With IPHost Network Monitor you can run simple snmp requests against a Nortel device in your network.
vrPpTbseMaxInfo
Virtual Router Passport Tbse Max Info
This attribute specifies the maximum size of the information field in a TB frame. This excludes the header field.
Back to Nortel-Magellan-Passport-BridgeMIB MIB page.
IPHost Network monitor allows you to monitor vrPpTbseMaxInfo 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.