| 摘要 |
During call establishment through at least one call server (20), where at least one calling or called party (A,B) owns at least one service (22,24) which is to be invoked each time that a call involving that party is to be established, the following steps are carried out : (a) any party who owns at least one service which is intended to monitor or control any call involving that party is required to register that service with a call server ; (b) establishing a list of controlling services, and inserting services into the list each time a specific call involving a specific party is being established, by first inserting into the list any service owned by the calling party, and then inserting into the same list any service owned by a called party; (c) requiring the call server which is handling the call to visit each service in the list of controlling services in the order starting from the lastmost service inserted in the list; and if the then visited service is not invoked, then the call server will visit the next lastmost service. If a service is invoked, then each previously inserted service in the list is ignored, unless the invoked service permits otherwise. |
