With IPHost Network Monitor you can run simple snmp requests against a Nortel device in your network.
vrMmNetSentryHeapSpaceAllocated
Virtual Router Mm Net Sentry Heap Space Allocated
1.3.6.1.4.1.562.2.4.1.100.2.11.1.8
The percentage of this Virtual Router's dynamic memory which is currently allocated to this Virtual Router's NetSentry.
Back to Nortel-Magellan-Passport-VirtualRouterMIB MIB page.
IPHost Network monitor allows you to monitor vrMmNetSentryHeapSpaceAllocated 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 switches right now.