[...]... registration-state information P-CSCF subscription to Tobias’s registration-state information User-initiated re-registration (without re-authentication) Network-initiated re-authentication User-initiated de-registration Network-initiated de-registration Example early IMS security flow IMS session establishment call flow Routing an initial INVITE request and its responses Routing of subsequent requests and. .. Subscriber Server resolution with the Subscription Locator Function High-level IMS registration Example of implicit registration sets High-level IMS session establishment flow Relationship between user identities IP Multimedia Services Identity Module Sharing a single user identity between multiple devices A GPRS-specific mechanism for discovering the P-CSCF A generic mechanism for discovering the P-CSCF... Multimedia messaging The role of IMS in packet-switched networks IMS connectivity options when a user is roaming Overview of IMS security IMS charging overview IMS/ CS roaming alternatives IMS and layered architecture Access-independent IMS S-CSCF routing and basic IMS session setup Structure of HSS Relationship between different application server types Signalling conversion in the SGW IMS architecture... establishing a connection By dialing the peer, the network can establish an ad hoc connection between any two terminals over the IP network This critical IP connectivity capability is offered only in isolated and single-service provider environments in the Internet; The IMS: IP Multimedia Concepts and Services, Second Edition Miikka Poikselkä, Georg Mayer, Hisham Khartabil and Aki Niemi © 2006 John Wiley... definition for the IMS is: IMS is a global, access-independent and standard-based IP connectivity and service control architecture that enables various types of multimedia services to end-users using common Internet-based protocols True integration of voice and data services increases productivity and overall effectiveness, while the development of innovative applications integrating voice, data and multimedia. .. required by any communication architecture In this book we describe security threats and the models used to secure communications in IMS IMS security, along with concepts such as registration, session establishment, charging and service provisioning, are explained in Chapter 3 Since both wireless and wireline networks are involved in IMS architecture, IMS becomes an inexpensive medium for Fixed to Mobile... 8.1 List of figures Event- and session-based online charging example IMS charging correlation Distribution of charging information Structure of IMS user profile Media authorization in the S-CSCF Structure of initial filter criteria Structure of Service Point Trigger IMS CS interworking configuration when an IMS user calls a CS user IMS CS interworking configuration when a CS user calls an IMS user End-to-end... S-CSCF Authentication information flows during IMS registration SA establishment during initial registration Two sets of SAs during re-authentication Taking a new set of SAs into use and dropping an old set of SAs Request and response routing between UE and P-CSCF over UDP Request and response routing between UE and P-CSCF over TCP Sip-Sec-Agree during initial registration Tobias’s subscription to his... circuit-switched functionality in the packetswitched domain The IMS is a key technology for such network consolidation Introduction 1.2 5 Example of IMS services Switching on my Internet Protocol Multimedia Subsystem (IMS) enabled device, it will automatically register to the IMS network using information in the identity module (such as USIM) During registration both device and network are authenticated... Architecture: network entities and reference points including charging functions Architecture: interworking (CS, other IP networks, WLAN) and a few, new entities and reference points Architecture: voice call continuity between CS and PS domains, fixed broadband connection to the IMS Signalling: general routing principles, registration, session initiation, session modification, session teardown, network-initiated .