Understanding Session Border Controllers
Over the past 10 years the Session Initiation Protocol (SIP) has moved from the toy of researchers and academics to the de-facto standard for telephony and multimedia services in mobile and fixed networks. Probably one of the most emotionally fraught discussions in the context of SIP was whether Session Border Controllers (SBC) are good or evil. SIP was designed with the vision of revolutionizing the way communication services are developed, deployed and operated. Following the end-to-end spirit of the Internet SIP was supposed to turn down the walled gardens of PSTN networks and free communication services from the grip of large telecom operators.