With IPHost Network Monitor you can run simple snmp requests against a Nortel device in your network.
traceSessionX25VcDuplicatesFromSubnet
trace Session X25 Vc Duplicates From Subnet
1.3.6.1.4.1.562.2.4.1.106.3.2.2.12.1.3
This attribute counts the number of subnet packets discarded due to duplication. It is used to detect software error fault or duplication caused by retransmitting.
Back to Nortel-Magellan-Passport-X25TraceRcvrMIB MIB page.
IPHost Network monitor allows you to monitor traceSessionX25VcDuplicatesFromSubnet 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.