With IPHost Network Monitor you can run simple snmp requests against a Nortel device in your network.
vctVcMaxSubnetPktSize
VC Tester Vc Max Subnet Packet Size
1.3.6.1.4.1.562.2.4.1.5130.4.10.1.27
This attribute displays the maximum packet size allowed on Vc.
Back to Nortel-Magellan-Passport-VcTesterMIB MIB page.
IPHost Network monitor allows you to monitor vctVcMaxSubnetPktSize 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.