Re: [MMUSIC] Questions about ICE candidates with BUNDLE
Paul Kyzivat <pkyzivat@alum.mit.edu> Thu, 18 February 2016 16:40 UTC
Return-Path: <pkyzivat@alum.mit.edu>
X-Original-To: mmusic@ietfa.amsl.com
Delivered-To: mmusic@ietfa.amsl.com
Received: from localhost (ietfa.amsl.com [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 814AA1ACE50 for <mmusic@ietfa.amsl.com>; Thu, 18 Feb 2016 08:40:41 -0800 (PST)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -1.235
X-Spam-Level:
X-Spam-Status: No, score=-1.235 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, SPF_SOFTFAIL=0.665] autolearn=no
Received: from mail.ietf.org ([4.31.198.44]) by localhost (ietfa.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 85OL6IeORtIJ for <mmusic@ietfa.amsl.com>; Thu, 18 Feb 2016 08:40:39 -0800 (PST)
Received: from resqmta-po-04v.sys.comcast.net (resqmta-po-04v.sys.comcast.net [IPv6:2001:558:fe16:19:96:114:154:163]) (using TLSv1.2 with cipher DHE-RSA-AES128-SHA (128/128 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id 58E9E1ACE77 for <mmusic@ietf.org>; Thu, 18 Feb 2016 08:40:39 -0800 (PST)
Received: from resomta-po-13v.sys.comcast.net ([96.114.154.237]) by resqmta-po-04v.sys.comcast.net with comcast id Ksfv1s00357bBgG01sgezx; Thu, 18 Feb 2016 16:40:38 +0000
Received: from Paul-Kyzivats-MacBook-Pro.local ([73.218.51.154]) by resomta-po-13v.sys.comcast.net with comcast id Ksge1s0013KdFy101sgeVe; Thu, 18 Feb 2016 16:40:38 +0000
To: mmusic@ietf.org
References: <CAJrXDUHutBgaPOV73-CyD_Knz+G5RFE0VX4s3+GqGV8K=B1LNA@mail.gmail.com> <7594FB04B1934943A5C02806D1A2204B37BED248@ESESSMB209.ericsson.se> <CAJrXDUE0zutaCci2pojS6+=015DKqd7ocR5a9AWLoTC6jV+x6w@mail.gmail.com> <7594FB04B1934943A5C02806D1A2204B37BEF98E@ESESSMB209.ericsson.se> <CAJrXDUFZUkogpX9Jnz-y1BxSbE0SnQE3CAg-EXy12-k9tFzjuA@mail.gmail.com> <7594FB04B1934943A5C02806D1A2204B37C1D520@ESESSMB209.ericsson.se> <CAJrXDUHaizhhikRVERNR4aDbe_KdE_RESWZY-1d57x1gtuFs_g@mail.gmail.com> <7594FB04B1934943A5C02806D1A2204B37C4815B@ESESSMB209.ericsson.se> <CAJrXDUEKAdmV+LX1xER6+Km1mzLPbKFWrf9iRYLV_Rj0Mh3_dA@mail.gmail.com> <7594FB04B1934943A5C02806D1A2204B37DF9E40@ESESSMB209.ericsson.se> <7594FB04B1934943A5C02806D1A2204B37E061CD@ESESSMB209.ericsson.se>
From: Paul Kyzivat <pkyzivat@alum.mit.edu>
Message-ID: <56C5F405.1020305@alum.mit.edu>
Date: Thu, 18 Feb 2016 11:40:37 -0500
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.10; rv:38.0) Gecko/20100101 Thunderbird/38.6.0
MIME-Version: 1.0
In-Reply-To: <7594FB04B1934943A5C02806D1A2204B37E061CD@ESESSMB209.ericsson.se>
Content-Type: text/plain; charset="UTF-8"; format="flowed"
Content-Transfer-Encoding: 8bit
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=comcast.net; s=q20140121; t=1455813638; bh=iJg/AOP9ycatjX3DgRWXgCNBsVvRDruRPvGGoNvWkLw=; h=Received:Received:Subject:To:From:Message-ID:Date:MIME-Version: Content-Type; b=Iko6jNW+y0ktxvMt4PQP/b470ul4HXMCjCIcx2KmuXF0MB5hCs8BRDayhEKh+Q+1P 0Q4kOmEEEvOOkV6vOho5MNKwgfOhNlHeHRQeuWVe5o8Vj7QiE0ke2xj+4SSjy/NqUx wh/WP61kfNtHu30SKHQFa416UF8LRBuUgCaX2mqi6IJwPbeIZ98s3Aq6w/RzMuVKFP MtOVPnExnX0gyKJTuDF8O1Pe3OzX+TNlUBhlYkOP7wz8FSHXEsKFl0GUMPhE06mPcT 7Sp762SFh6nN5yoJvg6kI/MUo0zfkOf02MxT5QbtYg0xLOw+fkjjYW34MM4W7bY5h5 AS9UdK0BecYWw==
Archived-At: <http://mailarchive.ietf.org/arch/msg/mmusic/VscRBS5PXFTGjj9AM8k81MCgA3I>
Subject: Re: [MMUSIC] Questions about ICE candidates with BUNDLE
X-BeenThere: mmusic@ietf.org
X-Mailman-Version: 2.1.15
Precedence: list
List-Id: Multiparty Multimedia Session Control Working Group <mmusic.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/mmusic>, <mailto:mmusic-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/mmusic/>
List-Post: <mailto:mmusic@ietf.org>
List-Help: <mailto:mmusic-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/mmusic>, <mailto:mmusic-request@ietf.org?subject=subscribe>
X-List-Received-Date: Thu, 18 Feb 2016 16:40:41 -0000
On 2/18/16 7:19 AM, Christer Holmberg wrote: > **sounds of crickets** > > Ok, so assuming the scope of this change would only be ICE, we could say > that shared ICE candidates don’t have to be associated with each m- line > within a BUNDLE group – it’s enough if they are associated with one m- line. I haven't been following this discussion closely, so forgive me if I have misunderstood... I see how it might be inconvenient to redundantly provide all the candidates with each m-line. But at the least this exception will need very careful specification, or else it could lead to very confusing implementations. (For instance, different subsets of the candidates associated with different m-lines.) So if this is to be done, I think it should be quite restrictive. Perhaps either duplicate candidates with every m-line or else all the candidates with only one m-line, and no candidates with any of the other m-lines in the bundle. If in all m-lines of the offer then also in all accepted m-lines in the answer. If in only one m-line in the offer, then only in the corresponding m-line of the answer. Even then, what is to be done if the candidates are with only one of the m-lines in the offer, and the answerer wants to reject *that* m-line but accept others in the bundle? Does the answerer pick a different m-line to carry the candidates in the answer? Thanks, Paul > Q1: Does this apply only to the SDP ‘candidate’ attribute, or also to > other ICE-related SDP attributes? > > Q2: Is it a RECOMMENDED/SHOULD/MAY/MUST/MUST NOT? > > Now, if I don’t hear any feedback on this, I am NOT going to do the > change. Those who asked for this change (or otherwise have an opinion on > it), please speak up now. > > Regards, > > Christer > > *From:*mmusic [mailto:mmusic-bounces@ietf.org] *On Behalf Of *Christer > Holmberg > *Sent:* 16. helmikuuta 2016 17:15 > *To:* Peter Thatcher > *Cc:* mmusic@ietf.org > *Subject:* Re: [MMUSIC] Questions about ICE candidates with BUNDLE > > Hi, > > We still need to conclude this issue before we can ship BUNDLE, so I’d > like to hear some input from people. I do intend to request agenda time > to discuss it in Buenos Aires, but if we can find a solution before that > there will be more time for cookies… > > Regards, > > Christer > > *From:*Peter Thatcher [mailto:pthatcher@google.com] > *Sent:* 17. marraskuuta 2015 1:06 > *To:* Christer Holmberg > *Cc:* mmusic@ietf.org <mailto:mmusic@ietf.org> > *Subject:* Re: [MMUSIC] Questions about ICE candidates with BUNDLE > > On Mon, Nov 16, 2015 at 2:58 PM, Christer Holmberg > <christer.holmberg@ericsson.com <mailto:christer.holmberg@ericsson.com>> > wrote: > > Hi, > > >> I thinking mandating the candidates be duplicated in the answer has > three issues: > >> > >> 1. It conflicts with trickle ICE. > >> 2. It's slightly more complex to implement (we have to go add extra > logic to go duplicate these things) > >> 3. It's a complete waste of time/space/effort. The recipient of > these duplicate candidates is never going to anything with them. > > > > Those are all fair points. I wish we'd had more implementation input > when we write our specs. > > > > That's what I'm providing now :). We can still change the spec, > can't we? > > Sure. > > However, as we are talking about a design wise big (in my opinion) > change, at a late stage, I'd like to hear what other people think. > > That sounds fair. I'd like to hear what others think about this. > > > > > >>>Also keep in mind that, when a subsequent offer is sent, the > bundle-only attribute is no longer used. > >> > >>Can you point out where in the draft it says that? I tried > finding it and I had a difficult time seeing where bundle-only > wasn't allowed in a reoffer. > >> > >> Section 8.5.1 says: > >> > >> "When an offerer generates a subsequent offer, it MUST > assign the > >> previously selected offerer BUNDLE address [Section > 8.3.2], to each > >> bundled "m=" line (including any bundle-only "m=" line), > except if:" > >> > >> And, as the usage of the attribute is only defined when the port > value is zero, it would not work when the BUNDLE address (read: > non-zero port) must be associated with the m- line. > >> > >> Section 6 says: > >> > >> "The usage of the 'bundle-only' attribute is only defined for a > >> bundled "m=" line with a zero port value, within an offer. Other > >> usage is unspecified." > > > > Thanks. That text would be more clear as "with an initial offer" > instead of "whithin an offer", since that's what it really means in > conjuction with 8.5.1. > > Ok. > > > However, that's precisely the text that I think we could change. > I think we could change the bundle-only attribute to > > be allowed in answers and in subsequent offers. Then clients > could use the attribute as a way of avoiding duplication > > of candidates and the complications with trickle ICE. > > Assuming we would remove the duplication of candidates, I don't > think that would require us to change a semantics of the attribute. > We could simply say that the candidates don't need to be duplicated > in bundled m- lines, no matter if those m- lines are bundle-only or not. > > That would work as well. > > > > > >>>> Would you then also in the subsequent offer only assign > possible candidates to only one m- line within the bundle group? > >>> > >>> That sounds logical to me. They aren't included in the first > offer. Why add them to subsequent offers? It's inconsistent, and a > waste. > >> > >> Then someone could ask: what about other (non-candidate) > attributes that must have identical values for each bundled m- line? > Should those also be assigned to only one of the m- lines? > > > > If it's something unique to the bundle group, and not the m-line, > that seems reasonable to me. > > > > But candidates are more painful than those would be because of > the interactions with trickle ICE. If it weren't for trickle ICE > this wouldn't be as big of a deal. > > Correct. We just need to make it very clear whether it applies only > to candidate attributes, or to attributes with identical values in > general. > > >>>>>>>> 2. If the answerer does not include any candidates in the > answer and instead trickles them later, should it trickle them > >>>>>>>> N times (once for each m-line in the BUNDLE group) or >1 > time? 1 time seems much more reasonable than N times, but > >>>>>>>> if we duplicate candidates in the answer, but not > duplicate them while trickling, that's a bit inconsistent. Yet > >another reason to not duplicate in the answer :). > >>>>>>> > >>>>>>> Assuming you use SDP to signal the trickled candidates, > it’s true that you would duplicate them, > >>>>>>> > >>>>>>What's the rationale for that? These duplicates provide no > value, and in the case of many m-lines (such as a conferencing > >>>>>>system with many participants), we could be talking about 30x > the number of candidates being signaled. > >>>> > >>>> I hear what you are saying. > >>>> > >>>> But, if we would do a change, we also need to look at the full > picture, and consider subsequent offers etc. > >>> > >>> I think a simple rule would be "if you know it's going to be > bundled onto another m-line, don't include > >>> candidates". That would go for bundle-only m-lines in an > offer, bundled m-lines in an answer, and bundled m-lines in a re-offer. > >>> > >> Bundled m- lines in a re-offer can still be rejected by the > answerer. > > > > That sounds the same as an initial offer. How does it imply that > a re-offer must duplicate > > candidates across m-lines, even when an initial offer doesn't > need to? > > In the initial offer each m- line contains candidates (unique). If > an m- line in the offer is rejected, the answerer must select the > offerer BUNDLE address (and the associated candidiates) from another > m- line. > > Now, in a re-offer, if the m- line containing the candidates is > rejected, the answerer needs to include its candidates in another m- > line in the answer. That's doable, but it would need to be clearly > documented. In other words: it needs to be clear that the candidates > can occur in ANY of the bundled m- lines, and that m- line may > change between offers and answers. > > So a rule of "the candidates can be in any one of the m-lines, and it > doesn't matter which, and it can change any time". That seems > reasonable to me. It leave the most flexibility to the one writing the > SDP, and it's very easy to implement for the one reading the SDP. > > > Regards, > > Christer > > > > _______________________________________________ > mmusic mailing list > mmusic@ietf.org > https://www.ietf.org/mailman/listinfo/mmusic >
- [MMUSIC] Questions about ICE candidates with BUND… Peter Thatcher
- Re: [MMUSIC] Questions about ICE candidates with … Christer Holmberg
- Re: [MMUSIC] Questions about ICE candidates with … Peter Thatcher
- Re: [MMUSIC] Questions about ICE candidates with … Christer Holmberg
- Re: [MMUSIC] Questions about ICE candidates with … Peter Thatcher
- Re: [MMUSIC] Questions about ICE candidates with … Christer Holmberg
- Re: [MMUSIC] Questions about ICE candidates with … Christer Holmberg
- Re: [MMUSIC] Questions about ICE candidates with … Peter Thatcher
- Re: [MMUSIC] Questions about ICE candidates with … Christer Holmberg
- Re: [MMUSIC] Questions about ICE candidates with … Peter Thatcher
- Re: [MMUSIC] Questions about ICE candidates with … Christer Holmberg
- Re: [MMUSIC] Questions about ICE candidates with … Christer Holmberg
- Re: [MMUSIC] Questions about ICE candidates with … Bernard Aboba
- Re: [MMUSIC] Questions about ICE candidates with … Christer Holmberg
- Re: [MMUSIC] Questions about ICE candidates with … Christer Holmberg
- Re: [MMUSIC] Questions about ICE candidates with … Christer Holmberg
- Re: [MMUSIC] Questions about ICE candidates with … Paul Kyzivat
- Re: [MMUSIC] Questions about ICE candidates with … Christer Holmberg
- Re: [MMUSIC] Questions about ICE candidates with … Paul Kyzivat
- Re: [MMUSIC] Questions about ICE candidates with … Christer Holmberg
- Re: [MMUSIC] Questions about ICE candidates with … Peter Thatcher
- Re: [MMUSIC] Questions about ICE candidates with … Christer Holmberg
- Re: [MMUSIC] Questions about ICE candidates with … Roman Shpount
- Re: [MMUSIC] Questions about ICE candidates with … Christer Holmberg
- Re: [MMUSIC] Questions about ICE candidates with … Peter Thatcher
- Re: [MMUSIC] Questions about ICE candidates with … Christer Holmberg
- Re: [MMUSIC] Questions about ICE candidates with … Peter Thatcher
- Re: [MMUSIC] Questions about ICE candidates with … Peter Thatcher
- Re: [MMUSIC] Questions about ICE candidates with … Christer Holmberg
- Re: [MMUSIC] Questions about ICE candidates with … Christer Holmberg
- Re: [MMUSIC] Questions about ICE candidates with … Paul Kyzivat
- Re: [MMUSIC] Questions about ICE candidates with … Christer Holmberg
- Re: [MMUSIC] Questions about ICE candidates with … Paul Kyzivat
- Re: [MMUSIC] Questions about ICE candidates with … Justin Uberti
- Re: [MMUSIC] Questions about ICE candidates with … Christer Holmberg
- Re: [MMUSIC] Questions about ICE candidates with … Christer Holmberg
- Re: [MMUSIC] Questions about ICE candidates with … Suhas Nandakumar
- Re: [MMUSIC] Questions about ICE candidates with … Christer Holmberg
- Re: [MMUSIC] Questions about ICE candidates with … Suhas Nandakumar
- Re: [MMUSIC] Questions about ICE candidates with … Christer Holmberg
- Re: [MMUSIC] Questions about ICE candidates with … Taylor Brandstetter
- Re: [MMUSIC] Questions about ICE candidates with … Christer Holmberg
- Re: [MMUSIC] Questions about ICE candidates with … Taylor Brandstetter
- Re: [MMUSIC] Questions about ICE candidates with … Christer Holmberg
- Re: [MMUSIC] Questions about ICE candidates with … Taylor Brandstetter
- Re: [MMUSIC] Questions about ICE candidates with … Christer Holmberg