Re: [CCAMP] draft-ietf-ccamp-te-metric-recording-02

"Matt Hartley (mhartley)" <mhartley@cisco.com> Fri, 09 August 2013 15:15 UTC

Return-Path: <mhartley@cisco.com>
X-Original-To: ccamp@ietfa.amsl.com
Delivered-To: ccamp@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 93D6421F84B8 for <ccamp@ietfa.amsl.com>; Fri, 9 Aug 2013 08:15:21 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -10.599
X-Spam-Level:
X-Spam-Status: No, score=-10.599 tagged_above=-999 required=5 tests=[AWL=0.000, BAYES_00=-2.599, RCVD_IN_DNSWL_HI=-8]
Received: from mail.ietf.org ([12.22.58.30]) by localhost (ietfa.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 08ep1DWZoJeO for <ccamp@ietfa.amsl.com>; Fri, 9 Aug 2013 08:15:12 -0700 (PDT)
Received: from rcdn-iport-2.cisco.com (rcdn-iport-2.cisco.com [173.37.86.73]) by ietfa.amsl.com (Postfix) with ESMTP id 0F11921F862B for <ccamp@ietf.org>; Fri, 9 Aug 2013 08:07:17 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=cisco.com; i=@cisco.com; l=1697; q=dns/txt; s=iport; t=1376060838; x=1377270438; h=from:to:cc:subject:date:message-id:references: in-reply-to:content-transfer-encoding:mime-version; bh=/d8SPUu5/2aSzrfkQNYLTEOrXWCm4mPtu+GNPXDk7Sc=; b=X7gpntpq/x0sdikn4XTbaLrCb19sQm/OnDy9MQBDTFXCgkOm+bXeff+R oFCi2Uvo+AHrDYajtkuvTGV5D92Fgfm7KDKKSnfV8K2gkjGA+7dC4zKcP hgHamdsF9Pwj26uKjHKYNfnFqLw8recDYXAnzvcKx5fOri17kt91QjYYU Q=;
X-IronPort-Anti-Spam-Filtered: true
X-IronPort-Anti-Spam-Result: AhMFAOYEBVKtJXG+/2dsb2JhbABbgwY1UL5RgRoWdIIkAQEBAwEBAQE3NAsFCwIBCCIUECcLJQEBBAENBQiIAgYMuSEEj2oxB4MadAOpMIMYgio
X-IronPort-AV: E=Sophos;i="4.89,846,1367971200"; d="scan'208";a="245453922"
Received: from rcdn-core2-3.cisco.com ([173.37.113.190]) by rcdn-iport-2.cisco.com with ESMTP; 09 Aug 2013 15:07:17 +0000
Received: from xhc-rcd-x12.cisco.com (xhc-rcd-x12.cisco.com [173.37.183.86]) by rcdn-core2-3.cisco.com (8.14.5/8.14.5) with ESMTP id r79F7HGB027358 (version=TLSv1/SSLv3 cipher=AES128-SHA bits=128 verify=FAIL); Fri, 9 Aug 2013 15:07:17 GMT
Received: from xmb-rcd-x03.cisco.com ([169.254.7.202]) by xhc-rcd-x12.cisco.com ([173.37.183.86]) with mapi id 14.02.0318.004; Fri, 9 Aug 2013 10:07:17 -0500
From: "Matt Hartley (mhartley)" <mhartley@cisco.com>
To: John E Drake <jdrake@juniper.net>, "CCAMP (ccamp@ietf.org)" <ccamp@ietf.org>
Thread-Topic: draft-ietf-ccamp-te-metric-recording-02
Thread-Index: Ac6UeCOcyiZvNP7VTj6v1XoohGG+nwAmJqLQ
Date: Fri, 09 Aug 2013 15:07:17 +0000
Message-ID: <9D50FCE7413E3D4EA5E42331115FB5BC105AD55C@xmb-rcd-x03.cisco.com>
References: <fef00ba6c7f24978ad08fb60ee929a79@BY2PR05MB142.namprd05.prod.outlook.com>
In-Reply-To: <fef00ba6c7f24978ad08fb60ee929a79@BY2PR05MB142.namprd05.prod.outlook.com>
Accept-Language: en-US
Content-Language: en-US
X-MS-Has-Attach:
X-MS-TNEF-Correlator:
x-originating-ip: [161.44.212.251]
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: quoted-printable
MIME-Version: 1.0
Subject: Re: [CCAMP] draft-ietf-ccamp-te-metric-recording-02
X-BeenThere: ccamp@ietf.org
X-Mailman-Version: 2.1.12
Precedence: list
List-Id: Discussion list for the CCAMP working group <ccamp.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/ccamp>, <mailto:ccamp-request@ietf.org?subject=unsubscribe>
List-Archive: <http://www.ietf.org/mail-archive/web/ccamp>
List-Post: <mailto:ccamp@ietf.org>
List-Help: <mailto:ccamp-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/ccamp>, <mailto:ccamp-request@ietf.org?subject=subscribe>
X-List-Received-Date: Fri, 09 Aug 2013 15:15:22 -0000

John,

The point you raise is a good one, but I don't think it has much to do with this draft.

> I think there is a basic issue with this draft, which is that the server
> network manages its own TE metrics and those metrics almost certainly have
> nothing in common with the TE metrics used in a given client network.

So if I understand you correctly, you're just saying that "cost" is a somewhat vague thing that may mean different things to different network operators? This is true sometimes, but that doesn't mean it will always be the case. And I think concepts such as latency and latency variation are less prone to this problem; when we talk about "latency", I'm reasonably sure we all mean the same thing.

> Given this, would it not be better to have policy in the client nodes that
> maps the characteristics of a given LSP established across the server network
> into the TE metric to be advertised with that LSP in the client network?

Certainly that might be a good idea... but it's beyond the scope of this draft. If you want to map the characteristics of a given LSP established across the server network into the TE metric to be advertised with that LSP in the client network, you first have to know what the characteristics of the LSP across the server network are... and that's what this draft is for; it's simply about the discovery of the information, not what you choose to do with it afterwards.

Cheers

Matt

> 
> Yours Irrespectively,
> 
> John
> 
> 
> _______________________________________________
> CCAMP mailing list
> CCAMP@ietf.org
> https://www.ietf.org/mailman/listinfo/ccamp