With VPLS based aggregation service from A-PE, normal SRRP message exchange can take place between the active and standby BNGs. An active or standby decision and switch-over is based on the SRRP state. An SRRP instance is configured per group-interface corresponding to PW port. Fate-sharing groups (FSG) can be configured for a set of SRRP instances (for example, SRRP instances corresponding to PW ports sharing the same subnet). A standard oper-group grp-id should be configured with messaging SAPs for all PW ports that are in the same FSG, and monitor-oper-group grp-id should be configured under each SRRP instance in same FSG. Existing SRRP support defined in Triple-play services guide for ESM over regular group-interfaces and subscriber SAPs is applicable identically to ESM over PW ports and PW SAPs.
With ESM over PW, redundancy in the aggregation network based on MC-LAG between A-PE and dual BNGs is not supported.
