Re: Hard questions (was: Diffserv PIB approved as Informational RFC)

Dan Grossman wrote:
> 
> Kathie,
> Comments inline
> 
> Kathleen Nichols wrote:
> 
> > Dan,
> >
> > You do have to consider whether these "hard questions" are best
> > answered by an IETF working group. It seems that the next steps
> > require deployment experience not more standards.
> 
> Actually, I was quite careful about what I asked the group to consider and why.  I wonder
> if the lack of deployment experience might not result, in part, from  our work  not being
> complete enough to deploy.

If by "our work" you mean the IETF Diffserv WG, then I'm still
not convinced that we need more IETF work at this time. If
by "our work" you mean the Internet community in the tradition
of running code, then I agree that more work is needed, but
we are in a chicken-and-egg situation, perhaps exacerbated
by the fall-out amoung service providers.

...(non-issue deleted)
> >
> > As for PDBs, Brian and I passed the bulk handling PDB on for its
> > next revision to be done by Roland Bless and Klaus Wehrle. They
> > are renaming it to Lower Effort PDB and did send us a revision
> > last week. As the WG is closing this can be submitted as
> > an individual draft, thought discussion should probably take
> > place on this list.
> 
> Good, I suppose, although I recollect that the need for such a PDB was controversial at
> best.  I was among those who did not appreciate the need for such a PDB.  'twould be a pity
> if that were the only one.

We heard from a number of enterprise operators and someone
who sells to them (Yoram Bernet when he was a Microsoft)
as well as a couple of service providers that this was
interesting. It isn't for everyone, but I expect no PDB
will be.

....(my stuff deleted)
> 
> My perception was that many people believed that Diffserv would allow delay-jitter
> sensitive telephony, video and multimedia application flows to be aggregated and
> transported over a stateless core.  This was believed by many to be _the_ principal
> application of Diffserv. 

So, I'm slightly astounded at this. This is where I put a lot
of technical time myself, but I heard early on in this process
(well before there was a diffserv WG) that many SPs didn't
even have this on their radar but just wanted some rough
differentiation, the kind of thing you can do with multiple
RR queues. You might take a look at the minutes of Brian's
original BoF. 

If someone knocks on my door with real interest in deploying a
delay-jitter sensitive PDB, I answer.

...(my stuff deleted)
> There are a lot of claimed implementations.  Whether these are substantive or not may be
> another question.  I suppose we won't know until there's be a call for implementation reports.
> 

Well, we have asked for this several times. Look at the diffserv
mailing list and meeting minutes. 
...(previous stuff deleted for brevity and not really an issue)
> 
> Perhaps you're thinking about something beyond the kind of 5-tuple classification that we
> discussed in the Model and elsewhere?
> 
Perhaps I am. I called out two kinds of classifiers in
the pre-WG strawman, a DSCP classifier and a multiple
field classifier. The common 5-tuple was given as
an *example* of the latter, not the end-all. Multiple
fields was just that. Yes, I know some routers have
implemented this, but perhaps not enough or perhaps
it has not been made easy to set these up.
> >
> >
> > You correctly note that there are difficult problems that remain in
> > diffserv, but it's not clear that they can be solved in an IETF WG.
> > So, I would say that we are taking a breather before finishing the
> > job and further that the breather is required so we can get some
> > experience.
> 
> I think that addresses my question.  The question back to you is "until when"?
> 

I think you need to address that question to our AD. I'm not
sure what event would be considered the appropriate one
to start a new WG, though I heard in NSIS that they wanted
to take another stab at defining "quality of service classes"
so maybe the charter is going to be changed.

	Kathie

_______________________________________________
diffserv mailing list
[email protected]
https://www1.ietf.org/mailman/listinfo/diffserv
Archive: http://www.ietf.org/mail-archive/working-groups/diffserv/current/maillist.html