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

Roman Shpount <> Thu, 04 July 2019 00:40 UTC

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From: Roman Shpount <>
Date: Wed, 3 Jul 2019 20:40:02 -0400
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To: Justin Uberti <>
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Subject: Re: [rtcweb] Is rtcweb the right place for draft-ietf-rtcweb-mdns-ice-candidates?
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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

<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 <> 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 <> 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