Re: [rsvp-dir] [PCN] Redundant aggregate reservations: draft-ietf-tsvwg-rsvp-pcn-03

Bob Briscoe <bob.briscoe@bt.com> Fri, 16 November 2012 20:03 UTC

Return-Path: <bob.briscoe@bt.com>
X-Original-To: rsvp-dir@ietfa.amsl.com
Delivered-To: rsvp-dir@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 39F5A21F8A74 for <rsvp-dir@ietfa.amsl.com>; Fri, 16 Nov 2012 12:03:22 -0800 (PST)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -3.489
X-Spam-Level:
X-Spam-Status: No, score=-3.489 tagged_above=-999 required=5 tests=[AWL=0.110, BAYES_00=-2.599, RCVD_IN_DNSWL_LOW=-1]
Received: from mail.ietf.org ([64.170.98.30]) by localhost (ietfa.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id dt56ItBGv8Al for <rsvp-dir@ietfa.amsl.com>; Fri, 16 Nov 2012 12:03:21 -0800 (PST)
Received: from hubrelay-by-03.bt.com (hubrelay-by-03.bt.com [62.7.242.139]) by ietfa.amsl.com (Postfix) with ESMTP id 5EE9421F8525 for <rsvp-dir@ietfa.amsl.com>; Fri, 16 Nov 2012 12:03:21 -0800 (PST)
Received: from EVMHR71-UKRD.domain1.systemhost.net (10.36.3.109) by EVMHR03-UKBR.bt.com (10.216.161.35) with Microsoft SMTP Server (TLS) id 8.3.279.1; Fri, 16 Nov 2012 20:03:16 +0000
Received: from rdw02134app71.domain1.systemhost.net (193.113.234.138) by EVMHR71-UKRD.domain1.systemhost.net (10.36.3.109) with Microsoft SMTP Server (TLS) id 8.3.279.1; Fri, 16 Nov 2012 20:03:17 +0000
Received: from cbibipnt08.iuser.iroot.adidom.com (147.149.100.81) by rdw02134app71.domain1.systemhost.net (10.36.6.87) with Microsoft SMTP Server id 14.2.309.2; Fri, 16 Nov 2012 20:03:16 +0000
Received: From bagheera.jungle.bt.co.uk ([132.146.168.158]) by cbibipnt08.iuser.iroot.adidom.com (WebShield SMTP v4.5 MR1a P0803.399); id 1353096194692; Fri, 16 Nov 2012 20:03:14 +0000
Received: from MUT.jungle.bt.co.uk ([10.215.130.204]) by bagheera.jungle.bt.co.uk (8.13.5/8.12.8) with ESMTP id qAGK3C3s014269; Fri, 16 Nov 2012 20:03:12 GMT
Message-ID: <201211162003.qAGK3C3s014269@bagheera.jungle.bt.co.uk>
X-Mailer: QUALCOMM Windows Eudora Version 7.1.0.9
Date: Fri, 16 Nov 2012 20:03:11 +0000
To: Tom Taylor <tom.taylor.stds@gmail.com>
From: Bob Briscoe <bob.briscoe@bt.com>
In-Reply-To: <50A56804.3090208@gmail.com>
References: <87222982-329F-43DF-BFD8-9D3705AFE101@mimectl> <E728D0E3C41E644A96A7CCA61863BED4081DE009@xmb-aln-x12.cisco.com> <201211141251.qAECpsn0005426@bagheera.jungle.bt.co.uk> <FF1A9612A94D5C4A81ED7DE1039AB80F2ED8FEDF@EXMBX04.ad.utwente.nl> <201211151307.qAFD7RA0009392@bagheera.jungle.bt.co.uk> <50A51B8C.4010806@gmail.com> <201211152102.qAFL2BWE010641@bagheera.jungle.bt.co.uk> <50A56804.3090208@gmail.com>
MIME-Version: 1.0
Content-Type: text/plain; charset="us-ascii"; format=flowed
X-Scanned-By: MIMEDefang 2.56 on 132.146.168.158
Cc: PCN IETF list <pcn@ietf.org>, karagian@cs.utwente.nl, anuragb@cisco.com, tsvwg@ietf.org, rsvp-dir@ietfa.amsl.com
Subject: Re: [rsvp-dir] [PCN] Redundant aggregate reservations: draft-ietf-tsvwg-rsvp-pcn-03
X-BeenThere: rsvp-dir@ietf.org
X-Mailman-Version: 2.1.12
Precedence: list
List-Id: RSVP directorate <rsvp-dir.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/rsvp-dir>, <mailto:rsvp-dir-request@ietf.org?subject=unsubscribe>
List-Archive: <http://www.ietf.org/mail-archive/web/rsvp-dir>
List-Post: <mailto:rsvp-dir@ietf.org>
List-Help: <mailto:rsvp-dir-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/rsvp-dir>, <mailto:rsvp-dir-request@ietf.org?subject=subscribe>
X-List-Received-Date: Fri, 16 Nov 2012 20:03:22 -0000

Tom,

The edge behaviour RFCs attempted to abstract over any signalling 
protcol, but I think they ended up being biased towards the ITU way 
of doing things, rather than an abstraction that encompassed both 
RACF and RSVP, which was probably too ambitious.

Is you piggy-backing draft effectively what I am describing - 
piggy-backing on e2e signalling?

I don't believe we need any more abstract drafts if that's what you 
mean - we need to focus on RSVP specifically now. We could perhaps 
re-boot from Francois's original draft.



Bob

At 22:09 15/11/2012, Tom Taylor wrote:
>OK, I guess I see your point. I was too focussed on the calculations 
>that are done at the Decision Point.
>
>It makes me wonder if I should revive that piggy-backing edge 
>behaviour draft I once started.
>
>On 15/11/2012 4:02 PM, Bob Briscoe wrote:
>>Tom,
>>
>>The RSVP message I'm proposing doesn't say "Never mind the SESSION in
>>this message, I'm related to every flow with the same first hop". It
>>says "These are the marking probabilities for the SESSION in this
>>message". Then the PCN-ingress (not the message) infers that all other
>>flows that share the same aggregate will share the same marking
>>probability, because PCN marking on interior nodes is random and unbiased.
>>
>>It's a subtle distinction, but it preserves the semantics of RSVP
>>messages, without the three disadvantages of setting up an RSVP
>>aggregate that I mentioned.
>>
>>You will have seen from the rest of the message that I have not rejected
>>the concept of aggregation, I am merely saying that the PCN-ingress and
>>PCN-egress can hold the concept internally.
>>
>>
>>Bob
>>
>>At 16:42 15/11/2012, Tom Taylor wrote:
>>>I'm not sure the semantics of the PCN information -- particularly as
>>>it relates to flow termination -- are correct without some sort of
>>>concept of aggregation. Or can you really define an RSVP object that
>>>has semantics "Never mind the SESSION in this message, I'm related to
>>>every flow with the same first hop"?
>...

________________________________________________________________
Bob Briscoe,                                BT Innovate & Design