Subject: [rtcweb] Regarding cloning of PeerConnections when multiple answers are received

From: Magnus Westerlund <[email-masked]>
Date: Thu, 29 Mar 2012 09:57:09 +0200

WG, as individual

As just discussed in the meeting Justin and Hadriel didn't think that
you could clone PeerConnections properly. I do believe it is possible.

If the API provides a method where you can clone a current
peerConnection you can actually share the transport layer information at
one end-point for multiple peer connections assuming that the other
end-points transport addresses are different between the different
peerConnections being cloned.

This works as the complete ICE username is the concatenation of both
sides, as long as an secondary answer contains a different username and
has candidates with different transport addresses (address+port). Then
end-point A receiving the second answer can have the ICE stack accept
both usernames and if connectivity checks works then you create
different 5-tuple filter to divide any media streams to the right peer
connections media handler.

When you clone a PC then must allocate the media decoding resources for
each cloning. And that is something the cloning function may block on.

Cheers

Magnus Westerlund

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