With IPHost Network Monitor you can run simple snmp requests against a Nortel device in your network.
frMuxDlciABitStatusFromIf
Frame Relay Mux Dlci A Bit Status From If
1.3.6.1.4.1.1570.1.4.12.1.1
This attribute is the most recent A-Bit status received from the interface.
Back to Nortel-Magellan-Passport-FrameRelayMuxMIB MIB page.
IPHost Network monitor allows you to monitor frMuxDlciABitStatusFromIf 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.