Re: UDP encaps for SCTP and SCCP

[Bob Briscoe <[e-mail]>]

Lars,

At 08:37 18/05/2010, Lars Eggert wrote:
>Hi,
>
>the discussion has touched on lots of things related to UDP encaps, 
>but I haven't seen anything I'd call consensus on the question 
>below. I'd therefore like to ask folks to specifically state which 
>option they support:
>
>(1) do one SCTP-specific and one DCCP-specific UDP encaps
>(2) do one generic UDP encaps that can be used with both
>(3) do neither (don't do any sort of UDP encaps for SCTP and DCCP)

I vote for (2), which requires more work (and may turn out not to be 
possible), but GUT is a good start. It can also be used to encap new 
TCP options if/when they get dropped by middleboxes (e.g. MPTCP, 
window scaling, ECN).

Second pref is (3), given existing tunnelling can be used, but it's 
heavyweight for some apps.


Bob


>Thanks,
>Lars
>
>On 2010-4-22, at 12:57, Eggert Lars (Nokia-NRC/Espoo) wrote:
> > Hi,
> >
> > as most of you probably know, there are two different proposals 
> for how to encapsulate SCTP and DCCP inside UDP.
> >
> > One approach proposes two protocol-specific encapsulation schemes 
> (described in draft-tuexen-sctp-udp-encaps and draft-ietf-dccp-udpencap).
> >
> > The second approach proposes a generic encapsulation scheme that 
> can be applied to both SCTP and DCCP (draft-manner-tsvwg-gut).
> >
> > As a community, we do need to come to consensus on which of these 
> two approaches we want to follow when it comes to UDP encapsulation 
> of SCTP and DCCP. I believe it would be very confusing if we were 
> to standardize both approaches.
> >
> > I'd hence like to ask folks to read the three documents and post 
> their views to the [e-mail] list. I'm personally especially 
> interested in hearing from folks who aren't on the author lists of 
> the documents, but obviously, the authors expert opinions do matter.
> >
> > Thanks,
> > Lars
> >
> > PS: I'm pushing on this topic, because UDP encapsulation is the 
> last remaining work item in the DCCP working group before it can close...
>
>

________________________________________________________________
Bob Briscoe,                                BT Innovate & Design