Patent ID: 8364827

Claim:
A communication system comprising: a session control server for controlling communication sessions between a plurality of terminals and an application server; the application server for performing third party call control (3PCC) and communicating with the session control server; a web server for communicating with the application server; and a network for coupling the session control server, the application server and the web server, wherein the application server periodically detects information of a communication session status between each of the plurality of terminals and the application server, detect termination or failure of any communication session between the plurality of terminals and the application server based on the detected information, and transmit status related information including information of any such detected termination or failure of any communication session to the web server, wherein the web server detects the communication session status between each of the plurality of terminals and the application server based on the received status related information, and, when the received status related information includes a detected termination or failure of any communication session that has not yet been terminated by the web server, transmit a request for terminating a 3PCC service related to the terminated or failed communication session to the application server, wherein the application server: refers to periods of detecting the information on the communication session status between each of the plurality of terminals and the application server in a case where a call control time period is controlled based on the status related information; determines a value smaller than a smallest period among the checked periods as the call control time period; and transmits the status related information including the determined call control time period to the web server, and wherein the web server further controls the call control time period based on the determined call control time period included in the received status related information.