IETF Logo Mail Archive

Re: [dispatch] Fwd: New Version Notification for draft-procter-dispatch-outbound-discovery-00.txt

Michael Procter <michael.ietf@gmail.com> Thu, 28 August 2014 13:54 UTC

Return-Path: <michael.ietf@gmail.com>
X-Original-To: dispatch@ietfa.amsl.com
Delivered-To: dispatch@ietfa.amsl.com
Received: from localhost (ietfa.amsl.com [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 7AC3F1A0475 for <dispatch@ietfa.amsl.com>; Thu, 28 Aug 2014 06:54:01 -0700 (PDT)
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, SPF_PASS=-0.001] autolearn=ham
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 Ak-xMGp-7FOM for <dispatch@ietfa.amsl.com>; Thu, 28 Aug 2014 06:53:57 -0700 (PDT)
Received: from mail-wg0-x22f.google.com (mail-wg0-x22f.google.com [IPv6:2a00:1450:400c:c00::22f]) (using TLSv1 with cipher ECDHE-RSA-RC4-SHA (128/128 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id A7CC81A0422 for <dispatch@ietf.org>; Thu, 28 Aug 2014 06:53:56 -0700 (PDT)
Received: by mail-wg0-f47.google.com with SMTP id z12so777080wgg.18 for <dispatch@ietf.org>; Thu, 28 Aug 2014 06:53:54 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type; bh=jG+DessNWkscEJcJTMCDkIFJf/TyP+pdVgh6RS4vXB0=; b=M1j1sdxPRoL9QOggGQW8oqzGO/dUo1hYHGdyhkaJ9oeiyhe+iolc8U3SMvQjNjT9iU eIWqcVzZV21K1fIQH7UUyeDHf/UGf7evMuf2j+0Loh3pT9JdFTIPka90tUpmauIY/yLX rKrHYmi+Sx/PzDr8YLutNDqd1abzQpP4BkCvSBIhzYERMGE8cAKrvYQRI0tylcAOMi5s ITD1Uy9+2VLD+DA3ita2HuBdTT4U+PHPLKdxLisstOBoklkmOzcS3eLo6jVu/gPRr4uH vDox8wN4Ab8ti8UyoN2qtvCxSX58LLf+gBfiuafZewR+OfmJtyxCnc4MVi/CbhiIItL7 bzsA==
MIME-Version: 1.0
X-Received: by 10.180.208.111 with SMTP id md15mr6223672wic.3.1409234034131; Thu, 28 Aug 2014 06:53:54 -0700 (PDT)
Received: by 10.194.39.231 with HTTP; Thu, 28 Aug 2014 06:53:54 -0700 (PDT)
In-Reply-To: <CANO7kWDoGz3ioQH46i_Y7=CCm8G3LpZ+5dt_DHr0yrH3=D=eOQ@mail.gmail.com>
References: <20140704155153.17916.76121.idtracker@ietfa.amsl.com> <CAPms+wR0hrfiw6gWsCxRNHU=Puqw-9wVJyue08cBCKv2+jVN8g@mail.gmail.com> <201408272134.s7RLYMMS026386@hobgoblin.ariadne.com> <CANyXLXZoJfZFNCKkycizos7mxMBCE2J1yvN3eOkaxnAK6mtNEQ@mail.gmail.com> <CANO7kWDoGz3ioQH46i_Y7=CCm8G3LpZ+5dt_DHr0yrH3=D=eOQ@mail.gmail.com>
Date: Thu, 28 Aug 2014 14:53:54 +0100
Message-ID: <CANyXLXYrpTt8J8YOOJRSZenrWzPytKfwd6oaSCPkVA6t0_cJzg@mail.gmail.com>
From: Michael Procter <michael.ietf@gmail.com>
To: Simon Perreault <sperreault@jive.com>
Content-Type: multipart/alternative; boundary="001a11c382ca028d620501b0deab"
Archived-At: http://mailarchive.ietf.org/arch/msg/dispatch/GC6rqZVrgPJLyfFfOU4_PuNIAcQ
Cc: dispatch@ietf.org
Subject: Re: [dispatch] Fwd: New Version Notification for draft-procter-dispatch-outbound-discovery-00.txt
X-BeenThere: dispatch@ietf.org
X-Mailman-Version: 2.1.15
Precedence: list
List-Id: DISPATCH Working Group Mail List <dispatch.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/dispatch>, <mailto:dispatch-request@ietf.org?subject=unsubscribe>
List-Archive: <http://www.ietf.org/mail-archive/web/dispatch/>
List-Post: <mailto:dispatch@ietf.org>
List-Help: <mailto:dispatch-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/dispatch>, <mailto:dispatch-request@ietf.org?subject=subscribe>
X-List-Received-Date: Thu, 28 Aug 2014 13:54:01 -0000

On Thu, Aug 28, 2014 at 1:18 PM, Simon Perreault <sperreault@jive.com>
wrote:

> On Thu, Aug 28, 2014 at 3:52 AM, Michael Procter <michael.ietf@gmail.com>
> wrote:
> > I agree that using the list of advertised SRV targets as a list of
> > outbound-proxies should work, and that is the basic approach used in the
> > draft.  As far as I am aware, there is currently no document describing
> this
> > approach, which is why I wrote the draft.
>
> Does anyone well versed in IETF lore remember why this seemingly
> obvious approach was not defined in RFC 5626? It appears too easy, and
> things are never easy with SIP...
>
> Simon
>

Interestingly, draft-jennings-sipping-outbound-01[0] contains a paragraph:

   A UA that needs to establish multiple flows needs a way to use DNS to
   select candidate addresses for the formation of flows.  The
   recommended way to do this is to look at the DNS records resulting
   from the algorithm described in RFC 3263 [3] and select distinct
   addresses from the target set.

But the next revision (draft-ietf-sip-outbound-00[1]) removes this and has
a changelog comment of:

   Changed to use a configured set of backup proxies instead of playing
   DNS games to try and figure out what backup proxies to use.

I have searched both the sip and sipping list archives over the relevant
timeframe (Feb 2005 to July 2005) and can't find any mention of the change.
 The minutes of the sip meeting at IETF62[2] contain no reference to this
part either.

The conclusion I draw is that it was removed keep things simple, given that
at the time the config framework was almost complete and would provide a
general solution to all these configuration issues.  Maybe someone else can
remember if there were other questions raised at the time?

Regards,

Michael

[0] http://www.ietf.org/archive/id/draft-jennings-sipping-outbound-01.txt
[1] http://tools.ietf.org/id/draft-ietf-sip-outbound-00.txt
[2] http://www.ietf.org/proceedings/62/sip.html

v2.23.0 | Report a Bug | By Email