With IPHost Network Monitor you can run simple snmp requests against a Nortel device in your network.
x25DteLapbFramerOctetFromIf
x25 Dte Lapb Framer Octet From If
1.3.6.1.4.1.562.2.4.1.90.5.2.13.1.3
The number of bytes received from the link interface by Framer.
Back to Nortel-Magellan-Passport-X25DteMIB MIB page.
IPHost Network monitor allows you to monitor x25DteLapbFramerOctetFromIf 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 multiplexers right now.