The Great Exchange

Wed May 27 22:39:56 UTC 1998

> In the long run, why are we assuming there will be locality of
> traffic?

I think the right question is: How much local traffic will there 
be and is that enough to make local shortcuts cost effective? 

Part of that discussion may involve what "local" means.

Things get complicated because current practice is not to charge 
by the packet-mile but rather by the size of the access pipe.  A 
local shortcut might avoid the need for a larger access pipe or give 
better response over an existing pipe.  So we are still talking real 
money, it's just that we are looking through a foggy window. 

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Does anybody have back-of-envelope type numbers for per-mile link 
costs?

What does it cost when I fetch a file or web page from the wrong 
side of the country or ocean?

I know the cost won't show up on my bill.  I'm looking for some handwaving 
estimate of the incremental cost to the whole system. 