This is used in the Group ID field sent to the peer PW endpoint system within the maintenance protocol used for VC setup, and it is zero if not used. This lets an admin tag this pseudowire as belonging to a logical group, commonly so the far end can recognize and manage several related VCs together, such as all pseudowires terminating on the same access node, without needing per-VC configuration for grouped operations. For example, assigning the same cpwVcLocalGroupID to a batch of pseudowires all terminating on one particular customer-facing access device lets the remote PE recognize and potentially bulk-manage that whole group together, such as bringing them all down at once if that access device is being decommissioned.