RE: [tcpm] WGLC for UTO

<> Wed, 10 October 2007 15:26 UTC

Return-path: <>
Received: from [] ( by with esmtp (Exim 4.43) id 1IfdRp-0002S5-6y; Wed, 10 Oct 2007 11:26:09 -0400
Received: from tcpm by with local (Exim 4.43) id 1IfdRm-0002RV-RJ for; Wed, 10 Oct 2007 11:26:06 -0400
Received: from [] ( by with esmtp (Exim 4.43) id 1IfdRm-0002RD-Ej for; Wed, 10 Oct 2007 11:26:06 -0400
Received: from ([]) by with esmtp (Exim 4.43) id 1IfdRl-00085f-UT for; Wed, 10 Oct 2007 11:26:06 -0400
Received: from ([]) by with Microsoft SMTPSVC(6.0.3790.1830); Wed, 10 Oct 2007 16:26:05 +0100
X-MimeOLE: Produced By Microsoft Exchange V6.5
Content-class: urn:content-classes:message
MIME-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: quoted-printable
Subject: RE: [tcpm] WGLC for UTO
Date: Wed, 10 Oct 2007 16:22:18 +0100
Message-ID: <>
In-Reply-To: <>
Thread-Topic: [tcpm] WGLC for UTO
Thread-Index: AcgLQ0KJZRmr48wbRky8tgHms9+eQQACfPsg
X-OriginalArrivalTime: 10 Oct 2007 15:26:05.0034 (UTC) FILETIME=[DF84D4A0:01C80B51]
X-Spam-Score: 0.0 (/)
X-Scan-Signature: 6cca30437e2d04f45110f2ff8dc1b1d5
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: TCP Maintenance and Minor Extensions Working Group <>
List-Unsubscribe: <>, <>
List-Post: <>
List-Help: <>
List-Subscribe: <>, <>

Generally the UTO draft seems absolutely fine and I would support it
moving to RFC. There seems no obvious reason for it to be experimental
rather than proposed standard. 

I do have one potential concern and some nits:


Section 4.1 Middleboxes suggests that "In the future, such [stateful]
firewalls may learn to parse the TCP User Timeout Option and adapt
connection state management accordingly." Would it be worth adding that
in this case this could become a potential security issue as it would
allow cooperative users to cause a stateful firewall to maintain
connection state for over 22 hours?


Section 3: 
'LOCAL_UTO' "If unspecified, it default to the default system-wide USER
TIMEOUT." change to "...defaults to the default..."

Para starting 'Before opening a connection...' "The default is to allow
this for connections that do not have a specific user timeout concerns."
delete "a"
" prevent UTO options from the other end to override local
application requests." change to "options from the other end overriding

Next para: "... is a reliable way to initially exchange and potentially
adapt to UTO values." add commas: "... is a reliable way to initially
exchange, and potentially adapt to, UTO values."

Section 3.1 para 1. Delete the first comma in the last sentence so it
reads: "In this case they SHOULD, however, notify the application about
the user timeout value received from the other end."

Para starting "This means that..." change last sentence (remove
nevertheless) " can still close or abort..."

Section 4.2 last sentence change to "Therefore, if a connection that
enables keep-alives is also using the TCP User Timeout Option, ..."


Toby Moncaster, <> Networks Research Centre, BT
B54/70 Adastral Park, Martlesham Heath, Ipswich, IP53RE, UK.  +44 1473

-----Original Message-----
From: Mark Allman [] 
Sent: 10 October 2007 14:36
Subject: [tcpm] WGLC for UTO


We are starting a WGLC on the UTO specification,
draft-ietf-tcpm-tcp-uto-06.txt.  We believe the document has addressed
the concerns raised by the WG and that there is good consensus for
publishing the document.  Our charter says the intended status for the
document is "Proposed Standard".  However, in the draft tracker it says
"Experimental".  We cannot seem to recall crisply deciding this issue.
So, please review the document one last time and raise issues on the
mailing list and please also weigh in on whether you think it should be
Experimental or Proposed Standard.  Also, notes of the form "looks fine
to me" are encouraged.  The WGLC will run through October 24.

Mark & Ted

tcpm mailing list