Re: [rtcweb] Proposal to break the ICE impasse

Adam Roach <adam@nostrum.com> Thu, 24 January 2019 21:02 UTC

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From: Adam Roach <adam@nostrum.com>
To: Roman Shpount <roman@telurix.com>, "rtcweb@ietf.org" <rtcweb@ietf.org>
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Subject: Re: [rtcweb] Proposal to break the ICE impasse
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On 1/24/19 1:39 PM, Roman Shpount wrote:
> Would you prefer to reply to you directly with my comments or as a 
> comment on the Github?


Here for discussion, there for specific text change proposals.


>
> The text you are proposing is slightly ambiguous due to trickle-ice. 
> Theoretically, during trickle ICE candidate collection SDP might 
> contain only TCP candidates but UDP candidates can be added at some 
> point in the future. Based on the proposed text proto will start of as 
> TCP/DTLS/RTP/SAVP and then change when UDP candidates are collected.


I don't think that's true -- the way JSEP specifies trickle ice, offers 
for trickle ice will always start with zero candidates, and so the 
trickling will always use UDP/DTLS/RTP/SAVPF from the start.


> Also, for consistency, the next paragraph, which is talking about 
> UDP/DTLS/SCTP should be updated as well to use TCP/DTLS/SCTP when 
> offer does not initiate ICE restart and only TCP candidates are present.


I'm okay if we require applications that use WebRTC data channels to 
have to do things the WebRTC way.

/a