Patent ID: 8886730

Claim:
A method for changing a collaborative communications session, the method comprising: receiving, by an IP multimedia subsystem (IMS) server, a Session Initiation Protocol (SIP) INVITE message from a first device to request a change of a media portion of a collaborative communications session; sending, by the IMS server based on the received SIP INVITE message, a SIP NOTIFY or SIP INFO message requesting authorization for the change of the media portion of the collaborative communications session to an end device of the collaborative communications session, wherein the media portion is between the first device and a second device, which is not the end device, and at least another portion of the collaborative communications session is between the end device and the first device or the second device; determining whether a SIP REFER or SIP INFO message authorizing the change is received from the end device in response to the SIP NOTIFY or SIP INFO message sent; and changing the media portion of the collaborative communications session, in case it is determined that a SIP REFER or SIP INFO message authorizing the change is received from the end device in response to the SIP NOTIFY or SIP INFO message sent.