A method of providing a selected Quality of Service for calls traversing an IP Multimedia Subsystem. A control-plane Home IP Multimedia Gateway is interposed between the IP Multimedia Subsystem and at least one non-SIP client, such that SIP signaling may be exchanged with a remote client on behalf of the at least one non-SIP client. The Home IP Multimedia Gateway identifies a Quality of Service type by reference to the SDP part of one or more SIP messages, and the call leg between the non-SIP client and a residential gateway is configured accordingly.