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}}
A star network is an implementation of a spoke–hub distribution paradigm in computer networks. In a star network, every host is connected to a central hub. In its simplest form, one central hub acts as a conduit to transmit messages.{{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
}} The star network is one of the most common computer network topologies.
Network
The hub and hosts, and the transmission lines between them, form a graph with the 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
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.{{cite web|url=http://searchnetworking.techtarget.com/dictionary/definition/what-is-star-network.html# |title=Star Network |publisher=TechTarget |access-date=2014-06-24}}
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.{{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}}
- 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.
- 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.