Subject: [Dcpel] questions related to DCPEL scope

From: "Georgios Karagiannis" <[email-masked]>
Date: Tue, 21 Feb 2006 11:29:03 +0100

Dear all

I have read the following draft, but I am not sure if I really understood 
what is the
scope of staring the DCPEL BOF/WG.

http://www.pollere.net/Txtdocs/draft-vandenberghe-dcpel-basics-00.txt

Bellow are some questions for you:

Is the scope of starting this BOF/WG the specification of new Per
Domain Behaviours (PDBs) and the specification of new interfaces that can be 
used
by existing signaling protocols (such as NSIS) to influence/ manage these 
PDB's?

>From what I have read, another scope of this BOF/WG will be
the specification of a new Difsserv control plane architecture and 
framework.
This architecture can be centralized or distributed.

Could you specify what do you mean by a distributed Difsserv control plane 
approach?
Will this distributed approach impact an individual Diffserv router, e.g., a 
Diffserv core router?

>From what I know other stardardisation bodies are working for a long time 
already
on a centralized (bandwidth broker like) architecture/framework.
Such standardisation bodies are:
the ITU-t, ETSI-tispan, DSL, packetcable, 3gpp, 3gpp2,  ipshere, wimax.
My question is how is the DCPEL effort related to this work?

Best Regards,
Georgios

_______________________________________________
Dcpel mailing list
[email-masked]
https://www1.ietf.org/mailman/listinfo/dcpel

---

From: Kathleen Nichols <[email-masked]>
Date: Wed, 22 Feb 2006 11:34:43 -0800

Georgios,
> Domain Behaviours (PDBs) and the specification of new interfaces that
> can be used by existing signaling protocols (such as NSIS) to
> influence/ manage these PDB's?

Those items are in the scope of our current proposal. In addition,
we want to have the discussion that will result in specification
of service models and metrics that can be used externally by network
operators to describe their offerings (without exposing the
internal implementations). We've proposed a starting point of
looking at the NSIS Qspec which in turn builds on the ITU Y1554.
However, we don't feel the dcpel effort should be bound to those
metrics if they are not sufficient.

> Could you specify what do you mean by a distributed Difsserv control
> plane approach? Will this distributed approach impact an individual
> Diffserv router, e.g., a Diffserv core router?

I'm just giving a short answer here. A distributed DiffServ control
plane is one where the control plane actions do not reside in
one physical location and probably not in one logical location.
We would expect an impact on DiffServ edge routers, but probably
not DiffServ core routers. Following the model of RFC3290, we
expect to spend time on the QoS agent and the configuration and
management interface. In draft-nichols-dcpel-strawman-arch-00, this is
where we located the DiffServ Control Plane Agent or DCPA. I
believe a longer answer is the work of the proposed working group.
Please note that we have put out some proposals based on our
own work and based on meeting with several folks last November.
The final form of a solution would be an outcome of the consensus
process.

> My question is how is the DCPEL effort related to this work? 

Well, we have contributors and reviewers of our work who are
involved with some of these efforts who still feel IETF work is
needed. Since IETF sets standards and practices for the more general
internet, this seems appropriate to me. However, the IETF framework
for a DCP ought to look at some of these approaches as specific
instances of solutions and it would be good if they fit into the
framework. Unless we come to the consensus opinion that someone
is just doing it wrong! So I would hope we would have some cross-
participation. (I coauthored my first document in this area in
November of 1997, now rfc2638, and one of my coauthors had been
working on the architecture a few years before that, so I think there
is a history in the IETF and the IRTF too).

The feedback we've gotten is that "something"
is needed and we were told from a provider perspective that
the acknowleged "big problem" is having common notions of the
differentiated services that are openly provided along with
a few examples of how to achieve these. Getting to that point
is clearly best done through the open, consensus-driven,
experience-driven process.

	regards,
		Kathie

---

From: "Georgios Karagiannis" <[email-masked]>
Date: Thu, 23 Feb 2006 07:28:33 +0100 (MET)

Hi Kathie

Thank you very much for your quick reply!

Please see in line!

On 2/22/2006, "Kathleen Nichols" <[email-masked]> wrote:

>not DiffServ core routers. 

Georgios: But I suppose that this will of depend on the specified PDBs.
What if a PDB requires a control plane support for a core Diffserv router?

>Following the model of RFC3290, we

Georgios: Maybe it is very useful to perform an extensive state of the
art study on the area of centralized control plane architectures that
are developed in ITU-t, ETSI-tispan, DSL, packetcable, 3gpp, 3gpp2, 
ipshere, wimax. The outcome of this state of the art study could then
help to define
the final charter of the DCPEL BOF/WG.

Best Regards,
Georgios

---

From: Kathleen Nichols <[email-masked]>
Date: Thu, 23 Feb 2006 13:47:13 -0800

Trimmed to reply (in-line) to your comments:

Georgios Karagiannis wrote:
...
[G]>>> Could you specify what do you mean by a distributed Difsserv control
>>> Diffserv router, e.g., a Diffserv core router?
[K]>> I'm just giving a short answer here. A distributed DiffServ control
> What if a PDB requires a control plane support for a core Diffserv router?

If by core Diffserv router you mean a diffserv router interior to a
domain, one would not normally expect the need for control of
classifiers and policers, but just configuration of the PHBs as
realized by queues and their scheduler, as described in RFC 2475
and other diffserv documents. However, this doesn't preclude an
operator from using the diffserv "edge" functions interior to a
network if desired.

...
> the final charter of the DCPEL BOF/WG.

Do you believe that the work of these groups obviates an IETF DCPEL WG?

	regards,
		Kathie

---

From: "Georgios Karagiannis" <[email-masked]>
Date: Fri, 24 Feb 2006 13:48:53 +0100

Hi Kathie

Please do not understand me wrong!
I am in favour of starting the DCPEL WG.
My concerns are related to the match between the DCPEL charter activities
and the work that has been by theITU-t, ETSI-tispan, DSL, packetcable, 3gpp, 
3gpp2,
ipshere, wimax  goups on the area of centralized control plane 
architectures.
I think that it is useful to start the work in DCPEL WG considering as 
starting point
the work that has been done already in the other groups.

Best Regards,
Georgios