With IPHost Network Monitor you can run simple snmp requests against a Nortel device in your network.
x25DteLapbStatusTable
x25 Dte Lapb Status Table
1.3.6.1.4.1.562.2.4.1.90.5.12
This group contains the status for the LAPB interface.
Back to Nortel-Magellan-Passport-X25DteMIB MIB page.
IPHost Network monitor allows you to monitor x25DteLapbStatusTable 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.