With IPHost Network Monitor you can run simple snmp requests against a Nortel device in your network.
vrPpFddiETBInDiscards
Virtual Router Passport Fddi ETB In Discards
This attribute is indicative of the number of frames that were received by this bridge port and were discarded by the forwarding process. This includes frames that could have been discarded due to filtering. A repidly increasing value for this attribute could indicate a shrtage of resource in terms of memory needed to process the incoming frames. More memory can be provisioned through the VirtualRouter's memory manager.
Back to Nortel-Magellan-Passport-BridgeMIB MIB page.
IPHost Network monitor allows you to monitor vrPpFddiETBInDiscards 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.