With IPHost Network Monitor you can run simple snmp requests against a Nortel device in your network.
aal1CesIdlePattern
aal1 Ces Idle Pattern
This attribute specifies the pattern which the bytes of an ATM payload, up to the partialFill level, must match in order for the cell to be classified as idle. Payload bytes beyond the partialFill level are not checked. The suppression of idle cells is controlled by the attribute idleSuppression. If idleSuppression is on, at least 75% of cells are suppressed under idle conditions.
Back to Nortel-Magellan-Passport-CircuitEmulationServiceMIB MIB page.
IPHost Network monitor allows you to monitor aal1CesIdlePattern 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.