Method and apparatus for initiating IMS based communications

摘要

A method of operating an Application Sever in order to initiate an IP Multimedia Subsystem communication for a user that is not registered a priori with the IP Multimedia Subsystem. The method comprises receiving a communication request from said user via an interface to an external network, or receiving an internally or externally generated stimulus requiring the establishment of an IP Multimedia Subsystem communication ,allocating a Serving Call/State Control Function to the user, and forwarding a Session Initiation Protocol request to the allocated Serving Call/State Control Function.