Public & Private Peering Defined
Public peering is accomplished across a Layer 2 access technology, generally called a shared fabric. At these locations, multiple carriers interconnect with one or more other carriers across a single physical port. Historically, public peering locations were known as network access points (NAPs). Today they are most often called Exchange Points or Internet Exchanges (IXs for short). Many of the largest exchange points in the world can have hundreds of participants, and some span multiple buildings and colocation facilities across a city.
Since public peering allows networks interested in peering to interconnect with many other networks through a single port, it is often considered to offer “less capacity” than private peering, but to a larger number of networks. Many smaller networks, or networks who are just beginning to peer, find that public peering exchange points provide an excellent way to meet and interconnect with other networks who may be open to peering with them. Some larger networks utilize public peering as a way to aggregate a large number of “smaller peers,” or as a location for conducting low-cost “trial peering” without the expense of provisioning private peering on a temporary basis while other larger networks are not willing to participate at public exchanges at all.
Private peering is the direct interconnection between only two networks, across a Layer 1 or 2 media that offers dedicated capacity that is not shared by any other parties. Early in the history of the Internet, many private peers occurred across ‘telco’ provisioned SONET circuits between individual carrier-owned facilities. Today, most private interconnections occur at carrier hotels or carrier neutral colocation facilities where a direct crossconnect can be provisioned between participants within the same building, usually for a much lower cost than telco circuits.
CityNAP Core Peering Fabric
San Antonio’s CityNAP is a next-generation, carrier-class facility, utilizing the most advanced networking standards in the world. The network architecture of CityNAP boasts as its core an efficient high-speed switch fabric. This key equipment has a forwarding capacity of up to 96,000,000 packets per second and provides gigabit speed connectivity to the meshed 64 Gbps core peering fabric.