With IPHost Network Monitor you can run simple snmp requests against a Nortel device in your network.
x25DtePeerOutWindowSize
x25 Dte Peer Out Window Size
1.3.6.1.4.1.562.2.4.1.90.2.12.1.4
This attribute specifies the default transmit window size. A window size of 0 indicates the outWindowSize setting for the X.25 interface is used during call setup to the Peer identified by this component. A window size greater than 7 is only valid when the packetSequencing attribute of the X25Dte component is set to modulo128.
Back to Nortel-Magellan-Passport-X25DteMIB MIB page.
IPHost Network monitor allows you to monitor x25DtePeerOutWindowSize 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.