What is a Session Border Controller (SBC)?
A Session Border Controller (SBC) is a special-purpose device that protects and regulates IP communications flows. As the name implies, session border controllers are deployed at network borders to control IP communications sessions. Originally conceived to protect and control VoIP networks, SBCs are now used to regulate all forms of real-time communications including VoIP, IP video, text chat and collaboration sessions.
SBCs manipulate IP communications signaling and media streams, providing a variety of functions including:
- Security - SBCs safeguard against toll fraud and service theft and provide media and signaling encryption to ensure confidentiality and protect against impersonation.
- Multivendor interoperability - SBCs normalize SIP (Session Initiation Protocol) signaling stream headers and messages to mitigate multivendor incompatibilities.
- Protocol interworking - SBCs enable interworking between diverse protocols.
- Quality of service (QoS) - SBCs enforce call admission control (CAC) policies for service quality assurance.
- Session routing - SBCs route sessions across network interfaces to ensure high availability.