Search code examples
webrtcturn

Will WebRTC clients work with TURN servers which support only Channels and Not Data/Send mechanisms?

I was reading TURN server RFCs. All related RFCs ( 5766 and the more recent 8656) support Channel mechanism to avoid the 36 bytes overheads of STUN headers (Section 2.5 of RFC 5766) required for the send/data approach:

For some applications (e.g., Voice over IP), the 36 bytes of overhead
that a Send indication or Data indication adds to the application
data can substantially increase the bandwidth required between the
client and the server.  To remedy this, TURN offers a second way for
the client and server to associate data with a specific peer.

For WebRTC, clearly there is no point in using the send/data mechanism. How do browsers choose between the two mechanisms for relaying? Is send/data a fallback? Will support for Channels alone in a TURN server be sufficient for WebRTC use-case?

Solution

  • They will usually do SendIndications while waiting for the Channel to be created.

    SendIndications also are important if you get something on the relay before the Channel is created. Some clients only create the Channel when they send and not right when the permission is created.