Re: [tsvwg] RDMA Support by UDP FRAG Option

["C. M. Heard" <[e-mail]>]

On Mon, Jun 21, 2021 at 3:20 PM Joseph Touch wrote:

> It's true that OCS is optional when UDP CS==0, but my understanding is
> that per the current spec, if it is present, the receiver is required to
> check it and drop the options if it does not follow the rule specified for
> OCS.
>
>
> Yes, and that makes sense - if you’ve added OCS, regardless of whether the
> UDP CS==0 or not, then you want the options checked. All we currently have
> been saying is that “OCS can be omitted when CS==0”, not that it MUST be.
>
> And that rule is not that the surplus area sums to zero, but that the
> surplus area plus the pseudo-header consisting of the surplus are length
> sums to zero.
>
>
> It was originally (through draft-ietf-tsvwg-udp-options-05)  to cover the
> surplus area only; it was in the additional CCO-like behavior that it
> changed to add the pseudo header  (the surplus length). So are we going
> back to the pre-CCO definition?
>

I'm certainly not advocating for that! Tom Hernert seems to want that, but
I sure don't, and as I indicated in my reply to him, I think that going
back to the pre-CCO definition would undermine the chances of successful
deployment.

Mike