CODEWITHSUNDEEP
google-chromefirefoxwebrtc
N. McA.
N. McA.

Reputation: 4946

Is the ID of a RTCDataChannels global or specific to a RTCPeerConnection?

Is the ID of a RTCDataChannels global or specific to a RTCPeerConnection?

Eg, if I have a p1 and p2, two peer connections, can I create a data channel on each that has id 7, or will they collide?

I have tried this on Chrome with the webrtc shim, an it appears that ids are specific to a RTCPeerConnection. I can't, however, find where in the spec this is specified...

Does anyone know?

Upvotes: 1

Views: 370

Answers (1)

jib
jib

Reputation: 42450

The id comes from the transport layer of the connection. It's a number between 0 and 65534, and is unique only to that connection (the pair of RTCPeerConnections communicating).

See "Stream Identifier" in section 3 of https://www.ietf.org/id/draft-ietf-rtcweb-data-protocol-09.txt

There's a workaround however. You're allowed to specify your own id with createDataChannel:

let channel = createDataChannel("foo", { id: 3 });

So you could use localStorage to keep them unique for your app (up to a point of course) if that's what you want.

In other words, you don't have to worry about collisions between RTCPeerConnections, unless they're the two ends of the same connection.

Upvotes: 1

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