Editing Internet backbone (section)

{{Short description|Vital infrastructure of the networks of the Internet}}
{{Use American English|date=January 2019}}
[[File:Internet map 1024.jpg|thumb|right|242x242px|Each line is drawn between two nodes, representing two [[IP address]]es. This is a small look at the backbone of the Internet.]]

The '''Internet backbone''' is the [[backbone network|principal data routes]] between large, strategically interconnected [[computer network]]s and [[core router]]s of the [[Internet]]. These data routes are hosted by commercial, government, academic and other high-capacity network centers as well as the [[Internet exchange point]]s and [[network access point]]s, which exchange Internet traffic internationally. [[Internet service provider]]s (ISPs) participate in Internet backbone traffic through privately negotiated [[Interconnect agreement|interconnection agreements]], primarily governed by the principle of settlement-free [[peering]].

The Internet, and consequently its backbone networks, do not rely on central control or coordinating facilities, nor do they implement any global network policies. The [[Resilience (network)|resilience]] of the Internet results from its principal architectural features, such as the idea of placing as few network [[State (computer science)|state]] and control functions as possible in the network elements, instead relying on the endpoints of communication to handle most of the processing to ensure data integrity, reliability, and authentication. In addition, the high degree of [[Redundancy (engineering)|redundancy]] of today's network links and sophisticated real-time [[routing]] protocols provide alternate paths of communications for [[Load balancing (computing)|load balancing]] and congestion avoidance.

The largest providers, known as [[Tier 1 network|Tier 1 networks]], have such comprehensive networks that they do not purchase [[Internet transit|transit]] agreements from other providers.<ref name="crossroads" />