relay encapsulation and then attach the VC class to an interface, subinterface, or VC. The following task creates a VC class that specifies the ATM cell relay encapsulation and attaches it to a main interface.


Note You can configure VC class configuration mode only in VC mode. VC class configuration mode is not supported on VP or port mode.


SUMMARY STEPS

1. enable

2. configure terminal

3. vc-class atm name

4. encapsulation layer-type

5. exit

6. interface typeslot/port

7. class-int vc-class-name

8. pvc [name] vpi/vci l2transport

9. xconnect peer-router-id vcid encapsulation mpls

DETAILED STEPS

 
Command or Action
Purpose

Step 1 

enable

Example:

Router> enable

Enables privileged EXEC mode.

Enter your password if prompted.

Step 2 

configure terminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3 

vc-class atm name

Example:

Router(config)# vc-class atm cellrelay

Creates a VC class and enters VC class configuration mode.

Step 4 

encapsulation layer-type

Example:

Router(config-vc-class)# encapsulation aal0

Configures the AAL and encapsulation type.

Step 5 

exit

Example:

Router(config-vc-class)# exit

Exits VC class configuration mode.

Step 6 

interface typeslot/port

Example:

Router(config)# interface atm1/0

Specifies the interface by type, slot, and port number, and enters interface configuration mode.

Step 7 

class-int vc-class-name

Example:

Router(config-if)# class-int cellrelay

Applies a VC class to the ATM main interface or subinterface.

Note You can also apply a VC class to a PVC.

Step 8 

pvc [name] vpi/vci l2transport

Example:

Router(config-if)# pvc 1/200 l2transport

Creates or assigns a name to an ATM PVC and enters L2transport VC configuration mode.

The l2transport keyword indicates that the PVC is a switched PVC instead of a terminated PVC.

Step 9 

xconnect peer-router-id vcid encapsulation mpls

Example:

Router(config-if-atm-l2trans-pvc)# xconnect 10.13.13.13 100 encapsulation mpls

Binds the attachment circuit to a pseudowire VC.

Examples

The following example configures ATM cell relay over MPLS in VC class configuration mode. The VC class is then applied to an interface.

enable
configure terminal
vc-class atm cellrelay
encapsulation aal0
interface atm1/0
class-int cellrelay
pvc 1/200 l2transport
xconnect 10.13.13.13 100 encapsulation mpls

The following example configures ATM cell relay over MPLS in VC class configuration mode. The VC class is then applied to a PVC.

enable
configure terminal
vc-class atm cellrelay
encapsulation aal0
interface atm1/0
pvc 1/200 l2transport
class-vc cellrelay
xconnect 10.13.13.13 100 encapsulation mpls

Configuring ATM Cell Relay over MPLS in PVP Mode

VP mode allows cells coming into a predefined PVP on the ATM interface to be transported over the MPLS backbone to a predefined PVP on the egress ATM interface. You can use VP mode to send single cells or packed cells over the MPLS backbone.

To configure VP mode, you must specify the following:

The VP for transporting cell relay cells.

The IP address of the peer PE router and the VC ID.

When configuring ATM cell relay over MPLS in VP mode, use the following guidelines:

You do not need to enter the encapsulation aal0 command in VP mode.

One ATM interface can accommodate multiple types of ATM connections. VP cell relay, VC cell relay, and ATM AAL5 over MPLS can coexist on one ATM interface. On the Cisco 12000 series router, this is true only on the engine 0 ATM line cards.

If a VPI is configured for VP cell relay, you cannot configure a PVC using the same VPI.

VP trunking (mapping multiple VPs to one emulated VC label) is not supported. Each VP is mapped to one emulated VC.

Each VP is associated with one unique emulated VC ID. The AToM emulated VC type is ATM VP cell transport.

The AToM control word is supported. However, if a peer PE does not support the control word, it is disabled. This negotiation is done by LDP label binding.

VP mode (and VC mode) drop idle cells.

Perform this task to configure ATM cell relay in PVP mode.

SUMMARY STEPS

1. enable

2. configure terminal

3. interface atmslot/port

4. atm pvp vpi l2transport

5. xconnect peer-router-id vcid encapsulation mpls

6. exit

7. exit

8. exit

9. show atm vp

DETAILED STEPS

 
Command or Action
Purpose

Step 1 

enable

Example:

Router> enable

Enables privileged EXEC mode.

Enter your password if prompted.

Step 2 

configure terminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3 

interface atmslot/port

Example:

Router(config)# interface atm1/0

Defines the interface and enters interface configuration mode.

Step 4 

atm pvp vpi l2transport

Example:

Router(config-if)# atm pvp 1 l2transport

Specifies that the PVP is dedicated to transporting ATM cells and enters l2transport PVP configuration submode.

The l2transport keyword indicates that the PVP is for cell relay. This submode is for Layer 2 transport only; it is not for regular PVPs.

Step 5 

xconnect peer-router-id vcid encapsulation mpls

Example:

Router(config-if-atm-l2trans-pvp)# xconnect 10.0.0.1 123 encapsulation mpls

Binds the attachment circuit to a pseudowire VC. The syntax for this command is the same as for all other Layer 2 transports.

Step 6 

exit

Example:

Router(config-if-atm-l2trans-pvc)# exit

Exits L2transport configuration mode.

Step 7 

exit

Example:

Router(config-if)# exit

Exits interface configuration mode.

Step 8 

exit

Example:

Router(config)# exit

Exits global configuration mode.

Step 9 

show atm vp

Example:

Router# show atm vp

Displays output that shows OAM cell emulation is enabled on the ATM VP.

Examples

The following example transports single ATM cells over a virtual path:

pseudowire-class vp-cell-relay
encapsulation mpls
int atm 5/0 
atm pvp 1 l2transport 
xconnect 10.0.0.1 123 pw-class vp-cell-relay

The following show atm vp command in the following example shows that the interface is configured for VP mode cell relay:

Router# show atm vp 1

ATM5/0  VPI: 1, Cell Relay, PeakRate: 149760, CesRate: 0, DataVCs: 1, CesVCs: 0, Status: 
ACTIVE

  VCD    VCI   Type   InPkts   OutPkts   AAL/Encap     Status
  6      3     PVC    0        0         F4 OAM        ACTIVE  
  7      4     PVC    0        0         F4 OAM        ACTIVE  

TotalInPkts: 0, TotalOutPkts: 0, TotalInFast: 0, TotalOutFast: 0,
TotalBroadcasts: 0 TotalInPktDrops: 0, TotalOutPktDrops: 0

Configuring ATM Cell Relay over MPLS in Port Mode

Port mode cell relay allows cells coming into an ATM interface to be packed into an MPLS packet and transported over the MPLS backbone to an egress ATM interface.

To configure port mode, issue the xconnect command from an ATM main interface and specify the destination address and the VC ID. The syntax of the xconnect command is the same as for all other transport types. Each ATM port is associated with one unique pseudowire VC label.

When configuring ATM cell relay over MPLS in port mode, use the following guidelines:

The pseudowire VC type is set to ATM transparent cell transport (AAL0).

The AToM control word is supported. However, if the peer PE does not support a control word, the control word is disabled. This negotiation is done by LDP label binding.

Port mode and VP and VC mode are mutually exclusive. If you enable an ATM main interface for cell relay, you cannot enter any PVP or PVC commands.

If the pseudowire VC label is withdrawn due to an MPLS core network failure, the PE router sends a line AIS to the CE router.

SUMMARY STEPS

1. enable

2. configure terminal

3. interface atm slot/port

4. xconnect peer-router-id vcid encapsulation mpls

5. exit

6. exit

7. show atm route

8. show mpls l2transport vc

DETAILED STEPS

 
Command or Action
Purpose

Step 1 

enable

Example:

Router> enable

Enables privileged EXEC mode.

Enter your password if prompted.

Step 2 

configure terminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3 

interface atmslot/port

Example:

Router(config)# interface atm1/0

Specifies an ATM interface and enters interface configuration mode.

Step 4 

xconnect peer-router-id vcid encapsulation mpls

Example:

Router(config-if)# xconnect 10.0.0.1 123 encapsulation mpls

Binds the attachment circuit to the interface.

Step 5 

exit

Example:

Router(config-if)# exit

Exits interface configuration mode.

Step 6 

exit

Example:

Router(config)# exit

Exits global configuration mode.

Step 7 

show atm route

Example:

Router# show atm route

Displays output that shows ATM cell relay in port mode has been enabled.

Step 8 

show mpls l2transport vc

Example:

Router# show mpls l2transport vc

Displays the attachment circuit and the interface.

Examples

The following example shows interface ATM 5/0 set up to transport ATM cell relay packets:

pseudowire-class atm-cell-relay
encapsulation mpls
interface atm 5/0 
xconnect 10.0.0.1 123 pw-class atm-cell-relay

The show atm route command in the following example displays port mode cell relay state. The following example shows that atm interface 1/0 is for cell relay, the VC ID is 123 and the tunnel is down.

Router# show atm route

Input Intf        Output Intf     Output VC       Status
ATM1/0            ATOM Tunnel     123             DOWN

The show mpls l2transport vc command in the following example also shows configuration information.

Router# show mpls l2transport vc

Local intf     Local circuit        Dest address    VC ID      Status    
-------------  -------------------- --------------- ---------- ----------
AT1/0          ATM CELL ATM1/0      10.1.1.121     1121       UP      

Troubleshooting Tips

The debug atm l2transport and debug mpls l2transport vc display troubleshooting information.

Configuring ATM Single Cell Relay over MPLS

The single cell relay feature allows you to insert one ATM cell in each MPLS packet. You can use single cell relay in both VP and VC mode. The configuration steps show how to configure single cell relay in VC mode. For VP mode, see the "Configuring ATM Cell Relay over MPLS in PVP Mode" section.

SUMMARY STEPS

1. enable

2. configure terminal

3. interface atmslot/port

4. pvc vpi/vci l2transport

5. encapsulation aal0

6. xconnect peer-router-id vcid encapsulation mpls

DETAILED STEPS

 
Command or Action
Purpose

Step 1 

enable

Example:

Router> enable

Enables privileged EXEC mode.

Enter your password if prompted.

Step 2 

configure terminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3 

interface atmslot/port

Example:

Router(config)# interface atm1/0

Specifies an ATM interface and enters interface configuration mode.

Step 4 

pvc vpi/vci l2transport

Example:

Router(config-if)# pvc 1/100 l2transport

Assigns a VPI and VCI and enters L2transport VC configuration mode.

The l2transport keyword indicates that the PVC is a switched PVC instead of a terminated PVC.

Step 5 

encapsulation aal0

Example:

Router(config-if-atm-l2trans-pvc)# encapsulation aal0

Specifies raw cell encapsulation for the interface. Make sure you specify the same encapsulation type on the PE and CE routers.

Step 6 

xconnect peer-router-id vcid encapsulation mpls

Example:

Router(config-if-atm-l2trans-pvc)# xconnect 10.0.0.1 123 encapsulation mpls

Binds the attachment circuit to a pseudowire VC.

Configuring ATM Packed Cell Relay over MPLS

The packed cell relay feature allows you to insert multiple concatenated ATM cells in an MPLS packet. The packed cell relay feature is more efficient than single cell relay, because each ATM cell is 52 bytes, and each AToM packet is at least 64 bytes.

At a high level, packed cell relay configuration consists of the following steps:

1. You specify the amount of time a PE router can wait for cells to be packed into an MPLS packet. You can set up three timers by default with different amounts of time attributed to each timer.

2. You enable packed cell relay, specify how many cells should be packed into each MPLS packet, and choose which timer to use during the cell packing process.

Restrictions

The cell-packing command is available only if you use AAL0 encapsulation in VC mode. If the command is configured with ATM AAL5 encapsulation, the command is not valid.

Only cells from the same VC, VP, or port can be packed into one MPLS packet. Cells from different connections cannot be concatenated into the same MPLS packet.

When you change, enable, or disable the cell-packing attributes, the ATM VC, VP, or port and the MPLS emulated VC are reestablished.

If a PE router does not support packed cell relay, the PE router sends only one cell per MPLS packet.

The number of packed cells does not need to match between the PE routers. The two PE routers agree on the lower of the two values. For example, if PE1 is allowed to pack 10 cells per MPLS packet and PE2 is allowed to pack 20 cells per MPLS packet, the two PE routers would agree to send no more than 10 cells per packet.

If the number of cells packed by the peer PE router exceeds the limit, the packXet is dropped.

Issue the atm mcpt-timers command on an ATM interface before issuing the cell-packing command.

See the following sections for configuration information:

Configuring ATM Packed Cell Relay over MPLS in VC Mode

Configuring ATM Packed Cell Relay over MPLS in VC Mode Using VC Class Configuration Mode

Configuring ATM Packed Cell Relay over MPLS in VP Mode

Configuring ATM Packed Cell Relay over MPLS in Port Mode

Configuring ATM Packed Cell Relay over MPLS in VC Mode

Perform this task to configure the ATM packed cell relay over MPLS feature in VC mode.

SUMMARY STEPS

1. enable

2. configure terminal

3. interface atmslot/port

4. shutdown

5. atm mcpt-timers [timer1-timeout timer2-timeout timer3-timeout]

6. no shutdown

7. pvc vpi/vci l2transport

8. encapsulation aal0

9. xconnect peer-router-id vcid encapsulation mpls

10. cell-packing [cells] [mcpt-timer timer]

DETAILED STEPS

 
Command or Action
Purpose

Step 1 

enable

Example:

Router> enable

Enables privileged EXEC mode.

Enter your password if prompted.

Step 2 

configure terminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3 

interface atmslot/port

Example:

Router(config)# interface atm1/0

Defines the interface and enters interface configuration mode.

Step 4 

shutdown

Example:

Router(config-if)# shutdown

Shuts down the interface.

Step 5 

atm mcpt-timers [timer1-timeout timer2-timeout timer3-timeout]

Example:

Router(config-if)# atm mcpt-timers 100 200 250


Sets up the cell-packing timers, which specify how long the PE router can wait for cells to be packed into an MPLS packet.

You can set up to three timers. For each timer, you specify the maximum cell-packing timeout (MCPT). This value gives the cell-packing function a limited amount of time to complete. If the timer expires before the maximum number of cells are packed into an AToM packet, the packet is sent anyway. The timeout's default and range of acceptable values depends on the ATM link speed.

The respective default values for the PA-A3 port adapters are:

OC-3: 30, 60, and 90 microseconds

T3: 100, 200, and 300 microseconds

E3: 130, 260, and 390 microseconds

You can specify either the number of microseconds or use the default.

The respective range of values for the PA-A3 port adapters are:

OC-3: 10 to 4095 microseconds

T3: 30 to 4095 microseconds

E3: 40 to 4095 microseconds

Step 6 

no shutdown

Example:

Router(config-if)# no shutdown

Enables the interface.

Step 7 

pvc vpi/vci l2transport

Example:

Router(config-if)# pvc 1/100 l2transport

Assigns a VPI and VCI and enters L2transport VC configuration mode.

The l2transport keyword indicates that the PVC is a switched PVC instead of a terminated PVC.

Step 8 

encapsulation aal0

Example:

Router(config-if-atm-l2trans-pvc)# encapsulation aal0

Specifies raw cell encapsulation for the interface. Make sure you specify the same encapsulation type on the PE routers.

Step 9 

xconnect peer-router-id vcid encapsulation mpls 
Example:
Router(config-if-atm-l2trans-pvc)# xconnect 
10.0.0.1 123 encapsulation mpls 

Binds the attachment circuit to a pseudowire VC.

Step 10 

cell-packing [cells] [mcpt-timer timer]
Example:
Router(config-if-atm-l2trans-pvc)# cell-packing 
10 mcpt-timer 1

Enables cell packing and specifies the cell-packing parameters.

The cells argument represents the maximum number of cells to be packed into an MPLS packet. The range is from 2 to the MTU of the interface divided by 52. The default is MTU/52.

The timer argument allows you to specify which timer to use. The default is timer 1.

See the cell-packing command page for more information.

Examples

The following example shows that ATM PVC 1/100 is an AToM cell relay PVC. There are three timers set up, with values of 1000 milliseconds, 800 milliseconds, and 500 milliseconds, respectively. The cell-packing command specifies that five ATM cells are to be packed into an MPLS packet. The cell-packing command also specifies that timer 1 is to be used.

int atm 1/0
shutdown
atm mcpt-timer 1000 800 500
no shutdown
pvc 1/100 l2transport
encapsulation aal0
xconnect 10.0.0.1 123 encapsulation mpls
cell-packing 5 mcpt-timer 1

Configuring ATM Packed Cell Relay over MPLS in VC Mode Using VC Class Configuration Mode

You can create a VC class that specifies the ATM cell relay encapsulation and the cell packing parameters and then attach the VC class to an interface, subinterface, or VC. The following task creates a VC class that specifies the ATM cell relay encapsulation and cell packing and attaches it to a main interface.


Note You can configure VC class configuration mode only in VC mode. VC class configuration mode is not supported on VP or port mode.


When you configure cell packing in VC class configuration mode and then apply the VC class to an interface, the settings in the VC class apply to all the VCs on the interface, unless you specify a different cell packing value at a lower level, such as the subinterface or VC level. For example, you can create a VC class that specifies three cells to be packed. You can apply the VC class to an interface. Then, for one PVC, you can specify two cells to be packed. All the PVCs on the interface pack three cells, except for the one PVC that was set to set two cells.

SUMMARY STEPS

1. enable

2. configure terminal

3. vc-class atm name

4. encapsulation layer-type

5. cell-packing [cells] [mcpt-timer timer]

6. exit

7. interface typeslot/port

8. shutdown

9. atm mcpt-timers [timer1-timeout timer2-timeout timer3-timeout]

10. no shutdown

11. class-int vc-class-name

12. pvc [name] vpi/vci l2transport

13. xconnect peer-router-id vcid encapsulation mpls

DETAILED STEPS

 
Command or Action
Purpose

Step 1 

enable

Example:

Router> enable

Enables privileged EXEC mode.

Enter your password if prompted.

Step 2 

configure terminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3 

vc-class atm name

Example:

Router(config)# vc-class atm cellpacking

Creates a VC class and enters VC class configuration mode.

Step 4 

encapsulation layer-type

Example:

Router(config-vc-class)# encapsulation aal0

Configures the AAL and encapsulation type.

Step 5 

cell-packing [cells] [mcpt-timer timer]

Example:

Router(config-vc-class)# cell-packing 10 mcpt-timer 1

Enables cell packing and specifies the cell-packing parameters.

The cells argument represents the maximum number of cells to be packed into an MPLS packet. The range is from 2 to the MTU of the interface divided by 52. The default is MTU/52.

The timer argument allows you to specify which timer to use. The default is timer 1.

See the cell-packing command page for more information.

Step 6 

exit

Example:

Router(config-vc-class)# exit

Exits VC class configuration mode.

Step 7 

interface typeslot/port

Example:

Router(config)# interface atm1/0

Specifies the interface by type, slot, and port number, and enters interface configuration mode.

Step 8 

shutdown

Example:

Router(config-if)# shutdown

Shuts down the interface.

Step 9 

atm mcpt-timers [timer1-timeout timer2-timeout timer3-timeout]

Example:

Router(config-if)# atm mcpt-timers 100 200 250


Sets up the cell-packing timers, which specify how long the PE router can wait for cells to be packed into an MPLS packet.

You can set up to three timers. For each timer, you specify the MCPT. This value gives the cell-packing function a limited amount of time to complete. If the timer expires before the maximum number of cells are packed into an AToM packet, the packet is sent anyway. The timeout's default and range of acceptable values depends on the ATM link speed.

The respective default values for the PA-A3 port adapters are:

OC-3: 30, 60, and 90 microseconds

T3: 100, 200, and 300 microseconds

E3: 130, 260, and 390 microseconds

You can specify either the number of microseconds or use the default.

The respective range of values for the PA-A3 port adapters are:

OC-3: 10 to 4095 microseconds

T3: 30 to 4095 microseconds

E3: 40 to 4095 microseconds

Step 10 

no shutdown

Example:

Router(config-if)# no shutdown

Enables the interface.

Step 11 

class-int vc-class-name

Example:

Router(config-if)# class-int cellpacking

Applies a VC class to the ATM main interface or subinterface.

Note You can also apply a VC class to a PVC.

Step 12 

pvc [name] vpi/vci l2transport

Example:

Router(config-if)# pvc 1/200 l2transport

Creates or assigns a name to an ATM PVC and enters L2transport VC configuration mode.

The l2transport keyword indicates that the PVC is a switched PVC instead of a terminated PVC.

Step 13 

xconnect peer-router-id vcid encapsulation mpls

Example:

Router(config-if-atm-l2trans-pvc)# xconnect 10.13.13.13 100 encapsulation mpls

Binds the attachment circuit to a pseudowire VC.

Examples

The following example configures ATM cell relay over MPLS with cell packing in VC class configuration mode. The VC class is then applied to an interface.

enable
configure terminal
vc-class atm cellpacking
encapsulation aal0
cell-packing 10 mcpt-timer 1
interface atm1/0
shutdown
atm mcpt-timers 100 200 250
no shutdown
class-int cellpacking 
pvc 1/200 l2transport
xconnect 10.13.13.13 100 encapsulation mpls

The following example configures ATM cell relay over MPLS in VC class configuration mode. The VC class is then applied to a PVC.

enable
configure terminal
vc-class atm cellpacking 
encapsulation aal0
cell-packing 10 mcpt-timer 1
interface atm1/0
shutdown
atm mcpt-timers 100 200 250
no shutdown
pvc 1/200 l2transport
class-vc cellpacking 
xconnect 10.13.13.13 100 encapsulation mpls

Configuring ATM Packed Cell Relay over MPLS in VP Mode

Perform this task to configure the ATM cell-packing feature in VP mode.

SUMMARY STEPS

1. enable

2. configure terminal

3. interface atmslot/port

4. shutdown

5. atm mcpt-timers [timer1-timeout timer2-timeout timer3-timeout]

6. no shutdown

7. atm pvp vpi l2transport

8. xconnect peer-router-id vcid encapsulation mpls

9. cell-packing [cells] [mcpt-timer timer]

DETAILED STEPS

 
Command or Action
Purpose

Step 1 

enable

Example:

Router> enable

Enables privileged EXEC mode.

Enter your password if prompted.

Step 2 

configure terminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3 

interface atmslot/port

Example:

Router(config)# interface atm1/0

Defines the interface and enters interface configuration mode.

Step 4 

shutdown

Example:

Router(config-if)# shutdown

Shuts down the interface.

Step 5 

atm mcpt-timers [timer1-timeout timer2-timeout timer3-timeout]

Example:

Router(config-if)# atm mcpt-timers 100 200 250


Sets up the cell-packing timers, which specify how long the PE router can wait for cells to be packed into an MPLS packet.

You can set up to three timers. For each timer, you specify the MCPT. This value gives the cell-packing function a limited amount of time to complete. If the timer expires before the maximum number of cells are packed into an AToM packet, the packet is sent anyway. The timeout's default and range of acceptable values depends on the ATM link speed.

The respective default values for the PA-A3 port adapters are:

OC-3: 30, 60, and 90 microseconds

T3: 100, 200, and 300 microseconds

E3: 130, 260, and 390 microseconds

You can specify either the number of microseconds or use the default.

The respective range of values for the PA-A3 port adapters are:

OC-3: 10 to 4095 microseconds

T3: 30 to 4095 microseconds

E3: 40 to 4095 microseconds

Step 6 

no shutdown

Example:

Router(config-if)# no shutdown

Enables the interface.

Step 7 

atm pvp vpi l2transport

Example:

Router(config-if)# atm pvp 1 l2transport

Specifies that the PVP is dedicated to transporting ATM cells and enters L2transport PVP configuration submode.

The l2transport keyword indicates that the PVP is for cell relay. This submode is for Layer 2 transport only; it is not for regular PVPs.

Step 8 

xconnect peer-router-id vcid encapsulation mpls

Example:

Router(cfg-if-atm-l2trans-pvp)# xconnect 10.0.0.1 123 encapsulation mpls

Binds the attachment circuit to a pseudowire VC. The syntax for this command is the same as for all other Layer 2 transports.

Step 9 

cell-packing [cells] [mcpt-timer timer]

Example:

Router(cfg-if-atm-l2trans-pvp)# cell-packing 10 mcpt-timer 1

Enables cell packing and specifies the cell-packing parameters.

The cells argument represents the maximum number of cells to be packed into an MPLS packet. The range is from 2 to the MTU of the interface divided by 52. The default is MTU/52.

The timer argument allows you to specify which timer to use. The default is timer 1.

See the cell-packing command page for more information.

Examples

The following example shows packed cell relay enabled on an interface set up for PVP mode. The cell-packing command specifies that 10 ATM cells are to be packed into an MPLS packet. The cell-packing command also specifies that timer 2 is to be used.

interface atm 1/0
shutdown
atm mcpt-timer 1000 800 500
no shutdown
atm pvp 100 l2transport
xconnect 10.0.0.1 234 encapsulation mpls
cell-packing 10 mcpt-timer 2

Configuring ATM Packed Cell Relay over MPLS in Port Mode

Perform this task to configure ATM packed cell relay over MPLS in port mode.

SUMMARY STEPS

1. enable

2. configure terminal

3. interface atmslot/port

4. shutdown

5. atm mcpt-timers [timer1-timeout timer2-timeout timer3-timeout]

6. no shutdown

7. cell-packing [cells] [mcpt-timer timer]

8. xconnect peer-router-id vcid encapsulation mpls

9. exit

10. exit

11. show atm cell-packing

12. show atm vp

DETAILED STEPS

 
Command or Action
Purpose

Step 1 

enable

Example:

Router> enable

Enables privileged EXEC mode.

Enter your password if prompted.

Step 2 

configure terminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3 

interface atmslot/port

Example:

Router(config)# interface atm1/0

Specifies an ATM interface and enters interface configuration mode.

Step 4 

shutdown

Example:

Router(config-if)# shutdown

Shuts down the interface.

Step 5 

atm mcpt-timers [timer1-timeout timer2-timeout timer3-timeout]

Example:

Router(config-if)# atm mcpt-timers 100 200 250


Sets up the cell-packing timers, which specify how long the PE router can wait for cells to be packed into an MPLS packet.

You can set up to three timers. For each timer, you specify the MCPT. This value gives the cell-packing function a limited amount of time to complete. If the timer expires before the maximum number of cells are packed into an AToM packet, the packet is sent anyway. The timeout's default and range of acceptable values depends on the ATM link speed.

The respective default values for the PA-A3 port adapters are:

OC-3: 30, 60, and 90 microseconds

T3: 100, 200, and 300 microseconds

E3: 130, 260, and 390 microseconds

You can specify either the number of microseconds or use the default.

The respective range of values for the PA-A3 port adapters are:

OC-3: 10 to 4095 microseconds

T3: 30 to 4095 microseconds

E3: 40 to 4095 microseconds

Step 6 

no shutdown

Example:

Router(config-if)# no shutdown

Enables the interface.

Step 7 

cell-packing [cells] [mcpt-timer timer]

Example:

Router(config-if)# cell-packing 10 mcpt-timer 1

Enables cell packing and specifies the cell-packing parameters.

The cells argument represents the maximum number of cells to be packed into an MPLS packet. The range is from 2 to the MTU of the interface divided by 52. The default is MTU/52.

The timer argument allows you to specify which timer to use. The default is timer 1.

See the cell-packing command page for more information.

Step 8 

xconnect peer-router-id vcid encapsulation mpls

Example:

Router(config-if)# xconnect 10.0.0.1 123 encapsulation mpls

Binds the attachment circuit to the interface.

Step 9 

exit

Example:

Router(config-if)# exit

Exits interface configuration mode.

Step 10 

exit

Example:

Router(config)# exit

Exits global configuration mode.

Step 11 

show atm cell-packing

Example:

Router# show atm cell-packing

Displays cell-packing statistics.

Step 12 

show atm vp

Example:

Router#show atm vp

Displays cell-packing information.

Examples

The following example shows packed cell relay enabled on an interface set up for port mode. The cell-packing command specifies that 10 ATM cells are to be packed into an MPLS packet. The cell-packing command also specifies that timer 2 is to be used.

interface atm 5/0 
shutdown
atm mcpt-timer 1000 800 500
no shutdown
cell-packing 10 mcpt-timer 2
xconnect 10.0.0.1 123 encapsulation mpls

The show atm cell-packing command in the following example displays the following statistics:

The number of cells that are to be packed into an MPLS packet on the local and peer routers

The average number of cells sent and received

The timer values associated with the local router


Router# show atm cell-packing

                         average                 average 
        circuit  local  nbr of cells    peer    nbr of cells    MCPT
        type     MNCP   rcvd in one pkt MNCP    sent in one pkt (us)
==============================================================================
atm 1/0 vc 1/200  20    15              30              20       60      
atm 1/0 vp 2      25    21              30              24      100

The show atm vp command in the following example displays the cell packing information at the end of the output:

Router# show atm vp 12

ATM5/0  VPI: 12, Cell Relay, PeakRate: 149760, CesRate: 0, DataVCs: 1, CesVCs: 0, Status: 
ACTIVE

  VCD    VCI   Type   InPkts   OutPkts   AAL/Encap     Status
  6      3     PVC    0        0         F4 OAM        ACTIVE  
  7      4     PVC    0        0         F4 OAM        ACTIVE  

TotalInPkts: 0, TotalOutPkts: 0, TotalInFast: 0, TotalOutFast: 0,
TotalBroadcasts: 0 TotalInPktDrops: 0, TotalOutPktDrops: 0
Local MNCP: 5, average number of cells received: 3
Peer MNCP: 1, average number of cells sent: 1
Local MCPT: 100 us

Troubleshooting Tips

To debug ATM cell packing, issue the debug atm cell-packing command.

Configuring Ethernet over MPLS in VLAN Mode

A VLAN is a switched network that is logically segmented by functions, project teams, or applications regardless of the physical location of users. Ethernet over MPLS allows you to connect two VLAN networks that are in different locations. You configure the PE routers at each end of the MPLS backbone and add a point-to-point VC. Only the two PE routers at the ingress and egress points of the MPLS backbone know about the VCs dedicated to transporting Layer 2 VLAN traffic. All other routers do not have table entries for those VCs. Ethernet over MPLS in VLAN mode transports Ethernet traffic from a source 802.1Q VLAN to a destination 802.1Q VLAN over a core MPLS network.


Note You must configure Ethernet over MPLS (VLAN mode) on the subinterfaces.


SUMMARY STEPS

1. enable

2. configure terminal

3. interface gigabitethernetslot/interface.subinterface

4. encapsulation dot1q vlan-id

5. xconnect peer-router-id vcid encapsulation mpls

DETAILED STEPS

 
Command or Action
Purpose

Step 1 

enable

Example:

Router> enable

Enables privileged EXEC mode.

Enter your password if prompted.

Step 2 

configure terminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3 

interface gigabitethernetslot/interface.subinterface

Example:

Router(config)# interface gigabitethernet4/0.1

Specifies the Gigabit Ethernet subinterface and enters subinterface configuration mode. Make sure the subinterface on the adjoining CE router is on the same VLAN as this PE router.

Step 4 

encapsulation dot1q vlan-id

Example:

Router(config-subif)# encapsulation dot1q 100

Enables the subinterface to accept 802.1Q VLAN packets.

The subinterfaces between the CE and PE routers that are running Ethernet over MPLS must be in the same subnet. All other subinterfaces and backbone routers do not.

Step 5 

xconnect peer-router-id vcid encapsulation mpls

Example:

Router(config-subif)# xconnect 10.0.0.1 123 encapsulation mpls

Binds the attachment circuit to a pseudowire VC. The syntax for this command is the same as for all other Layer 2 transports.

Configuring Ethernet over MPLS in Port Mode

Port mode allows a frame coming into an interface to be packed into an MPLS packet and transported over the MPLS backbone to an egress interface. The entire Ethernet frame without the preamble or FCS is transported as a single packet. To configure port mode, you use the xconnect command in interface configuration mode and specify the destination address and the VC ID. The syntax of the xconnect command is the same as for all other transport types. Each interface is associated with one unique pseudowire VC label.

When configuring Ethernet over MPLS in port mode, use the following guidelines:

The pseudowire VC type is set to Ethernet.

Port mode and Ethernet VLAN mode are mutually exclusive. If you enable a main interface for port-to-port transport, you cannot also enter commands on a subinterface.

SUMMARY STEPS

1. enable

2. configure terminal

3. interface gigabitethernetslot/interface

4. xconnect peer-router-id vcid encapsulation mpls

5. exit

6. exit

7. show mpls l2transport vc

DETAILED STEPS

 
Command or Action
Purpose

Step 1 

enable

Example:

Router> enable

Enables privileged EXEC mode.

Enter your password if prompted.

Step 2 

configure terminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3 

interface gigabitethernetslot/interface

Example:

Router(config)# interface gigabitethernet4/0

Specifies the Gigabit Ethernet interface and enters interface configuration mode. Make sure the interface on the adjoining CE router is on the same VLAN as this PE router.

Step 4 

xconnect peer-router-id vcid encapsulation mpls

Example:

Router(config-if)# xconnect 10.0.0.1 123 encapsulation mpls

Binds the attachment circuit to a pseudowire VC. The syntax for this command is the same as for all other Layer 2 transports.

Step 5 

exit

Example:

Router(config-if)# exit

Exits interface configuration mode.

Step 6 

exit

Example:

Router(config)# exit

Exits router configuration mode.

Step 7 

show mpls l2transport vc

Example:

Router# show mpls l2transport vc

Displays information about Ethernet over MPLS port mode.

Examples

The following example configures VC 123 in Ethernet port mode:

pseudowire-class ethernet-port
encapsulation mpls
  
int gigabitethernet1/0 
xconnect 10.0.0.1 123 pw-class ethernet-port

The command output in the following example shows two VCs for Ethernet over MPLS:

VC 2 is in Ethernet VLAN mode.

VC 8 is in Ethernet port mode.

Router# show mpls l2transport vc 

Local intf     Local circuit        Dest address    VC ID      Status    
-------------  -------------------- --------------- ---------- ----------
Gi4/0.1        Eth VLAN 2           10.1.1.1        2          UP        
Gi8/0/1        Ethernet             10.1.1.1        8          UP        

If you issue the show mpls l2transport vc detail command, the output is similar:

Router# show mpls l2transport vc detail

Local interface: Gi4/0.1 up, line protocol up, Eth VLAN 2 up
Destination address: 10.1.1.1, VC ID: 2, VC status: up
.
.
.
Local interface: Gi8/0/1 up, line protocol up, Ethernet up
  Destination address: 10.1.1.1, VC ID: 8, VC status: up

Configuring Ethernet over MPLS with VLAN ID Rewrite

The VLAN ID rewrite feature enables you to use VLAN interfaces with different VLAN IDs at both ends of the tunnel.

The Cisco 12000 series router requires you to configure VLAN ID rewrite manually, as described in the following sections.

The following routers automatically perform VLAN ID rewrite on the disposition PE router. No configuration is required:

Cisco 7200 series routers.

Cisco 7500 series routers.

Cisco 10720 series routers.

Routers supported on Cisco IOS Release 12.4(11)T. (Use Cisco Feature Navigator to find information about platform support and Cisco IOS and Catalyst OS software image support.)

The following sections explain how to configure the VLAN ID rewrite feature:

Configuring Ethernet over MPLS with VLAN ID Rewrite for the Cisco 12000 Series Routers for Cisco IOS Releases 12.0(29)S and Earlier Releases

Configuring Ethernet over MPLS with VLAN ID Rewrite for the Cisco 12000 Series Routers for Cisco IOS Releases 12.0(30)S and Later Releases

Configuring Ethernet over MPLS with VLAN ID Rewrite for the Cisco 12000 Series Routers for
Cisco IOS Releases 12.0(29)S and Earlier Releases

Use the following guidelines for the VLAN ID rewrite feature for the Cisco 12000 series routers in
Cisco IOS releases earlier than 12.0(29)S:

The IP Service Engine (ISE) 4-port Gigabit Ethernet line card performs the VLAN ID rewrite on the disposition side at the edge-facing line card.

The engine 2 3-port Gigabit Ethernet line card performs the VLAN ID rewrite on the imposition side at the edge-facing line card.

The VLAN ID rewrite functionality requires that both ends of the Ethernet over MPLS connections be provisioned with the same line cards. Make sure that both edge-facing ends of the virtual circuit use either the engine 2 or ISE Ethernet line card. The following example shows the system flow with the VLAN ID rewrite feature:

The ISE 4-port Gigabit Ethernet line card:

Traffic flows from VLAN1 on CE1 to VLAN2 on CE2. As the frame reaches the edge-facing line card of the disposition router PE2, the VLAN ID in the dot1Q header changes to the VLAN ID assigned to VLAN2.

The engine 2 3-port Gigabit Ethernet line card:

Traffic flows from VLAN1 on CE1 to VLAN2 on CE2. As the frame reaches the edge-facing line card of the imposition router PE1, the VLAN ID in the dot1Q header changes to the VLAN ID assigned to VLAN2.

For the Cisco 12000 series router engine 2 3-port Gigabit Ethernet line card, you must issue the remote circuit id command as part of the Ethernet over MPLS VLAN ID rewrite configuration.

Configuring Ethernet over MPLS with VLAN ID Rewrite for the Cisco 12000 Series Routers for
Cisco IOS Releases 12.0(30)S and Later Releases

In Cisco IOS Release 12.0(30)S, the following changes to VLAN ID rewrite were implemented:

The ISE 4-port Gigabit Ethernet line card can perform VLAN ID rewrite at both the imposition and disposition sides of the edge-facing router.

The remote circuit id command is not required as part of the Ethernet over MPLS VLAN ID rewrite configuration, as long as both PE routers are running Cisco IOS Release 12.0(30)S. The VLAN ID rewrite feature is implemented automatically when you configure Ethernet over MPLS.

The VLAN ID rewrite feature in Cisco IOS Release 12.0(30)S can interoperate with routers that are running earlier releases. If you have a PE router at one end of the circuit that is using an earlier
Cisco IOS release and the remote circuit id command, the other PE can run Cisco IOS
Release 12.0(30)S and still perform VLAN ID rewrite.

You can mix the line cards on the PE routers, as shown in the following table

Table 6 Supported Line Cards for VLAN ID Rewrite Feature:

If PE1 Has These Line Cards
Then PE2 Can Use These Line Cards

Engine 2 3-port Gigabit Ethernet line card
or
ISE 4-port Gigabit Ethernet line card

Engine 2 3-port Gigabit Ethernet line card
or
ISE 4-port Gigabit Ethernet line card

ISE 4-port Gigabit Ethernet line card

Any Cisco 12000 series router line card


SUMMARY STEPS

1. enable

2. configure terminal

3. interface gigabitethernetslot/port.subinterface

4. encapsulation dot1q vlan-id

5. xconnect peer-router-id vcid encapsulation mpls

6. remote circuit id remote-vlan-id

7. exit

8. exit

9. exit

10. show controllers eompls forwarding-table

DETAILED STEPS

 
Command or Action
Purpose

Step 1 

enable

Example:

Router> enable

Enables privileged EXEC mode.

Enter your password if prompted.

Step 2 

configure terminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3 

interface gigabitethernetslot/interface.subinterface

Example:

Router(config)# interface gigabitethernet4/0.1

Specifies the Gigabit Ethernet subinterface and enters subinterface configuration mode.

Make sure the subinterfaces between the CE and PE routers that are running Ethernet over MPLS are in the same subnet. All other subinterfaces and backbone routers do not need to be in the same subnet.

Step 4 

encapsulation dot1q vlan-id

Example:

Router(config-subif)# encapsulation dot1q 100

Enables the subinterface to accept 802.1Q VLAN packets.

Make sure the subinterface on the adjoining CE router is on the same VLAN as this PE router.

Step 5 

xconnect peer-router-id vcid encapsulation mpls

Example:

Router(config-subif)# xconnect 10.0.0.1 123 encapsulation mpls

Binds the attachment circuit to a pseudowire VC and enters xconnect configuration mode. The syntax for this command is the same as for all other Layer 2 transports.

Step 6 

remote circuit id remote-vlan-id

Example:

Router(config-subif-xconn)# remote circuit id 101

Enables you to use VLAN interfaces with different VLAN IDs at both ends of the tunnel. This command is required only for the Cisco 12000 series router engine 2 3-port Gigabit Ethernet line card.

Step 7 

exit

Example:

Router(config-subif-xconn)# exit

Exits xconnect configuration mode.

Step 8 

exit

Example:

Router(config-subif)# exit

Exits subinterface configuration mode.

Step 9 

exit

Example:

Router(config)# exit

Exits global configuration mode.

Step 10 

show controllers eompls forwarding-table

Example:

Router# execute slot 0 show controllers eompls forwarding-table

Displays information about VLAN ID rewrite.

Examples

The following example configures VLAN ID rewrite on peer PE routers with Cisco 12000 series router engine 2 3-port Gigabit Ethernet line cards.

PE1
PE2
interface GigabitEthernet0/0.2
encapsulation dot1Q 2
no ip directed-broadcast
no cdp enable
xconnect 10.5.5.5 2 encapsulation mpls
remote circuit id 3
interface GigabitEthernet3/0.2
encapsulation dot1Q 3
no ip directed-broadcast
no cdp enable
xconnect 10.3.3.3 2 encapsulation mpls
remote circuit id 2

The command output of the show controllers eompls forwarding-table command in the following example shows VLAN ID rewrite configured on the Cisco 12000 series routers with an engine 2 3-port Gigabit Ethernet line card. In the following example, the bolded command output show the VLAN ID rewrite information.

On PE1

Router# execute slot 0 show controllers eompls forwarding-table 0 2

Port # 0, VLAN-ID # 2, Table-index 2
EoMPLS configured: 1
tag_rew_ptr             = D001BB58
Leaf entry?     = 1
FCR index       = 20
           **tagrew_psa_addr    = 0006ED60
           **tagrew_vir_addr    = 7006ED60
           **tagrew_phy_addr    = F006ED60
        [0-7] loq 8800 mtu 4458  oq 4000 ai 3 oi 04019110 (encaps size 4)
        cw-size 4 vlanid-rew 3
        gather A30 (bufhdr size 32 EoMPLS (Control Word) Imposition profile 81)
        2 tag: 18 18
        counters 1182, 10 reported 1182, 10.
    Local OutputQ (Unicast):    Slot:2  Port:0  RED queue:0  COS queue:0
    Output Q (Unicast):         Port:0          RED queue:0  COS queue:0

On PE2

Router# execute slot 0 show controllers eompls forwarding-table 0 3 

Port # 0, VLAN-ID # 3, Table-index 3
EoMPLS configured: 1
tag_rew_ptr             = D0027B90
Leaf entry?     = 1
FCR index       = 20
           **tagrew_psa_addr    = 0009EE40
           **tagrew_vir_addr    = 7009EE40
           **tagrew_phy_addr    = F009EE40
        [0-7] loq 9400 mtu 4458  oq 4000 ai 8 oi 84000002 (encaps size 4)
        cw-size 4 vlanid-rew 2
        gather A30 (bufhdr size 32 EoMPLS (Control Word) Imposition profile 81)
        2 tag: 17 18
        counters 1182, 10 reported 1182, 10.
    Local OutputQ (Unicast):    Slot:5  Port:0  RED queue:0  COS queue:0
    Output Q (Unicast):         Port:0          RED queue:0  COS queue:0

Configuring Ethernet over MPLS with MTU Values in xconnect Configuration Mode

Cisco IOS Release 12.2(33)SRC introduces the ability to specify MTU values in xconnect configuration mode. When you use xconnect configuration mode to set the MTU value, you establish a pseudowire connection for situations where the interfaces have different MTU values, which cannot be changed.

If you specify an MTU value in xconnect configuration mode that is outside the range of supported MTU values (64 bytes to the maximum number of bytes supported by the interface), the command might be rejected. If you specify an MTU value that is out of range in xconnect configuration mode, the router enters the command in subinterface configuration mode.

For example, if you specify an MTU of 1501 in xconnect configuration mode, and that value is out of range, the router enters the command in subinterface configuration mode, where it is accepted:

router# configure terminal
router(config)# interface gigabitethernet0/2.1
router(config-subif)# xconnect 10.10.10.1 100 encapsulation mpls
router(config-subif-xconn)# mtu ?
<64 - 1500> MTU size in bytes
router(config-subif-xconn)# mtu 1501
router(config-subif)# 
router(config-subif)# mtu ?
<64 - 17940> MTU size in bytes

If the MTU value is not accepted in either xconnect configuration mode or subinterface configuration mode, then the command is rejected, as shown in the following example:

router# configure terminal
router(config)# interface gigabitethernet0/2.1
router(config-subif)# xconnect 10.10.10.1 100 encapsulation mpls
router(config-subif-xconn)# mtu ?
<64 - 1500> MTU size in bytes
router(config-subif-xconn)# mtu 63
% Invalid input detected at ^ marker

Restrictions

Configuring the MTU value in xconnect configuration mode has the following restrictions:

The following features do not support MTU values in xconnect configuration mode:

Layer 2 Tunnel Protocol Version 3 (L2TPv3)

Virtual Private LAN services (VPLS)

L2VPN Pseudowire Switching

Configuring the MTU value in xconnect configuration mode applies only to the following interfaces and subinterfaces:

Ethernet

FastEthernet

GigabitEthernet

The router uses an MTU validation process for remote VCs established through LDP, which compares the MTU value configured in xconnect configuration mode to the MTU value of the remote customer interface. If an MTU value has not been configured in xconnect configuration mode, then the validation process compares the MTU value of the local customer interface to the MTU value of the remote xconnect, either explicitly configured or inherited from the underlying interface or subinterface.

When you configure the MTU value in xconnect configuration mode, the specified MTU value is not enforced by the dataplane. The dataplane enforces the MTU values of the interface (port mode) or subinterface (VLAN mode).

Ensure that the interface MTU is larger than the MTU value configured in xconnect configuration mode. If the MTU value of the customer-facing subinterface is larger than the MTU value of the core-facing interface, traffic may not be able to travel across the pseudowire.

SUMMARY STEPS

1. enable

2. configure terminal

3. interface gigabitethernetslot/interface

4. mtu mtu-value

5. interface gigabitethernetslot/interface.subinterface

6. encapsulation dot1q vlan-id

7. xconnect peer-router-id vcid encapsulation mpls

8. mtu mtu-value

9. end

10. show mpls l2transport binding

DETAILED STEPS

 
Command or Action
Purpose

Step 1 

enable

Example:

Router> enable

Enables privileged EXEC mode.

Enter your password if prompted.

Step 2 

configure terminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3 

interface gigabitethernetslot/interface

Example:

Router(config)# interface gigabitethernet4/0

Specifies the Gigabit Ethernet interface and enters interface configuration mode.

Step 4 

mtu mtu-value

Example:

Router(config-if)# mtu 2000

Specifies the MTU value for the interface. The MTU value specified at the interface level can be inherited by a subinterface.

Step 5 

interface gigabitethernetslot/interface.subinterface

Example:

Router(config-if)# interface gigabitethernet4/0.1

Specifies the Gigabit Ethernet subinterface and enters subinterface configuration mode. Make sure the subinterface on the adjoining CE router is on the same VLAN as this PE router.

Step 6 

encapsulation dot1q vlan-id

Example:

Router(config-subif)# encapsulation dot1q 100

Enables the subinterface to accept 802.1Q VLAN packets.

The subinterfaces between the CE and PE routers that are running Ethernet over MPLS must be in the same subnet. All other subinterfaces and backbone routers do not.

Step 7 

xconnect peer-router-id vcid encapsulation mpls

Example:

Router(config-subif)# xconnect 10.0.0.1 123 encapsulation mpls

Binds the attachment circuit to a pseudowire VC. The syntax for this command is the same as for all other Layer 2 transports. Enters xconnect configuration mode.

Step 8 

mtu mtu-value

Example:

Router(config-if-xconn)# mtu 1400

Specifies the MTU for the VC.

Step 9 

end

Example:

Router(config-if-xconn)# end

Exits xconnect configuration mode and returns to global configuration mode.

Step 10 

show mpls l2transport binding

Example:

Router# show mpls l2transport binding

Displays the MTU values assigned to the local and remote interfaces.

Configuring Frame Relay over MPLS with DLCI-to-DLCI Connections

Frame Relay over MPLS encapsulates Frame Relay PDUs in MPLS packets and forwards them across the MPLS network. For Frame Relay, you can set up data-link connection identifier (DLCI)-to-DLCI connections or port-to-port connections. With DLCI-to-DLCI connections, the PE routers manipulate the packet by removing headers, adding labels, and copying control word elements from the header to the PDU.

Perform this task to configure Frame Relay over MPLS with DLCI-to-DLCI connections.

SUMMARY STEPS

1. enable

2. configure terminal

3. frame-relay switching

4. interface serial slot/port

5. encapsulation frame-relay [cisco | ietf]

6. frame-relay intf-type dce

7. exit

8. connect connection-name interface dlci l2transport

9. xconnect peer-router-id vcid encapsulation mpls

DETAILED STEPS

 
Command or Action
Purpose

Step 1 

enable

Example:

Router> enable

Enables privileged EXEC mode.

Enter your password if prompted.

Step 2 

configure terminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3 

frame-relay switching

Example:

Router(config)# frame-relay switching

Enables PVC switching on a Frame Relay device.

Step 4 

interface serialslot/port

Example:

Router(config)# interface serial3/1

Specifies a serial interface and enters interface configuration mode.

Step 5 

encapsulation frame-relay [cisco | ietf]

Example:

Router(config-if)# encapsulation frame-relay ietf

Specifies Frame Relay encapsulation for the interface. You can specify different types of encapsulations. You can set one interface to Cisco encapsulation and the other interface to IETF encapsulation.

Step 6 

frame-relay intf-type dce

Example:

Router(config-if)# frame-relay intf-type dce

Specifies that the interface is a DCE switch. You can also specify the interface to support Network-to-Network Interface (NNI) and DTE connections.

Step 7 

exit

Example:

Router(config-if)# exit

Exits from interface configuration mode.

Step 8 

connect connection-name interface dlci l2transport

Example:

Router(config)# connect fr1 serial5/0 1000 l2transport

Defines connections between Frame Relay PVCs and enters connect configuration submode. Using the l2transport keyword specifies that the PVC will not be a locally switched PVC, but will be tunneled over the backbone network.

The connection-name argument is a text string that you provide.

The interface argument is the interface on which a PVC connection will be defined.

The dlci argument is the DLCI number of the PVC that will be connected.

Step 9 

xconnect peer-router-id vcid encapsulation mpls

Example:

Router(config-fr-pw-switching)# xconnect 10.0.0.1 123 encapsulation mpls

Creates the VC to transport the Layer 2 packets. In a DLCI-to DLCI connection type, Frame Relay over MPLS uses the xconnect command in connect configuration submode.

Configuring Frame Relay over MPLS with Port-to-Port Connections

Frame Relay over MPLS encapsulates Frame Relay PDUs in MPLS packets and forwards them across the MPLS network. For Frame Relay, you can set up DLCI-to-DLCI connections or port-to-port connections. With port-to-port connections, you use HDLC mode to transport the Frame Relay encapsulated packets. In HDLC mode, the whole HDLC packet is transported. Only the HDLC flags and FCS bits are removed. The contents of the packet are not used or changed, including the backward explicit congestion notification (BECN), forward explicit congestion notification (FECN) and discard eligibility (DE) bits.

Perform this task to set up Frame Relay port-to-port connections.

SUMMARY STEPS

1. enable

2. configure terminal

3. interface serialslot/port

4. encapsulation hdlc

5. xconnect peer-router-id vcid encapsulation mpls

DETAILED STEPS

 
Command or Action
Purpose

Step 1 

enable

Example:

Router> enable

Enables privileged EXEC mode.

Enter your password if prompted.

Step 2 

configure terminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3 

interface serialslot/port

Example:

Router(config)# interface serial5/0

Specifies a serial interface and enters interface configuration mode.

Step 4 

encapsulation hdlc

Example:

Router(config-if)# encapsulation hdlc

Specifies that Frame Relay PDUs will be encapsulated in HDLC packets.

Step 5 

xconnect peer-router-id vcid encapsulation mpls

Example:

Router(config-if)# xconnect 10.0.0.1 123 encapsulation mpls

Creates the VC to transport the Layer 2 packets.

Configuring HDLC and PPP over MPLS

With HDLC over MPLS, the whole HDLC packet is transported. The ingress PE router removes only the HDLC flags and FCS bits. The contents of the packet are not used or changed.

With PPP over MPLS, the ingress PE router removes the flags, address, control field, and the FCS.

Restrictions

The following restrictions pertain to the HDLC over MPLS feature:

Asynchronous interfaces are not supported.

You must configure HDLC over MPLS on router interfaces only. You cannot configure HDLC over MPLS on subinterfaces.

The following restrictions pertain to the PPP over MPLS feature:

Zero hops on one router is not supported. However, you can have back-to-back PE routers.

Asynchronous interfaces are not supported. The connections between the CE and PE routers on both ends of the backbone must have similar link layer characteristics. The connections between the CE and PE routers must both be synchronous.

Multilink PPP (MLP) is not supported.

You must configure PPP on router interfaces only. You cannot configure PPP on subinterfaces.

SUMMARY STEPS

1. enable

2. configure terminal

3. interface serialslot/port

4. encapsulation encapsulation-type

5. xconnect peer-router-id vcid encapsulation mpls

DETAILED STEPS

 
Command or Action
Purpose

Step 1 

enable

Example:

Router> enable

Enables privileged EXEC mode.

Enter your password if prompted.

Step 2 

configure terminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3 

interface serialslot/port

Example:

Router(config)# interface serial5/0

Specifies a serial interface and enters interface configuration mode. You must configure HDLC and PPP over MPLS on router interfaces only. You cannot configure HDLC over MPLS on subinterfaces.

Step 4 

encapsulation ppp

or

encapsulation hdlc

Example:

Router(config-if)# encapsulation ppp

or

Example:

Router(config-if)# encapsulation hdlc

Specifies HDLC or PPP encapsulation and enters connect configuration mode.

Step 5 

xconnect peer-router-id vcid encapsulation mpls

Example:

Router(config-fr-pw-switching)# xconnect 10.0.0.1 123 encapsulation mpls

Creates the VC to transport the Layer 2 packets.

Configuring Tunnel Selection

The tunnel selection feature allows you to specify the path that traffic uses. You can specify either an MPLS TE tunnel or destination IP address or domain name server (DNS) name.

You also have the option of specifying whether the VCs should use the default path (the path LDP uses for signaling) if the preferred path is unreachable. This option is enabled by default; you must explicitly disable it.

You configure tunnel selection when you set up the pseudowire class. You enable tunnel selection with the preferred-path command. Then, you apply the pseudowire class to an interface that has been configured to transport AToM packets.

The following guidelines provide more information about configuring tunnel selection:

The preferred-path command is available only if the pseudowire encapsulation type is MPLS.

This tunnel selection feature is enabled when you exit from pseudowire submode.

The selected path should be an LSP destined to the peer PE router.

The selected tunnel must be an MPLS TE tunnel.

If you select a tunnel, the tunnel tailend must be on the remote PE router.

If you specify an IP address, that address must be the IP address of the loopback interface on the remote PE router. The address must have a /32 mask. There must be an LSP destined to that selected address. The LSP need not be a TE tunnel.

SUMMARY STEPS

1. enable

2. configure terminal

3. pseudowire-class name

4. encapsulation mpls

5. preferred-path {interface tunnel tunnel-number | peer {ip-address | host-name}} [disable-fallback]

6. exit

7. interface slot/port

8. encapsulation encapsulation-type

9. xconnect peer-router-id vcid pw-class name

DETAILED STEPS

 
Command or Action
Purpose

Step 1 

enable

Example:

Router> enable

Enables privileged EXEC mode.

Enter your password if prompted.

Step 2 

configure terminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3 

pseudowire-class name

Example:

Router(config)# pseudowire-class ts1

Establishes a pseudowire class with a name that you specify and enters pseudowire configuration mode.

Step 4 

encapsulation mpls

Example:

Router(config-pw)# encapsulation mpls

Specifies the tunneling encapsulation. For AToM, the encapsulation type is mpls.

Step 5 

preferred-path {interface tunnel tunnel-number | peer {ip-address | host-name}} [disable-fallback]

Example:

Router(config-pw)# preferred path peer 10.18.18.18

Specifies the MPLS traffic engineering tunnel or IP address or hostname to be used as the preferred path.

Step 6 

exit

Example:

Router(config-pw)# exit

Exits from pseudowire configuration mode.

Step 7 

interface slot/port

Example:

Router(config)# interface atm1/1

Specifies an interface and enters interface configuration mode.

Step 8 

encapsulation encapsulation-type

Example:

Router(config-if)# encapsulation aal5

Specifies the encapsulation for the interface.

Step 9 

xconnect peer-router-id vcid pw-class name

Example:

Router(config-if)# xconnect 10.0.0.1 123 pw-class ts1

Binds the attachment circuit to a pseudowire VC.

Examples

The following example sets up two preferred paths for PE1. One preferred path specifies an MPLS traffic engineering tunnel. The other preferred path specifies an IP address of a loopback address on PE2. There is a static route configured on PE1 that uses a TE tunnel to reach the IP address on PE2.

PE1 Configuration

mpls label protocol ldp
mpls traffic-eng tunnels
tag-switching tdp router-id Loopback0
pseudowire-class pw1
 encapsulation mpls
 preferred-path interface Tunnel1 disable-fallback
!
pseudowire-class pw2
 encapsulation mpls
 preferred-path peer 10.18.18.18
!
interface Loopback0
 ip address 10.2.2.2 255.255.255.255
 no ip directed-broadcast
 no ip mroute-cache
!
interface Tunnel1
 ip unnumbered Loopback0
 no ip directed-broadcast
 tunnel destination 10.16.16.16
 tunnel mode mpls traffic-eng
 tunnel mpls traffic-eng priority 7 7
 tunnel mpls traffic-eng bandwidth 1500
 tunnel mpls traffic-eng path-option 1 explicit name path-tu1
!
interface Tunnel2
 ip unnumbered Loopback0
 no ip directed-broadcast
 tunnel destination 10.16.16.16
 tunnel mode mpls traffic-eng
 tunnel mpls traffic-eng priority 7 7
 tunnel mpls traffic-eng bandwidth 1500
 tunnel mpls traffic-eng path-option 1 dynamic
!
interface gigabitethernet0/0/0
 no ip address
 no ip directed-broadcast
 no negotiation auto
!
interface gigabitethernet0/0/0.1
 encapsulation dot1Q 222
 no ip directed-broadcast
 xconnect 10.16.16.16 101 pw-class pw1
!
interface ATM1/0/0
 no ip address
 no ip directed-broadcast
 no atm enable-ilmi-trap
 no atm ilmi-keepalive
 pvc 0/50 l2transport
  encapsulation aal5
  xconnect 10.16.16.16 150 pw-class pw2
!
interface Ethernet2/0/1
 ip address 10.0.0.1 255.255.255.0
 no ip directed-broadcast
 tag-switching ip
 mpls traffic-eng tunnels
 ip rsvp bandwidth 15000 15000
!
router ospf 1
 log-adjacency-changes
 network 10.0.0.0 0.0.0.255 area 0
 network 10.2.2.2 0.0.0.0 area 0
 mpls traffic-eng router-id Loopback0
 mpls traffic-eng area 0
!
ip route 10.18.18.18 255.255.255.255 Tunnel2
!
ip explicit-path name path-tu1 enable
 next-address 10.0.0.1
 index 3 next-address 10.0.0.1

PE2 Configuration

mpls label protocol ldp
mpls traffic-eng tunnels
mpls ldp router-id Loopback0
interface Loopback0
 ip address 10.16.16.16 255.255.255.255
 no ip directed-broadcast
 no ip mroute-cache
!
interface Loopback2
 ip address 10.18.18.18 255.255.255.255
 no ip directed-broadcast
!
interface Ethernet3/1
 ip address 10.0.0.2 255.255.255.0
 no ip directed-broadcast
 mpls traffic-eng tunnels
 mpls ip
 no cdp enable
 ip rsvp bandwidth 15000 15000
!
interface Ethernet3/3 
 no ip address 
 no ip directed-broadcast 
 no cdp enable 
! 
interface Ethernet3/3.1 
 encapsulation dot1Q 222 
 no ip directed-broadcast 
 no cdp enable 
 mpls l2transport route 10.2.2.2 101 
! 
interface ATM5/0
 no ip address
 no ip directed-broadcast
 no atm enable-ilmi-trap
 no atm ilmi-keepalive
 pvc 0/50 l2transport
  encapsulation aal5
  xconnect 10.2.2.2 150 encapsulation mpls
!
router ospf 1
 log-adjacency-changes
 network 10.0.0.0 0.0.0.255 area 0
 network 10.16.16.16 0.0.0.0 area 0
 mpls traffic-eng router-id Loopback0
 mpls traffic-eng area 0

In the following example, the show mpls l2transport vc command shows the following information about the VCs:

VC 101 has been assigned a preferred path called Tunnel1. The default path is disabled, because the preferred path specified that the default path should not be used if the preferred path fails.

VC 150 has been assigned an IP address of a loopback address on PE2. The default path can be used if the preferred path fails.

In the following example, command output that is bolded shows the preferred path information.

Router# show mpls l2transport vc detail

Local interface: Gi0/0/0.1 up, line protocol up, Eth VLAN 222 up
  Destination address: 10.16.16.16, VC ID: 101, VC status: up
    Preferred path: Tunnel1,  active
    Default path: disabled
    Tunnel label: 3, next hop point2point
    Output interface: Tu1, imposed label stack {17 16}
  Create time: 00:27:31, last status change time: 00:27:31
  Signaling protocol: LDP, peer 10.16.16.16:0 up
    MPLS VC labels: local 25, remote 16
    Group ID: local 0, remote 6
    MTU: local 1500, remote 1500
    Remote interface description:
  Sequencing: receive disabled, send disabled
  VC statistics:
    packet totals: receive 10, send 10
    byte totals:   receive 1260, send 1300
    packet drops:  receive 0, send 0

Local interface: AT1/0/0 up, line protocol up, ATM AAL5 0/50 up
  Destination address: 10.16.16.16, VC ID: 150, VC status: up
    Preferred path: 10.18.18.18, active
    Default path: ready
    Tunnel label: 3, next hop point2point
    Output interface: Tu2, imposed label stack {18 24}
  Create time: 00:15:08, last status change time: 00:07:37
  Signaling protocol: LDP, peer 10.16.16.16:0 up
    MPLS VC labels: local 26, remote 24
    Group ID: local 2, remote 0
    MTU: local 4470, remote 4470
    Remote interface description:
  Sequencing: receive disabled, send disabled
  VC statistics:
    packet totals: receive 0, send 0
    byte totals:   receive 0, send 0
    packet drops:  receive 0, send 0

Troubleshooting Tips

You can use the debug mpls l2transport vc event command to troubleshoot tunnel selection. For example, if the tunnel interface that is used for the preferred path is shut down, the default path is enabled. The debug mpls l2transport vc event command provides the following output:

AToM SMGR [10.2.2.2, 101]: Processing imposition update, vc_handle 62091860, update_action 
3, remote_vc_label 16 
AToM SMGR [10.2.2.2, 101]: selected route no parent rewrite: tunnel not up 
AToM SMGR [10.2.2.2, 101]: Imposition Programmed, Output Interface: Et3/2 

Setting Experimental Bits with AToM

MPLS AToM uses the three experimental bits in a label to determine the queue of packets. You statically set the experimental bits in both the VC label and the LSP tunnel label, because the LSP tunnel label might be removed at the penultimate router. The following sections explain the transport-specific implementations of the EXP bits.


Note For information about setting EXP bits on the Cisco 12000 series router for Cisco IOS
Release 12.0(30)S, see the AToM: L2 QoS feature module.


For configuration steps and examples, see the "Setting Experimental Bits with AToM" section.

Restrictions

The following restrictions apply to ATM AAL5 over MPLS with EXP bits:

ATM AAL5 over MPLS allows you to statically set the experimental bits.

If you do not assign values to the experimental bits, the priority bits in the header's "tag control information" field are set to zero.

On the Cisco 7500 series routers, distributed Cisco Express Forwarding must be enabled before you set the experimental bits.

The following restrictions apply to ATM Cell Relay over MPLS with EXP bits:

ATM Cell Relay over MPLS allows you to statically set the experimental bits in VC, PVP, and port modes.

If you do not assign values to the experimental bits, the priority bits in the header's "tag control information" field are set to zero.

On the Cisco 7500 series routers, distributed Cisco Express Forwarding must be enabled before you set the experimental bits.

The following restrictions apply to Ethernet over MPLS with EXP bits:

On the Cisco 7200 and 7500 Series Routers

Ethernet over MPLS allows you to set the EXP bits by using either of the following methods:

Writing the priority bits into the experimental bit field, which is the default.

Using the match any command with the set mpls exp command.

If you do not assign values to the experimental bits, the priority bits in the 802.1Q header's "tag control information" field are written into the experimental bit fields.

On the Cisco 7500 series routers, distributed Cisco Express Forwarding must be enabled before you set the experimental bits.

On the Cisco 10720 Internet Router

Table 7 lists the commands that are supported on the Cisco 10720 Internet router for Ethernet over MPLS. The letter Y means that the command is supported on that interface. A dash (—) means that command is not supported on that interface.


Note The match cos command is supported only on subinterfaces, not main interfaces.


Table 7 Commands Supported on the Cisco 10720 Router for Ethernet over MPLS

Commands
Imposition
Disposition
Traffic Matching Commands
In
Out
In
Out

match any

Y

Y

Y

Y

match cos

Y

match input-interface

Y

Y

match mpls exp

Y

Y

match qos-group

Y

Y

Traffic Action Commands
In
Out
In
Out

set cos

Y

set mpls exp

Y

set qos-group

Y

Y

set srp-priority

Y


The following restrictions apply to Frame Relay over MPLS and EXP bits:

If you do not assign values to the experimental bits, the priority bits in the header's "tag control information" field are set to zero.

On the Cisco 7500 series routers, distributed Cisco Express Forwarding must be enabled before you set the experimental bits.

The following restrictions apply to HDLC over MPLS and PPP over MPLS and EXP bits:

If you do not assign values to the experimental bits, zeros are written into the experimental bit fields.

On the Cisco 7500 series routers, enable distributed Cisco Express Forwarding before setting the experimental bits.

Set the experimental bits in both the VC label and the LSP tunnel label. You set the experimental bits in the VC label, because the LSP tunnel label might be removed at the penultimate router. Perform this task to set the experimental bits.

SUMMARY STEPS

1. enable

2. configure terminal

3. class-map class-name

4. match any

5. policy-map policy-name

6. class class-name

7. set mpls experimental value

8. exit

9. exit

10. interface slot/port

11. service-policy input policy-name

12. exit

13. exit

14. show policy-map interface interface-name [vc [vpi/] vci] [dlci dlci] [input | output]

DETAILED STEPS

 
Command or Action
Purpose

Step 1 

enable

Example:

Router> enable

Enables privileged EXEC mode.

Enter your password if prompted.

Step 2 

configure terminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3 

class-map class-name

Example:

Router(config)# class-map class1

Specifies the user-defined name of the traffic class and enters class map configuration mode.

Step 4 

match any

Example:

Router(config-cmap)# match any

Specifies that all packets will be matched. Use only the any keyword. Other keywords might cause unexpected results.

Step 5 

policy-map policy-name

Example:

Router(config-cmap)# policy-map policy1

Specifies the name of the traffic policy to configure and enters policy-map configuration mode.

Step 6 

class class-name

Example:

Router(config-pmap)# class class1

Specifies the name of a predefined traffic class, which was configured with the class-map command, used to classify traffic to the traffic policy and enters policy-map class configuration mode.

Step 7 

set mpls experimental value

Example:

Router(config-pmap-c)# set mpls experimental 7

Designates the value to which the MPLS bits are set if the packets match the specified policy map.

Step 8 

exit

Example:

Router(config-pmap-c)# exit

Exits policy-map class configuration mode.

Step 9 

exit

Example:

Router(config-pmap)# exit

Exits policy-map configuration mode.

Step 10 

interface slot/port

Example:

Router(config)# interface atm4/0

Specifies the interface and enters interface configuration mode.

Step 11 

service-policy input policy-name

Example:

Router(config-if)# service-policy input policy1

Attaches a traffic policy to an interface.

Step 12 

exit

Example:

Router(config-if)# exit

Exits interface configuration mode.

Step 13 

exit

Example:

Router(config)# exit

Exits global configuration mode.

Step 14 

show policy-map interface interface-name [vc [vpi/] vci] [dlci dlci] [input | output]

Example:

Router# show policy-map interface serial3/0

Displays the traffic policy attached to an interface.

Setting the Frame Relay Discard Eligibility Bit on the Cisco 7200 and 7500 Series Routers

You can use the DE bit in the address field of a Frame Relay frame to prioritize frames in congested Frame Relay networks. The Frame Relay DE bit has only one bit and can therefore only have two settings, 0 or 1. If congestion occurs in a Frame Relay network, frames with the DE bit set to 1 are discarded before frames with the DE bit set to 0. Therefore, important traffic should have the DE bit set to 0, and less important traffic should be forwarded with the DE bit set at 1. The default DE bit setting is 0. You can change the DE bit setting to 1 with the set fr-de command.


Note The set fr-de command can be used only in an output service policy.


Perform this task to set the Frame Relay DE bit on the Cisco 7200 and 7500 series routers.

SUMMARY STEPS

1. enable

2. configure terminal

3. policy-map policy-name

4. class class-name

5. set fr-de

DETAILED STEPS

 
Command or Action
Purpose

Step 1 

enable

Example:

Router> enable

Enables privileged EXEC mode.

Enter your password if prompted.

Step 2 

configure terminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3 

policy-map policy-name

Example:

Router(config)# policy-map policy1

Specifies the name of the traffic policy to configure and enters policy-map configuration mode. Names can be a maximum of 40 alphanumeric characters.

Step 4 

class class-name

Example:

Router(config-pmap)# class class1

Specifies the name of a predefined traffic class and enters policy-map class configuration mode.

Step 5 

set fr-de

Example:

Router(config-pmap-c)# set fr-de

Sets the Frame Relay DE bit setting for all packets that match the specified traffic class from 0 to 1.

Examples

The following example shows how to configure the service policy called set-de and attach it to an interface. In this example, the class map called data evaluates all packets exiting the interface for an IP precedence value of 1. If the exiting packet has been marked with the IP precedence value of 1, the packet's DE bit is set to 1.

class-map data 
match ip precedence 1 

policy-map set-de 
class data 
set fr-de 
interface Serial0/0/0 
encapsulation frame-relay 
interface Serial0/0/0.1 point-to-point 
ip address 192.168.249.194 255.255.255.252 
frame-relay interface-dlci 100 
service output set-de 

Matching the Frame Relay DE Bit on the Cisco 7200 and 7500 Series Routers

You can use the match fr-de command to enable frames with a DE bit setting of 1 to be considered a member of a defined class and forwarded according to the specifications set in the service policy.

Perform this task to match frames with the FR DE bit set to 1.

SUMMARY STEPS

1. enable

2. configure terminal

3. class-map class-map-name

4. match fr-de

DETAILED STEPS

 
Command or Action
Purpose

Step 1 

enable

Example:

Router> enable

Enables privileged EXEC mode.

Enter your password if prompted.

Step 2 

configure terminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3 

class-map class-map-name

Example:

Router(config)# class-map de-bits

Specifies the name of a predefined traffic class and enters class-map configuration mode.

Step 4 

match fr-de

Example:

Router(config-cmap)# match fr-de

Classifies all frames with the DE bit set to 1.

Examples

The following example shows how to configure the service policy called match-de and attach it to an interface. In this example, the class map called data evaluates all packets entering the interface for a DE bit setting of 1. If the entering packet has been a DE bit value of 1, the packet's EXP bit setting is set to 3.

class-map data 
match fr-de 
policy-map match-de
class data 
set mpls exp 3 
ip routing 
ip cef distributed 
mpls label protocol ldp 
interface Loopback0 
 ip address 10.20.20.20 255.255.255.255 
interface Ethernet1/0/0 
 ip address 10.0.0.2 255.255.255.0 
 mpls ip 
interface Serial4/0/0 
 encapsulation frame-relay 
service input match-de 
connect 100 Serial4/0/0 100 l2transport 
 xconnect 10.10.10.10 100 encapsulation mpls 

Configuration Examples for Any Transport over MPLS

This section contains the following configuration examples:

ATM over MPLS: Example

Ethernet over MPLS with MPLS Traffic Engineering Fast Reroute: Example

Configuring MTU Values in xconnect Configuration Mode for AToM: Example

Configuring MTU Values in xconnect Configuration Mode for L2VPN Interworking: Example

ATM over MPLS: Example

Example 1 shows the configuration of ATM over MPLS on two PE routers.

Example 1 ATM over MPLS Configuration Example

PE1
PE2

mpls label protocol ldp

mpls ldp router-id Loopback0 force

!

interface Loopback0

ip address 10.16.12.12 255.255.255.255

!

interface ATM4/0

pvc 0/100 l2transport

encapsulation aal0

xconnect 10.13.13.13 100 encapsulation mpls

!

interface ATM4/0.300 point-to-point

no ip directed-broadcast

no atm enable-ilmi-trap

pvc 0/300 l2transport

encapsulation aal0

xconnect 10.13.13.13 300 encapsulation mpls

mpls label protocol ldp

mpls ldp router-id Loopback0 force

!

interface Loopback0

ip address 10.13.13.13 255.255.255.255

interface ATM4/0

pvc 0/100 l2transport

encapsulation aal0

xconnect 10.16.12.12 100 encapsulation mpls

!

interface ATM4/0.300 point-to-point

no ip directed-broadcast

no atm enable-ilmi-trap

pvc 0/300 l2transport

encapsulation aal0

xconnect 10.16.12.12 300 encapsulation mpls


Ethernet over MPLS with MPLS Traffic Engineering Fast Reroute: Example

The following configuration example and Figure 2 show the configuration of Ethernet over MPLS with fast reroute on AToM PE routers.

Routers PE1 and PE2 have the following characteristics:

A TE tunnel called Tunnel41 is configured between PE1and PE2, using an explicit path through a link called L1. AToM VCs are configured to travel through the FRR-protected tunnel Tunnel41.

The link L1 is protected by FRR, the backup tunnel is Tunnel1.

PE2 is configured to forward the AToM traffic back to PE1 through the L2 link.

Figure 2 Fast Reroute Configuration

PE1 Configuration
mpls label protocol ldp
mpls traffic-eng tunnels
mpls ldp router-id Loopback1 force
!
pseudowire-class T41
 encapsulation mpls
 preferred-path interface Tunnel41 disable-fallback
!
pseudowire-class IP1
 encapsulation mpls
 preferred-path peer 10.4.0.1 disable-fallback
!
interface Loopback1
 ip address 10.0.0.27 255.255.255.255
!
interface Tunnel1
 ip unnumbered Loopback1
 tunnel destination 10.0.0.1
 tunnel mode mpls traffic-eng
 tunnel mpls traffic-eng priority 1 1
 tunnel mpls traffic-eng bandwidth  10000
 tunnel mpls traffic-eng path-option 1 explicit name FRR
!
interface Tunnel41
 ip unnumbered Loopback1
 tunnel destination 10.0.0.4
 tunnel mode mpls traffic-eng
 tunnel mpls traffic-eng priority 1 1
 tunnel mpls traffic-eng bandwidth  1000
 tunnel mpls traffic-eng path-option 1 explicit name name-1
 tunnel mpls traffic-eng fast-reroute
!
interface POS0/0
 description pe1name POS8/0/0
 ip address 10.1.0.2 255.255.255.252
 mpls traffic-eng tunnels
 mpls traffic-eng backup-path Tunnel1
 crc 16
 clock source internal
 pos ais-shut
 pos report lrdi
 ip rsvp bandwidth 155000 155000
!
interface POS0/3
 description pe1name POS10/1/0
 ip address 10.1.0.14 255.255.255.252
 mpls traffic-eng tunnels
 crc 16   
 clock source internal
 ip rsvp bandwidth 155000 155000
!
interface gigabitethernet3/0.1
 encapsulation dot1Q 203
 xconnect 10.0.0.4 2 pw-class IP1
!         
interface gigabitethernet3/0.2
 encapsulation dot1Q 204
 xconnect 10.0.0.4 4 pw-class T41
!
router ospf 1
 network 10.0.0.0 0.255.255.255 area 0
 mpls traffic-eng router-id Loopback1
 mpls traffic-eng area 0
!
ip classless
ip route 10.4.0.1 255.255.255.255 Tunnel41
!
ip explicit-path name xxxx-1 enable
 next-address 10.4.1.2
 next-address 10.1.0.10

P Configuration

ip cef
mpls traffic-eng tunnels
!
interface Loopback1
 ip address 10.0.0.1 255.255.255.255
!
interface FastEthernet1/0/0
 ip address 10.4.1.2 255.255.255.0
 mpls traffic-eng tunnels
 ip rsvp bandwidth 10000 10000
!
interface POS8/0/0
 description xxxx POS0/0
 ip address 10.1.0.1 255.255.255.252
 mpls traffic-eng tunnels
 pos ais-shut
 pos report lrdi
 ip rsvp bandwidth 155000 155000
!
interface POS10/1/0
 description xxxx POS0/3
 ip address 10.1.0.13 255.255.255.252
 mpls traffic-eng tunnels
 ip rsvp bandwidth 155000 155000
!
router ospf 1
 network 10.0.0.0 0.255.255.255 area 0
 mpls traffic-eng router-id Loopback1
 mpls traffic-eng area 0

PE2 Configuration

ip cef
mpls label protocol ldp
mpls traffic-eng tunnels
mpls ldp router-id Loopback1 force
!
interface Loopback1
 ip address 10.0.0.4 255.255.255.255
!
interface loopback 2
ip address 10.4.0.1 255.255.255.255
!
interface Tunnel27
 ip unnumbered Loopback1
 tunnel destination 10.0.0.27
 tunnel mode mpls traffic-eng
 tunnel mpls traffic-eng autoroute announce
 tunnel mpls traffic-eng priority 1 1
 tunnel mpls traffic-eng bandwidth  1000
 tunnel mpls traffic-eng path-option 1 explicit name xxxx-1
!
interface FastEthernet0/0.2
 encapsulation dot1Q 203
 xconnect 10.0.0.27 2 encapsulation mpls
!
interface FastEthernet0/0.3
 encapsulation dot1Q 204
 xconnect 10.0.0.27 4 encapsulation mpls 
!
interface FastEthernet1/1
 ip address 10.4.1.1 255.255.255.0
 mpls traffic-eng tunnels
 ip rsvp bandwidth 10000 10000
!
router ospf 1
 network 10.0.0.0 0.255.255.255 area 0
 mpls traffic-eng router-id Loopback1
 mpls traffic-eng area 0
!
ip explicit-path name xxxx-1 enable
 next-address 10.4.1.2
 next-address 10.1.0.10

Configuring MTU Values in xconnect Configuration Mode for AToM: Example

Figure 3 shows a configuration that enables matching MTU values between VC endpoints.

As shown in Figure 3, PE1 is configured in xconnect mode with an MTU value of 1500 bytes in order to establish an end-to-end VC with PE2, that also has an MTU value of 1500 bytes. If PE1 was not set with an MTU value of 1500 bytes, in xconnect mode, the subinterface would inherit the MTU value of 2000 bytes set on the interface. This would cause a mismatch in MTU values between the VC endpoints and the VC would not come up.

Figure 3 Configuring MTU Values in xconnect Configuration Mode

The following examples show the router configurations in Figure 3:

CE1 configuration

interface g0/0
 mtu 1500
 no ip address
!
interface g0/0.1
 encapsulation dot1Q 100
 ip address 10.181.182.1 255.255.255.0

PE1 configuration

interface g0/0
 mtu 2000
 no ip address
!
interface g0/0.1
 encapsulation dot1Q 100
 xconnect 10.1.1.152 100 encapsulation mpls
  mtu 1500
!
interface g0/0.2
 encapsulation dot1Q 200
 ip address 10.151.100.1 255.255.255.0
 mpls ip

PE2 configuration

interface g1/0
 mtu 2000
 no ip address
!
interface g1/0.2
 encapsulation dot1Q 200
 ip address 10.100.152.2 255.255.255.0
 mpls ip
!
interface f0/0
 no ip address
!
interface f0/0.1
 description default MTU of 1500 for FastEthernet
 encapsulation dot1Q 100
 xconnect 10.1.1.151 100 encapsulation mpls

CE2 configuration

interface f0/0
 no ip address
interface f0/0.1
 encapsulation dot1Q 100
 ip address 10.181.182.2 255.255.255.0

The show mpls l2transport binding command, issued from router PE1, shows a matching MTU value of 1500 bytes on both the local and remote routers:

Router# show mpls l2transport binding 

Destination Address: 10.1.1.152,  VC ID: 100
    Local Label: 100
        Cbit: 1,    VC Type: Ethernet,    GroupID: 0
        MTU: 1500,   Interface Desc: n/a
        VCCV: CC Type: CW [1], RA [2]
              CV Type: LSPV [2]
    Remote Label: 202
        Cbit: 1,    VC Type: Ethernet,    GroupID: 0
        MTU: 1500,   Interface Desc: n/a
        VCCV: CC Type: RA [2]
              CV Type: LSPV [2]
Router# show mpls l2transport vc detail

Local interface: Gi0/0.1 up, line protocol up, Eth VLAN 100 up
  Destination address: 10.1.1.152, VC ID: 100, VC status: up
    Output interface: Gi0/0.2, imposed label stack {202}
    Preferred path: not configured  
    Default path: active
    Next hop: 10.151.152.2
  Create time: 1d11h, last status change time: 1d11h
  Signaling protocol: LDP, peer 10.1.1.152:0 up
    Targeted Hello: 10.1.1.151(LDP Id) -> 10.1.1.152
    MPLS VC labels: local 100, remote 202 
    Group ID: local 0, remote 0
    MTU: local 1500, remote 1500
    Remote interface description: 
  Sequencing: receive disabled, send disabled
  VC statistics:
    packet totals: receive 41, send 39
    byte totals:   receive 4460, send 5346
    packet drops:  receive 0, send 0

Configuring MTU Values in xconnect Configuration Mode for L2VPN Interworking: Example

The following example shows an L2VPN Interworking example. The PE1 router has a serial interface configured with an MTU value of 1492 bytes. The PE2 router uses xconnect configuration mode to set a matching MTU of 1492 bytes, which allows the two routers to form an interworking VC. If the PE2 router did not set the MTU value in xconnect configuration mode, the interface would be set to 1500 bytes by default and the VC would not come up.

PE1 Configuration

pseudowire-class atom-ipiw
 encapsulation mpls
 interworking ip 
!
interface Loopback0
 ip address 10.1.1.151 255.255.255.255
!
interface Serial2/0
 mtu 1492 
 no ip address
 encapsulation ppp
 no fair-queue
 serial restart-delay 0
 xconnect 10.1.1.152 123 pw-class atom-ipiw
!
interface Serial4/0
 ip address 10.151.100.1 255.255.255.252
 encapsulation ppp
 mpls ip
 serial restart-delay 0
!
router ospf 1
 log-adjacency-changes
 network 10.1.1.151 0.0.0.0 area 0
 network 10.151.100.0 0.0.0.3 area 0
!
mpls ldp router-id Loopback0

PE2 Configuration

pseudowire-class atom-ipiw
 encapsulation mpls
 interworking ip 
!
interface Loopback0
 ip address 10.1.1.152 255.255.255.255
!
interface Ethernet0/0 
 no ip address
 xconnect 10.1.1.151 123 pw-class atom-ipiw
  mtu 1492 
!
interface Serial4/0
 ip address 10.100.152.2 255.255.255.252
 encapsulation ppp
 mpls ip
 serial restart-delay 0
!
router ospf 1
 log-adjacency-changes
 network 10.1.1.152 0.0.0.0 area 0
 network 10.100.152.0 0.0.0.3 area 0
!
mpls ldp router-id Loopback0

The show mpls l2transport binding command shows that the MTU value for the local and remote routers is 1492 bytes.

PE1

Router# show mpls l2transport binding 

Destination Address: 10.1.1.152,  VC ID: 123
    Local Label: 105
        Cbit: 1,    VC Type: PPP,    GroupID: 0
        MTU: 1492,   Interface Desc: n/a
        VCCV: CC Type: CW [1], RA [2]
              CV Type: LSPV [2]
    Remote Label: 205
        Cbit: 1,    VC Type: Ethernet,    GroupID: 0
        MTU: 1492,   Interface Desc: n/a
        VCCV: CC Type: RA [2]
              CV Type: LSPV [2]

Router# show mpls l2transport vc detail

Local interface: Se2/0 up, line protocol up, PPP up
  MPLS VC type is PPP, interworking type is IP 
  Destination address: 10.1.1.152, VC ID: 123, VC status: up
    Output interface: Se4/0, imposed label stack {1003 205}
    Preferred path: not configured  
    Default path: active
    Next hop: point2point
  Create time: 00:25:29, last status change time: 00:24:54
  Signaling protocol: LDP, peer 10.1.1.152:0 up
    Targeted Hello: 10.1.1.151(LDP Id) -> 10.1.1.152
    Status TLV support (local/remote)   : enabled/supported
      Label/status state machine        : established, LruRru
      Last local dataplane   status rcvd: no fault
      Last local SSS circuit status rcvd: no fault
      Last local SSS circuit status sent: no fault
      Last local  LDP TLV    status sent: no fault
      Last remote LDP TLV    status rcvd: no fault
    MPLS VC labels: local 105, remote 205 
    Group ID: local n/a, remote 0
    MTU: local 1492, remote 1492
    Remote interface description: 
  Sequencing: receive disabled, send disabled
  VC statistics:
    packet totals: receive 30, send 29
    byte totals:   receive 2946, send 3364
    packet drops:  receive 0, send 0

PE2

Router# show mpls l2transport binding 

Destination Address: 10.1.1.151,  VC ID: 123
    Local Label: 205
        Cbit: 1,    VC Type: Ethernet,    GroupID: 0
        MTU: 1492,   Interface Desc: n/a
        VCCV: CC Type: RA [2]
              CV Type: LSPV [2]
    Remote Label: 105
        Cbit: 1,    VC Type: Ethernet,    GroupID: 0
        MTU: 1492,   Interface Desc: n/a
        VCCV: CC Type: CW [1], RA [2]
              CV Type: LSPV [2]

Router# show mpls l2transport vc detail

Local interface: Et0/0 up, line protocol up, Ethernet up
  MPLS VC type is Ethernet, interworking type is IP
  Destination address: 10.1.1.151, VC ID: 123, VC status: up
    Output interface: Se4/0, imposed label stack {1002 105}
    Preferred path: not configured  
    Default path: active
    Next hop: point2point
  Create time: 00:25:19, last status change time: 00:25:19
  Signaling protocol: LDP, peer 10.1.1.151:0 up
    Targeted Hello: 10.1.1.152(LDP Id) -> 10.1.1.151
    Status TLV support (local/remote)   : enabled/supported
      Label/status state machine        : established, LruRru
      Last local dataplane   status rcvd: no fault
      Last local SSS circuit status rcvd: no fault
      Last local SSS circuit status sent: no fault
      Last local  LDP TLV    status sent: no fault
      Last remote LDP TLV    status rcvd: no fault
    MPLS VC labels: local 205, remote 105 
    Group ID: local n/a, remote 0
    MTU: local 1492, remote 1492 
    Remote interface description: 
  Sequencing: receive disabled, send disabled
  VC statistics:
    packet totals: receive 29, send 30
    byte totals:   receive 2900, send 3426
    packet drops:  receive 0, send 0

Additional References

The following sections provide references related to the Any Transport over MPLS feature.

Related Documents

Related Topic
Document Title

Any Transport over MPLS

Overview: Cisco Any Transport over MPLS

Any Transport over MPLS for the Cisco 10000 series router

Cisco 10000 Series Router Broadband Aggregation, Leased-Line, and MPLS Configuration Guide

Layer 2 Tunnel Protocol Version 3 (L2TPv3): Provides the ability to tunnel any Layer 2 payload over an IP core network using Layer 2 virtual private networks (L2VPNs)

Layer 2 Tunnel Protocol Version 3 (L2TPv3)

L2VPN interworking

L2VPN interworking


Standards

Standard
Title

draft-martini-l2circuit-trans-mpls-08.txt

Transport of Layer 2 Frames Over MPLS

draft-martini-l2circuit-encap-mpls-04.txt

Encapsulation Methods for Transport of Layer 2 Frames Over MPLS


MIB
MIBs Link

ATM AAL5 over MPLS and ATM Cell Relay over MPLS:

MPLS LDP MIB (MPLS-LDP-MIB.my)

ATM MIB (ATM-MIB.my)

CISCO AAL5 MIB (CISCO-AAL5-MIB.my)

Cisco Enterprise ATM Extension MIB (CISCO-ATM-EXT-MIB.my)

Supplemental ATM Management Objects (CISCO-IETF-ATM2-PVCTRAP-MIB.my)

Interfaces MIB (IF-MIB.my)

Ethernet over MPLS

CISCO-ETHERLIKE-CAPABILITIES.my

Ethernet MIB (ETHERLIKE-MIB.my)

Interfaces MIB (IF-MIB.my)

MPLS LDP MIB (MPLS-LDP-MIB.my)

Frame Relay over MPLS

Cisco Frame Relay MIB (CISCO-FRAME-RELAY-MIB.my)

Interfaces MIB (IF-MIB.my)

MPLS LDP MIB (MPLS-LDP-MIB.my)

HDLC and PPP over MPLS

MPLS LDP MIB (MPLS-LDP-MIB.my)

Interface MIB (IF-MIB.my)

To locate and download MIBs for selected platforms, Cisco IOS releases, and feature sets, use Cisco MIB Locator found at the following URL:

http://tools.cisco.com/go/mibs


MIBs

RFCs

RFC
Title

RFC 3032

MPLS Label Stack Encoding

RFC 3036

LDP Specification


Technical Assistance

Description
Link

The Cisco Support website provides extensive online resources, including documentation and tools for troubleshooting and resolving technical issues with Cisco products and technologies. Access to most tools on the Cisco Support website requires a Cisco.com user ID and password. If you have a valid service contract but do not have a user ID or password, you can register on Cisco.com.

http://www.cisco.com/techsupport


Command Reference

This section documents only commands that are new or modified.

cell-packing

encapsulation (Any Transport over MPLS)

oam-ac emulation-enable

cell-packing

To enable ATM over Multiprotocol Label Switching (MPLS) or Layer 2 Tunneling Protocol Version 3 (L2TPv3) to pack multiple ATM cells into each MPLS or L2TPv3 packet, use the cell-packing command in the appropriate configuration mode. To disable cell packing, use the no form of this command.

cell-packing [cells] [mcpt-timer timer]

no cell-packing

Syntax Description

cells

(Optional) The number of cells to be packed into an MPLS or L2TPv3 packet.

The range is from 2 to the maximum transmission unit (MTU) of the interface divided by 52. The default number of ATM cells to be packed is the MTU of the interface divided by 52.

If the number of cells packed by the peer provider edge router exceeds this limit, the packet is dropped.

mcpt-timer timer

(Optional) Specifies which timer to use. Valid values are 1, 2, or 3. The default value is 1.


Command Default

Cell packing is disabled.

Command Modes

Interface configuration
L2transport VC configuration—for ATM VC
L2transport VP configuration—for ATM VP
VC class configuration

Command History

Release
Modification

12.0(25)S

This command was introduced.

12.0(29)S

Support for L2TPv3 sessions was added.

12.0(30)S

This command was updated to enable cell packing as part of a virtual circuit (VC) class.

12.0(31)S

This command was integrated into Cisco IOS Release 12.0(31)S.

12.2(28)SB

This command was integrated into Cisco IOS Release 12.2(28)SB.

12.4(11)T

This command was integrated into Cisco IOS Release 12.4(11)T.

12.2(33)SRB

This command was integrated into Cisco IOS Release 12.2(33)SRB.

12.2(33)SXH

This command was integrated into Cisco IOS Release 12.2(33)SXH.


Usage Guidelines

The cell-packing command is available only if you configure the ATM VC or virtual path (VP) with ATM adaptation layer 0 (AAL0) encapsulation. If you specify ATM adaptation layer 5 (AAL5) encapsulation, the command is not valid.

Only cells from the same VC or VP can be packed into one MPLS or L2TPv3 packet. Cells from different connections cannot be concatenated into the same packet.

When you change, enable, or disable the cell-packing attributes, the ATM VC or VP and the MPLS or L2TPv3 emulated VC are reestablished.

If a provider edge (PE) router does not support cell packing, the PE routers sends only one cell per MPLS or L2TPv3 packet.

The number of packed cells need not match between the PE routers. The two PE routers agree on the lower of the two values. For example, if PE1 is allowed to pack 10 cells per MPLS or L2TPv3 packet and PE2 is allowed to pack 20 cells per MPLS or L2TPv3 packet, the two PE routers would agree to send no more than 10 cells per packet.

If the number of cells packed by the peer PE router exceeds the limit, the packet is dropped.

If you issue the cell-packing command without first specifying the atm mcpt-timers command, you get the following error:

Please set mcpt values first

Examples

The following example shows cell packing enabled on an interface set up for VP mode. The cell-packing command specifies that ten ATM cells be packed into each MPLS packet. The command also specifies that the second maximum cell-packing timeout (MCPT) timer be used.


Router> enable
Router# configure terminal
Router(config)# interface atm1/0
Router(config-if)# atm mcpt-timers 1000 800 500
Router(config-if)# atm pvp 100 l2transport
Router(config-if-atm-l2trans-pvp)# xconnect 10.0.0.1 234 encapsulation mpls
Router(config-if-atm-l2trans-pvp)# cell-packing 10 mcpt-timer 2

The following example configures ATM cell relay over MPLS with cell packing in VC class configuration mode. The VC class is then applied to an interface.

Router> enable
Router# configure terminal
Router(config)# vc-class atm cellpacking
Router(config-vc-class)# encapsulation aal0
Router(config-vc-class)# cell-packing 10 mcpt-timer 1
Router(config-vc-class)# exit
Router(config)# interface atm1/0
Router(config-if)# atm mcpt-timers 100 200 250
Router(config-if)# class-int cellpacking 
Router(config-if)# pvc 1/200 l2transport
Router(config-if-atm-l2trans-pvc)# xconnect 10.13.13.13 100 encapsulation mpls

The following example configures ATM AAL5 over L2TPv3 in VC class configuration mode. The VC class is then applied to an interface.

Router(config)# vc-class atm aal5class
Router(config-vc-class)# encapsulation aal5
!
Router(config)# interface atm1/0
Router(config-if)# class-int aal5class
Router(config-if)# pvc 1/200 l2transport
Router(config-if-atm-l2trans-pvc)# xconnect 10.13.13.13 100 encapsulation l2tpv3

Related Commands

Command
Description

atm mcpt-timers

Creates cell-packing timers, which specify how long the PE router can wait for cells to be packed into an MPLS or L2TPv3 packet.

debug atm cell-packing

Displays ATM cell relay cell packing debugging information.

show atm cell-packing

Displays information about the VCs and VPs that have ATM cell packing enabled.


encapsulation (Any Transport over MPLS)

To configure the ATM adaptation layer (AAL) encapsulation for an Any Transport over MPLS (AToM), use the encapsulation command in the appropriate configuration mode. To remove the ATM encapsulation, use the no form of this command.

encapsulation layer-type

no encapsulation layer-type

Syntax Description

layer-type

The adaptation layer type, which is one of the following:

aal5—ATM adaptation layer 5

aal0—ATM adaptation layer 0


Command Default

The default encapsulation is AAL5.

Command Modes

L2transport VC configuration—for ATM PVCs
VC class configuration—for VC class

Command History

Release
Modification

12.0(23)S

This command was introduced.

12.2(14)S

This command was integrated into Cisco IOS Release 12.2(14)S.

12.2(15)T

This command was integrated into Cisco IOS Release 12.2(15)T.

12.0(30)S

This command was updated to enable ATM encapsulations as part of a virtual circuit (VC) class.

12.0(31)S

This command was integrated into Cisco IOS Release 12.0(31)S.

12.2(28)SB

This command was integrated into Cisco IOS Release 12.2(28)SB.

12.2(33)SRA

This command was integrated into Cisco IOS Release 12.2(33)SRA.

12.4(11)T

This command was integrated into Cisco IOS Release 12.4(11)T.

12.2(33)SXH

This command was integrated into Cisco IOS Release 12.2(33)SXH.


Usage Guidelines

In L2transport VC configuration mode, the pvc command and the encapsulation command work together. Use the commands for AToM differently than for all other applications. Table 8 shows the differences in how the commands are used.

Table 8 AToM-Specific Variations of the pvc and encapsulation Commands

Other Applications
AToM

Router(config-if)# pvc 1/100

Router(config-if-atm-vc)# encapsulation aal5snap

Router(config-if)# pvc 1/100 l2transport

Router(config-if-atm-l2trans-pvc)# encapsulation aal5


The following list highlights the differences:

pvc command: For most applications, you create a permanent virtual circuit (PVC) by using the pvc vpi/vci command. For AToM, you must add the l2transport keyword to the pvc command. The l2transport keyword enables the PVC to transport Layer 2 packets.

encapsulation command: The encapsulation command for AToM has only two keyword values: aal5 or aal0. You cannot specify an encapsulation type, such as aal5snap. In contrast, the encapsulation aal5 command you use for most other applications requires you to specify the encapsulation type, such as aal5snap.

You cannot create switched virtual circuits or VC bundles to transport Layer 2 packets.

When you use the aal5 keyword, incoming cells (except Operation, Administration, and Maintenance [OAM] cells) on that PVC are treated as AAL5 encapsulated packets. The router reassembles the packet from the incoming cells. The router does not check the contents of the packet, so it does not need to know the encapsulation type (such as aal5snap and aal5mux). After imposing the Multiprotocol Label Switching (MPLS) label stack, the router sends the reassembled packet over the MPLS core network.

When you use the aal0 keyword, the router strips the header error control (HEC) byte from the cell header and adds the MPLS label stack. The router sends the cell over the MPLS core network.

Examples

The following example shows how to configure a PVC to transport ATM cell relay packets for AToM:

Router> enable
Router# configure terminal
Router(config)# interface atm1/0
Router(config-if)# pvc 1/100 l2transport
Router(config-if-atm-l2trans-pvc)# encapsulation aal0 
Router(config-if-atm-l2trans-pvc)# xconnect 10.13.13.13 100 encapsulation mpls

The following example shows how to configure ATM AAL5 over MPLS in VC class configuration mode. The VC class is applied to a PVC.

Router> enable
Router# configure terminal
Router(config)# vc-class atm aal5class
Router(config-vc-class)# encapsulation aal5
Router(config)# interface atm1/0
Router(config-if)# pvc 1/200 l2transport
Router(config-if-atm-l2trans-pvc)# class-vc aal5class
Router(config-if-atm-l2trans-pvc)# xconnect 10.13.13.13 100 encapsulation mpls

Related Commands

Command
Description

pvc

Creates or assigns a name to an ATM PVC.


oam-ac emulation-enable

To enable Operation, Administration, and Maintenance (OAM) cell emulation on ATM adaptation layer 5 (AAL5) over Multiprotocol Label Switching (MPLS) or Layer 2 Tunnel Protocol Version 3 (L2TPv3), use the oam-ac emulation-enable command in the appropriate configuration mode on both provider edge (PE) routers. To disable OAM cell emulation, use the no form of this command on both routers.

oam-ac emulation-enable [seconds]

no oam-ac emulation-enable [seconds]

Syntax Description

seconds

(Optional) The rate (in seconds) at which the alarm indication signal (AIS) cells should be sent. The range is 0 to 60 seconds. If you specify 0, no AIS cells are sent. The default is 1 second, which means that one AIS cell is sent every second.


Command Default

OAM cell emulation is disabled.

Command Modes

L2transport VC configuration—for an ATM PVC
VC class configuration mode—for a VC class

Command History

Release
Modification

12.0(23)S

This command was introduced.

12.2(14)S

This command was integrated into Cisco IOS Release 12.2(14)S.

12.2(15)T

This command was integrated into Cisco IOS Release 12.2(15)T.

12.0(30)S

This command was updated to enable OAM cell emulation as part of a virtual circuit (VC) class.

12.0(31)S

This command was integrated into Cisco IOS Release 12.0(31)S.

12.2(27)SBC

This command was integrated into Cisco IOS Release 12.2(27)SBC.

12.2(28)SB

This command was integrated into Cisco IOS Release 12.2(28)SB.

12.2(33)SRA

This command was integrated into Cisco IOS Release 12.2(33)SRA.

12.4(11)T

This command was integrated into Cisco IOS Release 12.4(11)T.

12.2(33)SXH

This command was integrated into Cisco IOS Release 12.2(33)SXH.


Usage Guidelines

This command is used with AAL5 over MPLS or L2TPv3 and is not supported with ATM cell relay over MPLS or L2TPv3.

Examples

The following example shows how to enable OAM cell emulation on an ATM permanent virtual circuit (PVC):

Router# interface ATM 1/0/0

Router(config-if)# pvc 1/200 l2transport

Router(config-if-atm-l2trans-pvc)# oam-ac emulation-enable

The following example shows how to set the rate at which an AIS cell is sent every 30 seconds:

Router# interface ATM 1/0/0

Router(config-if)# pvc 1/200 l2transport

Router(config-if-atm-l2trans-pvc)# oam-ac emulation-enable 30

The following example configures OAM cell emulation for ATM AAL5 over MPLS in VC class configuration mode. The VC class is then applied to an interface.

Router> enable
Router# configure terminal
Router(config)# vc-class atm oamclass
Router(config-vc-class)# encapsulation aal5

Router(config-vc-class)# oam-ac emulation-enable 30

Router(config-vc-class)# oam-pvc manage

Router(config)# interface atm1/0
Router(config-if)# class-int oamclass
Router(config-if)# pvc 1/200 l2transport
Router(config-if-atm-l2trans-pvc)# xconnect 10.13.13.13 100 encapsulation mpls

Related Commands

Command
Description

show atm pvc

Displays all ATM PVCs and traffic information.


Feature Information for Any Transport over MPLS

Table 9 lists the release history for this feature.

Not all commands may be available in your Cisco IOS software release. For release information about a specific command, see the command reference documentation.

Cisco IOS software images are specific to a Cisco IOS software release, a feature set, and a platform. Use Cisco Feature Navigator to find information about platform support and Cisco IOS software image support. Access Cisco Feature Navigator at http://www.cisco.com/go/fn. You must have an account on Cisco.com. If you do not have an account or have forgotten your username or password, click Cancel at the login dialog box and follow the instructions that appear.


Note Table 9 lists only the Cisco IOS software release that introduced support for a given feature in a given Cisco IOS software release train. Unless noted otherwise, subsequent releases of that Cisco IOS software release train also support that feature.


Table 9 Feature Information for Any Transport over MPLS  

Feature Name
Releases
Feature Information

Any Transport over MPLS

12.0(10)ST

Any Transport over MPLS: ATM AAL5 over MPLS was introduced on the Cisco 12000 series routers.

 

12.1(8a)E

In 12.1(8a)E, Ethernet over MPLS was introduced on the Cisco 7600 series Internet router.

 

12.0(21)ST

Any Transport over MPLS: Ethernet over MPLS was introduced on the Cisco 12000 series routers. ATM AAL5 over MPLS was updated.

 

12.0(22)S

In 12.0(22)S, Ethernet over MPLS was integrated into this release. Support for the Cisco 10720 Internet router was added. ATM AAL5 over MPLS was integrated into this release for the Cisco 12000 series routers.

 

12.0(23)S

In 12.0(23)S, the following new features were introduced:

ATM Cell Relay over MPLS (single cell relay, VC mode)

Frame Relay over MPLS

HDLC over MPLS

PPP over MPLS

These features were supported on the Cisco 7200 and 7500 series routers.

The Cisco 12000, 7200, and 7500 series routers added support for the following features:

ATM AAL5 over MPLS

Ethernet over MPLS (VLAN mode)

 

12.2(14)S

The AToM features were integrated into Cisco IOS Release 12.2(14)S.

 

12.2(15)T

The AToM features were integrated into Cisco IOS Release 12.2(15)T.

 

12.0(25)S

In 12.0(25)S, the following new features were introduced:

New commands for configuring AToM

Ethernet over MPLS: port mode

ATM Cell Relay over MPLS: packed cell relay

ATM Cell Relay over MPLS: VP mode

ATM Cell Relay over MPLS: port mode

Distributed Cisco Express Forwarding mode for Frame Relay, PPP, and HDLC over MPLS

Fast reroute with AToM

Tunnel selection

Traffic policing

QoS support

 

12.0(26)S

In 12.0(26)S, the following new features were introduced:

Support for connecting disparate attachment circuits. See L2VPN Interworking for more information.

QoS functionality with AToM for the Cisco 7200 series routers.

Support for FECN and BECN marking with Frame Relay over MPLS. (See BECN and FECN Marking for Frame Relay over MPLS for more information.)

 

12.0(27)S

In 12.0(27)S, the following new features were introduced:

ATM Cell Relay over MPLS: Packed Cell Relay for VC, PVP, and port mode for the
Cisco 12000 series router.

Support for ATM over MPLS on the Cisco 12000 series 4-port OC-12X/STM-4 ATM ISE line card.

 

12.2(25)S

This feature was integrated into Cisco IOS Release 12.2(25)S for the Cisco 7200 and 7500 series routers.

 

12.0(29)S

In 12.0(29)S, the "Any Transport over MPLS Sequencing Support" feature was added for the Cisco 7200 and 7500 series routers. See the Any Transport over MPLS (AToM) Sequencing Support document for more information.

 

12.0(30)S

In 12.0(30)S, the following new features were introduced:

ATM VC Class Support—You can specify AAL5 and AAL0 encapsulations as part of a VC class. You can also enable cell packing and OAM emulation as part of a VC class. A VC class can be attached to an interface, subinterface, or VC. See the "How to Configure Any Transport over MPLS" section for links to the sections that explain the ATM VC Class Support feature.

VLAN ID Rewrite—This feature was enhanced to enable the IP Service Engine (ISE) 4-port Gigabit Ethernet line card to perform VLAN ID rewrite at both the imposition and disposition sides of the edge-facing router. See the "Configuring Ethernet over MPLS with VLAN ID Rewrite" section for more information.

 

12.0(31)S

In 12.0(31)S, the Cisco 12000 series router introduced the following enhancements:

AToM VC Independence—With this enhancement, fast reroute is accomplished in less than 50 milliseconds, regardless of the number of VCs configured. See the "MPLS Traffic Engineering Fast Reroute" section for more information.

Support for ISE line cards on the 2.5G ISE SPA Interface Processor (SIP).

 

12.0(32)S

In 12.0(32)S, the Cisco 12000 series router added engine 5 line card support for the following transport types:

Ethernet over MPLS

Frame Relay over MPLS

HDLC over MPLS

PPP over MPLS

 

12.2(28)SB

This feature was integrated into Cisco IOS Release 12.2(28)SB on the Cisco 10000 series routers. Platform-specific configuration information is contained in the "Configuring Any Transport over MPLS" section of the Cisco 10000 Series Router Broadband Aggregation, Leased-Line, and MPLS Configuration Guide.

 

12.4(11)T

Any Transport over MPLS was integrated into Cisco IOS Release 12.4(11)T and supports the following features:

Any Transport over MPLS: Ethernet over MPLS: Port Mode

Any Transport over MPLS: Ethernet over MPLS: VLAN Mode

Any Transport over MPLS: Ethernet over MPLS: VLAN ID Rewrite

Any Transport over MPLS: Frame Relay over MPLS

Any Transport over MPLS: AAL5 over MPLS

Any Transport over MPLS: ATM OAM Emulation

 

12.2(33)SRB

This feature was integrated into Cisco IOS Release 12.2(33)SRB to support the following features on the Cisco 7600 router:

Any Transport over MPLS: Frame Relay over MPLS

Any Transport over MPLS: ATM Cell Relay over MPLS: Packed Cell Relay

Any Transport over MPLS: Ethernet over MPLS

AToM Static Pseudowire Provisioning

Platform-specific configuration information is contained in the following documents:

The "Configuring PFC3BXL and PFC3B Mode Multiprotocol Label Switching" module of the Cisco 7600 Series Cisco IOS Software Configuration Guide, Release 12.2SR

The "Configuring Multiprotocol Label Switching on the Optical Services Modules" module of the OSM Configuration Note, Release 12.2SR

The "Configuring Multiprotocol Label Switching on FlexWAN and Enhanced FlexWAN Modules" module of the FlexWAN and Enhanced FlexWAN Modules Configuration Guide

The "Configuring Any Transport over MPLS on a SIP" section of the Cisco 7600 Series Router SIP, SSC, and SPA Software Configuration Guide

The "Configuring AToM VP Cell Mode Relay Support" section of the Cisco 7600 Series Router SIP, SSC, and SPA Software Configuration Guide

The Release Notes for Cisco IOS Release 12.2SR for the Cisco 7600 Series Routers

 

12.2(33)SXH

This feature was integrated into Cisco IOS Release 12.2(33)SXH and supports the following features:

Any Transport over MPLS: Ethernet over MPLS: Port Mode

Any Transport over MPLS: AAL5 over MPLS

Any Transport over MPLS: ATM OAM Emulation

Any Transport over MPLS: Single Cell Relay - VC Mode

Any Transport over MPLS: ATM Cell Relay over MPLS - VP Mode

Any Transport over MPLS: Packed Cell Relay - VC/VP Mode

Any Transport over MPLS: Ethernet over MPLS

ATM Port Mode Packed Cell Relay over AToM

AToM Tunnel Selection

 

12.2(33)SRC

This feature was integrated into Cisco IOS Release 12.2(33)SRC and supports the following features:

Ethernet over MPLS with MTU Values in xconnect Configuration Mode