Editing Autonomous system (Internet) (section)

==Types==
Autonomous systems (AS) can be grouped into four categories, depending on their connectivity and operating policy.

# ''[[multihoming|multihomed]]'': An AS that maintains connections to more than one other AS. This allows the AS to remain connected to the Internet in the event of a complete failure of one of their connections. However, unlike a transit AS, this type of AS would not allow traffic from one AS to pass through on its way to another AS.
# ''[[Stub network|stub]]'': An AS that is connected to only one other AS. This may be an apparent waste of an AS number if the network's routing policy is the same as its upstream AS's. However, the stub AS may have [[peering]] with other autonomous systems that is not reflected in public [[Looking Glass server|route-view servers]]. Specific examples include private interconnections in the financial and transportation sectors.
# ''[[Internet transit|transit]]'': An AS that acts as a router between two ASes is called a transit. Since not all ASes are directly connected with every other AS, a transit AS carries data traffic between one AS to another AS to which it has links.<ref name="Paul 2016 BGP" />
# ''[[Internet Exchange Point]]'' (IX or IXP): A physical infrastructure through which ISPs or [[content delivery network]]s (CDNs) exchange Internet traffic between their networks (autonomous systems). These are often groups of local ISPs that band together to exchange data by splitting the costs of a local networking hub, avoiding the higher costs (and bandwidth charges) of a Transit AS. IXP ASNs are usually transparent. By having presence in an IXP, ASes shorten the transit path to other participating ASes, thereby reducing [[network latency]] and improving [[round-trip delay]].<ref name="Paul 2016 BGP">{{cite web|title= Understanding Autonomous Systems: Routing and Peering|url=https://people.cs.rutgers.edu/~pxk/352/notes/autonomous_systems.html|first=Paul|last= Krzyzanowski|access-date=29 March 2022|date=21 March 2016|publisher=[[Rutgers University]], Department of Computer Science|archive-url=https://web.archive.org/web/20220303153053/https://people.cs.rutgers.edu/~pxk/352/notes/autonomous_systems.html|archive-date=3 March 2022|url-status=live}}</ref><ref>{{cite web|url=https://www.cloudflare.com/en-gb/learning/cdn/glossary/internet-exchange-point-ixp/|title=Glossary: Internet exchange point (IXP)|access-date=29 March 2022|publisher=[[CloudFlare]]|url-status=live|archive-url=https://ghostarchive.org/archive/20220330010306/https://www.cloudflare.com/en-gb/web/20211103131937/https://www.cloudflare.com/en-gb/learning/cdn/glossary/internet-exchange-point-ixp/|archive-date=30 March 2022}}</ref>