With IPHost Network Monitor you can run simple snmp requests against a Nortel device in your network.
rtgDpnLgFarEndRid
rtg Dpn Lg Far End Rid
This attribute indicates the far end neighbor RID. If the neighbor is an AM then the RID is that of the Passport node.
Back to Nortel-Magellan-Passport-DpnRoutingMIB MIB page.
IPHost Network monitor allows you to monitor rtgDpnLgFarEndRid on Allied Telesis device via the SNMP protocol. Download IPHost Network Monitor (500 monitors for 30 days, 50 monitors free forever) to start monitoring Nortel switches right now.