You can enable the VPG to notify a PGC when it experiences processing overload that could prevent the timely execution of H.248 transactions. The PGC can then adjust the rate at which H.248 transactions are passed to the VPG.
The PGC activates the overload control feature by setting the overload control event. When overload control is active, incoming H.248 transactions are pushed into a work queue. The VPG sends an overload notification to the PGC when the content of the work queue reaches a configured limit, defined as a percentage of the maximum queue size (queue-limit-percentage). The VPG then sends an overload notification for each received ADD command in incoming H.248 transactions. The PGC should lower the rate used to admit calls to the VPG (the admitted rate). This lower rate is configured on the PGC. When transactions in the work queue occupy 100 percent of the work queue's maximum size, the VPG drops received transactions and sends error code 510 (Insufficient resources). When transactions in the work queue occupy less than the queue-limit-percentage, overload notifications are no longer sent.
You configure overload control by configuring the queue limit percentage.
Step-by-Step Procedure
To configure overload-control for voice calls:
- [edit services pgcp gateway vpg-1]
- user@host#edit overload-control
- [edit services pgcp gateway vpg-1 overload-control]
- user@host#set queue-limit-percentage 85
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Note: Only one work queue exists for the entire device. The queue limit percentage that you configure applies to the entire device, not just the VPG named in the hierarchy level you have chosen. If you enter multiple queue limit percentages for different VPGs, only the last entry is used. |