With IPHost Network Monitor you can run simple snmp requests against a Nortel device in your network.
appnDlciVcPktRetryTimeouts
appn Dlci Vc Packet Retry Timeouts
This attribute displays the number of packets which have retransmission time-outs. When this count is excessive, the network is very congested and packets have been discarded in the subnet.
Back to Nortel-Magellan-Passport-AppnMIB MIB page.
IPHost Network monitor allows you to monitor appnDlciVcPktRetryTimeouts 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.