METHOD AND APPARATUSES FOR ESTABLISHING A SECURE CHANNEL BETWEEN A USER TERMINAL AND A SIP SERVER

摘要

A method of establishing a secure communication channel between a user terminal (2) and a SIP server (14) for the purpose of controlling a service such as an IPTV service. The method comprises sending from the user terminal (2) to the SIP server (14) a session initiation request, via an IP Multimedia Subsystem network, where the IP Multimedia Subsystem network incorporates into the request a P-Asserted-Identity. At the SIP server (14), access to the service is authorised on the basis of said P-Asserted-Identity and, upon successful authorisation, a security token is sent to the user terminal (2), via the IP Multimedia Subsystem network. The SIP server (14) and the user terminal (2) use said security token to establish a secure communication channel between each other.