With IPHost Network Monitor you can run simple snmp requests against a Nortel device in your network.
frMuxFramerIndex
Frame Relay Mux Framer Index
1.3.6.1.4.1.1570.1.2.1.1.10
This variable represents the index for the frMuxFramer tables.
Back to Nortel-Magellan-Passport-FrameRelayMuxMIB MIB page.
IPHost Network monitor allows you to monitor frMuxFramerIndex 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.