IETF Logo Mail Archive

Re: [ippm] draft-baillargeon-ippm-twamp-value-added-octets

Andreas Johnsson A <andreas.a.johnsson@ericsson.com> Fri, 06 May 2011 14:54 UTC

Return-Path: <andreas.a.johnsson@ericsson.com>
X-Original-To: ippm@ietfa.amsl.com
Delivered-To: ippm@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id BE543E0747 for <ippm@ietfa.amsl.com>; Fri, 6 May 2011 07:54:08 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -6.599
X-Spam-Level:
X-Spam-Status: No, score=-6.599 tagged_above=-999 required=5 tests=[BAYES_00=-2.599, RCVD_IN_DNSWL_MED=-4]
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 mCls2ysm876Z for <ippm@ietfa.amsl.com>; Fri, 6 May 2011 07:54:07 -0700 (PDT)
Received: from mailgw10.se.ericsson.net (mailgw10.se.ericsson.net [193.180.251.61]) by ietfa.amsl.com (Postfix) with ESMTP id 3821AE06EA for <ippm@ietf.org>; Fri, 6 May 2011 07:54:06 -0700 (PDT)
X-AuditID: c1b4fb3d-b7bd5ae000002ba3-27-4dc40b8ed768
Received: from esessmw0197.eemea.ericsson.se (Unknown_Domain [153.88.253.125]) by mailgw10.se.ericsson.net (Symantec Mail Security) with SMTP id 7B.B6.11171.E8B04CD4; Fri, 6 May 2011 16:54:06 +0200 (CEST)
Received: from ESESSCMS0363.eemea.ericsson.se ([169.254.2.67]) by esessmw0197.eemea.ericsson.se ([153.88.115.87]) with mapi; Fri, 6 May 2011 16:54:05 +0200
From: Andreas Johnsson A <andreas.a.johnsson@ericsson.com>
To: 'Xiangsong Cui' <Xiangsong.Cui@huawei.com>, Christofer Flinta <christofer.flinta@ericsson.com>, 'Henk Uijterwaal' <henk@uijterwaal.nl>, "ippm@ietf.org" <ippm@ietf.org>
Date: Fri, 06 May 2011 16:54:05 +0200
Thread-Topic: [ippm] draft-baillargeon-ippm-twamp-value-added-octets
Thread-Index: Acv0+75834dEnQOmRfmxSCKQk56+owURALxQAA6U49AAIV9eMAB/agWQ
Message-ID: <3B05069A569E6F4AB6397B968734EBEA196F7FB77A@ESESSCMS0363.eemea.ericsson.se>
References: <4383945B8C24AA4FBC33555BB7B829EF0DEC351277@EUSAACMS0701.eamcs.ericsson.se> <4D9D7225.6080506@uijterwaal.nl> <00e201cc0944$3c598e70$b50cab50$%cui@huawei.com> <8BB85B4B99C85249B3D5D006D534001D19F3CC1309@ESESSCMS0361.eemea.ericsson.se> <00af01cc0a00$2ebf79c0$8c3e6d40$%cui@huawei.com>
In-Reply-To: <00af01cc0a00$2ebf79c0$8c3e6d40$%cui@huawei.com>
Accept-Language: en-US
Content-Language: en-US
X-MS-Has-Attach:
X-MS-TNEF-Correlator:
acceptlanguage: en-US
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: quoted-printable
MIME-Version: 1.0
X-Brightmail-Tracker: AAAAAA==
Subject: Re: [ippm] draft-baillargeon-ippm-twamp-value-added-octets
X-BeenThere: ippm@ietf.org
X-Mailman-Version: 2.1.12
Precedence: list
List-Id: IETF IP Performance Metrics Working Group <ippm.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/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: Fri, 06 May 2011 14:54:08 -0000

Hi Xiangsong,
We are drifting away from the topic here. What we want to do is to include functionality in the TWAMP spec for measuring available capacity in both the forward and reverse direction. This interest was also raised by for example Al and Yaakov (maybe throughput was the main idea here?). The problems with loss measurements are outside the scope of this discussion, but do belong to draft-ietf-ippm-rt-loss-00 by Al.

There seem to be a little bit of confusion when it comes to TWAMP. As you know, TWAMP time stamps packets when a packet is sent at the session sender, when it is received at the reflector, when it is sent by the reflector and when it is again received by the session sender. From this it is very easy to deduct forward and reverse delay, and with our proposal also forward and reverse available capacity. Sure, OWAMP can be used to do these measurements, but the intention with TWAMP is to perform both measurements in both directions (and round trip) with only one trigger. I think this is a strong argument for trying to put new functionality into TWAMP and not only focus on OWAMP.

I hope this resolves any issues you have with the intention with our draft, although maybe the draft needs to be enhanced or split into several. Suggestions are welcome.

Best regards
Andreas Johnsson 

-----Original Message-----
From: ippm-bounces@ietf.org [mailto:ippm-bounces@ietf.org] On Behalf Of Xiangsong Cui
Sent: Wednesday, May 04, 2011 4:09 AM
To: Christofer Flinta; 'Henk Uijterwaal'; ippm@ietf.org
Subject: Re: [ippm] draft-baillargeon-ippm-twamp-value-added-octets


> This draft is trying to provide a means for measuring the capacity in 
> both
the
> forward and reverse directions as two separate measurements. This is
similar
> to the current capabilities of TWAMP, where e.g. delay and packet loss 
> can
be
> measured separately in both directions. 

If you are referring to one-way metric, e.g. one-way packet loss, how can you get the one-way metric by the two-way test?
That said, how can the session-sender get to know whether the packet is lost before or after the session-reflector?

Regards,
Xiangsong


_______________________________________________
ippm mailing list
ippm@ietf.org
https://www.ietf.org/mailman/listinfo/ippm

v2.23.0 | Report a Bug | By Email