US Patent 11716363 Messaging resource function

A method of exchanging content between a User Equipment, UE, and an Application Server, AS, of an IP Multimedia Subsystem, IMS, or between the UE and a peer UE. The method comprises establishing a Session Initiation Protocol, SIP, session between said messaging resource function and the AS; establishing a Message Session Relay Protocol, MSRP, session between the UE and a messaging resource function of the IMS; and exchanging content between the first mentioned UE and the messaging resource function in messages sent over the established MSRP session.