Cabletron Systems 7C04-R, 7C03 manual LEM Rate, LEM Reject Rate, Viewing Fddi Port Graphs

FDDI Management

Estimate can range from 10-4to 10-15, but is always displayed as the absolute value of the exponent; for example, if the port’s LER Estimate is computed to be 10-5, the value displayed in the Port Status box will be 5, which represents an actual rate of 1,250 bit errors per second. The lower LER Estimate numbers represent the highest bit error rates.

LEM Rate

The LEM (Link Error Monitor) Rate displays the number of times each port’s Link Error Monitor has detected a link error, expressed as link errors per second. A link error occurs when a port’s line state goes from Idle to Unknown and remains there for at least 80 ns, or when the line state goes from Active to Unknown and remains there for at least 320 ns. A growing LEM Count usually indicates a physical problem with the connectors or the cable between a port and the node at the other end of its cable segment. If you can wiggle the cable and watch the LEM Count increase, you know you have a faulty cable or connector. Dirt or film on the connector cable ends can also add to the LEM Count.

LEM Reject Rate

The number of times the port’s link has exceeded the configured LER Cutoff level and been removed as faulty (disabled by station management), expressed as rejects per second. SMT automatically re-enables a port when the error rate falls below the cutoff value.

To exit the FDDI Port Meters window, click .

NOTE

See Alarm Configuration, page 4-9, for more information on the statistics described above and their associated alarms.

Viewing FDDI Port Graphs

If you are running SPMA in conjunction with HP Network Node Manager or IBM NetView, the Port Configuration window will include a Graph button; select this button to display FDDI variables for the selected port via the graphing application provided by your network management platform.

If you are running SPMA in conjunction with SunNet Manager or in a stand-alone mode, no graphing capabilities are available, and no graph-related options will appear.

4-8 Port Configuration