North American Network Operators Group
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Re: More Questions of Exchange Points

  • From: bmanning
  • Date: Sat Apr 06 21:01:49 2002 
>     >> The difference between a peering exchange and a transit exchange is a much
>     >> more easily technically-defined difference: a peering exchange is one
>     >> across which, by and large, the participants just exchange peering routes.
>     >
>     > Do you mean the participants just exchange BGP routing information?  So the
>     > traceroute data will only discover the peering point they exchange traffic?
> 
> The assumtion is that all ISPs exchange routes via BGP.  What's at issue

	well, there are a fair number of exchanges built on a model
	developed by B.Greene, when BGP capability was not always there
	(often not a technology problem... :)  They are still a number of 
	them in existence.  The exchange routes using an IGP and fate
	share over the exchange.  The BGP'ness occurs at each of their
	upstreams. 
	
> is the degree of redundancy in the routes which they're exchanging.  If
> they're purchasing transit at or through a facility, it's to provide
> reachability to things that they couldn't otherwise reach, either normally
> or under conditions of failed peering.  That makes the service much more
> critical than peering, which is, by definition, an economic optimization
> over transit.  Thus, people are willing to spend much more money on a
> facility through which they're putting transit, and they're willing to
> tolerate a divided marketplace, as long as each facility is able to
> maintain at least three sellers.

	I really need to read your paper.  There appear to be a 
	number of presumptions that are "cultural", for want of 
	a better term, which bias your conclusions.  

>     > ISPs exchange their traffic at IXs or private peering points, so which
>     > is more important to the ISPs (in term of traffic volume or other
>     > measures)? Maybe I should also mention co-locators, then what's the
>     > difference between co-locator and the "carrier hotel"? Are they like
>     > "physical layer exchange points" (if there is such a concept)?
> 
> These aren't necessarily useful distinctions you're making.  They're
> distinctions of marketing positioning.  What matters economically and
> technically is how people use the facilities, not what they're called.

	Amen. 
> 
>                                 -Bill
> 
>