With IPHost Network Monitor you can run simple snmp requests against a Nortel device in your network.
x25DteRgLinkToProtocolPort
x25 Dte Rg Link To Protocol Port
1.3.6.1.4.1.562.2.4.1.90.7.11.1.1
This attribute contains a protocol port component name. The attribute associates the application with a protocol port.
Back to Nortel-Magellan-Passport-X25DteMIB MIB page.
IPHost Network monitor allows you to monitor x25DteRgLinkToProtocolPort 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 modems right now.