Specifications

encapsulation (Any Transport over MPLS)
MP-61
Cisco IOS Multiprotocol Label Switching Command Reference
January 2010
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 aa
l5 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 aa
l0 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# configu
re 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 enca
psulation 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# configu
re 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 enca
psulation mpls
Related Commands
Ta b l e 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)#
en
capsulation aal5
Command Description
pvc Creates or assigns a name to an ATM PVC.