Editing Internet backbone (section)

==Infrastructure==
[[File:Submarine cable map umap.png|alt=Undersea Internet cables|thumb|270x270px|Routing of prominent undersea cables that serve as the physical infrastructure of the Internet.]]

The Internet backbone consists of many networks owned by numerous companies. 

[[Fiber-optic communication]] remains the medium of choice for Internet backbone providers for several reasons. Fiber-optics allow for fast data speeds and large [[Bandwidth (signal processing)|bandwidth]], suffer relatively little [[attenuation]] — allowing them to cover long distances with few [[repeater]]s — and are immune to [[crosstalk]] and other forms of electromagnetic interference.{{citation needed|date=January 2021}} 

The real-time routing protocols and redundancy built into the backbone is also able to reroute traffic in case of a failure.<ref>{{Cite book|last=Nuechterlein, Jonathan E., author.|title=Digital crossroads: telecommunications law and policy in the internet age|date=5 July 2013|publisher=MIT Press |isbn=978-0-262-51960-1|oclc=827115552}}</ref> The data rates of backbone lines have increased over time. In 1998,<ref>{{Cite SSRN |last1=Kesan|first1=Jay P.|last2=Shah|first2=Rajiv C.|date=2002|title=Shaping Code|ssrn=328920}}</ref> all of the United States' backbone networks had utilized the slowest data rate of 45 Mbit/s. However, technological improvements allowed for 41 percent of backbones to have [[Data signaling rate|data rates]] of 2,488&nbsp;Mbit/s or faster by the mid 2000s.<ref>{{Cite journal|last=Malecki|first=Edward J.|date=October 2002|title=The Economic Geography of the Internet's Infrastructure|journal=Economic Geography|volume=78|issue=4|pages=399–424|doi=10.2307/4140796|jstor=4140796|issn=0013-0095}}</ref>