With IPHost Network Monitor you can run simple snmp requests against a Nortel device in your network.
dpnGateDiscardUnforward
dpn Gate Discard Unforward
This attribute counts the number of packets received from the remote module that have been discarded. This counter wraps around to zero when the maximum value is reached. Two main reasons that cause this counter to increment are: the remote protocol is not compatible to the local protocol stack or, the packet cannot be forwarded due to either a recent loss of connectivity or due to congestion.
Back to Nortel-Magellan-Passport-DpnTrunksMIB MIB page.
IPHost Network monitor allows you to monitor dpnGateDiscardUnforward 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 modems right now.