Configuring Sonet Clocking; Configuring The Signal Fail Threshold - Extreme Networks PoS Installation And User Manual

Configuring the PoS Module

Configuring SONET Clocking

You can configure each port on the PoS module to use either line clocking, where the
clock source is recovered from the received bit stream, or internal clocking, where the
clock source is based on an internal clock. The default is internal.
To configure the clocking source for the specified SONET port, use the following
command:
config sonet clocking [line | internal] ports <portlist>
The following command example selects line clocking for port 1 of the PoS module
installed in slot 8 of the BlackDiamond switch.
config sonet clocking line ports 8:1

Configuring the Signal Fail Threshold

A Signal Failure (SF) event is generated if the bit error rate (BER) for the SONET line
exceeds the configured threshold. An SF event brings the port down. If Automatic
Protection Switching (APS) is enabled on the port, an SF event initiates a line switch.
To configure the Signal Fail threshold for the specified SONET port, use the following
command:
config sonet threshold signal fail <error_rate> ports <portlist>
The parameter is an integer in the range from 3 to 5, where the SF BER is
error_rate
-error_rate
10 . The default value of the
-5
bit error rate of 10 , or 1 per hundred thousand.
The following command example sets the Signal Fail threshold value to 3 for port 1 of
the PoS module installed in slot 8 of the BlackDiamond switch.
config sonet threshold signal fail 3 ports 8:1
You might set the signal fail threshold lower than the default value of 5 if your
particular application has a very low tolerance for errors. In general, you should
not change the default setting unless you are an expert and have a specific
reason for the change.
3-14
parameter is 5, which equates to an SF
error_rate
Packet Over SONET Module Installation and User Guide