Subject: RE: [Diffserv] DHCP user class

From: John Schnizlein <[email-masked]>
Date: Mon, 10 Jul 2000 14:44:10 -0400

??
I had to check which mailing list this objection was on.
I am surprised to see a preference for signalling on the Diff-Serv list.

Why not enable simple, static classifiers for single-user computers
(the sort most often using DHCP for address assignment)? This seems
perfectly consistent with the minimalist model in RFC 2474.

Why should a simple extension of DHCP to support this simple model
require an explanation of relationships between various models?
Adding building blocks and observing if they are used in practice
is a reasonable approach.

RFC 2474 says
   Differentiated services enhancements to the Internet protocol are
  intended to enable scalable service discrimination in the Internet
   without the need for per-flow state and signaling at every hop.  
...
   The configuration of network elements with respect to which packets
   get special treatment and what kinds of rules are to be applied to
   the use of resources is much less well-understood.  Nevertheless, it
   is possible to deploy useful differentiated services in networks by
   using simple policies and static configurations.  ...
   Experiences with the construction of such services will continue for
   some time, thus we avoid standardizing this construction as it is
   premature.  
...
   Marking is performed by traffic conditioners at network boundaries,
   including the edges of the network (first-hop router or source host)
   and administrative boundaries.  

At 10:27 AM 07/10/2000 -0700, Yoram Bernet wrote:
>... When such signaling is available to provide the network with the 
>classification information corresponding to users, it seems to be a 
>preferable approach. For cases in which signaling is not available, 
>the dhcp approach might be used.
>
>> From: Grenville Armitage [mailto:[email-masked]] 
>> ... I hope the IESG will request that the document authors 
>> either clarify the relationship between Diffserv/Intserv 
>> and their service differentiation model, 
>> or simply remove the 'classify on source address' example. 

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---

From: Grenville Armitage <[email-masked]>
Date: Mon, 10 Jul 2000 19:35:05 -0700

> I am surprised to see a preference for signalling on the Diff-Serv list.

Merely an artifact of Brian noticing the intro text and using
the diffserv mailing list to solicit comments from those of
us interested in IP QoS models. Yoram's comments clearly fall
within that more general context.

Just to be clear about MHO - while I can see the value in the
proposed DHCP extension (and I have no reason to object to it)
I do suggest clarification of the motivational intro text. Like
I said, it is only the first part of the Intro that I believe
needs clarification, since it implies a QoS architecture that
the IETF hasn't (to my limited knowledge) particularly discussed.
If it has been discussed somewhere, citations would be extremely
useful and I'm sure the draft's authors can include them easily
enough.

cheers,
gja
________________________________________________________________________
Grenville Armitage                    http://members.home.net/garmitage/
Bell Labs Research Silicon Valley