Businesses, as well as schools and government entities, use wide area networks to relay data to staff, students, clients, buyers and suppliers from various locations around the world. In essence, this mode of telecommunication allows a business to effectively carry out its daily function regardless of location. The Internet may be considered a WAN.[2]
The textbook definition of a WAN is a computer network spanning regions, countries, or even the world.[3][4] However, in terms of the application of communication protocols and concepts, it may be best to view WANs as computer networking technologies used to transmit data over long distances, and between different networks. This distinction stems from the fact that common local area network (LAN) technologies operating at lower layers of the OSI model (such as the forms of Ethernet or Wi-Fi) are often designed for physically proximal networks, and thus cannot transmit data over tens, hundreds, or even thousands of miles or kilometres.
WANs are used to connect LANs and other types of networks together so that users and computers in one location can communicate with users and computers in other locations. Many WANs are built for one particular organization and are private. Others, built by Internet service providers, provide connections from an organization's LAN to the Internet.
WANs are often built using leased lines. At each end of the leased line, a router connects the LAN on one side with a second router within the LAN on the other. Because leased lines can be very expensive, instead of using leased lines, WANs can also be built using less costly circuit switching or packet switching methods. Network protocols including TCP/IP deliver transport and addressing functions. Protocols including Packet over SONET/SDH, Multiprotocol Label Switching (MPLS), Asynchronous Transfer Mode (ATM) and Frame Relay are often used by service providers to deliver the links that are used in WANs.
Of the approximately four billion addresses defined in IPv4, about 18 million addresses in three ranges are reserved for use in private networks. Packets addressed in these ranges are not routable on the public Internet; they are ignored by all public routers. Therefore, private hosts cannot directly communicate with public networks, but require network address translation at a routing gateway for this purpose.
Since two private networks, e.g., two branch offices, cannot directly communicate via the public Internet, the two networks must be bridged across the Internet via a virtual private network (VPN) or other form of IP tunnel that encapsulates packets, including their headers containing the private addresses, for transmission across the public network. Additionally, encapsulated packets may be encrypted to secure their data.
Connection technology
Many technologies are available for wide area network links. Examples include circuit-switched telephone lines, radio wave transmission, and optical fiber. New developments have successively increased transmission rates. In ca. 1960, a 110 bit/s line was normal on the edge of the WAN, while core links of 56 or 64 kbit/s were considered fast. Today, households are connected to the Internet with dial-up, asymmetric digital subscriber line (ADSL), cable, WiMAX, cellular network or fiber. The speeds that people can currently use range from 28.8 kbit/s through a 28K modem over a telephone connection to speeds as high as 100 Gbit/s using 100 Gigabit Ethernet.
The following communication and networking technologies have been used to implement WANs.
AT&T conducted trials in 2017 for business use of 400-gigabit Ethernet.[6] Researchers Robert Maher, Alex Alvarado, Domaniç Lavery, and Polina Bayvel of University College London were able to increase networking speeds to 1.125 terabits per second.[7] Christos Santis, graduate student Scott Steger, Amnon Yariv, Martin and Eileen Summerfield developed a new laser that potentially quadruples transfer speeds with fiber optics.[8]
^Y. Rekhter; B. Moskowitz; D. Karrenberg; G. J. de Groot; E. Lear (February 1996). Address Allocation for Private Internets. Network Working Group IETF. doi:10.17487/RFC1918. BCP 5. RFC 1918.
^"AT&T Completes Industry-Leading 400 Gb Ethernet Testing, Establishing A Future Network Blueprint for Service Providers and Businesses". www.att.com. September 8, 2017.
^Maher, Robert; Alvarado, Alex; Lavery, Domaniç; Bayvel, Polina (11 February 2016). "Increasing the information rates of optical communications via coded modulation: a study of transceiver performance". Scientific Reports. 6 (1): 21278. Bibcode:2016NatSR...621278M. doi:10.1038/srep21278. PMC4750034. PMID 26864633.
^"A New Laser for a Faster Internet - Caltech". Cal Tech.
External links
"What is WAN (wide area network)? - Definition from WhatIs.com", SearchEnterpriseWAN, retrieved 2017-04-21
What is a software-defined wide area network?
January 07, 2023
wide, area, network, this, article, needs, additional, citations, verification, please, help, improve, this, article, adding, citations, reliable, sources, unsourced, material, challenged, removed, find, sources, news, newspapers, books, scholar, jstor, july, . This article needs additional citations for verification Please help improve this article by adding citations to reliable sources Unsourced material may be challenged and removed Find sources Wide area network news newspapers books scholar JSTOR July 2015 Learn how and when to remove this template message A wide area network WAN is a telecommunications network that extends over a large geographic area Wide area networks are often established with leased telecommunication circuits 1 A local area network LAN with connection to a wide area network WAN Businesses as well as schools and government entities use wide area networks to relay data to staff students clients buyers and suppliers from various locations around the world In essence this mode of telecommunication allows a business to effectively carry out its daily function regardless of location The Internet may be considered a WAN 2 Contents 1 Design options 2 Private networks 3 Connection technology 4 See also 5 References 6 External linksDesign options EditThe textbook definition of a WAN is a computer network spanning regions countries or even the world 3 4 However in terms of the application of communication protocols and concepts it may be best to view WANs as computer networking technologies used to transmit data over long distances and between different networks This distinction stems from the fact that common local area network LAN technologies operating at lower layers of the OSI model such as the forms of Ethernet or Wi Fi are often designed for physically proximal networks and thus cannot transmit data over tens hundreds or even thousands of miles or kilometres WANs are used to connect LANs and other types of networks together so that users and computers in one location can communicate with users and computers in other locations Many WANs are built for one particular organization and are private Others built by Internet service providers provide connections from an organization s LAN to the Internet WANs are often built using leased lines At each end of the leased line a router connects the LAN on one side with a second router within the LAN on the other Because leased lines can be very expensive instead of using leased lines WANs can also be built using less costly circuit switching or packet switching methods Network protocols including TCP IP deliver transport and addressing functions Protocols including Packet over SONET SDH Multiprotocol Label Switching MPLS Asynchronous Transfer Mode ATM and Frame Relay are often used by service providers to deliver the links that are used in WANs Academic research into wide area networks can be broken down into three areas mathematical models network emulation and network simulation Performance improvements are sometimes delivered via wide area file services or WAN optimization Private networks EditOf the approximately four billion addresses defined in IPv4 about 18 million addresses in three ranges are reserved for use in private networks Packets addressed in these ranges are not routable on the public Internet they are ignored by all public routers Therefore private hosts cannot directly communicate with public networks but require network address translation at a routing gateway for this purpose Reserved private IPv4 network ranges 5 Name CIDR block Address range Number of addresses Obsolete classful description24 bit block 10 0 0 0 8 10 0 0 0 10 255 255 255 16777 216 Single Class A 20 bit block 172 16 0 0 12 172 16 0 0 172 31 255 255 1048 576 Contiguous range of 16 Class B blocks 16 bit block 192 168 0 0 16 192 168 0 0 192 168 255 255 65536 Contiguous range of 256 Class C blocks Since two private networks e g two branch offices cannot directly communicate via the public Internet the two networks must be bridged across the Internet via a virtual private network VPN or other form of IP tunnel that encapsulates packets including their headers containing the private addresses for transmission across the public network Additionally encapsulated packets may be encrypted to secure their data Connection technology EditMany technologies are available for wide area network links Examples include circuit switched telephone lines radio wave transmission and optical fiber New developments have successively increased transmission rates In ca 1960 a 110 bit s line was normal on the edge of the WAN while core links of 56 or 64 kbit s were considered fast Today households are connected to the Internet with dial up asymmetric digital subscriber line ADSL cable WiMAX cellular network or fiber The speeds that people can currently use range from 28 8 kbit s through a 28K modem over a telephone connection to speeds as high as 100 Gbit s using 100 Gigabit Ethernet The following communication and networking technologies have been used to implement WANs Asynchronous Transfer Mode Cable modem Dial up internet Digital subscriber line Fiber optic communication Frame Relay ISDN Leased line SD WAN Synchronous optical networking X 25 AT amp T conducted trials in 2017 for business use of 400 gigabit Ethernet 6 Researchers Robert Maher Alex Alvarado Domanic Lavery and Polina Bayvel of University College London were able to increase networking speeds to 1 125 terabits per second 7 Christos Santis graduate student Scott Steger Amnon Yariv Martin and Eileen Summerfield developed a new laser that potentially quadruples transfer speeds with fiber optics 8 See also EditCell relay Internet area network IAN Label switching Low power wide area network LPWAN Wide area application services Wireless WANReferences Edit A WAN Is a Wide Area Network Here s How They Work Lifewire Retrieved 2017 04 21 Groth David and Skandler Toby 2005 Network Study Guide Fourth Edition Sybex Inc ISBN 0 7821 4406 3 Forouzan Behrouz 2012 02 17 Data Communications and Networking McGraw Hill p 14 ISBN 9780073376226 Zhang Yan Ansari Nirwan Wu Mingquan Yu Heather 2011 10 13 On Wide Area Network Optimization IEEE Communications Surveys amp Tutorials 14 4 1090 1113 doi 10 1109 SURV 2011 092311 00071 ISSN 1553 877X S2CID 18060 Y Rekhter B Moskowitz D Karrenberg G J de Groot E Lear February 1996 Address Allocation for Private Internets Network Working Group IETF doi 10 17487 RFC1918 BCP 5 RFC 1918 AT amp T Completes Industry Leading 400 Gb Ethernet Testing Establishing A Future Network Blueprint for Service Providers and Businesses www att com September 8 2017 Maher Robert Alvarado Alex Lavery Domanic Bayvel Polina 11 February 2016 Increasing the information rates of optical communications via coded modulation a study of transceiver performance Scientific Reports 6 1 21278 Bibcode 2016NatSR 621278M doi 10 1038 srep21278 PMC 4750034 PMID 26864633 A New Laser for a Faster Internet Caltech Cal Tech External links EditCisco Introduction to WAN Technologies What is WAN wide area network Definition from WhatIs com SearchEnterpriseWAN retrieved 2017 04 21 What is a software defined wide area network Retrieved from https en wikipedia org w index php title Wide area network amp oldid 1121354735, wikipedia, wiki, book, books, library,
