Cabletron Systems 7C03, 7C04-R manual Viewing the Fddi Port Chart, LEM Count, LEM Reject Count

FDDI Management

Viewing the FDDI Port Chart

To view the FDDI Port Chart window, highlight an entry in the scroll list and click

. The FDDI Port Chart window, Figure 4-3, will appear.

Figure 4-3. FDDI Port Chart Window

The FDDI Port Chart window displays the following information about the selected port or ports, in both numeric and graphical format:

LEM Count

The LEM (Link Error Monitor) Count displays the number of times each port’s Link Error Monitor has detected a link error. 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 Count

The number of times the port’s link has exceeded the configured LER Cutoff level and been removed as faulty (disabled by station management). SMT automatically re-enables a port when the error rate falls below the cutoff value. See Alarm Configuration, page 4-9, for more information on setting the LER Cutoff threshold.

4-6 Port Configuration