Subject: Re[2]: Differential Services waypoint

From: [email-masked]
Date: Fri, 17 Oct 1997 15:28:09 -0500

At 11:04 AM  10/17/97 [email-masked] wrote:

>>At 11:57 AM -0500 10/17/97,[email-masked] wrote: 
>>>the edge.
     
>which edge? The edge of each of the backbones a message crosses? The edge 
>of one of the layered ISPs that fed it to those backbones? The edge of 
>the company? The edge of the LAN that the fellow is attached to?
     
>I think conceptually you're probably right, but identifying the point 
>you're talking about is not so easy.
     
     Agreed.
Thank you for your reply.

Here's a stab at identifying the edge(if there is already a body of work on 
this can someone please send pointers/info on it to this list?):

1. The vast majority of the users on the internet are using ISP's to access 
it. The ISP's employ routers in the concentrator role prior to placing 
traffic on the net via a backbone connection from their POPs. For ISP's the 
edge is the "fat pipe" out of the POP. The edge can be in either the NAS or 
a concentrator router if it's present.

2. Universities and corporations also employ a concentrator router(s), but 
with a more stratified/hierarchical network between the end user and the 
final concentrator. If we picture a baseball diamond, with the concentrator 
router at home, and the bases as the routers that are next hop to home, the 
edge is an arc covering the first and third baselines that can be 
slid/pushed to or from home. The edge grooming can take place at first or 
third base, or at home. The arc may be uneven and allow grooming to take 
place at first base and at home for the third base line connection. As long 
as the grooming is done before it hits the last concentration point under 
the organizations control. Clearly the provider of the backbone and the 
customer need to agree on where grooming will be done. (The customer saves 
money if they do it.) The edge is negotiable.

(Please forgive duplicate transmission of the previous message, our ccmail 
is ill.)

Ken