With IPHost Network Monitor you can run simple snmp requests against a Nortel device in your network.
vrPpSrclSteRdLimit
Virtual Router Passport Srcl Ste Rd Limit
This attribute specifies the number of route descriptors allowed in a Spanning Tree Explore frame received on a SourceRouteBridgePort or SourceRouteTransparentBridgePort. Current source route bridge implementations limit the steRdLimit to a value in the range 0 to 8.
Back to Nortel-Magellan-Passport-BridgeMIB MIB page.
IPHost Network monitor allows you to monitor vrPpSrclSteRdLimit 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.