Design And Realization Of Softswitch Bulk Call Simulator

Softswitch which means separates the call control function from the media gatewayachieves to control the call by designing software. Compare to the traditional switcher,Softswitch can cut down the cost, support many new operation and be convenient toapplicate . But because of shortage of the time after its'generation, and also the Internet is a"best effort delivery"Network, the reliability of the Softswitch equipments is not as good asthe traditional switcher. So how to improve the reliability of the equipments is the key topopularize Softswitch. Stress test is a important process when checking up the reliability ofthe equipments. The bulk call simulator is the main implement when executing the stress test.It can simulate many phones, and sends calling requirements to the Softswitch equipmentsat the same time of alternate.The softswitch network is based on standard protocols, transferred by grouping anddrived by the operation. The network can support routing, accounting, network managementand authentication. The softswtich equipments exchange message with the media gateways,terminals and servers. This architecture of the softswitch network includes 5 layers: theaccess layer, the transaction layer, the operation control layer, the operation managementlayer and the network management layer. In H.323 network architecture, there are 3 layers:gateway layer, gatekeeper layer and backend server layer.When the bulk call simulator running on WINOWS and uses TCP protocol to establishconnect, how to choose the task architecture is a very important problem. The technology ofthread pool can enhance the capability of the simulator and reduce the congestion of thenetwork. To predigest the call flow is also profit to enhance the capability of the simulator.Also how to import the abnormal call flows, pay attention to the transplant of the simulatorand establish the statistics table is very import.Based on the Object Oriented thesis, each terminal could be seen as a object. Theyexchange the messages with the softswitch equipments. The architecture of the simulator isdivided into 3 layers: the user layer, the flow control layer and the protocol stack layer. Theuser layer is used to input and show the configuration. The flow control layer is used tocontrol the register and call flow. The protocol stack layer is used to coding and decodingthe protocol messages.At last, the article tests the gatekeeper with the simulator and the test results issatisfactory .