Re: [tsvwg] Fwd: New Version Notification for draft-touch-tsvwg-udp-options-05.txt
Joe Touch <touch@isi.edu> Tue, 28 February 2017 22:20 UTC
Return-Path: <touch@isi.edu>
X-Original-To: tsvwg@ietfa.amsl.com
Delivered-To: tsvwg@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id E0F34128DF6 for <tsvwg@ietfa.amsl.com>; Tue, 28 Feb 2017 14:20:14 -0800 (PST)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -1.901
X-Spam-Level:
X-Spam-Status: No, score=-1.901 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, RP_MATCHES_RCVD=-0.001] autolearn=ham autolearn_force=no
Received: from mail.ietf.org ([4.31.198.44]) by localhost (ietfa.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 8qCSdf5Szwm4 for <tsvwg@ietfa.amsl.com>; Tue, 28 Feb 2017 14:20:14 -0800 (PST)
Received: from nitro.isi.edu (nitro.isi.edu [128.9.208.207]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id E4BB3128AC9 for <tsvwg@ietf.org>; Tue, 28 Feb 2017 14:20:13 -0800 (PST)
Received: from [128.9.160.81] (nib.isi.edu [128.9.160.81]) (authenticated bits=0) by nitro.isi.edu (8.13.8/8.13.8) with ESMTP id v1SMK6xL012826 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES128-SHA bits=128 verify=NOT); Tue, 28 Feb 2017 14:20:07 -0800 (PST)
To: tsvwg <tsvwg@ietf.org>
References: <148823787288.13843.6091386736320524682.idtracker@ietfa.amsl.com> <800de1a6-cb9b-f22b-946a-8b6832fc9a05@isi.edu> <20170228163751.GA89477@cowbell.employees.org> <7d58ead9-2d1a-d35c-7cd2-90526918838c@isi.edu> <20170228204607.GA71184@cowbell.employees.org> <d03f54c3-46cd-7023-0d2f-70b3831ad067@isi.edu> <20170228213620.GA4674@cowbell.employees.org>
From: Joe Touch <touch@isi.edu>
Message-ID: <20c0adc2-816a-0a92-8bc4-3b890c896eb3@isi.edu>
Date: Tue, 28 Feb 2017 14:20:07 -0800
User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.7.1
MIME-Version: 1.0
In-Reply-To: <20170228213620.GA4674@cowbell.employees.org>
Content-Type: text/plain; charset="windows-1252"
Content-Transfer-Encoding: 7bit
X-MailScanner-ID: v1SMK6xL012826
X-ISI-4-69-MailScanner: Found to be clean
X-MailScanner-From: touch@isi.edu
Archived-At: <https://mailarchive.ietf.org/arch/msg/tsvwg/UlRumJ4xVTVDqHHvkS9ozCYBIow>
Subject: Re: [tsvwg] Fwd: New Version Notification for draft-touch-tsvwg-udp-options-05.txt
X-BeenThere: tsvwg@ietf.org
X-Mailman-Version: 2.1.17
Precedence: list
List-Id: Transport Area Working Group <tsvwg.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/tsvwg>, <mailto:tsvwg-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/tsvwg/>
List-Post: <mailto:tsvwg@ietf.org>
List-Help: <mailto:tsvwg-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/tsvwg>, <mailto:tsvwg-request@ietf.org?subject=subscribe>
X-List-Received-Date: Tue, 28 Feb 2017 22:20:15 -0000
Hi, Derek, On 2/28/2017 1:36 PM, Derek Fawcus wrote: > On Tue, Feb 28, 2017 at 01:16:07p.m. -0800, Joe Touch wrote: >>> Sorry, I've lost the thread here. >>> >>> I was not suggesting altering how the normal UDP checksum works. >>> >>> I was mainly driving at how in implementing this in a host stack I'd >>> like to verify the options. Namely that in the absense of the Lite >>> option, it would allow one to use the existing checksum validation >>> routine to run across the whole of the surplus area, and if it summed >>> to the usual (1's complement) zero, it is good. >> I'm not sure I see that. >> The existing checksum runs over the IP pseudoheader, the UDP header, and >> the UDP body. >> >> OCS runs over just the option area. >> >> Even in the absence of LITE, the UDP checksum wouldn't cover the option >> area. > We're at cross purposes here... > > I'm not suggesting altering the UDP checksum, I'm referring to replacing > (discarding) the OCS option. > > So in section 4, figure 3 where you describe the surplus area, which is > essentially an array of bytes used for options. I'm proposing instead to > give it a structure: > > +------+-------+ > | checksum | > +------+-------+ > ... options ... > +------+-------+ > > Where options is zero or more options as you describe (omitting OCS). We discussed that before. The issue is whether OCS is optional or not. If it isn't, yes - it can come first as you note. > Where checksum is the usual checksum algorith over the whole of the > surplus area. i.e. such that when the receiver sums the whole of the > area checksum through to the end of options, it should sum to 1s-complement > zero. (taking in to consideration the length of options being odd). > > Then for your LITE header scheme, still require that the LITE header > be the first option, and rather than swap 4 bytes (the LITE header) > as you describe, instead swap 6 bytes (the checksum followed by the > LITE header). Hence why I was the referring to partial sums. I see now. Yes, that's another possibility. It depends on what the WG wants in terms of whether OCS is optional or not. Joe
- [tsvwg] Regarding DTLS and UDP options Joe Touch
- Re: [tsvwg] Regarding DTLS and UDP options Gorry Fairhurst
- Re: [tsvwg] Regarding DTLS and UDP options Joe Touch
- Re: [tsvwg] Regarding DTLS and UDP options Tom Herbert
- Re: [tsvwg] Regarding DTLS and UDP options Joe Touch
- Re: [tsvwg] Regarding DTLS and UDP options Joe Touch
- Re: [tsvwg] Regarding DTLS and UDP options Joe Touch
- Re: [tsvwg] Regarding DTLS and UDP options Tom Herbert
- Re: [tsvwg] Regarding DTLS and UDP options Joe Touch
- Re: [tsvwg] Regarding DTLS and UDP options Tom Herbert
- Re: [tsvwg] Regarding DTLS and UDP options Joe Touch
- Re: [tsvwg] Regarding DTLS and UDP options Tom Herbert
- Re: [tsvwg] Regarding DTLS and UDP options Joe Touch
- Re: [tsvwg] Regarding DTLS and UDP options Joe Touch
- Re: [tsvwg] Regarding DTLS and UDP options Tom Herbert
- Re: [tsvwg] Regarding DTLS and UDP options Gorry Fairhurst
- Re: [tsvwg] Regarding DTLS and UDP options Tom Herbert
- Re: [tsvwg] Regarding DTLS and UDP options Tom Herbert
- Re: [tsvwg] Regarding DTLS and UDP options Joe Touch
- Re: [tsvwg] Regarding DTLS and UDP options Tom Herbert
- Re: [tsvwg] Regarding DTLS and UDP options Joe Touch
- Re: [tsvwg] Regarding DTLS and UDP options Joe Touch
- [tsvwg] Fwd: New Version Notification for draft-t… Joe Touch
- Re: [tsvwg] Fwd: New Version Notification for dra… Derek Fawcus
- Re: [tsvwg] New Version Notification for draft-to… C. M. Heard
- Re: [tsvwg] Fwd: New Version Notification for dra… Joe Touch
- Re: [tsvwg] Fwd: New Version Notification for dra… Tom Herbert
- Re: [tsvwg] New Version Notification for draft-to… Joe Touch
- Re: [tsvwg] Fwd: New Version Notification for dra… Derek Fawcus
- Re: [tsvwg] Fwd: New Version Notification for dra… Tom Herbert
- Re: [tsvwg] Fwd: New Version Notification for dra… Joe Touch
- Re: [tsvwg] Fwd: New Version Notification for dra… Joe Touch
- Re: [tsvwg] Fwd: New Version Notification for dra… Derek Fawcus
- Re: [tsvwg] Fwd: New Version Notification for dra… Derek Fawcus
- Re: [tsvwg] Fwd: New Version Notification for dra… Joe Touch
- Re: [tsvwg] Fwd: New Version Notification for dra… Tom Herbert
- Re: [tsvwg] Fwd: New Version Notification for dra… Joe Touch
- Re: [tsvwg] Fwd: New Version Notification for dra… Joe Touch
- [tsvwg] summary of issues for draft-touch-tsvwg-u… Joe Touch
- Re: [tsvwg] Fwd: New Version Notification for dra… Tom Herbert
- Re: [tsvwg] New Version Notification for draft-to… C. M. Heard
- Re: [tsvwg] Fwd: New Version Notification for dra… Joe Touch
- Re: [tsvwg] New Version Notification for draft-to… Joe Touch
- Re: [tsvwg] New Version Notification for draft-to… C. M. Heard
- Re: [tsvwg] New Version Notification for draft-to… Joe Touch
- Re: [tsvwg] New Version Notification for draft-to… C. M. Heard
- Re: [tsvwg] New Version Notification for draft-to… Joe Touch
- Re: [tsvwg] New Version Notification for draft-to… Gorry Fairhurst
- Re: [tsvwg] New Version Notification for draft-to… C. M. Heard
- Re: [tsvwg] New Version Notification for draft-to… Joe Touch
- Re: [tsvwg] New Version Notification for draft-to… C. M. Heard
- Re: [tsvwg] New Version Notification for draft-to… Joe Touch
- Re: [tsvwg] New Version Notification for draft-to… Gorry Fairhurst
- Re: [tsvwg] New Version Notification for draft-to… C. M. Heard
- Re: [tsvwg] New Version Notification for draft-to… Joe Touch