ISP Peering

The Internet is composed of a hierarchical structure of multi-tiered ISPs. These individual ISPs interconnect with each other in an arrangement known as peering.

Peering is a voluntary interconnection of administratively separate Internet networks (ISPs) for the purpose of exchanging traffic between the "down-stream" users of each network. Typically, such peering is "settlement-free" meaning that there is no monetary exchange between the networks, as peering is mutually beneficial to both connected networks. There may be other agreements in other cases, especially when traffic may be asymmetrically distributed between the networks.

Peering typically takes two forms:

  • Public peering - This is accomplished using an Internet Exchange Point (IXP).
  • Private peering - this involves a direct interconnection between two networks across either a Layer 2 or Layer 2 physical medium that offers dedicated capacity and is not shared with any other parties.