Peering Inclinations and Peering Policies What are the Tier 1 ISPs' motivations? To answer this question, we need to separate the Tier 1 ISP Peering Inclination from its articulated Peering Policy.
Definition: A Peering Inclination is a predisposition towards or against peering as demonstrated by Peering behavior in an Internet Peering Ecosystem.
Definition: A Peering Policy is an articulation of the Peering Inclination; it documents and defines the prerequisites to peering.
The Peering Policy is what one might find on an ISP web site, or it may be received after signing a nondisclosure agreement. But to predict the peering behavior, the underlying Peering Inclination is important.
There are roughly four categories of Peering Inclination observed in the field, as shown in Figure 9-5.
An "Open" Peering Inclination is a willingness to peer with any other player in the ecosystem and articulated as an Open Peering Policy.
Definition: An Open Peering Policy is an articulation of an inclination to peer with anyone.
A "Selective" Peering Inclination is the willingness to peer with any other player, but with a few requirements. A common requirement is that there must be a minimum traffic volume for peering to be worth setting up as articulated in a Selective Peering Policy.
Definition: A Selective Peering Policy is an articulation of an inclination to peer, but with some conditions.
A "Restrictive" Peering Inclination reflects a desire not to peer with anyone else. If they have a publicy available Restrictive Peering Policy it will be difficult to meet. More commonly, the policy will not be publicly available, but perhaps available after signing a Non-Disclosure Agreement.
Definition: A Restrictive Peering Policy is an articulation of an inclination not to peer with any more entities.
A "No Peering" inclination reflects the desire not to peer at all. Purchasing transit is the preferred method for these players. You will not likely find a No-Peering Policy articulated anywhere.
Definition: A No-Peering Policy is an articulation of an inclination not to peer at all.