Re: [rtcweb] Is rtcweb the right place for draft-ietf-rtcweb-mdns-ice-candidates?

[Justin Uberti <[e-mail]>]

https://tools.ietf.org/html/rfc4566#section-9

; sub-rules of 'c='

connection-address =  multicast-address / unicast-address

...

unicast-address =     IP4-address / IP6-address / FQDN / extn-addr


On Wed, Jul 3, 2019 at 11:08 PM Bernard Aboba <[e-mail]>
wrote:

> Nils said:
>
> "assuming it includes using mDNS in the connection line, will break
> interop"
>
> [BA]  Can someone provide a legacy citation relating to FQDNs in the
> connection line?  I am struggling to find one.
>
> draft-ietf-mmusic-rfc4566bis
> <https://tools.ietf.org/html/draft-ietf-mmusic-rfc4566bis>  Section 5.7
> only talks about IPv4 and IPv6 addresses.  I do not see mention of FQDNs.
>
> draft-ietf-mmusic-ice-sip-sdp does not mention FQDNs in the "c=" line and
> all examples show IPv4 or IPv6 addresses.
>
> RFC 3264 does not mention FQDNs in c= lines in the text, although it uses
> FQDNs within examples (such as Sections 10.1 and 10.2).
>
> JSEP does not mention FQDNs in "c=" lines as far as I can tell.
>
> Also in these documents, I do not see instructions on how a legacy
> implementation should gracefully react to FQDNs in the connection line
> (e.g. ignoring it).
>
> On Wed, Jul 3, 2019 at 9:50 PM Nils Ohlmeier <[e-mail]>
> wrote:
>
>> Probably not the ideal forum to point this out, but I hope the Chrome
>> team is aware that rolling out this feature, assuming it includes using
>> mDNS in the connection line, will break interop with Firefox.
>> So I have to concur that rolling this out appears to be premature to me.
>>
>> Best
>>   Nils Ohlmeier
>>
>> On 3Jul, 2019, at 17:58, Justin Uberti <
>> juberti=[e-mail]> wrote:
>>
>> Hmm, that's unfortunate. I think this is a mistake, given that we are
>> about to throw the switch to enable mDNS for 100% of Chrome endpoints;
>> Chrome (and soon all browsers) will have to ignore ice-sip-sdp until this
>> extension spec is written.
>>
>> ice-sip-sdp isn't published yet, so it seems an update to that document
>> could still be a possibility. If that's not an option, putting forth #1 as
>> a specific extension that allows FQDN candidates to be generated in certain
>> situations seems like the right path.
>>
>>
>>
>> On Wed, Jul 3, 2019 at 5:40 PM Roman Shpount <[e-mail]> wrote:
>>
>>> Part of the problem is that mmusic have decided to punt on the FQDN
>>> support. In the current mmusic-ice-sip-sdp the final language that was
>>> included:
>>>
>>> <connection-address>:  is taken from RFC 4566 [RFC4566].  It is the IP
>>> address of the candidate, allowing for IPv4 addresses, IPv6 addresses, and
>>> fully qualified domain names (FQDNs).  When parsing this field, an agent
>>> can differentiate an IPv4 address and an IPv6 address by presence of a
>>> colon in its value - the presence of a colon indicates IPv6.  *An agent
>>> generating local candidates MUST NOT use FQDN addresses.  An agent
>>> processing remote candidates MUST ignore candidate lines that include
>>> candidates with FQDN *or IP address versions that are not supported or
>>> recognized.  *The procedures for generation and handling of FQDN
>>> candidates, as well as, how agents indicate support for such procedures,
>>> need to be specified in an extension specification.*
>>>
>>> So, at this point we have two options:
>>> 1. draft-ietf-rtcweb-mdns-ice-candidates can update ice-sip-sdp and
>>> define how FQDN candidates generated by mdns are handled
>>> 2. write a new draft in mmusic which defines FQDN handling
>>>
>>> In any case some sort of mmusic discussion is needed to reconcile this.
>>>
>>> Best Regards,
>>> _____________
>>> Roman Shpount
>>>
>>>
>>> On Wed, Jul 3, 2019 at 8:28 PM Justin Uberti <[e-mail]> wrote:
>>>
>>>> The problem this draft is trying to solve is fairly RTCWEB-specific. If
>>>> there are individual issues to resolve, we can send them out to mmusic for
>>>> discussion, but AFAIK no changes to existing ICE specs are needed.
>>>>
>>>> On Wed, Jul 3, 2019 at 4:26 PM Roman Shpount <[e-mail]> wrote:
>>>>
>>>>> Hi All,
>>>>>
>>>>> Is rtcweb the right place for draft-ietf-rtcweb-mdns-ice-candidates?
>>>>> This entire draft seems to be ICE/SDP specific and not limited to rtcweb.
>>>>> Also, there are significant interop implications for this draft
>>>>> between browser and non-browser end points which probably warrant larger
>>>>> discussion outside of rtcweb group. I would think mmusic would be a much
>>>>> better place for this draft. I know there is an incentive to complete this
>>>>> draft quickly but this has a potential to break a lot of things (it already
>>>>> did break interop with almost every existing ICE implementation).
>>>>>
>>>>> Regards,
>>>>> _____________
>>>>> Roman Shpount
>>>>> _______________________________________________
>>>>> rtcweb mailing list
>>>>> [e-mail]
>>>>> https://www.ietf.org/mailman/listinfo/rtcweb
>>>>>
>>>> _______________________________________________
>> rtcweb mailing list
>> [e-mail]
>> https://www.ietf.org/mailman/listinfo/rtcweb
>>
>>
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>>
>