Editing Peering (section)

===Public peering===
'''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 point]]s (NAPs). Today they are most often called [[Internet exchange point|exchange points]] or ''Internet exchanges'' ("IXP"). Many of the largest exchange points in the world can have hundreds of participants, and some span multiple buildings and [[Colocation centre|colocation]] facilities across a city.<ref>{{cite web |url=http://pch.net/ixpdir |title=Internet Exchange Directory|website = Packet Clearing House}}</ref>

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 which are just beginning to peer, find that public peering exchange points provide an excellent way to meet and interconnect with other networks which 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.

A few exchange points, particularly in the United States, are operated by commercial carrier-neutral third parties which often are data centers, which are critical for achieving cost-effective [[data center]] connectivity.<ref name=DRJ_Choosing>{{Citation | title = Choosing a Data Center  | url=http://www.atlantic.net/images/pdf/choosing_a_data_center.pdf | publisher = Disaster Recovery Journal | year = 2009 | author = Cosmano, Joe | access-date = 21 July 2012}}</ref>