Each vendor connection can be automatically monitored on two parameters - ACD (average call duration) and ASR (average success rate). You can choose to monitor one of them or both. When a measured parameter passes your defined threshold then the connection can either be demoted to lowest priority, blocked, or no action except an alert email will be sent to the switch administrator. Measuring of the quality is done using the "floating window" which consists of a configurable number of calls.
Connection Quality Recovery Algorithm
A bad quality connection is fully or partially disabled, so it is difficult to evaluate its current quality. To prevent indefinite blocking of a connection, the quality of a bad connections is periodically tested be sending a small percentage of calls to that connection. If the calls succeed, and the quality of that connection rises above the defined threshold then the "Bad Quality Action" will be reverted.
Quality Monitoring Tunable's
The Edit Vendor Connection form contains the following options that you can set manually.
- ACD Threshold - The Average Call Duration that is measured only for calls with non-zero duration, measured in seconds, When the ACD drops below this value then the connection is treated as bad, and the "Bad Quality Action" is executed.
- ASR Threshold - The Average Success Rate threshold expressed as a percentage which describes the correlation between Total count of calls and non-zero duration calls. When the ASR precentage drops below this value then the connection is treated as bad, and the "Bad Quality Action" is executed.
Statistics Window - The number of calls used to calculate the ACD and ASR metrics. ACD & ASR will be calculated on the last N calls made to the given connection. The Statistics window is shifted when the new call comes. Example: if the window is 5 calls, either ASR or ACD is calculated for those 5 calls. Once the 6th call comes, the ASR or ACD is recalculated for the calls from 2nd till 6th, the same thing happens when 7th call comes (from 3rd till 7th call are used to measure the new value)
Retry Interval - Number of seconds after which the switch will start sending a "Retry" calls to determine if the connection's health has improved from bad to good.
- Retry Batch - Number of calls to send as "tests" to test if the health of the connection has improved from bad to good
- Bad Quality Action - When the chosen metric drops below the defined threshold, you can have one of the following actions take place
Make Last In Routing - The Vendor connection will be dropped to lowest priority in the associated routing group(s). Retry calls will be sent after the 'Retry Interval' timer has elapsed, the connection will be temporary returned to its normal place in routing. If the Retry calls succeed, and the quality metric rises above the threshold, the connection priority will be returned to its previous position in routing on permanent basis, until the quality goes down again.
- Block - The Vendor connection will be blocked. Retry calls will be sent after the 'Retry Interval' timer has elapsed, the block will be removed temporary. If the Retry calls succeed, and the quality metric rises above the threshold, the block will be removed fully until the quality goes down again.
Notify Only - No action will be taken, but the root user of the switch will be notified via email that is configured in his preferences.
- Notify On Status Change - This causes a messages to be sent to the e-mail address of the root customer on each change of the status of a connection. The messages are sent only on real not temporary status changes.