Hmm..If you were (or are) starting an ISP, more than likely you will be buying transit. You won't meet many of the larger ISPs peering agreements. For example UUNET (Or Worldcom, whatever they call themselves today, maybe it will be UUcom soon!) requires an OC-12 backone, presence in 15 states, ability to peer at OC-12 level at atleast 4 points, and you must already be at 3 of the following MAE-EAST, MAE-WEST, AADS, MAE-CENTRAL and peered with them. Most other ISPs are similiar in these requirements, however, some are more open than UUNET/Worldcom. There are some advantages to buying transit, however. Obviously there is a larger cost incurred with transit but you get SLA's, more tech support, ability to tune routes with metrics/etc. Additionally you might only need a DS3 to some providers while you need more to others (OC3+). So in reality buying transit could give you more control to use your bandwidth to larger ISPs more effectively. In the beginning you should look into a mixture of public peering at various public peering points and perhaps some strategic purchase of transit. Times are hard in the Internet right now. Honestly a big factor (Atleast in my mind) in going to one backbone or another is cost and performance. Additionally you need to think about what your backbone will be providing. If you plan on mainly doing dialup, cable modems, lower end providing sometimes just getting packets from A too B is more important than adding an additional 10-20ms on each of these packets. If you are doing more of a performance based ISP, higher speed customers, content hosting, etc, the previous statement may (and more than likely will not) hold up. Customers will not be happy with a trans USA path being 100-120ms instead of 60-70ms. In reality you need to think about your game plan. You just can't go out and say, "Hey I'm building an ISP", and get a blanket answer. There are many factors that should determine the approach you take. Of course that's just my opinion. I could be wrong. =] On Sun, 1 Jul 2001, EA Louie wrote:

List - I'm curious as to how one chooses to Peer versus buy Transit in the Internet. What are the determining factors, if I were to start an ISP, on which I would do to get my network recognized by the Internet and how I would get my customers out into the backbone.

thanks Eric