dig through the nanog archives. you will see a few "brief" discussions on the peering/ratio topic.
On Tue, 7 May 2002, Scott Granados wrote: > > I'm not overly familiar with this but I wondered if someone could detail > for me the basics of using ratios to determine elegibility to peer? I > have heard that some carrers especially the largest require a specific > ratio is this in fact true and is the logic as simple as just insuring > equal use of the peer? > > Thanks > > Scott > > /rf