Subject: Re: [Diffserv] QoSSIG BOF now After diffserv, ......

From: Bob Braden <[email-masked]>
Date: Wed, 2 Feb 2000 00:53:42 GMT

*> Andrew,
  *> 
  *> Beforehand I must state that in no way am I an ATM fan. But I still
  *> believe that in some cases separating the interface between the host and
  *> the network from the interface between network nodes is a good idea.
  *> This separates two businesses: OS/Apps and networking and makes much
  *> easier to change or modify networking protocols. It also allows local
  *> domains to use whatever protocol they wish without affecting hosts. This
  *> thing is also called modularity.
  *> 
  *> Besides, the idea is already used.

Indeed it is.  It (the host/network interface) is called X.25.

We've been there, and that experience helped the decision in RSVP to
use basically the SAME protocol for both the DCE/DTE and the DCE/DCE
communication.  I have not seen any strong reason to think this was
the wrong decision.  For one thing, it handles the DTE/DTE case
without fuss.

Bob Braden

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From: Ping Pan <[email-masked]>
Date: Wed, 02 Feb 2000 15:19:15 -0500

> the wrong decision.  For one thing, it handles the DTE/DTE case

Agree. The original idea of Host vs Network is like a conspiracy by the
telco's to limit customer's access and selection so that they can charge
their usual retail prices to end-users. The concept was defined in
telco's interest, but is not meant for the Internet.

In our proposed model, users have the choice to subscribe service from
more than one ISP and have the choice to put their data through any
inter-domain reservation "tunnel". RSVP and other end-user drive
reservation protocols fit in this model without a problem. For example
in RSVP, to across an inter-domain reservation interconnecting network X
and Y, RSVP can simply allow the Next-Hop to point to Y, and
Previous-Hop to point to X. That's it!

BR,

--
Ping Pan         http://www.cs.columbia.edu/~pingpan

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From: Zoltan Richard Turanyi <[email-masked]>
Date: Thu, 03 Feb 2000 11:05:42 +0100

> telco's interest, but is not meant for the Internet.

Gentlemen, please. Separating Network-Host and Network-Network (or
Router-Router) interface (in general not only in case of QoS) has
*technical* merits. It allows the easy deployment of different mechanism
in the network without affecting the end systems. (Remember: You can use
whatever multicast routing protocol you wish without changing the hosts.
IGMP is used on the Host-Network interface and the multicast routing
protocol is used on the Router-Router interface. That clearly has
benefits.)

Again: I do not care what was the reason for this separation in ATM,
X.25 or whatever. Had RSVP/Intserv been designed like this, now it would
be much easier to employ different mechanisms in different domains. But,
perhaps it is not a requirement and should not be an issue.

Finally: I accept that the people developing RSVP had really thought
this issue through and rejected it if Bob says so. I just wanted to
point out that the idea is not a complete nonsense from the technical
point of view and is not only a devil telco invention.

/Zoltan
-- 
Zoltan Richard Turanyi  
Research Fellow, Ericsson Hungary
Traffic Analysis and Network Performance Lab

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From: Masataka Ohta <[email-masked]>
Date: Thu, 3 Feb 0 20:03:05 JST

Zoltan;

> protocol is used on the Router-Router interface. That clearly has

Wrong.

As it is clearly demonstrated by IGMP and RSVP,if you want to allow
whatever multicast routing protocl you wish, Network-Host protocol
(IGMP) or multicast-related Network-Network protocol (RSVP) must
be compatible with all the possible (including those which does
not scale at all) Network-Network multicast routing protocols,
which makes the Network-Host protocol (IGMP) or the multicast-related
Network-Network protocol (RSVP) unnecessarily complex and, worse,
not scalable.

> this issue through and rejected it if Bob says so.

They did not rejected it w.r.t. multicast routing protocols.

						Masataka Ohta