Editing Star network

{{Short description|Computer network topology}}
{{About|the network topology|the interbank network|STAR (interbank network)|the television network|Star Television Network|other uses|Starnet (disambiguation){{!}}Starnet}}
{{Redirect|Hub and spokes architecture|the network of alliances in the Asia-Pacific region|San Francisco System}}
{{Use American English|date=January 2020}}
[[File:Star Topology.png|thumb|Star topology in use in a network]]

A '''star network''' is an implementation of a [[spoke–hub distribution paradigm]] in [[computer network]]s. In a star network, every [[host (network)|host]] is connected to a central [[hub (network science)|hub]]. In its simplest form, one central hub acts as a conduit to transmit messages.<ref>{{citation
 | last1 = Roberts | first1 = Lawrence G.
 | last2 = Wessler | first2 = Barry D.
 | contribution = Computer network development to achieve resource sharing
 | doi = 10.1145/1476936.1477020
 | location = New York, NY, USA
 | pages = 543–549
 | publisher = ACM
 | title = AFIPS '70 (Spring): Proceedings of the May 5–7, 1970, spring joint computer conference
 | year = 1970| s2cid = 9343511
 }}</ref>  The star network is one of the most common [[Network topology|computer network topologies]].

==Network==
The hub and hosts, and the transmission lines between them, form a [[graph (discrete mathematics)|graph]] with the [[star (graph theory)|topology of a star]]. Data on a star network passes through the hub before continuing to its destination. The hub manages and controls all functions of the network. It also acts as a [[repeater]] for the data flow. In a typical network the hub can be a [[network switch]], [[Ethernet hub]], [[wireless access point]] or a [[router (computing)|router]] 

The star topology reduces the impact of a transmission line failure by independently connecting each host to the hub. Each host may thus communicate with all others by transmitting to, and receiving from, the hub. The failure of a transmission line linking any host to the hub will result in the isolation of that host from all others, but the rest of the network will be unaffected.<ref>{{cite web|url=http://searchnetworking.techtarget.com/dictionary/definition/what-is-star-network.html# |title=Star Network |publisher=TechTarget |access-date=2014-06-24}}</ref>

The star configuration is commonly used with [[twisted pair cable]] and [[optical fiber]] cable. However, it can also be used with [[coaxial cable]] as in, for example, a [[video router]].

== Advantages and disadvantages ==

===Advantages===
* If one node or its connection fails, it does not affect the other nodes.<ref name="teach-ict.com">{{Cite web|title = Teach-ICT OCR GCSE Computing - computer network topologies, bus network, ring network, star network|url = http://teach-ict.com/gcse_computing/ocr/215_communications_networking/network_topologies/miniweb/pg4.htm |website = teach-ict.com |archive-url=https://web.archive.org/web/20151222163638/http://teach-ict.com/gcse_computing/ocr/215_communications_networking/network_topologies/miniweb/pg4.htm |archive-date = 2015-12-22}}</ref>
* Devices can be added or removed without disturbing the network.
*Works well under heavy load.
*Appropriate for a large network.

===Disadvantages===
* Expensive due to the number and length of cables needed to wire each host to the central hub.<ref name="teach-ict.com" />
* The central hub is a [[single point of failure]] for the network.
* Each device needs a separate cable connection to the central hub, leading to higher cable usage.
* The number of devices is limited by the capacity of the central hub. 

== References ==
{{reflist}}

{{Network topologies}}

[[Category:Network topology]]