Re: [MMUSIC] Please Read and Comment: Re: ICE SDP/JSEP peace accords

[Roman Shpount <[e-mail]>]

On Fri, Jan 25, 2019 at 9:05 AM Flemming Andreasen <[e-mail]>
wrote:

>
>
> On 1/22/19 4:42 PM, Adam Roach wrote:
>
> On 1/22/19 3:40 PM, Roman Shpount wrote:
>
> On Tue, Jan 22, 2019 at 4:36 PM Adam Roach <[e-mail]> wrote:
>
>> On 1/22/19 3:33 PM, Roman Shpount wrote:
>>
>> On Tue, Jan 22, 2019 at 4:25 PM Adam Roach <[e-mail]> wrote:
>>
>>> On 1/22/19 3:15 PM, Roman Shpount wrote:
>>> > The issue is the offer generated when ICE restart is not initiated and
>>> > TCP candidate is currently nominated. TCP candidate is the only
>>> > candidate which is present in both offer and answer. It is also the
>>> > default candidate. No UDP candidate will be added it any point during
>>> > the offer/answer exchange.
>>>
>>>
>>> This is what I tried to indicate with the use of an italicized "always"
>>> in my previous reply.
>>>
>>> EVEN IF it is generating an offer when ICE restart is initiated and the
>>> TCP candidate is nominated, Chrome will still always (always, always)
>>> generate an SDP that includes a UDP candidate and use that candidate's
>>> value in the m=/o= lines.
>>>
>>
>> Unless I am mistaken, if ICE restart is not initiated, only the nominated
>> candidate must be included. No other candidates must be present. If Chrome
>> does not follow this, then it is most likely not complaint with either ICE
>> or JSEP specifications.
>>
>>
>> Based on the conversation I had with their engineers, that seems to be
>> the case.
>>
>
> Based on RFC 5245 section 9.1.2.2 (
> https://tools.ietf.org/html/rfc5245#section-9.1.2.2) this is wrong:
>
> The agent MUST include candidate attributes for candidates matching the
> default destination for each component of the media stream, and MUST NOT
> include any other candidates.
>
>
> I'm not disagreeing.
>
>
> So where does this leave us ?
>
>
I think JSEP sections 5.1.2 (
https://tools.ietf.org/html/draft-ietf-rtcweb-jsep-25#section-5.1.2) and
potentially 5.2.2 (
https://tools.ietf.org/html/draft-ietf-rtcweb-jsep-25#section-5.2.2) would
need to be updated to be consistent with each other and mmusic drafts.

There is currently a discussion on RTCWEB of pull request
https://github.com/rtcweb-wg/jsep/pull/862/files which attempts to fix this.

Regards,
_____________
Roman Shpount