Re: [rtcweb] JSEP and ice-pacing attribute

Christer Holmberg <christer.holmberg@ericsson.com> Wed, 31 July 2019 06:02 UTC

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From: Christer Holmberg <christer.holmberg@ericsson.com>
To: Harald Alvestrand <harald@alvestrand.no>, "rtcweb@ietf.org" <rtcweb@ietf.org>
Thread-Topic: [rtcweb] JSEP and ice-pacing attribute
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Date: Wed, 31 Jul 2019 06:02:26 +0000
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Subject: Re: [rtcweb] JSEP and ice-pacing attribute
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Hi Harald,

>> I noted that JSEP does not specify the usage of the ice-pacing 
>> attribute. Is there a reason for that? It does explicitly specify how 
>> all the other ICE related SDP attributes are used.
>
> I think we overlooked it.
>
> "ice-pacing" was introduced in draft-ietf-mmusic-ice-sip-sdp-03 (July 2014), so we can't claim
> it's because it's too new..... JSEP was only at its version -07 at that time.
>
> According to RFC 8445 section 14.2, this attribute sets the value of the Ta timer (or at least this 
> is the only interpretation that I can see that makes sense).

Correct.

> According to draft-ietf-mmusic-ice-sip-sdp-36, "ice-pacing" only allows increasing the value of Ta 
> to a value larger than its default (50 ms) (while 8445 seems to indicate that a single agent can go 
> all the way down to 5 ms, but not lower).

I gave the exact same comment some time ago, wrote a PR about it, and it has now been fixed in -37, that was submitted yesterday :)

Regards,

Christer