Table Of Contents
Configuring the OC-3c/STM-1, OC-12c/STM-4, and OC-48c/STM-16 SONET/SDH Optical Services Modules
SONET/SDH Error, Alarm, and Performance Monitoring
Dynamic Packet Transport Protocol
Routing and Scalability Protocols
Understanding Packet-Over-SONET
Initial Configuration of the POS/SDH OSMs
Customizing the POS/SDH OSM Configuration
Using show Commands to Check System Status
Configuring Automatic Protection Switching
Configuring Frame Relay and Frame Relay Traffic Shaping
Configuring Dynamic Packet Transport Protocol
Configuring Bridging Control Protocol
OC-3c/STM-1 POS Module Configuration Example
Configuring the OC-3c/STM-1, OC-12c/STM-4, and OC-48c/STM-16 SONET/SDH Optical Services Modules
This chapter describes the OC-3c/STM-1, OC-12c/STM-4, and OC-48c/STM-16 Packet over Synchronous Optical Network (SONET) (POS)/synchronous digital hierarchy t(SDH) Optical Services Modules (OSMs).
This chapter consists of these sections:
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Understanding Packet-Over-SONET
Supported Features
These sections list the standard Cisco IOS POS and SDH features supported on the OC-3c/STM-1, OC-12c/STM-4, and OC-48c/STM-16 POS/SDH OSMs:
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SONET/SDH Compliance
This section lists the SONET/SDH Compliance features:
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SONET/SDH Error, Alarm, and Performance Monitoring
This section lists supported SONET/SDH error, alarms, and performance monitoring:
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SONET/SDH Synchronization
This section lists supported SONET/SDH synchronization:
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WAN Protocols
This section lists the supported WAN protocols:
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Configure the POS interfaces for Frame Relay as described in the Cisco IOS Wide-Area Networking Configuration Guide, Release 12.1 under "Configuring Frame Relay" and in the Cisco IOS Wide-Area Networking Command Reference, Release 12.1 at these URLs:
http://www.cisco.com/univercd/cc/td/doc/product/software/ios121/121cgcr/wan_c/wcdfrely.htm
http://www.cisco.com/univercd/cc/td/doc/product/software/ios121/121cgcr/wan_r/wrdfrely.htm
Configure traffic shaping for Frame Relay as described in the Cisco IOS Quality of Service
Solutions Configuration Guide under "Configuring Distributed Traffic Shaping" at this URL:
http://www.cisco.com/univercd/cc/td/doc/product/software/ios122/122cgcr/fqos_c/fqcprt4/qcfdts.htm
See the "Configuring Frame Relay and Frame Relay Traffic Shaping" section for information about platform-specific configurations, commands, and limitations.
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Dynamic Packet Transport Protocol
The 2-port OC-48c/STM-16 POS/DPT OSMs (OSM-2OC48/1DPT) support these Dynamic Packet Transport (DPT) protocol features:
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Bridging Control Protocol
Bridging Control Protocol (BCP) enables forwarding of Ethernet frames over SONET networks and provides a high-speed extension of enterprise LAN backbone traffic through a metropolitan area. The implementation of BCP on the OSMs includes support for IEEE 802.1D, IEEE 802.1Q Virtual LAN (VLAN), and high-speed switched LANs.
The following OSMs support BCP as defined in RFC 3518:
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Figure 3-1 shows a topology where BCP is used to allow transparent forwarding of VLAN traffic over a SONET network.
Figure 3-1 BCP Topology in a SONET Network
Figure 3-2 shows a topology where VLAN IDs are used to create VPNs for different customers and BCP is used to forward the VPN traffic over a SONET network.
Figure 3-2 BCP Topology in a VPN Network
For information on configuring BCP, see the "Configuring Bridging Control Protocol" section.
Quality of Service Support with BCP
Quality of Service (QoS) is supported on BCP links using the three experimental bits in a label to determine the priority of packets. To support QoS between LERs, you set the experimental bits in both the VC and tunnel labels. The experimental bits need to be set in the VC label because the tunnel label is popped at the penultimate router.
Routing and Scalability Protocols
This section lists the supported routing and scalability protocols:
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Network Management
This section lists the supported network management features:
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Quality of Service Protocols
This section lists the supported QoS features:
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Security Protocols
This section lists the supported security features:
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Multiprotocol Label Switching
Multiprotocol Label Switching (MPLS) and Ethernet over MPLS (EoMPLS) are supported on the GE-WAN ports on the 4-port GE-WAN-GBIC OSM.
MPLS is supported on the following Catalyst 6500 and Cisco 7600 series modules:
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For information on configuring MPLS, refer to the Multiprotocol Label Switching on Cisco Routers feature module at this URL:
http://www.cisco.com/univercd/cc/td/doc/product/software/ios121/121newft/121t/121t5/mpls4t.htm
For information about EoMPLS and how to configure it on the 4-port Gigabit Ethernet WAN (GBIC) and POS OSMs, refer to the Ethernet over MPLS Feature Module at this URL:
http://www.cisco.com/univercd/cc/td/doc/product/software/ios121/121newft/121limit/121e/121e8/tryvlan.htm
For information about platform-specific limitations and restrictions, see Chapter 11, "Configuring Multiprotocol Label Switching on the Optical Services Modules."
Understanding Packet-Over-SONET
Packet-over-SONET is a high-speed method of transporting IP traffic between two points. This technology combines the Point-to-Point Protocol (PPP) with SONET and Synchronous Digital Hierarchy (SDH) interfaces.
SONET is an octet-synchronous multiplex scheme defined by the American National Standards Institute (ANSI) standard (T1.1051988) for optical digital transmission at hierarchical rates from 51.840 Mbps to 2.5 Gbps (Synchronous Transport Signal, STS-1 to STS-48) and greater. SDH is an equivalent international standard for optical digital transmission at hierarchical rates from 155.520 Mbps (STM-1) to 2.5 gigabits per second (Gbps) (STM-16) and greater. SONET electrical specifications have been defined for single-mode fiber, multimode fiber, and CATV 75-ohm coaxial cable. The OC-3c/STM-1, OC-12c/STM-4, and OC-48c/STM-16 POS/SDH OSMs allow transmission over single-mode and multimode optical fiber at Optical Carrier 3, 12, and 48 (OC-3, OC-12, and OC-48) rates.
SONET/SDH transmission rates are integral multiples of 51.840 Mbps. The following transmission multiples are currently specified and commonly used:
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The POS specification (RFC 1619) describes the use of PPP encapsulation over SONET/SDH links. Because SONET/SDH is, by definition, a point-to-point circuit, PPP is well-suited for use over these links. PPP treats SONET/SDH transport as octet-oriented full-duplex synchronous links. PPP presents an octet interface to the physical layer. The octet stream is mapped into the SONET/SDH Synchronous Payload Envelope (SPE), with the octet boundaries aligned with the SPE octet boundaries. The PPP frames are located by row within the SPE payload. Because frames are variable in length, the frames are allowed to cross SPE boundaries.
The basic rate for POS is OC-3/STM-1, which is 155.520 Mbps. The available information bandwidth is 149.760 Mbps, which is the OC-3c/STM-1 SPE with section, line, and path overhead removed.
SONET Distance Limitations
The specification for optical fiber transmission defines two types of fiber: single-mode and multimode. Within the single-mode category, three transmission types are defined: short reach, intermediate reach, and long reach. Within the multimode category, only short reach is available.
For information on cable distance limitations and power budget, see http://www.cisco.com/univercd/cc/td/doc/product/core/cis7600/hardware/osmodule/02prep.htm.
Configuring the Interfaces
This section describes how to configure the OC-3c/STM-1, OC-12c/STM-4, and OC-48c/STM-16 OSMs:
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Initial Configuration of the POS/SDH OSMs
If you installed a new POS/SDH OSM or want to change the configuration of an existing interface, you must enter configuration mode by using the configure command in the privileged EXEC mode. Table 3-1 shows the default configuration of an enabled module. For more information, see the "Customizing the POS/SDH OSM Configuration" section.
Configuring the Interface
After you verify that the new POS/SDH OSM is installed correctly, use the configure command in the privileged EXEC mode to configure the new interface. Be prepared with the information you will need, such as the interface IP address.
The following procedure is for creating a basic configuration, which includes enabling an interface and specifying IP routing.
A Catalyst 6500 series switch and Cisco 7600 series router identifies an interface address by its module slot number and port number in the format slot/port. For example, the slot/port address of an interface on a 1-port OC-48c/STM-16 POS/SDH OSM installed in slot 4 is 4/1. Even though the card contains only one port, you must use the slot/port notation.
Before using the configure command, you must enter the privileged level mode of the EXEC command interpreter by using the enable command. The system will prompt you for a password if one is set.
To configure the POS/SDH OSMs (press the Return key after each configuration step unless otherwise noted), perform this task:
Customizing the POS/SDH OSM Configuration
This section documents new platform-specific commands. Other commands used in OSM configuration are documented in the Cisco IOS Release 12.1 command reference publications.
You can change the default values of all POS/SDH OSM configuration parameters to match your network environment. Perform the tasks in the following sections if you need to customize the POS/SDH OSM configuration:
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Selecting a POS/SDH OSM Interface
An OC-3c/STM-1, OC-12c/STM-4, or OC-48c/STM-16 interface is referred to as pos, for packet-over-SONET, in the configuration commands. To select a specific POS interface, use the interface pos slot/port command in the configuration mode:
Router(config)# interface pos slot/portConfiguring Framing
The pos framing command allows you to set framing to SONET OC or SDH STM. The default is SONET.
Router(config-if)# pos framing [sdh|sonet]Specifying SONET Overhead
The pos flag command allows you to specify values for the specific elements of the frame header.
Router(config-if)# pos flag [c2 value] [j0 value] [s1s0 value]where
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Configuring POS SPE Scrambling
The POS scrambling command allows you to scramble the POS SPE (synchronous payload envelope) payload. The default is no POS SPE scramble.
Router(config-if)#[no] pos scramble-atmUsing show Commands to Check System Status
Each OSM maintains information about its configuration, traffic, and errors. You can access this information by using the show commands.
Descriptions and examples of module and system status show commands follow:
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Router#show interfaces pos 5/1POS5/1 is administratively down, line protocol is downHardware is Packet over SONETMTU 4470 bytes, BW 155000 Kbit, DLY 100 usec, rely 255/255, load 1/255Encapsulation HDLC, crc 32, loopback not set, keepalive set (10 sec)Scramble disabledLast input never, output never, output hang neverLast clearing of "show interface" counters neverQueueing strategy: fifoOutput queue 0/40, 0 drops; input queue 0/75, 0 drops5 minute input rate 0 bits/sec, 0 packets/sec5 minute output rate 0 bits/sec, 0 packets/sec0 packets input, 0 bytes, 0 no bufferReceived 0 broadcasts, 0 runts, 0 giants, 0 throttles0 parity0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort0 packets output, 0 bytes, 0 underruns0 output errors, 0 applique, 0 interface resets0 output buffer failures, 0 output buffers swapped out0 carrier transitions...(output truncated)•
Router# show versionWS-C6509 Software, Version NmpSW: 6.1(2)Copyright (c) 1995-2001 by Cisco SystemsNMP S/W compiled on Jan 25 2001, 12:28:23System Bootstrap Version: 6.1(2)Hardware Version: 2.0 Model: WS-C6509 Serial #: SCA042101NGMod Port Model Serial # Versions--- ---- ------------------- ----------- ----------------------------------- ---1 2 WS-X6K-SUP2-2GE SAD044102J9 Hw : 1.1Fw : 6.1(2)Fw1: 6.1(3)Sw : 6.1(2)Sw1: 6.1(2)WS-F6K-PFC2 SAD04470KPP Hw : 1.03 8 WS-X6408-GBIC SAD03090264 Hw : 1.4Fw : 4.2(0.24)VAI78Sw : 6.1(2)4 8 WS-X6408A-GBIC SAD043500LE Hw : 1.3Fw : 5.4(2)Sw : 6.1(2)5 4 OSM-4OC12-POS-MM SAD050202EJ Hw : 0.101Fw : 12.1(6.5)E1Sw : 12.1(6.5)E16 24 WS-X6224-100FX-MT SAD03040765 Hw : 1.2Fw : 4.2(0.24)VAI78Sw : 6.1(2)9 48 WS-X6248 SAD03200773 Hw : 1.1Fw : 4.2(0.24)VAI78Sw : 6.1(2)15 1 WS-F6K-MSFC2 SAD044803FK Hw : 1.1Fw : 12.1(3a)E4Sw : 12.1(3a)E4DRAM FLASH NVRAMModule Total Used Free Total Used Free Total Used Free------ ------- ------- ------- ------- ------- ------- ----- ----- -----1 130944K 57316K 73628K 16384K 6647K 9737K 512K 302K 210KUptime is 2 days, 19 hours, 50 minutesConsole> (enable))•
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Router# show running-configBuilding configuration...Current configuration:!version 11.2no service udp-small-serversno service tcp-small-servers!hostname Maxwell!enable secret 5 $1$ZBC0$tJO8EeP3VI769LAw.3edJ1enable password xxxx!ip host ray 172.27.136.253ip host crusty 171.69.209.28ip domain-name cisco.comip name-server 171.69.209.10clock timezone EST -5clock summer-time EDT recurring!interface POS0/0no ip addressshutdowncrc 32!interface POS0/1no ip addressshutdowncrc 32!(output truncated)Configuring Automatic Protection Switching
Automatic protection switching (APS) allows switchover of packet-over-SONET (POS) circuits and is often required when connecting SONET equipment to telecommunications equipment. When APS is configured, a protect POS interface is brought into the SONET network from the intervening SONET equipment and the protect POS interface becomes the working POS interface on the circuit.
The protect interface is configured with the IP address of the router that has the working interface. The APS Protect Group Protocol provides communication between the process controlling the working interface and the process controlling the protect interface. When you use the APS Protect Group Protocol, POS interfaces can be switched in the event of a router failure, degradation or loss of channel signal, or manual intervention.
Two SONET connections are required to support APS. In a telecommuncations environment, the SONET circuits must be provisioned as APS. You must also provision the operation, mode, and revert options. If the SONET connections are homed on two separate routers (the normal configuration), an out-of-band (OOB) communications channel between the two routers needs to be set up for APS communication.
When configuring APS, we recommend that you configure the working interface first, along with the IP address of the interface being used as the APS OOB communications path.
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For more information on APS and configuration information for additional APS features, refer to the Cisco IOS Interface Configuration Guide, Release 12.1 at this URL:
http://www.cisco.com/univercd/cc/td/doc/product/software/ios121/121cgcr/inter_c/index.htm
Configuring the Working Interface
To configure the working interface, perform this task:
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Configuring the Protect Interface
To configure the protect interface, perform this task beginning in global configuration mode:
Configuring Basic APS
The following example shows the configuration of APS on router A and router B (see Figure 3-3). In this example, router A is configured with the working interface, and router B is configured with the protect interface. If the working interface on router A becomes unavailable, the connection will automatically switch over to the protect interface on router B. The working and protect interfaces are configured at the controller level.
Figure 3-3 Basic APS Configuration
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Router# configure terminalRouter(config)# interface loopback 1Router(config-if)# ip address 7.7.7.7 255.255.255.0Router(config)# exitRouter(config)# interface pos 2/0Router(config-if)# aps working 1router(config-if)# pos ais-shutRouter(config-if)# endRouter#Step 2
Router# configure terminalRouter(config)# interface loopback 2Router(config-if)# ip address 7.7.7.6 255.255.255.0Router(config)# exitRouter(config-if)# interface pos 3/0Router(config-if)# aps protect 1 7.7.7.7router(config-if)# pos ais-shutRouter(config-if)# endRouter#Multiple APS Interface Configuration
To configure more than one protect/working interface, use the aps group command. The following example in Figure 3-4 shows the configuration of grouping more than one working/protect interface. In this example, router A is configured with a working interface and a protect interface, and router B is configured with a working interface and a protect interface. If the working interface 2/0 on router A becomes unavailable, the connection will switch over to the protect interface 3/0 on router B because they are both in APS group 10. Similarly, if the working interface 2/0 on router B becomes unavailable, the connection will switch over to the protect interface 3/0 on router A because they are both in APS group 20.
Figure 3-4 Multiple Working and Protect Interfaces Configuration
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router# configure terminalrouter(config)# interface ethernet 0/0router(config-if)# ip address 7.7.7.6 255.255.255.0router(config-if)# exitrouter(config)# interface POS 2/0router(config-if)# aps group 10router(config-if)# aps working 1router(config-if)# exitrouter(config)# interface POS 3/0router(config-if)# aps group 20router(config-if)# aps protect 1 7.7.7.7router(config-if)# endrouter#Step 2
router# configure terminalrouter(config)# interface ethernet 0/0router(config-if)# ip address 7.7.7.7 255.255.255.0router(config-if)# exitrouter(config)# interface POS 2/0router(config-if)# aps group 20router(config-if)# aps working 1router(config-if)# exitrouter(config)# interface POS 3/0router(config-if)# aps group 10router(config-if)# aps protect 1 7.7.7.6router(config-if)# endrouter#Configuring Frame Relay and Frame Relay Traffic Shaping
This section describes Frame Relay configurations, platform-specific commands, and limitations:
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Configure the interfaces for Frame Relay as described in the Cisco IOS Wide-Area Networking Configuration Guide, Release 12.1 under "Configuring Frame Relay" and in the Cisco IOS Wide-Area Networking Command Reference, Release 12.1 at these URLs:
http://www.cisco.com/univercd/cc/td/doc/product/software/ios121/121cgcr/wan_c/wcdfrely.htm
http://www.cisco.com/univercd/cc/td/doc/product/software/ios121/121cgcr/wan_r/wrdfrely.htm
Configure traffic shaping for Frame Relay as described in the Cisco IOS Quality of Service
Solutions Configuration Guide under "Configuring Distributed Traffic Shaping" at this URL:
http://www.cisco.com/univercd/cc/td/doc/product/software/ios122/122cgcr/fqos_c/fqcprt4/qcfdts.htm.
Frame Relay Limitations and Restrictions
The following limitations and restrictions apply to Frame Relay:
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Frame Relay Traffic Shaping Configuration Example
To configure frame frelay traffic shaping, perform this task:
We recommend that you explicitly disable CDP on the subinterfaces. Should CDP be required on the subinterfaces, the input-queue depth may need to be adjusted. To accommodate the number of incoming CDP packets, configure the input-queue depth on the main interface to be slightly larger than the number of subinterfaces on which you have enabled CDP. The default input-queue depth is 75 and can be adjusted with the hold-queue interface command:
Router(config-if)# hold-queue 300 inThe following example shows a configuration that shapes the traffic for DLCI 18 to be 8 Mbps on both input and output traffic flows:
Router(config)# class-map match-all fr-classmapRouter(config-cmap)# match anyRouter(config-cmap)# exitRouter(config)# policy-map fr-mapRouter(config-pmap)# class fr-classmapRouter(config-pmap-c)# shape average 8000000 32000 32000Router(config-pmap-c)# exitRouter(config)# map-class frame-relay fr-shapingRouter(config-map-class)# no frame-relay adaptive-shapingRouter(config-map-class)# service-policy input fr-pmapRouter(config-map-class)# service-policy output fr-pmapRouter(config-map-class)# exitRouter(config)# interface POS7/15.1 point-to-pointRouter(config-subif)# ip address 72.0.0.1 255.255.0.0Router(config-subif)# no cdp enableRouter(config-subif)# frame-relay interface-dlci 18Router(config-fr-dlci)# class fr-shapingRouter(config-fr-dlci)# exitConfiguring Dynamic Packet Transport Protocol
Dynamic Packet Transport (DPT) is a packet ring technology that allows you to scale and distribute your Internet and IP services across a reliable optical packet ring infrastructure.
For general overview information for DPT, refer to the Dynamic Packet Transport Feature Guide at this URL:
http://www.cisco.com/univercd/cc/td/doc/product/software/ios120/120newft/120limit/120s/srpapsgs.htm
The 2-port OC-48c/STM-16c OSM can be used as a 2-port POS/SDH uplink module or as a single-port DPT module. When the 2-port OC-48c/STM-16c OSM is used as a DPT module, one of the OC-48 interfaces functions as the Side-A interface and the other as the Side-B interface.
Figure 3-5 shows a DPT ring created with two 1-port OC-48c/STM-16c SRP modules installed in the Cisco 12000 series router and one 2-port OC-48c/STM-16c OSM installed in the Cisco 7600 series routers.
Figure 3-5 SRP/DPT Ring Example
To configure DPT on the 2-port OC-48c/STM-16 OSM, perform this task from configuration mode:
This example shows how to configure the 2-port OC-48c/STM-16c OSM for SRP/DPT mode.
Router(config)# hw-module slot 4 srp
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Router(config)# interface srp 4/1Router(config-if)# ip address 10.1.2.1 255.255.255.0Router(config-if)# no cdp enableRouter(config-if)# no shutdownRouter(config-if)# exitRouter(config)# exitRouter# show interfaces srp 4/1SRP4/1 is up, line protocol is upHardware is SRP, address is 00d0.01d7.4c0a (bia 00d0.01d7.4c0a)Internet address is 10.1.2.1/24MTU 4470 bytes, BW 2488000 Kbit, DLY 100 usec,reliability 255/255, txload 1/255, rxload 41/255Encapsulation SRP2,Side A: loopback not setSide B: loopback not set3 nodes on the ring MAC passthrough not setSide A: not wrapped IPS local: IDLE IPS remote: IDLESide B: not wrapped IPS local: IDLE IPS remote: IDLEScramble enabledLast input 00:00:00, output 00:00:00, output hang neverLast clearing of "show interface" counters neverInput queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0Queueing strategy: fifoOutput queue :0/40 (size/max)Side A: 5 minutes output rate 0 bits/sec, 0 packets/sec5 minutes input rate 0 bits/sec, 0 packets/secSide B: 5 minutes output rate 0 bits/sec, 0 packets/sec5 minutes input rate 0 bits/sec, 0 packets/secL2 Switched: ucast: 0 pkt, 0 bytes - mcast: 0 pkt, 0 bytesL3 in Switched: ucast: 0 pkt, 0 bytes - mcast: 0 pkt, 0 bytes mcastL3 out Switched: ucast: 0 pkt, 0 bytes360563 packets input, 286645033 bytes, 0 no bufferReceived 0 broadcasts, 43 runts, 0 giants, 0 throttles50 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 7 abort847443 packets output, 34168034 bytes, 0 underruns0 output errors, 0 collisions, 3 interface resets0 output buffer failures, 0 output buffers swapped outSide A received errors:33 input errors, 0 CRC, 0 ignored,29 framer runts, 0 framer giants, 4 framer aborts,0 mac runts, 0 mac giants, 0 mac abortsSide B received errors:17 input errors, 0 CRC, 0 ignored,14 framer runts, 0 framer giants, 3 framer aborts,0 mac runts, 0 mac giants, 0 mac abortsRouter#Configuring Bridging Control Protocol
When BCP is used to forward Ethernet frames over SONET no Layer 3 routing information needs to be exchanged, and the POS links function like Ethernet trunks carrying VLAN traffic over the existing reliable high-speed SONET or DPT network.
Usage Guidelines and Restrictions
When configuring BCP, observe the following guidelines and restrictions.
VLANs
Each PXF complex supports only one instance of a VLAN. As a result, although more than one interface might be supported per PXF complex, the same VLAN cannot be configured on more than one interface per PXF complex. Depending on the particular POS OSM, each interface may share a PXF complex with other interfaces. For example, on a 4-port OC-12 POS OSM, port 1 and 2 share one PXF complex and port 3 and 4 share another PXF complex. If VLAN 400 is configured on port 1, that same VLAN cannot be configured on port 2. But VLAN 400 is allowed on either port 3 or port 4.
MTU
In order for a POS interface to support bridging, the POS interface minimum MTU size should be 24 bytes larger than the VLAN interfaces and Ethernet interfaces MTU size. This accounts for 6 bytes of RFC 3518 header and 18 bytes of 802.1Q header.
For example, if the MTU size on an ingress Ethernet port is 3000 bytes, the POS port MTU size should be at least 3024 bytes.
Quality of Service Support
OSMs use DSCP-based queueing and shaping, but because BCP does Layer 2 traffic forwarding, there is no DSCP value to look at. Instead, the 3-bit CoS field in the 802.1Q header is mapped to a 6-bit DSCP value.
When BCP is enabled, the CoS value in the 802.1Q header is mapped to the DSCP value in the IP header according to this default CoS to DSCP mapping:
For information about QoS on the Layer 3 OSM ports, see Chapter 9, "Configuring QoS on the Optical Services Modules." For information on PFC2 QoS support, refer to the QoS chapter of the Cisco 7600 Series Router Software Configuration Guide at this URL:
http://www.cisco.com/univercd/cc/td/doc/product/core/cis7600/12111bex/swcg/qos.htm
To configure BCP, peform this task:
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Router(config)# interface pos mod/port
Selects the interface.
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Router(config-if)# encapsulation ppp
Configures the interface for PPP encapsulation.
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Router(config-if)# bridge-enable1
Enables BCP on the interface.
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Router(config-if)# switchport trunk {allowed | pruning vlan {add | all | except | remove}}
Configures the trunk characteristics.
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Router(config-if)# end
Exits configuration mode.
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Displays interface configuration.
1 Enter the bridge-enable command while the port is in shutdown state. If you enter the bridge-enable command while the port is in up state, enter the shutdown command followed by the no shutdown command in order to bring up BCP on the POS port.
In this example, BCP forwarding of all VLANs except for VLAN 400 is configured on a POS interface:
Router# configure terminalEnter configuration commands, one per line. End with CNTL/Z.Router(config)# interface pos 3/2Router(config)# encapsulation pppRouter(config-if)# bridge-enableRouter(config-if)# switchport trunk allowed vlan allRouter(config-if)# switchport trunk allowed vlan remove vlan 400Router(config-if)# shutdownRouter(config-if)# no shutdownRouter(config-if)# endRouter# show running-config interface pos 3/2!interface POS3/2ip address 2.2.2.2 255.255.255.0encapsulation pppbridge-enableswitchportswitchport trunk allowed vlan 1-399,401-1005switchport mode trunkno cdp enableendRouter# show interface pos 3/2 switchportName:Po3/2Switchport:EnabledAdministrative Mode:trunkOperational Mode:trunkAdministrative Trunking Encapsulation:dot1qOperational Trunking Encapsulation:dot1qNegotiation of Trunking:OffAccess Mode VLAN:1 (default)Trunking Native Mode VLAN:1 (default)Administrative private-vlan host-association:noneAdministrative private-vlan mapping:noneOperational private-vlan:noneTrunking VLANs Enabled:1-399,401-1005Pruning VLANs Enabled:2-1001Router# show interface pos 3/2 trunkPort Mode Encapsulation Status Native vlanPo3/2 on 802.1q trunking 1Port Vlans allowed on trunkPo3/2 1-399,401-1005Port Vlans allowed and active in management domainPo3/2 1,31-32,34,91-92,100,500,1002-1005Port Vlans in spanning tree forwarding state and not prunedPo3/2 31-32,34,91-92,100,1002-1005OC-3c/STM-1 POS Module Configuration Example
The following is an example of configuration file commands for a Cisco 7600 series router (first router) with an OC-3c/STM-1 POS module in slot 3 connected back-to-back with a Cisco 7500 series router (second router) with a POS Interface Processor (POSIP) module in slot 3.
The configuration commands for the first router are as follows:
interface pos 3/1ip address 10.1.2.3 255.0.0.0clock source internalno shutdownno keepaliveno cdp enableno ip mroute-cachecrc 32The configuration commands for the second router are as follows:
interface pos 3/0/0ip address 10.1.2.4 255.0.0.0clock source internalno shutdownno keepaliveno cdp enablecrc 32
