Editing Internet service provider (section)

==Peering==
ISPs may engage in [[peering]], where multiple ISPs interconnect at [[peering point]]s or [[Internet exchange point]]s (IXPs), allowing routing of data between each network, without charging one another for the data transmitted—data that would otherwise have passed through a third upstream ISP, incurring charges from the upstream ISP.<ref name="ssrn"/>

ISPs requiring no upstream and having only customers (end customers or peer ISPs) are called [[Tier 1 carrier|Tier 1 ISPs]].

Network hardware, software and specifications, as well as the expertise of network management personnel are important in ensuring that data follows the most efficient route, and upstream connections work reliably. A tradeoff between cost and efficiency is possible.<ref name=":0">{{Cite web|title=Internet service provider.|url=http://masters.donntu.org/2009/kita/repryntsev/library/article6.htm|website=masters.donntu.org|access-date=2020-05-26|archive-date=2021-02-24|archive-url=https://web.archive.org/web/20210224042649/http://masters.donntu.org/2009/kita/repryntsev/library/article6.htm|url-status=dead}}</ref>

Tier 1 ISPs are also interconnected with a mesh network topology.<ref>{{cite book | url=https://books.google.com/books?id=fTPmJytNeosC&dq=tier+1+network&pg=PA10 | title=Alcatel-Lucent Scalable IP Networks Self-Study Guide: Preparing for the Network Routing Specialist I (NRS 1) Certification Exam | isbn=978-0-470-52938-6 | last1=Hundley | first1=Kent | date=31 August 2009 | publisher=John Wiley & Sons }}</ref><ref>{{cite book | url=https://books.google.com/books?id=92ZYiSTXkWMC&dq=tier+1+peering&pg=PT113 | title=The Internet Peering Playbook: Connecting to the Core of the Internet | isbn=978-1-937451-02-8 | last1=Norton | first1=William B. | date=8 August 2011 | publisher=DrPeering Press }}</ref> Internet Exchange Points (IXPs) are public locations where several networks are connected to each other.<ref>{{cite book | url=https://books.google.com/books?id=IM-Y2W0RIF0C&dq=tier+1+peering&pg=PA293 | title=Network Routing: Algorithms, Protocols, and Architectures | date=19 July 2010 | publisher=Elsevier | isbn=978-0-08-047497-7 }}</ref><ref>{{cite book | url=https://books.google.com/books?id=IM-Y2W0RIF0C&dq=internet+exchange+point+tier+1&pg=PA291 | isbn=978-0-08-047497-7 | title=Network Routing: Algorithms, Protocols, and Architectures | date=19 July 2010 | publisher=Elsevier }}</ref> Public peering is done at IXPs, while private peering can be done with direct links between networks.<ref>{{cite book | url=https://books.google.com/books?id=vXZODwAAQBAJ&dq=tier+1+peering&pg=PA156 | title=Information Network Engineering | date=20 July 2015 | publisher=株式会社 オーム社 | isbn=978-4-274-99991-8 }}</ref><ref name="Springer"/> IXPs or peering exchanges may be located in data centers.<ref>{{Cite web|url=https://www.telecomreviewamericas.com/es/?view=article&id=469&catid=14|title=InteRed Installs Internet Exchange Point at Sparkle's Panama Digital Gateway - Telecom Review Americas|date=February 11, 2025|website=www.telecomreviewamericas.com}}</ref><ref>{{Cite web|url=https://www.datacenterfrontier.com/colo/article/55125540/data-center-tours-equinix-dc12-ashburn-virginia|title=Data Center Tours: Equinix DC12, Ashburn, Virginia|first=Matt|last=Vincent|date=July 16, 2024|website=Data Center Frontier}}</ref><ref>{{Cite web|url=https://www.telecomreviewasia.com/news/network-news/4215-de-cix-jakarta-internet-exchange-now-live/|title=DE-CIX Jakarta Internet Exchange Now Live|date=May 9, 2024|website=www.telecomreviewasia.com}}</ref>