Re: [mpls] Last Call: <draft-ietf-mpls-in-udp-04.txt> (Encapsulating MPLS in UDP) to Proposed Standard

[Curtis Villamizar <[e-mail]>]

In message <[e-mail]>
[e-mail] writes:
> 
> "ASICs can't do IPv6 in hardware! IPv6 can only be done with slow
> software forwarding! We're stuck with v4!"
>  
> I think we've been here before.
>  
> Lloyd Wood
> http://about.me/lloydwood


At what point does this discussion no longer have any relevance at all
to draft-ietf-mpls-in-udp?

The draft is going to say SHOULD wrt UDP checksums.  If you have an
issue with the wording of the draft, please comment on the draft.

Curtis


> ________________________________________
> From: mpls [[e-mail]] On Behalf Of Joe Touch [[e-mail]]
> Sent: 27 January 2014 19:24
> To: Joel M. Halpern; joel jaeggli; [e-mail]
> Cc: [e-mail]; IETF discussion list
> Subject: Re: [mpls] Last Call: <draft-ietf-mpls-in-udp-04.txt> (Encapsulating MPLS in UDP) to Proposed Standard
>  
> On 1/27/2014 11:19 AM, Joel M. Halpern wrote:
> > Yes Joe, routers could ahve been built to do those calcualtions at that
> > performance scale.
> > There are however two major problems:
> >
> > 1) That is not how routers are built.
> > 2) The target performance scale is rather higher.
> >
> > So could someone build an ASIC to do what you want?
>  
> Has. It's already part of nearly every DMA ASIC in a network interface
> already.
>  
>  > Probably.  Is there
> > any reason in the world to expect operators to pay the significant extra
> > cost for such?Not that I can see.
>  
> We're talking about a ring of full adders, the specs for which are given
> in an RFC that's 18 years old, and that is already implemented in nearly
> every host interface, including 10Gps NICs.
>  
> And we're talking about "routers", many variants of which operate at
> very high speeds and transparently proxy TCP already. So this is a
> solved problem.
>  
> > And even if we could and they would, that is not the world into which we
> > are deploying these tunnels.
>  
> We're back to "that's not what they do now", at least in some devices.
>  
> Well, they don't use MPLS in UDP (since no spec exists), so clearly if
> they're limited to doing what they already do, this is an exercise in
> futility.
>  
> Joe
>  
> >
> > Yours,
> > Joel
> >
> > On 1/27/14 1:53 PM, Joe Touch wrote:
> >>
> >>
> >> On 1/27/2014 10:48 AM, joel jaeggli wrote:
> >>> On 1/27/14, 8:48 AM, Joe Touch wrote:
> >>>> Those same mechanisms have provided hardware checksum support for a
> >>>> very long time.
> >>>
> >>> The new header and the payload are actually in different parts of the
> >>> forwarding complex until they hit the output queue, you can't checksum
> >>> data you don't have.
> >>
> >> You can (and some do) the checksum component parts when things go into
> >> memory; the partial sums can be added as the parts are combined in the
> >> output queue.
> >>
> >> I appreciate that we're all taking about what might be done, but the
> >> reality is that there are many 'transparent TCP proxies' that have to do
> >> this, so there's clearly a solution, and it clearly runs fast enough.
> >>
> >> Joe