Quality of service for SIP sessions in 3GPP-based networks

This letter addresses how quality of service (QoS) for Session Initiation Protocol (SIP)-based multimedia sessions can be realized within the 3rd Generation Partnership Project (3GPP) architecture. It discusses a scenario for voice over IP (VoIP) to illustrate how relevant QoS mechanisms and signaling protocols such as SIP, Media Gateway Control Protocol (H.248/Megaco), and the Common Open Policy Service (COPS) interact. Related aspects of the Universal Mobile Telecommunications System (UNITS) access network and the IP Multimedia Subsystem (IMS) are explained. (C) 2004 Lucent Technologies Inc.