Re: [tsvwg] draft-ietf-udp-options issues from IETF 104

[Joe Touch <[e-mail]>]

Focusing on the end part...

On 2019-07-16 13:42, C. M. Heard wrote:

> In-line followups where where they seem to be warranted. 
> ... 
> 
>> Many of these simply won't work as automatically legacy-compatible with 
>> draft-herbert; the legacy data can easily exceed its limits, at a minimum. 
> 
> My take (as stated in the long message) is that we probably want both the 
> trailer format pretty much as defined in draft-ietf-tsvwg-udp-options-07 
> for the backward compatible / safe to ignore  options (MSS, TIME, REQ, RES, 
> dummy FRAG used for negotiation) and and a variant of the header format as 
> defined in draft-herbert for the others.

Safe-to-ignore needs the current structure, which isn't draft-herbert
compatible (because data can easily exceed the limit). 

udp-options in general aren't draft-herbert compatible because we do not
have (nor IMO do we want) a strict limit on using the option length for
udp-options. 
Unsafe-to-ignore can use LITE, at which point we can add - if needed - a
flag to force receivers to check OCS on receipt (to differentiate the
closest we can come to LITE vs. something close enough IMO to the
draft-herbert header approach).. 

Joe