Cabletron Systems 7C04-R, 7C03 manual Port Type, LER Estimate

Using the 7C0x SmartSwitch Hub View

desirable. You can view and configure the SMT Connection Policy by selecting the SMT Connection Policy option on the Module —>FDDI Utilities menu; see Chapter 4, FDDI Management, for more information.

•DIS (disabled) — the port has been disabled by management; note that this status does not indicate whether or not there is a physical link connected to the port.

Port Type

Displays the media type of each A and B port:

•MMF (multi-mode fiber)

•SMF (single-mode fiber)

•SON (SONET)

•LCF (low-cost fiber)

•TP (twisted pair)

LER Estimate

The Link Error Rate (LER) Estimate port display form displays a cumulative long-term average of the bit error rate, which represents the quality of the physical link. It is computed when the port is connected and every 10 seconds thereafter. The value of the LER 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, as summarized in the figure below:

.000000125

.00000125

.0000125

.000125

.00125

Bit Errors

.0125

per

.125

Second

1.25

12.5

125

1250

12500

4 5 6 7 8 9 10 11 12 13 14 15

Reported LER Estimate

Figure 2-7. LER Estimate Values

You can configure alarm thresholds for the LER Estimate; see Chapter 4, FDDI

TIP Management, for more information.

Monitoring Hub Performance 2-9