Cabletron Systems CSX1200, CSX1000 manual Idle Condition Monitoring

CONFIGURING CALL CONTROL

Throughput Monitor

IDLE CONDITION MONITORING

The CyberSWITCH monitors for the idle condition when only one connection to another site remains. The system detects when there is no longer a need to maintain connectivity with the other site. An absolute idle condition is defined as a number of consecutive sample periods with zero bytes transferred.

Keep-alive type frames may sometimes continue to flow when there is no actual device data flowing. The system would not detect a completely idle condition, and might leave a connection in use when it may no longer carry useful traffic. Instead of monitoring for zero traffic, the idle condition can be set up to detect extremely low, but non-zero, bandwidth utilization. This can be done by not requiring all samples in the window to be zero, or by monitoring for a low percentage utilization level.

Background traffic is often transmitted continuously. It may be necessary to have a minimum dedicated connection to handle the constant traffic, then use switched connections for peak loads and backup.

THROUGHPUT MONITOR CONFIGURATION EXAMPLE

Sample rate 5

Window 3

Trigger 2

Utilization 50%

50%

Time 5		0 of 1
10		1 of 2
15	Sliding Window	1 of 3
20		1 of 3
25		1 of 3
30		2 of 3 Overload condition met
35		0 of 1

In the above example, the sample rate is 5 seconds, the number of samples to examine per sample rate (the window) is 3, the configured percentage to compare against (utilization) is 50 percent, the number of times the sample’s utilization percentage must be greater than the configured utilization percentage (the trigger) is 2 out of 3 samples. To make things simpler for this example, there is only one call up and we are only checking to add another call (overload).

After 5 seconds the sample is checked and the average utilization for the 5 seconds was 40 percent. This is less than the configured utilization percentage of 50%, so no action is taken. For the second sample rate period, the average throughput is 60%. This percentage is greater than the configured utilization percentage, so the trigger must also be checked. At this point, only 2 samples have been taken, and the configured window is for 3 samples. The overload condition needs to be met 2 times (the trigger of 2) out of 3 samples (the window of 3) before any action is taken. This condition has not been met.

Workgroup Remote Access Switch 317