Session borders controllers: next step in full deployment of voice over IP services

Abstract

Session Border Controllers (SBCs) became an important element in implementation of modern Voice over IP (VoIP) services, as service providers look to protect the integrity of their networks and business models while offering new services to the customers. Meanwhile, the status of near-ubiquitous use of Network Address Translators (NATs) across the Internet and the great diversity of their behavior raise a serious obstacle in the VoIP’s deployment. The paper analyses one of the most popular and widely adopted VoIP signaling protocol, Session Initiation Protocol (SIP), the issues of NAT traversal, and the role of SBCs in solving it and extending the VoIP capabilities.