With IPHost Network Monitor you can run simple snmp requests against a Nortel device in your network.
vrNsDroppedStatsNoMem
Virtual Router Ns Dropped Stats No Memory
This counts the total number of packets that were actually dropped due to an inability to allocate memory to hold statistics for the packet. Such a packet must have had a NetSentry statistics gathering action applied to it, in order for the attempt to gather statistics to be made, and the dropConditions attribute must include the statsNoMem value.
Back to Nortel-Magellan-Passport-NetSentryMIB MIB page.
IPHost Network monitor allows you to monitor vrNsDroppedStatsNoMem 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 speech servers right now.