Cisco Cisco IOS Software Release 12.2(8)T

ATM Software Segmentation and Reassembly (SAR)

Cisco IOS Release 12.2(8)T

Configuring ATM on the Cisco 2600 Series

This section describes the ATM configuration tasks necessary to support Voice over ATM using AAL2
on Cisco 2600 series.

Note

If any DS0 groups (CAS groups), channel groups, or clear channels are configured on T1/E1
controller 0, you must remove them before configuring VoATM. Because ATM uses all the DS-0 time
slots on the controller, the ATM configuration cannot take place if any DS0s on controller 0 are used
by other applications.

You must perform the VoATM configuration on the Cisco 2600 series or Cisco 3660 concentrators at
both ends of the ATM link.

To configure a Cisco 2600 series or Cisco 3660 series concentrator to support VoATM on a T1/E1 trunk,
complete the following steps beginning in global configuration mode:

Command

Purpose

Step 1

Router(config)# controller {t1 | e1} 0/0

Selects the T1 or E1 controller 0/0.

Step 2

Router(config-controller)# mode atm

Specifies that the controller will support ATM
encapsulation and create ATM interface 0/0.

Step 3

Router(config-controller)# framing framing type

Specifies the T1 framing type as extended super
frame or esf.

When the controller is set to ATM mode, the
Controller framing is automatically set to Extended
SuperFrame (esf) on T1 and to crc4 on E1.

Step 4

Router(config-controller)# linecode linecode type

Specifies the T1 linecode type as b8zs.

The linecode is automatically set to b8zs on T1 and
to hdb3 on E1.

Step 5

Router(config-controller)# no shutdown

Ensures that the controller is activated.

Step 6

Router(config-controller)# exit

Exits controller configuration mode.

Step 7

Router(config)# interface atmslot/port

[subinterface-number [multipoint |

point-to-point

]]

Enters interface configuration mode to configure
ATM interface 0/0 or an ATM subinterface.

For subinterfaces, the default is multipoint.

Step 8

Router(config-if)# pvc [word] {vpi/vci | vci}

Creates an ATM PVC for voice traffic and enters
ATM virtual circuit configuration mode.

vpi= 0 to 255

vci= 1 to 1023

word= optional PVC identifier (letters only); if you
assign a PVC identifier, you can use it to specify this
PVC when configuring network dial peers

Note

AAL2 encap is not supported for ilmi and
qsaal PVCs.

Step 9

Router(config-if-atm-vc)# encapsulation aal2

Sets the encapsulation of the PVC to support AAL2
voice traffic. This automatically creates channel
identifiers (CIDs) 1 through 255.