Why don't ISPs peer with everyone?

Jon Lewis jlewis at lewis.org
Tue Jun 7 13:59:44 UTC 2011

On Tue, 7 Jun 2011 bmanning at vacation.karoshi.com wrote:

> in this context, anyone who is a BGP speaker is an ISP.

Peering costs money.  The transit bandwidth saved by peering with another 
network may not be sufficient to cover the cost of installing and 
maintaining whatever connections are necessary to peer.  Then there's the 
big networks who really don't want to peer with anyone other than 
similarly sized big networks...everyone else should be their transit 

I manage a network that's primarily a hosting network.  There's a similar 
hosting network at the other end of the building.  We both have multiple 
gigs of transit.  We don't peer with each other.  Perhaps we should, 
because the cost of the connection would be negligible (I think we already 
have multiple fiber pairs between our suites), but looking at my sampled 
netflow data, I'm guessing we average about 100kbit/s or less traffic in 
each direction between us.  At that low a level, is it even worth the time 
and trouble to coordinate setting up a peering connection, much less 
tying up a gigE port at each end?

Anyone from hostdime reading this?  :)
If so, what are your thoughts?

  Jon Lewis, MCP :)           |  I route
  Senior Network Engineer     |  therefore you are
  Atlantic Net                |
_________ http://www.lewis.org/~jlewis/pgp for PGP public key_________

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