Configuring ATM

Note	After configuring the parameters for an ATM PVC, you must exit interface-ATM-VC configuration mode in order to create the PVC and enable the settings.

To create a PVC on the ATM interface and enter interface-ATM-VC configuration mode, use the following command beginning in interface configuration mode:

Router(config-if)# pvc [name] vpi /vci

The ATM interface supports a static mapping scheme that identifies the network address of remote hosts or routers. This section describes how to map a PVC to an address, which is a required task for configuring a PVC.

Note	If you enable or disable broadcasting directly on a PVC using the protocol command, this configuration will take precedence over any direct configuration using the broadcast command.

See examples of PVC configurations in the section "ATM Configuration Examples".

To map a protocol address to a PVC, use the following command in interface-ATM-VC configuration mode:

Router(config-if-atm-vc)# protocol protocol protocol-address [[no] broadcast]

To configure the ATM adaptation layer (AAL) and encapsulation type, use the following command beginning in interface-ATM-VC configuration mode:

Router(config-if-atm-vc)# encapsulation aal5 encap

The supported traffic parameters are part of the following service categories: Constant Bit Rate (CBR), Unspecified Bit Rate (UBR), Variable Bit Rate Non Real-Time (VBR-NRT), and real-time Variable Bit Rate (VBR). Only one of these categories can be specified per PVC connection so if a new one is entered, it will replace the existing one.

Note	The commands in this section are not supported on the ATM port adapter (PA-A1 series). The 1-port ATM-25 network module only supports UBR.

The -pcr and -mcr arguments are the peak cell rate and minimum cell rate, respectively. The -scr and -mbs arguments are the sustainable cell rate and maximum burst size, respectively.

For a description of how to configure traffic parameters in a VC class and apply the VC class to an ATM interface or subinterface, refer to the section "Configuring VC Classes."

To configure PVC traffic parameters, use one of the following commands beginning in interface-ATM-VC configuration mode:

Router(config-if-atm-vc)# cbr  peak_cell_rate_KBPS

Router(config-if-atm-vc)# ubr output-pcr

Router(config-if-atm-vc)# vbr-nrt output-pcr output-scr output-mbs

Router(config-if-atm-vc)# vbr-rt peak-rate average-rate burst

1.   Do one of the following:

2.    Router(config-if)# pvc [name] vpi / vci

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

4.    Router(config-if-atm-vc)# inarp minutes

1.    enable

2.    configure terminal

3.    ancp adjacency timer interval

4.    interface atm slot / subslot / port . subinterface

5.    ip address ip-address mask

6.    pvc vpi / vci

7.    ancp enable

8.    exit

1.    Router(config-if-atm-vc)# oam-pvc [manage] frequency

2.    Router(config-if-atm-vc)# oam retry up-count down-count retry-frequency

To send duplicate broadcast packets for all protocols configured on a PVC, use the following command in interface-ATM-VC configuration mode:

Note	If you enable or disable broadcasting directly on a PVC using the protocol command, this configuration will take precedence over any direct configuration using the broadcast command.

Router(config-if-atm-vc)# broadcast

By creating a VC class, you can preconfigure a set of default parameters that you may apply to a PVC. To create a VC class, refer to the section "Configuring VC Classes".

Once you have created a VC class, use the following command in interface-ATM-VC configuration mode to apply the VC class to a PVC:

Router(config-if-atm-vc)# class-vc  vc-class-name

You can configure the PVC to provide failure notification by sending a trap when a PVC on an ATM interface fails or leaves the UP operational state.

• PVC Failure Notification
• PVC Status Tables
• Prerequisites
• Enabling PVC Trap Support

To create a VC class, use the following command in global configuration mode:

For examples of creating VC classes, see the section "Creating a VC Class Example".

Router(config)# vc-class atm name

After you create a VC class and enter vc-class configuration mode, configure VC parameters using one or more of the following commands:

• broadcast
• cbr
• encapsulation aal5
• idle-timeout
• inarp
• oam-pvc
• oam retry
• protocol
• ubr
• vbr-nrt

Refer to the sections "Configuring PVCs" and "Configuring PVC Trap Support" for descriptions of how to configure these commands for PVCs.

For examples of creating VC classes, see the section "Creating a VC Class Example".

1.    Router(config-if)# pvc [name] vpi / vci

2.    Router(config-if-atm-vc)# class-vcvc-class-name

1.   Do one of the following:

2.    Router(config-if)# class-int vc-class-name

1.   Do one of the following:

2.    Router(config-if)# pvc [name] vpi / vci

3.    Router(config-if-atm-vc)# oam-pvc manage [frequency]

4.    Router(config-if-atm-vc)# oam retry up-count down-count retry-frequency

The ATM Inverse ARP mechanism is applicable to networks that use PVCs, where connections are established but the network addresses of the remote ends are not known. A server function is not used in this mode of operation.

By default, Inverse ARP datagrams will be sent on this virtual circuit every 15 minutes. To adjust the Inverse ARP time period, use the inarp minutes command in interface-ATM-VC configuration mode.

Note	The ATM ARP mechanism works with IP only. The Inverse ATM ARP mechanism works with IP and IPX only. For all other protocols, the destination address must be specified.

In a PVC environment, the ATM Inverse ARP mechanism is enabled by default for IP and IPX when you use the following commands beginning in global configuration mode:

1.   Do one of the following:

2.    Router(config-if)# ip address address mask

3.    Router(config-if)# pvc [name] vpi / vci

4.    Router(config-if-atm-vc)# no shutdown

5.   

Each interface has a default maximum packet size or maximum transmission unit (MTU) size. For ATM interfaces, this number defaults to 4470 bytes. The maximum is 9188 bytes for the AIP and NPM, 17969 for the ATM port adapter, and 17998 for the ATM-CES port adapter. The MTU can be set on a per-sub-interface basis as long as the interface MTU is as large or larger than the largest subinterface MTU.

To set the maximum MTU size, use the following command in interface configuration mode:

Router(config-if)# mtu bytes

The following example shows how to create a PVC on an ATM main interface with AAL5/MUX encapsulation configured and a VBR-NRT QOS specified. For further information, refer to the sections "Creating a PVC" and "Configuring PVC Traffic Parameters".

interface 2/0
 pvc cisco 1/40
 encapsulation aal5mux ip
 vbr-nrt 100000 50000 20
 exit

The following example shows how to create a PVC 0/50 on ATM interface 3/0. It uses the global default LLC/SNAP encapsulation over AAL5. The interface is at IP address 1.1.1.1 with 1.1.1.5 at the other end of the connection. For further information, refer to the sections "Creating a PVC" and "Mapping a Protocol Address to a PVC".

interface atm 3/0
 ip address 1.1.1.1 255.255.255.0
 pvc 0/50
 protocol ip 1.1.1.5 broadcast
 exit
!
 ip route-cache cbus

The following example is a typical ATM configuration for a PVC:

interface atm 4/0
 ip address 172.21.168.112 255.255.255.0
 atm maxvc 512
 pvc 1/51
 protocol ip 171.21.168.110
 exit
!
 pvc 2/52
 protocol decnet 10.1 broadcast
 exit
!
 pvc 3/53
 protocol clns 47.004.001.0000.0c00.6e26.00 broadcast
 exit
!
 decnet cost 1
 clns router iso-igrp comet
 exit
!
router iso-igrp comet
 net 47.0004.0001.0000.0c00.6666.00
 exit
!
router igrp 109
 network 172.21.0.0
 exit
!
ip domain-name CISCO.COM

The figure below illustrates a fully meshed network. The configurations for routers A, B, and C follow the figure. In this example, the routers are configured to use PVCs. Fully meshed indicates that any workstation can communicate with any other workstation. Note that the two protocol statements configured in router A identify the ATM addresses of routers B and C. The two protocolstatements in router B identify the ATM addresses of routers A and C. The two protocol statements in router C identify the ATM addresses of routers A and B. For further information, refer to the sections "Creating a PVC" and "Mapping a Protocol Address to a PVC".

Figure 1

Fully Meshed ATM Configuration Example

ip routing
!
interface atm 4/0
 ip address 131.108.168.1 255.255.255.0
 pvc 0/32
 protocol ip 131.108.168.2 broadcast
 exit
!
 pvc 0/33
 protocol ip 131.108.168.3 broadcast
 exit

ip routing
!
interface atm 2/0
 ip address 131.108.168.2 255.255.255.0
 pvc test-b-1 0/32
 protocol ip 131.108.168.1 broadcast
 exit
!
 pvc test-b-2 0/34
 protocol ip 131.108.168.3 broadcast
 exit

ip routing
!
interface atm 4/0
 ip address 131.108.168.3 255.255.255.0
 pvc 0/33 
 protocol ip 131.108.168.1 broadcast
 exit
!
 pvc 0/34
 protocol ip 131.108.168.2 broadcast
 exit

The following example shows how to enable Inverse ARP on an ATM interface and specifies an Inverse ARP time period of 10 minutes. For further information, refer to the section "Enabling Inverse ARP".

interface atm 2/0
 pvc 1/32
 inarp 10
 exit

The following example shows how to enable ANCP on an ATM subinterface. In the example, ANCP is enabled on ATM subinterface 2/0/1.1.

interface ATM2/0/0.1 point-to-point
      description ANCP Link to one DSLAM
      no ip mroute-cache
      ip address 192.168.0.2 255.255.255.252      
      pvc 254/32
        protocol ip 192.168.0.1
        ancp enable
        no snmp trap link-status

The following example shows how to enable OAM management on an ATM PVC. The PVC is assigned the name routerA and the VPI and VCI are 0 and 32, respectively. OAM management is enabled with a frequency of 3 seconds between OAM cell transmissions. For further information, refer to the section "Enabling ANCP on an ATM Interface".

interface atm 2/0
 pvc routerA 0/32
 oam-pvc manage 3
 oam retry 5 5 10

The following example shows how to configure PVC trap support on your Cisco router:

!For PVC trap support to work on your router, you must first have SNMP support and 
!an IP routing protocol configured on your router:
Router(config)# snmp-server community public ro
Router(config)# snmp-server host 171.69.61.90 public
 
Router(config)# ip routing
Router(config)# router igrp 109
Router(config-router)# network 172.21.0.0
!
!Enable PVC trap support and OAM management:
Router(config)# snmp-server enable traps atm pvc interval 40 fail-interval 10
Router(config)# interface atm 1/0.1 
Router(config-if)# pvc 0/1
Router(config-if-atm-vc)# oam-pvc manage
!
! Now if PVC 0/1 goes down, host 171.69.61.90 will receive traps.

For further information, refer to the "Configuring PVC Trap Support" section.

The following example shows how to create a VC class named main and how to configure UBR and encapsulation parameters. For further information, refer to the sections "Creating a VC Class" and "Configuring VC Parameters".

vc-class atm main
 ubr 10000
 encapsulation aal5mux ip

The following example shows how to create a VC class named sub and how to configure UBR and PVC management parameters. For further information, refer to the sections "Creating a VC Class" and "Configuring VC Parameters".

vc-class atm sub
 ubr 15000
 oam-pvc manage 3

The following example shows how to create a VC class named pvc and how to configure VBR-NRT and encapsulation parameters. For further information, refer to the sections "Creating a VC Class" and "Configuring VC Parameters".

vc-class atm pvc
 vbr-nrt 10000 5000 64
 encapsulation aal5snap

The following example shows how to apply the VC class named main to the ATM main interface 4/0. For further information, refer to the section "Applying a VC Class on an ATM PVC".

interface atm 4/0
 class-int main
 exit

The following example shows how to apply the VC class named sub to the ATM subinterface 4/0.5:

interface atm 4/0.5 multipoint
 class-int sub
 exit

The following example shows how to apply the VC class named pvc directly on the PVC 0/56:

interface atm 4/0.5 multipoint
 pvc 0/56
 class-vc pvc
 exit

The following example shows how to enable OAM management on an ATM PVC. The PVC is assigned the name routerA and the VPI and VCI are 0 and 32, respectively. OAM management is enabled with a frequency of 3 seconds between OAM cell transmissions. For further information, refer to the section "Configuring OAM Management for PVCs".

interface atm 2/0
 pvc routerA 0/32
 oam-pvc manage 3
 oam retry 5 5 10
!
interface atm 4/0.1 point-to-point
 pvc 0/35
 exit

No map-group and map-list commands are needed for IP.

interface atm 4/0
 ip address 1.1.1.1 255.0.0.0
 pvc 1/33
 pvc 1/34
 pvc 1/35
 bridge-group 1
!
bridge 1 protocol dec