This read-only enumeration reports the local maintenance state -- in service, out of service for maintenance, or out of service due to hardware -- of the IP connection between this gateway and its peer, as determined locally. Admins use it to isolate IP-side connectivity issues from telephone-line-side issues covered by linePortLocMState. For example, a port showing its telephone line inService but its IP connection ooSHardware points to a network-side problem between gateways rather than any issue with the local telephony interface.