This is the local LSR identifier component of the composite index for the inbound MPLS-TE tunnel serving this pseudowire, used to correctly join against the corresponding row in the MPLS Tunnel MIB rather than being a value monitored on its own. It's part of the lookup key a management application needs to definitively identify which local router endpoint the inbound TE tunnel terminates on. This field being populated at all (nonzero) is itself informative, confirming the pseudowire's inbound direction really is riding a TE tunnel rather than a bare VC-only path.