With IPHost Network Monitor you can run simple snmp requests against a Nortel device in your network.
x25DteLapbRemoteBusy
x25 Dte Lapb Remote Busy
1.3.6.1.4.1.562.2.4.1.90.5.13.1.2
This attribute counts the number of times transmission of an I-frame was un-successful due to a perceived remote busy condition (window closed or remote busy).
Back to Nortel-Magellan-Passport-X25DteMIB MIB page.
IPHost Network monitor allows you to monitor x25DteLapbRemoteBusy 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 switches right now.