IP Multimedia System Security
The IP multimedia subsystem (IMS) is a core network subsystem within UMTS. It is based on the use of the Session Initiation Protocol (SIP)26 to initiate, terminate and modify multimedia sessions such as voice calls, video conferences, streaming and chat. SIP is specified by the Internet Engineering Task Force (IETF)27. IMS also uses the IETF Session Description Protocol (SDP)28 to specify the session parameters and to negotiate the codecs to be used. SIP runs on top of different IP transport protocols such as the User Datagram Protocol (UDP) and the Transmission Control Protocol (TCP).
A 3G IMS subscriber has one IP multimedia private identity (IMPI) and at least one IP multimedia public identity (IMPU). To participate in multimedia sessions, an IMS subscriber must register at least one IMPU with the IMS. The private identity is used only for authentication purposes.
Read more about this topic: UMTS Security
Famous quotes containing the words system and/or security:
“There are obvious places in which government can narrow the chasm between haves and have-nots. One is the public schools, which have been seen as the great leveler, the authentic melting pot. That, today, is nonsense. In his scathing study of the nation’s public school system entitled “Savage Inequalities,” Jonathan Kozol made manifest the truth: that we have a system that discriminates against the poor in everything from class size to curriculum.”
—Anna Quindlen (b. 1952)
“...I lost myself in my work and never felt that marriage would give me the security I wanted. I thought that through the trade union movement we working women could get better conditions and security of mind.”
—Mary Anderson (1872–1964)