With IPHost Network Monitor you can run simple snmp requests against a Nortel device in your network.
dpnGateDiscardTrunkPktFromIf
dpn Gate Discard Trunk Packet From If
This attribute counts the number of internal trunk protocol packets received from the remote module that have been discarded. This counter wraps around to zero when the maximum value is reached. The two main reasons that cause this counter to increment is if the DpnGateway is unsynchronized with DPN-100 and if the remote protocol is not the same version as the local protocol.
Back to Nortel-Magellan-Passport-DpnTrunksMIB MIB page.
IPHost Network monitor allows you to monitor dpnGateDiscardTrunkPktFromIf 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.