Page History

...

            The two WebRTC Agents now know enough details to attempt to connect to each other. WebRTC then uses another established technology called ICE.             ICE (Interactive Connectivity Establishment) is a protocol that pre-dates WebRTC. ICE allows the establishment of a connection between two Agents. These Agents could be on the same network, or                or on the other side of the world. ICE is the solution to establishing a direct connection without a central server.             The real magic here is ‘NAT Traversal’ and STUN/TURN Servers. These two concepts are all you need to communicate with an ICE Agent in another subnet. Once ICE successfully connects, WebRTC                WebRTC then moves on to establishing an encrypted transport. This transport is used for audio, video, and data.

...

           Now that we have bi-directional communication (via ICE) we need to establish secure communication. This is done through two protocols that pre-date WebRTC. The first protocol is DTLS (Datagram             Transport Datagram Transport Layer Security) which is just TLS over UDP. TLS is the cryptographic protocol used to secure communication over HTTPS. The second protocol is SRTP (Secure Real-time Transport                             Protocol).           FirstTransport Protocol). First, WebRTC connects by doing a DTLS handshake over the connection established by ICE. Unlike HTTPS, WebRTC doesn’t use a central authority for certificates.            WebRTC WebRTC then uses a different protocol for audio/video transmission called RTP. We secure our RTP packets using SRTP. We initialize our SRTP session by extracting the keys from the negotiated                     DTLS negotiated DTLS session.

• Communicating:

           We now have two WebRTC Agents with secure bi-directional communication. we use two pre-existing protocols: RTP (Real-time Transport Protocol), and SCTP (Stream Control Transmission                             ProtocolTransmission Protocol).  Use RTP to exchange media encrypted with SRTP, and use SCTP to send and receive DataChannel messages encrypted with DTLS.

...