With IPHost Network Monitor you can run simple snmp requests against a Nortel device in your network.
pppFramerLargeFrmErrors
ppp Framer Large Frm Errors
1.3.6.1.2.1.10.23.5.13.1.9
This attribute counts the total number of frames received which were too large. The frame execeeded the maximumFrameLengthLimit provisioned attribute or it contained more than the 255 block hardware limit.
Back to Nortel-Magellan-Passport-PppMIB MIB page.
IPHost Network monitor allows you to monitor pppFramerLargeFrmErrors 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 multiplexers right now.