Re: [rtcweb] Why is required to have local streams before running ICE gathering? (another SDP limitation?)

Iñaki Baz Castillo <> Fri, 14 June 2013 11:54 UTC

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Date: Fri, 14 Jun 2013 13:53:56 +0200
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To: Eric Rescorla <>
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Subject: Re: [rtcweb] Why is required to have local streams before running ICE gathering? (another SDP limitation?)
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2013/6/13 Eric Rescorla <>om>:
>> 1. There is agreement that there should be a mechanism to pre-specify
>> the size of a candidate pool to gather, though I just glanced in the spec
>> and I didn't see it. (May have missed it though).
> I see that there still is some (not quite up to date) text here:
> Create an ICE Agent as defined in [ICE] and let connection's
> RTCPeerConnection ICE Agent be that ICE Agent and provide it the STUN and
> TURN servers from the configuration array. The ICE Agent will proceed with
> gathering as soon as the IceTransports constraint is not set to "none". At
> this point the ICE Agent does not know how many ICE components it needs (and
> hence the number of candidates to gather), but it can make a reasonable
> assumption such as 2. As the RTCPeerConnection object gets more information,
> the ICE Agent can adjust the number of components.

Hi Eric, thanks a lot for the information you provide.

Is it feasible with the current API to ask for N ICE candidates prior
to having the local SDP set as local descriptor in the PeerConnection?

Iñaki Baz Castillo