IETF Logo Mail Archive

Re: [Tsvwg] reset of backoff with timestamps (RFC2988)

Reiner Ludwig <Reiner.Ludwig@ericsson.com> Tue, 29 July 2003 11:39 UTC

Received: from optimus.ietf.org (ietf.org [132.151.1.19] (may be forged)) by ietf.org (8.9.1a/8.9.1a) with ESMTP id HAA19256 for <tsvwg-archive@odin.ietf.org>; Tue, 29 Jul 2003 07:39:52 -0400 (EDT)
Received: from localhost.localdomain ([127.0.0.1] helo=www1.ietf.org) by optimus.ietf.org with esmtp (Exim 4.20) id 19hSpB-0007f2-UA for tsvwg-archive@odin.ietf.org; Tue, 29 Jul 2003 07:39:26 -0400
Received: (from exim@localhost) by www1.ietf.org (8.12.8/8.12.8/Submit) id h6TBdPdJ029415 for tsvwg-archive@odin.ietf.org; Tue, 29 Jul 2003 07:39:25 -0400
Received: from localhost.localdomain ([127.0.0.1] helo=www1.ietf.org) by optimus.ietf.org with esmtp (Exim 4.20) id 19hSon-0007dX-9T; Tue, 29 Jul 2003 07:39:01 -0400
Received: from odin.ietf.org ([132.151.1.176] helo=ietf.org) by optimus.ietf.org with esmtp (Exim 4.20) id 19hSoW-0007dI-Nb for tsvwg@optimus.ietf.org; Tue, 29 Jul 2003 07:38:44 -0400
Received: from ietf-mx (ietf-mx.ietf.org [132.151.6.1]) by ietf.org (8.9.1a/8.9.1a) with ESMTP id HAA19175 for <tsvwg@ietf.org>; Tue, 29 Jul 2003 07:38:40 -0400 (EDT)
Received: from ietf-mx ([132.151.6.1]) by ietf-mx with esmtp (Exim 4.12) id 19hSoW-0004a9-00 for tsvwg@ietf.org; Tue, 29 Jul 2003 07:38:44 -0400
Received: from albatross-ext.wise.edt.ericsson.se ([193.180.251.49] helo=albatross.tn.sw.ericsson.se) by ietf-mx with esmtp (Exim 4.12) id 19hSoV-0004a6-00 for tsvwg@ietf.org; Tue, 29 Jul 2003 07:38:43 -0400
Received: from esealnt613.al.sw.ericsson.se ([153.88.254.125]) by albatross.tn.sw.ericsson.se (8.12.9/8.12.9/WIREfire-1.6b) with ESMTP id h6TBceG6002875; Tue, 29 Jul 2003 13:38:40 +0200 (MEST)
Received: from eed.ericsson.se (mailhost.eed.ericsson.se [164.48.133.33]) by esealnt613.al.sw.ericsson.se with SMTP (Microsoft Exchange Internet Mail Service Version 5.5.2655.55) id N8XN34VL; Tue, 29 Jul 2003 13:38:40 +0200
Received: from res0010384da36.ericsson.com (dhcp5-109.eed.ericsson.se [164.48.135.109]) by eed.ericsson.se (8.8.8+Sun/1.1.mit) with ESMTP id NAA03643; Tue, 29 Jul 2003 13:38:39 +0200 (MET DST)
Message-Id: <5.2.0.9.0.20030729045316.024efa58@mailhost.eed.ericsson.se>
X-Sender: eedrel@mailhost.eed.ericsson.se
X-Mailer: QUALCOMM Windows Eudora Version 5.2.0.9
Date: Tue, 29 Jul 2003 13:39:23 +0200
To: Andrei Gurtov <gurtov@cs.helsinki.fi>
From: Reiner Ludwig <Reiner.Ludwig@ericsson.com>
Subject: Re: [Tsvwg] reset of backoff with timestamps (RFC2988)
Cc: tsvwg@ietf.org
In-Reply-To: <3F22F5C2.7050903@cs.helsinki.fi>
Mime-Version: 1.0
Content-Type: text/plain; charset="us-ascii"; format="flowed"
Sender: tsvwg-admin@ietf.org
Errors-To: tsvwg-admin@ietf.org
X-BeenThere: tsvwg@ietf.org
X-Mailman-Version: 2.0.12
Precedence: bulk
List-Unsubscribe: <https://www1.ietf.org/mailman/listinfo/tsvwg>, <mailto:tsvwg-request@ietf.org?subject=unsubscribe>
List-Id: Transport Area Working Group <tsvwg.ietf.org>
List-Post: <mailto:tsvwg@ietf.org>
List-Help: <mailto:tsvwg-request@ietf.org?subject=help>
List-Subscribe: <https://www1.ietf.org/mailman/listinfo/tsvwg>, <mailto:tsvwg-request@ietf.org?subject=subscribe>

At 23:42 26.07.2003, Andrei Gurtov wrote:
>Does TSV working group feel that it is appropriate? If yes, a following 
>correction could be submitted to RFC errata. 
>http://www.rfc-editor.org/errata.html
>
>(which can only happen when new data has been sent and acknowledged *or if 
>the timestamp option is used*)

This sounds fine to me. I always understood the text like that, anyway.

What this is saying is that the use of the TCP Timestamps option disables 
both parts of Karn's algorithm. That is, (1) an RTT sample can be taken 
from the ACK for retransmitted data, and (2) the RTO can be collapsed upon 
arrival of that ACK, i.e., it can be recomputed from SRTT and RTTVAR.

In fact, this is how it had already been implemented in BSD4.4-Lite.

///Reiner  


_______________________________________________
tsvwg mailing list
tsvwg@ietf.org
https://www1.ietf.org/mailman/listinfo/tsvwg

v2.23.0 | Report a Bug | By Email