With IPHost Network Monitor you can run simple snmp requests against a Nortel device in your network.
shelfBusTestPingTestsTable
shelf Bus Test Ping Tests Table
1.3.6.1.4.1.43.1.12.3.1.1.2.3.2.251
This attribute records the number of ping tests performed, indexed by the slot numbers of the cards containing the bus taps involved. Each test attempts to transmit a single low-priority frame from the transmitting bus tap to the receiving bus tap.
Back to Nortel-Magellan-Passport-ShelfMIB MIB page.
IPHost Network monitor allows you to monitor shelfBusTestPingTestsTable 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.