Re: [tsvwg] UDP options and header-data split (zero copy)

"C. M. Heard" <heard@pobox.com> Mon, 02 August 2021 23:00 UTC

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From: "C. M. Heard" <heard@pobox.com>
Date: Mon, 02 Aug 2021 16:00:18 -0700
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To: Joe Touch <touch@strayalpha.com>
Cc: Sebastian Moeller <moeller0@gmx.de>, Tom Herbert <tom@herbertland.com>, TSVWG <tsvwg@ietf.org>
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Subject: Re: [tsvwg] UDP options and header-data split (zero copy)
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On Mon, Aug 2, 2021 at 3:54 PM Joe Touch <touch@strayalpha.com> wrote:

>
>
> On Aug 2, 2021, at 3:13 PM, C. M. Heard <heard@pobox.com> wrote:
>
> 
> On Mon, Aug 2, 2021 at 12:31 PM Joe Touch wrote:
>
>> At a minimum, because there are options that could be used in either
>> place, eg. OCS, AUTH, and ENCR at least.
>
>
> The per-fragment OCS icovers both the fragment data and the options. Is
> there really a justification for a per-datagram version? I think not ...
> though of course opinions vary ...
>
>
> It would be a reassembly check, if that were desired.
>

We went through this discussion regarding a reassembly checksum for the
data and decided NOT to have one of those that uses the same checksum
algorithm as the one that covers the fragments. An extension of ACS to
cover reassembled per-datagram options (or another option similar to it but
covering just the options) would be a better choice, I think.

Mike