This reports which port, if any, terminates this virtual sub-ring onto its major ring: none, or specifically the west or east port. This value only has real meaning when the ring type is subRing; the specific termination port matters because sub-ring traffic protection is tied to that interconnection node and port, so a technician tracing why a sub-ring lost connectivity to the backbone needs to know exactly which port on this node forms that junction. For example, a value of westPortTerminate(2) tells an admin that this device's west port is the physical interconnection point where this sub-ring attaches to its parent major ring.