Re: [ippm] http://tools.ietf.org/html/draft-ietf-ippm-reporting-metrics-01
Donald McLachlan <Donald.McLachlan@crc.ca> Wed, 14 April 2010 17:30 UTC
Return-Path: <Donald.McLachlan@crc.ca>
X-Original-To: ippm@core3.amsl.com
Delivered-To: ippm@core3.amsl.com
Received: from localhost (localhost [127.0.0.1]) by core3.amsl.com (Postfix) with ESMTP id 0DD5B28C0F2 for <ippm@core3.amsl.com>; Wed, 14 Apr 2010 10:30:46 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -1.298
X-Spam-Level:
X-Spam-Status: No, score=-1.298 tagged_above=-999 required=5 tests=[AWL=1.300, BAYES_00=-2.599, HTML_MESSAGE=0.001]
Received: from mail.ietf.org ([64.170.98.32]) by localhost (core3.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id F-5z4-S204Yu for <ippm@core3.amsl.com>; Wed, 14 Apr 2010 10:30:45 -0700 (PDT)
Received: from mailgate01.crc.ca (mailgate01.crc.ca [142.92.160.36]) by core3.amsl.com (Postfix) with ESMTP id B3D1F28C1C9 for <ippm@ietf.org>; Wed, 14 Apr 2010 10:30:30 -0700 (PDT)
Received: from mail01.crc.ca ([142.92.39.50]) by mailgate01.crc.ca (8.13.8/8.13.8) with ESMTP id o3EHUMDb010664 for <ippm@ietf.org>; Wed, 14 Apr 2010 13:30:23 -0400
Received: from [142.92.34.101] (janus.dgrc.crc.ca [142.92.34.101]) by mail01.crc.ca (8.13.8/8.13.8) with ESMTP id o3EHUOVM032744; Wed, 14 Apr 2010 13:30:24 -0400
Message-ID: <4BC5FBAD.2090908@crc.ca>
Date: Wed, 14 Apr 2010 13:30:21 -0400
From: Donald McLachlan <Donald.McLachlan@crc.ca>
User-Agent: Mozilla/5.0 (X11; U; SunOS sun4u; en-US; rv:1.9.1.7) Gecko/20100115 Lightning/1.0b1 Thunderbird/3.0.1
MIME-Version: 1.0
To: ippm@ietf.org
Content-Type: multipart/alternative; boundary="------------070301010206090900060506"
X-Scanned-By: MIMEDefang 2.65 on 142.92.160.36
X-Scanned-By: MIMEDefang 2.65 on 142.92.39.50
X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-3.0 (mailgate01.crc.ca [142.92.160.36]); Wed, 14 Apr 2010 13:30:24 -0400 (EDT)
Subject: Re: [ippm] http://tools.ietf.org/html/draft-ietf-ippm-reporting-metrics-01
X-BeenThere: ippm@ietf.org
X-Mailman-Version: 2.1.9
Precedence: list
List-Id: IETF IP Performance Metrics Working Group <ippm.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/listinfo/ippm>, <mailto:ippm-request@ietf.org?subject=unsubscribe>
List-Archive: <http://www.ietf.org/mail-archive/web/ippm>
List-Post: <mailto:ippm@ietf.org>
List-Help: <mailto:ippm-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/ippm>, <mailto:ippm-request@ietf.org?subject=subscribe>
X-List-Received-Date: Wed, 14 Apr 2010 17:30:46 -0000
All, Below are some comments on http://tools.ietf.org/html/draft-ietf-ippm-reporting-metrics-01 which I previously provided by e-mail to Al Morton. Don -------- Original Message -------- Subject: Re: IETF Anaheim. Date: Tue, 30 Mar 2010 11:51:08 -0400 From: Donald McLachlan <Donald.McLachlan@crc.ca> To: Al Morton <acmorton@att.com> I've given http://tools.ietf.org/html/draft-ietf-ippm-reporting-metrics-01 a preliminary read. I will re-read it later but here are some initial comments. Re: section 4.1.3. For all sorts of reasons (listed in "PDV" RFC) I find PDV a much more useful metric than IPDV, and any/all received packets are then valid, unlike the IPDV if/when every second packet is lost, no measurements pairs are valid. Thus I wonder whether it isn't better to remove IPDV from this doc and just mention PDV? Re: section 4.2.<begin edit> should/could it also report the mode (or modes if there are multiple equal peaks.) Should/could it also report several PDF percentile values.<end edit> Re: section 5. Raw vs. Restricted Capacity. The document (vis-a-vis data uniqueness) implies, but does not state, that results from TCP tests report values closer to the Restricted Capacity capacity because TCP only returns 1 copy of duplicate data to the application layer. Whereas UDP tests (esp with checksums disabled) report values closer to Raw Capacity. Re: section 7.2. Re: temporal aggregation. It might be worth noting to avoid possible synchronisation with network events by randomising the start times. e.g. if one started 20 second tests once every 10 minutes via cron, it could sync with other periodic "top of the minute" load and bias the results. Automated tests should start on pseudo-random (Poisson-like?) start times. Then the aggregate should more correctly reflect reality. All for now, Don
- Re: [ippm] http://tools.ietf.org/html/draft-ietf-… Donald McLachlan