Re: [tram] Adam Roach's Discuss on draft-ietf-tram-stun-pmtud-10: (with DISCUSS and COMMENT)
Spencer Dawkins at IETF <spencerdawkins.ietf@gmail.com> Mon, 19 November 2018 20:57 UTC
Return-Path: <spencerdawkins.ietf@gmail.com>
X-Original-To: tram@ietfa.amsl.com
Delivered-To: tram@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 722A3128BCC; Mon, 19 Nov 2018 12:57:02 -0800 (PST)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -1.999
X-Spam-Level:
X-Spam-Status: No, score=-1.999 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, FREEMAIL_FROM=0.001, HTML_MESSAGE=0.001, RCVD_IN_DNSWL_NONE=-0.0001, SPF_PASS=-0.001] autolearn=ham autolearn_force=no
Authentication-Results: ietfa.amsl.com (amavisd-new); dkim=pass (2048-bit key) header.d=gmail.com
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 PYSyM0XQg9n0; Mon, 19 Nov 2018 12:56:59 -0800 (PST)
Received: from mail-lj1-x233.google.com (mail-lj1-x233.google.com [IPv6:2a00:1450:4864:20::233]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id 783AD130DD7; Mon, 19 Nov 2018 12:56:55 -0800 (PST)
Received: by mail-lj1-x233.google.com with SMTP id v15-v6so27352355ljh.13; Mon, 19 Nov 2018 12:56:55 -0800 (PST)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=LJgcTbn3IqYg/Yt4tumeue6eI5qXYXHOLxUT8LvzoFA=; b=TzX41q2BYWEpfYRuM5lFQdLzAxKrT7Y2bzdq8h/jF+xNg8HeK6WzICX5x5WzAgvq5I Ndu6p4UQ7vhz9OSy4J8RYAqCxbaXvTjz+9Ajtad767qkxW2p9+xp9nBmX9ZmBXJMXUnW TkJKOiLR79XeKtr1xUQcbQxwZlz8Gf//GsUqyY5hCK40xVa7xrtw6nRSj6vJgFGNWrod 1uBUfcYyByzGCh8yQFl3cEq+SHd4pUMFpy9yM9Js9x3WHLpdjyIjgnPmP4bcIG9sfhsG uxRM2A+DkSetK8Bu0zmOpYzqR7DvdkFmaGLQfTFBR3Tn2PoldaSSFgmdoNVwa/VL9Bq3 dvHA==
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=LJgcTbn3IqYg/Yt4tumeue6eI5qXYXHOLxUT8LvzoFA=; b=o5DO9+bQSJWsyt8NGN9b54pL6s3dygW7nUXED2oeTlLUAAgbh7Uh96sk1NpEYo1OvN SSNFKt7TZmNrPC6p/z8aLRoY2iGwWYtLCSciXT2fpl3OOrUYLOpCV//7snA9udP8LEqH PoDyvkC0EskmFcKmYvbS+Yy53hq0qxXNGFWXXIMSGNONdL+w0xWcIkaDlXfM5jrphuhR rwOTEFfex9zKPsQCEu7xcECp1CWnvdlvr4nTN1kEJfmVFILj5+cdNE3ibeM7vPw/nvOm GlooIL1h1QPzl9C0rIRQ0l5OPweocNL4bxIN6jijZ7JrQrJfnbfqiqzamvUlIa1O6sVG srJg==
X-Gm-Message-State: AGRZ1gJR1artoRpIDfwy5vgdFAdTeQo6uOA4mazMg27Sjku5d2OnRiKn x3DoONi02cudsq4BpmEoDlS994EeCaSw6pKbwOwy2g==
X-Google-Smtp-Source: AJdET5fL2dGQXJRVODG3jiaRC26J05VLDP3Kb3/TLIkA44ZPu851h16iuz9EuS4AzSp7+CIZVhQjy7P67eepCivG3wU=
X-Received: by 2002:a2e:197:: with SMTP id f23-v6mr12546541lji.144.1542661012997; Mon, 19 Nov 2018 12:56:52 -0800 (PST)
MIME-Version: 1.0
References: <153834237082.13405.1228259718885034461.idtracker@ietfa.amsl.com>
In-Reply-To: <153834237082.13405.1228259718885034461.idtracker@ietfa.amsl.com>
From: Spencer Dawkins at IETF <spencerdawkins.ietf@gmail.com>
Date: Mon, 19 Nov 2018 14:56:40 -0600
Message-ID: <CAKKJt-fouMOJa+eGUwEmQL+Uv5Fqe5KNM_fC0YxmhYojpFNzaA@mail.gmail.com>
To: Adam Roach <adam@nostrum.com>
Cc: IESG <iesg@ietf.org>, tram-chairs@ietf.org, draft-ietf-tram-stun-pmtud@ietf.org, Gonzalo Camarillo <gonzalo.camarillo@ericsson.com>, "Asveren, Tolga" <tasveren@rbbn.com>, tram@ietf.org
Content-Type: multipart/alternative; boundary="000000000000b04c0d057b0ac11d"
Archived-At: <https://mailarchive.ietf.org/arch/msg/tram/vb6sJEMR3EZ4QCW7wtQqg5iNTjY>
Subject: Re: [tram] Adam Roach's Discuss on draft-ietf-tram-stun-pmtud-10: (with DISCUSS and COMMENT)
X-BeenThere: tram@ietf.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: "Discussing the creation of a Turn Revised And Modernized \(TRAM\) WG, which goal is to consolidate the various initiatives to update TURN and STUN." <tram.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/tram>, <mailto:tram-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/tram/>
List-Post: <mailto:tram@ietf.org>
List-Help: <mailto:tram-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/tram>, <mailto:tram-request@ietf.org?subject=subscribe>
X-List-Received-Date: Mon, 19 Nov 2018 20:57:02 -0000
So, having been nudged on this one ... On Sun, Sep 30, 2018 at 4:19 PM Adam Roach <adam@nostrum.com> wrote: > Adam Roach has entered the following ballot position for > draft-ietf-tram-stun-pmtud-10: Discuss > > When responding, please keep the subject line intact and reply to all > email addresses included in the To and CC lines. (Feel free to cut this > introductory paragraph, however.) > > > Please refer to https://www.ietf.org/iesg/statement/discuss-criteria.html > for more information about IESG DISCUSS and COMMENT positions. > > > The document, along with other ballot positions, can be found here: > https://datatracker.ietf.org/doc/draft-ietf-tram-stun-pmtud/ > > > > ---------------------------------------------------------------------- > DISCUSS: > ---------------------------------------------------------------------- > > This seems like an interesting technique that warrants collection of > operational > experience. > > >From a process perspective, I think we have a bit of an issue, unless I've > overlooked something relevant. This is proposed as a Standards-Track > document, > but it relies on the use of the PADDING attribute defined in RFC 5780. RFC > 5780 is Experimental, so this is a formal downref. And RFC 5780 does not > appear in the downref registry [1], nor did the IETF last call [2] include > a > request that the IETF community consider allowing such a refernce. > > >From a practical perspective, the mechanism described in this document > seems > like the kind of thing that it would be useful to gather operational > experience > with prior to putting it on the standards track. I have some operational > concerns (described below) that I think could be either proven out or > dispelled > by experimental deployment of the technology. > > My recommendation is to recategorize this mechanism as experimental, > adding some > text about the desire to gather operational experience. > > For avoidance of doubt: My DISCUSS is only on the process issue, and I'll > happily clear regardless of how this issue is rationalized (e.g., either by > running IETF last call again, by reclassifying this mechanism as > experimental, > or perhaps some novel solution that I may not have thought of). Everything > else is merely a recommendation. > I don't think I've seen a specific response to Adam's point here, which I believe is that one of (at least) three things should happen - - a second Last Call, explicitly calling out this downref, OR - approval as an Experimental RFC, which makes the downref issue go away, OR - (and this didn't happen in this thread, but in some conversation, I remember that) Adam wondered if reusing the PADDING attribute was the right thing to do (and that was a question, not a concern, but relevant here, since if this document defined its own attribute, the downref would also go away). Any thoughts on this? Thanks, Spencer > ____ > [1] https://datatracker.ietf.org/doc/downref/ > [2] https://www.ietf.org/mail-archive/web/tram/current/msg02609.html > > > ---------------------------------------------------------------------- > COMMENT: > ---------------------------------------------------------------------- > > In the general case, STUN servers aren't aware of the signaling protocol > that is > in use. For example, when a TURN server is use with RTP and RTCP with a > session > set up via SIP, there is no requirement that the TURN server itself have > any > inherent knowledge of SIP or RTP or RTCP. From that perspective, the > following > text in section 4.2 is a bit confusing and/or problematic: > > Some application layer protocols may already have a way of > identifying each individual UDP packet, in which case these > identifiers SHOULD be used in the IDENTIFIERS attribute of the Report > Response. > > It seems odd that I would have to teach my TURN server about the protocols > I'm > using it with just so that it can identify the packets. > > This behavior, combined with the requirement that all behavior be > symmetrical > ("As a result of the fact that all endpoints implementing this > specification > are both clients and servers") leads me to believe that perhaps the use > cases > that drove this mechanism are tightly scoped to direct peer-to-peer uses > of ICE, > while the other common uses of STUN (e.g., public TURN servers used for > symmetric NAT traversal) were given no consideration. If that was > intentional, > then I think the abstract and introduction need to clearly describe the > scenarios the mechanism was defined for; and, more importantly, clarify > that it > does not work for the general case, including STUN servers used for NAT > traversal. > > I suspect that, once this mechanism begins to be deployed, the foregoing > limitations will cause operational difficulties, which may in turn suggest > changes to the mechanism that is currently defined, hence my suggestion > above > to recharacterize the mechanism as experimental. > > --------------------------------------------------------------------------- > > §4: > > > The Probing mechanism is used to discover the Path MTU in one > > direction only, from the client to the server. > > Nit: "...only: from..." > > > Two Probing mechanisms are described, a Simple Probing mechanism and > > Nit: "...described: a Simple..." > > > a more complete mechanism that can converge quicker and find an > > Nit: "...converge more quickly..." > > > appropriate PMTU in the presence of congestion. Additionally, the > > Nit: Please expand "PMTU" on first use. > > --------------------------------------------------------------------------- > > §4.2.5: > > > algorithm used for the FINGERPRINT attribute (i.e., the CRC-32 of the > > payload XOR'ed with the 32-bit value 0x5354554e [ITU.V42.2002]). > > The location of the citation in here implies that the XOR'ing described is > part > of V.42. Given that 0x53545554E is ASCII for "STUN," I'm pretty sure > that's not > part of the underlying CRC. Would suggest reworking as: > > algorithm used for the FINGERPRINT attribute (i.e., the CRC-32 > calculated per the algorithm defined in [ITU.V42.2002], such has > subsequently been XOR'ed with 32-bit value 0x5354554e). > > >
- [tram] Adam Roach's Discuss on draft-ietf-tram-st… Adam Roach
- Re: [tram] Adam Roach's Discuss on draft-ietf-tra… Spencer Dawkins at IETF
- Re: [tram] Adam Roach's Discuss on draft-ietf-tra… Simon Perreault
- Re: [tram] Adam Roach's Discuss on draft-ietf-tra… Spencer Dawkins at IETF
- Re: [tram] Adam Roach's Discuss on draft-ietf-tra… Simon Perreault
- Re: [tram] Adam Roach's Discuss on draft-ietf-tra… Spencer Dawkins at IETF
- Re: [tram] Adam Roach's Discuss on draft-ietf-tra… Gonzalo Camarillo
- Re: [tram] Adam Roach's Discuss on draft-ietf-tra… Spencer Dawkins at IETF
- Re: [tram] Adam Roach's Discuss on draft-ietf-tra… Gonzalo Salgueiro (gsalguei)
- Re: [tram] Adam Roach's Discuss on draft-ietf-tra… Gonzalo Camarillo
- Re: [tram] Adam Roach's Discuss on draft-ietf-tra… Gonzalo Salgueiro (gsalguei)
- Re: [tram] Adam Roach's Discuss on draft-ietf-tra… Gonzalo Camarillo
- Re: [tram] Adam Roach's Discuss on draft-ietf-tra… Gonzalo Camarillo
- Re: [tram] Adam Roach's Discuss on draft-ietf-tra… Gonzalo Salgueiro (gsalguei)
- Re: [tram] Adam Roach's Discuss on draft-ietf-tra… Gonzalo Camarillo
- Re: [tram] Adam Roach's Discuss on draft-ietf-tra… Gonzalo Salgueiro (gsalguei)
- Re: [tram] Adam Roach's Discuss on draft-ietf-tra… Felipe Garrido (fegarrid)
- Re: [tram] Adam Roach's Discuss on draft-ietf-tra… Felipe Garrido (fegarrid)
- Re: [tram] Adam Roach's Discuss on draft-ietf-tra… Adam Roach