This value, carried in an L2VPN OAM trap, reports whether the affected pseudowire is the primary(1) or second (backup, 2) pseudowire in a redundant pair, or zero if not applicable. An admin uses this to judge the severity of a reported fault: a failure on the primary(1) pseudowire likely means a failover to backup is needed or has occurred, while a fault on the second(2) pseudowire is less urgent since the primary should still be carrying traffic. Seeing primary(1) in a trap means the admin should confirm whether service actually failed over to the backup pseudowire.