From: Andreas Johnsson A <andreas.a.johnsson@ericsson.com>
To: "pmol@ietf.org" <pmol@ietf.org>
Date: Mon, 2 Jul 2012 11:31:22 +0200
Thread-Topic: [PMOL] Fwd: I-D Action: draft-sun-tsvwg-flowbased-pm-00.txt
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Message-ID: <3B05069A569E6F4AB6397B968734EBEA52499253DC@ESESSCMS0363.eemea.ericsson.se>
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Subject: Re: [PMOL] Fwd: I-D Action: draft-sun-tsvwg-flowbased-pm-00.txt
Precedence: list

Hi,
I have tried to put together a short review. Please see my comments below (=
and please provide further comments).

Best regards,
Andreas Johnsson

-----

Comments on draft-sun-tsvwg-flowbased-pm-00.txt.

1) The draft describes a new active measurement protocol with the aim of me=
asuring delay, jitter and loss over an IP path. The protocol is similar to =
TWAMP (RFC5357), however the measurement setup is performed in a TCP-like m=
anner instead of using a specific control plane. Despite its similarities t=
o TWAMP there are no references nor does the draft contain a comparison.=20

2) The draft includes a description on how to calculate statistics based on=
 time stamps obtained by the protocol. The metrics are delay, jitter and lo=
ss. An advice is to use RFC 6390 section 5.4.5 guidelines for describing th=
e metrics.=20

3) The draft does not reference prior art in IPPM (or elsewhere) related to=
 delay, jitter or loss. Suggested documents are=20

IPPM Delay (http://tools.ietf.org/html/rfc2679)
IPPM Loss (http://tools.ietf.org/html/rfc2680)
IPPM Delay variation (http://www.ietf.org/rfc/rfc3393.txt)

ITU-T Y.1540 (http://www.itu.int/rec/T-REC-Y.1540-200711-S)

4) I would like the authors to elaborate on their delay calculation method.=
 The draft assumes that the forward delay is always equal to the reverse de=
lay. How often is this the case?

5) The jitter calculations are based upon the delay calculations. Since the=
 delay is calculated as the RTT (minus the time a packet spends at the PM r=
esponder) divided by 2, the jitter will be the same in both directions. Doe=
s this really reflect what is happening on the path? Please elaborate on th=
is.




-----Original Message-----
From: pmol-bounces@ietf.org [mailto:pmol-bounces@ietf.org] On Behalf Of Al =
Morton
Sent: den 29 juni 2012 13:58
To: pmol@ietf.org
Subject: [PMOL] Fwd: I-D Action: draft-sun-tsvwg-flowbased-pm-00.txt

After reading the abstract, I just said "wow".

Would anyone volunteer to review this in a timely way?

Al
pmol admin


>From: internet-drafts@ietf.org
>To: i-d-announce@ietf.org
>Subject: I-D Action: draft-sun-tsvwg-flowbased-pm-00.txt
>X-Test-IDTracker: no
>X-IETF-IDTracker: 4.21p1
>Date: Fri, 29 Jun 2012 01:40:50 -0700
>X-BeenThere: i-d-announce@ietf.org
>X-Mailman-Version: 2.1.12
>Reply-To: internet-drafts@ietf.org
>
>
>A New Internet-Draft is available from the on-line Internet-Drafts=20
>directories.
>
>
>         Title           : Flow-based Performance Measurement
>         Author(s)       : Lishun Sun
>                           Wendong Wang
>                           Fang Yu
>         Filename        : draft-sun-tsvwg-flowbased-pm-00.txt
>         Pages           : 15
>         Date            : 2012-06-29
>
>Abstract:
>    The performance measurements of service flow are becoming significant
>    important for administrators monitoring the fitness of the network.
>    This memo defines an end-to-end application-based performance
>    measurement method, which is achieved by generating synthetic
>    measurement packets, injecting them to the network and analyzing the
>    statistics carried in the measurement packets.
>
>
>The IETF datatracker status page for this draft is:
>https://datatracker.ietf.org/doc/draft-sun-tsvwg-flowbased-pm
>
>There's also a htmlized version available at:
>http://tools.ietf.org/html/draft-sun-tsvwg-flowbased-pm-00
>
>
>Internet-Drafts are also available by anonymous FTP at:
>ftp://ftp.ietf.org/internet-drafts/
>
>_______________________________________________
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>Internet-Draft directories: http://www.ietf.org/shadow.html or=20
>ftp://ftp.ietf.org/ietf/1shadow-sites.txt

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