Configuring a loopback

If a loopback is configured on a spoke-SDP, all traffic on the ingress direction of the spoke-sdp and associated with the ingress vc-label is forwarded to the egress direction of the spoke-SDP. A loopback may be configured at either a T-PE or an S-PE. It is recommended that an administrative lock is configured before configuring the loopback on a spoke-SDP. This is enforced by the NMS.

A data path loopback is configured using a tools perform command, as follows:

tools
   perform
      service-id <svc-id> 
         loopback
            pw
               sdp <sdp-id>:<vc-id> {start | stop}

The following constraints and conditions apply for PW loopback configuration:

• The spoke-SDP cannot be an ICB or be bound to a VPLS interface.

• A PW path ID must be configured, that is, the spoke-SDP must be static and use MPLS-TP identifiers.

• The spoke-SDP must be bound to a VLL mate SAP or another spoke-SDP that is not an ICB.

• The control-channel-status must be shutdown.

• The following are disabled on a spoke-SDP for which a loopback is configured:

  • Filters

  • PW shaping

• Only network port QoS is supported.