Re: [Spud] New Version Notification for draft-kuehlewind-spud-use-cases-00.txt

[Brian Trammell <[e-mail]>]

hi Joe, all,

> On 08 Jul 2015, at 22:07, Joe Touch <[e-mail]> wrote:
> 
> 
> 
> On 7/8/2015 9:27 AM, Brian Trammell wrote:
>>> This is the appropriate
>>>> place for the policy/QoS information information described in the use
>>>> cases, and there are already facilities for both hop-by-hop options
>>>> and allowing middle boxes to modify options inflight.
>> 
>> Indeed. This presumes that new IP options are more realistically
>> widely deployable in the Internet than a new protocol over UDP. I would
>> need to see some data to back that up (indeed, this would fit nicely in
>> a measurement study we're running right now so we may well end up
>> generating that data. :) )
> 
> Check the discussions over in v6ops.
> 
> There has been a lot of work there trying to deprecate all IPv6 options,
> which has at least been successful in limiting the length of the option
> chain.
> 
> One challenge is that IPv6 options are processed differently than IPv4 -
> there's no way to "jump" straight into the transport header to find
> ports (for port-based load balancing, e.g.).

Yep. If the option chain had a small and easily-hardware-determinable set of possible lengths -- which is the case for v4 options -- this would be easier (but still harder to handle on the fast path than the arrangements we're proposing here).

> I suspect you'll find that IP options are basically a non-starter except
> for research purposes.

For the story on the v4 side, do you know of anything newer than Fonseca et al "IP Options are Not and Option" (tech report version at http://www.eecs.berkeley.edu/Pubs/TechRpts/2005/EECS-2005-24.pdf)? It's ten years old -- but given where the engineering effort has gone during that decade, I doubt strongly much has changed here.

Cheers,

Brian

> Joe
> 
> _______________________________________________
> Spud mailing list
> [e-mail]
> https://www.ietf.org/mailman/listinfo/spud