With IPHost Network Monitor you can run simple snmp requests against a Nortel device in your network.
x25DteRgLtPeerTable
x25 Dte Rg Lt Peer Table
1.3.6.1.4.1.562.2.4.1.90.7.211
This attribute gives a list of links to Peer components. The set of all Peer and PermLcn components which link to a given RemoteGroup determine the subset of remote hosts which are accessible to a particular Protocol Port (and ultimately a Virtual Router).
Back to Nortel-Magellan-Passport-X25DteMIB MIB page.
IPHost Network monitor allows you to monitor x25DteRgLtPeerTable 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.