Patent ID: 7715370
Filing Date: 2010-05-11
Classification: H04L

Abstract:
1. A method of subscribing a user to a service offered by a first application server of an Internet Protocol Multimedia Subsystem, the method comprising: receiving from the user in a Call Session Control Function unit a request for the service; evaluating in the Call Session Control Function unit the request based on filter criteria associated with the user, for deciding whether or not the user is subscribed to the service; determining whether the filter criteria associates the service with any application server offering the service; forwarding the request, when the determining has determined that the filter criteria associating the service with any application server offering the service is absent, from the Call Session Control Function unit to a second application server configured to handle user subscriptions for the service; and transmitting a message from the second application server to the user, the message including means for enabling the user to subscribe to the service offered by the first application server, wherein, in response to subscription data received from the user, a subscription service unit modifies, in a home subscriber server, the filter criteria associated with the user such that the service is associated with the first application server.