Notice, I didn't call this Peering vs Transit. I don't want to get into that discussion. :) Over the years, as economics have moved around and such, the question of whether its *profitable* to build a backbone and peer-off most or all traffic vs buying transit for all or some destinations has moved around. Some of the factors are economic, some have to do with onerous or non-existant peering possibilities with one or more networks. *IS* there a common sense number or an equation (better) anyone has worked out to figure whether building a backbone (national/international) to peering points (i.e. extending an existing, operational service network) to improve/add peering vs continuing to buy transit? I was in a discussion about this fairly recently, and I can imagine a number of people have started asking the same questions. To be fair, and hopefully eliminate any religious issues. Let's assume 1) The network-in-question's traffic is balanced [1:1 push/pull] -- I know, we are talking theoretical here. 2) That "transit" implies a few good networks, with redundancy and fault-tolerance. More specifically, it is not assumed that "peering" or "transit" has any net-effect on the customer base because 1) if peering is insufficient, some transit will remain, and 2) if some transit provider is behaving poorly, there is another transit provider available to shift traffic to. I hope this is a reasonable groundwork for a discussion. :) If you want to shoot out numbers (privately) I am fine with that. Let's start the bidding at 1Gb/s sustained. :) Deepak Jain AiNET