Configuring the Cisco NM-1A-T3/E3 Network Module
SVCs
12
Cisco IOS Release 12.4(15)T
Configuring the PVC That Performs SVC Call Setup
ATM uses out-of-band signaling. There is one dedicated PVC between the router and the ATM switch,
over which all SVC call establishment and call termination requests flow. After a call is established, data
transfer occurs over the SVC, from router to router. The signaling that accomplishes the call setup and
teardown is called Layer 3 signaling or the Q.2931 protocol.
For out-of-band signaling, a signaling PVC must be configured before any SVCs can be set up.
Figure 1
shows how a signaling PVC from the source router to the ATM switch is used to set up two SVCs. This
is a fully meshed network; workstations A, B, and C can all communicate with each other.
Figure 1
SVCs within a signaling PVC
To configure the signaling PVC for all SVC connections, use the following command in interface
configuration mode:
Note
This signaling PVC can be set up only on an ATM main interface, not on ATM subinterfaces.
The VPI and VCI values must be configured consistently with the local switch. The standard values for
VPI and VCI are 0 and 5, respectively.
ATM
Workstation A
Workstation B
62871
Workstation C
LAN
LAN
LAN
Source router
SVC2
SVC1
SVC1
Destination router
SVC2
Q.2931 protocol
Signaling PVC
SVC1
SVC2
Destination
router
Q.2931 protocol
Signaling PVC
Q.2931 protocol
Signaling PVC
Command
Purpose
Router(config-if)#
pvc
[
name
]
vpi/vci
qsaal
Example:
Router(config-if)# pvc cisco 0/5 qsaal
Configures the signaling PVC for an ATM main interface that
uses SVCs.