Method and apparatus for ascertaining the capacity of a network switch
View Patent ↗Performance parameters of a switch may be ascertained by observing its behavior during a brief interval of high call volume. This may be achieved by accumulating call messages on a queue before allowing them to be processed together as a group. Without increasing the rate of incident calls, an accumulation of messages is accomplished by altering the amount of time that elapses between transferring the accumulation to a processing queue. In one implementation, test calls are accumulated in call input queue. Ordinarily, these calls are transferred to a second queue for processing every few milliseconds (the transfer period). By increasing the transfer period, an increased number of calls are stored in the call input queue before being transferred to the second queue. This allows a larger number of calls to be processed by the telephone switch in a given cycle and, hence, allows the switch's operation under increased call volumes to be observed.
1. A method for testing the performance of a network switch, comprising:
inputting first calls to a first queue;
transferring the first calls after a first transfer period to second queue for processing by a network switch processor; and
generating a second transfer period longer than the first transfer period.
2. The method of claim 1 , wherein the first calls are test calls, wherein inputting the first calls occurs at a test call transfer rate.
3. The method of claim 2 , wherein the first calls comprise origination messages and progress messages.
4. The method of claim 1 , further comprising processing the first calls from the second queue during a first processing period, the first processing period being independent of the first transfer period and independent of the second transfer period.
5. The method of claim 4 , further comprising inputting second calls to the call input queue during the second transfer period, and transferring the second calls after the second transfer period to the second queue for processing by the network switch processor.
6. The method of claim 5 , further comprising processing the second calls during a second processing period, said second processing period being approximately equal to the first processing period.
7. The method of claim 6 , wherein the second transfer period is much longer than the first transfer period.
8. The method of claim 6 , wherein the first calls are test calls, the second calls are test calls, wherein inputting the first calls occurs at a test call transfer rate, and wherein inputting the second calls occurs at the test call transfer rate.
9. The method of claim 8 , wherein a larger number of second calls accumulates on the first queue during the second transfer period than accumulate on the first queue during the first transfer period.
10. The method of claim 1 , wherein the first queue is a call input queue and the second queue is an Origination/Progress (OP) queue.
11. The method of claim 1 , wherein testing the performance of the network switch comprises testing at least one network switch performance parameter, and wherein the network switch performance parameter is a capacity of the switch.
12. A telephone switch, comprising
a call input queue configured to receive call setup information;
an Origination and Progress (OP) queue configured to receive call setup information transferred from the call input queue and to store the call setup information; and
at least one call processor configured to process the call setup information from the OP queue;
wherein the call setup information is configured under normal operating conditions to be transferred from the call input queue to the OP queue periodically approximately every base transfer period; and
wherein the call setup information is configured under test operating conditions to be transferred from the call input queue to the OP queue periodically approximately every transfer period, said transfer period being longer than said base transfer period.
13. The telephone switch of claim 12 , further comprising transfer rate control software configured to adjust the transfer period.
14. The telephone switch of claim 12 , wherein the transfer period is at least twice as long as the base transfer period.
15. The telephone switch of claim 12 , wherein the processor is configured to process call setup information within a processing period.
16. The telephone switch of claim 15 , wherein the processing period under normal operating conditions is the same as the processing period under test operating conditions.
17. The telephone switch of claim 12 , wherein the transfer period is approximately a multiple of the base transfer period.
18. The telephone switch of claim 12 , wherein the call setup information comprises call origination messages and call progress messages.
19. A test call generator, comprising:
means for generating test call information;
means for outputting the test call information from the test call database to a telephone switch at a test call rate; and
a transfer rate control module configured to interact with the telephone switch to control how the telephone switch handles the test calls.
20. The test call generator of claim 19 , wherein the transfer rate control module is configured to simulate on the telephone switch a switch call rate larger than the test call rate.
21. The test call generator of claim 19 , wherein the transfer rate control module is configured to control a transfer period on the telephone switch between a call input queue on the telephone switch and an Origination and Progress (OP) queue on the telephone switch.