SBC stands for Session Border Controller.
An SBC is a network device that sits at the border between different networks, controlling and securing real-time communication sessions. In the WebRTC context, SBCs serve as bridges between WebRTC and traditional VoIP / PSTN networks.
SBC functions in WebRTC
When bridging WebRTC to enterprise or telecom infrastructure, an SBC handles:
- Protocol translation: Converting between WebRTC's signaling and SIP
- Media transcoding: Converting between Opus/VP8 and G.711/H.264
- Security: SRTP-to-RTP conversion, DTLS termination
- NAT traversal: Acting as a media anchor point
- Quality of Service: Bandwidth management and call admission control
Major SBC vendors (AudioCodes, Oracle, Ribbon) have all added WebRTC gateway capabilities to their products.
