Subject: Re: I-D ACTION:draft-francis-ipngwg-site-def-00.txt

From: "Matt Crawford" <[email-masked]>
Date: Tue, 03 Apr 2001 10:07:10 -0500

Since my site is 7 km wide, corner-to-corner, I'm going to choose to
regard this draft as indirectly supporting my own cherished opinion
that the definition of "site" must be independent of physical space.
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From: Brian E Carpenter <[email-masked]>
Date: Tue, 03 Apr 2001 10:46:32 -0500

Paul,

> http://www.ietf.org/internet-drafts/draft-francis-ipngwg-site-def-00.txt

>    This draft proposes the following rigorous definition of a site:  
>    A site is defined as the set of routers that fit inside a hexagonal 
>    shape with a distance of one kilometer between opposite corners.  
>    Any hosts sharing a link with a router in a given site are 
>    considered part of the site.  The hexagonal shape is chosen because 
>    it can be tiled while still approximating a circle. 
>     
>    The administrator is free to decide exactly where to lay the 
>    hexagons.  However, they MUST not overlap, and every router MUST be 
>    within the boundary of one and only one hexagon.  All stories of a 
>    multi-story building are considered to be in the site covered by the 
>    hexagon.  

Won't work, can't work. An organisation that happens to span 1.1 of these
hexagons, or even 20 of them, is not going to contort itself to meet
such a definition. I can't imagine why any campus style organisation would
even dream of defining a single campus as more than one site, and what about
slightly split campuses? Or campuses with 5 km between their two halves, but
running a single network? I think your "north bank/south bank" example shows
exactly why any attempt to define a site rigorously is doomed.

I think a site is whatever a site network manager says is a site. The scope
of site-local is whatever the site network manager says it is. 

Tell me a good reason why we couldn't run the whole of IBM world-wide
as a single site-local scope, if we wanted to?

   Brian