Delivering deep insight into the role of IMS in fixed line and mobile networks, this guide fosters a clear understanding of the next generation of converged communication. It discusses the sources of standards and their particular areas of activities. Most of the text centers on important aspects of IMS that go beyond session control and multimedia handling to include ID management, service profiles, event triggering, flow- and event-based charging mechanisms, and service-based quality of service. The author also examines network admission, security, border control, and legacy services, enabling a thorough appreciation of new network requirements.