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

[Derek Fawcus <[e-mail]>]

On Thu, Jul 11, 2019 at 07:07:39PM -0700, Joe Touch wrote:
> 
> Not sure I follow here - so there are only a few variants that seem viable:
> 
> 1.- at the front of the surplus space
> 2.- at the front of the surplus space after alignment NOPs
> 3.- at the end of the surplus space
> 4.- at the end of the surplus space with alignment
> 
> AFAICT, there’s no real help in requiring OCS be aligned (it can be designed to tolerate any alignment), which means we don’t need #2 or #4.

Agree.  I see no need for alignment.

> So what’s preferable here? #1 or #3?

Not sure.

I'd be inclined to pick 1, but could be convinced that 3 is better.

If we're talking of h/w offload engines [*], I imagine that they could
handle 'write to 2 bytes before end of packet' more easily than
'write to start of surplus'.

DF

[*] How many do this with random logic?  My current impression is that
    most such devices are programmable cores, e.g. ARM or MIPS cores.