Wide area network

A wide area network (WAN) is a telecommunications network that extends over a large geographical distance for the primary purpose of computer networking. Wide area networks are often established with leased telecommunication circuits.[1]

Business, education and government entities use wide area networks to relay data to staff, students, clients, buyers, and suppliers from various locations across 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]

Similar types of networks are personal area networks (PANs), local area networks (LANs), campus area networks (CANs), or metropolitan area networks (MANs) which are usually limited to a room, building, campus or specific metropolitan area, respectively.

LAN WAN scheme

Design options

The textbook definition of a WAN is a computer network spanning regions, countries, or even the world.[3] However, in terms of the application of computer networking protocols and concepts, it may be best to view WANs as computer networking technologies used to transmit data over long distances, and between different LANs, MANs and other localised computer networking architectures. This distinction stems from the fact that common 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 do not just necessarily connect physically disparate LANs. A CAN, for example, may have a localized backbone of a WAN technology, which connects different LANs within a campus. This could be to facilitate higher bandwidth applications or provide better functionality for users in the CAN.[4]

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. 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. X.25 was an important early WAN protocol, and is often considered to be the "grandfather" of Frame Relay as many of the underlying protocols and functions of X.25 are still in use today (with upgrades) by Frame Relay.[5]

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.

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 in technologies have successively increased transmission rates. In ca. 1960, a 110 bit/s (bits per second) line was normal on the edge of the WAN, while core links of 56 kbit/s to 64 kbit/s were considered fast. As of 2014, households are connected to the Internet with Dial-Up, ADSL, Cable, Wimax, 4G 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 over an Ethernet 100GBaseY connection.

The following communication and networking technologies have been used to implement WANs.

400 Gigabit Ethernet

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 quadruples transfer speeds with fiber optics.[8] If these two technologies were combined, then a transfer speed of up to 4.5 terabits per second could potentially be achieved.

See also

References

  1. ^ "A WAN Is a Wide Area Network. Here's How They Work". Lifewire. Retrieved 2017-04-21.
  2. ^ Groth, David and Skandler, Toby (2005). Network+ Study Guide, Fourth Edition. Sybex, Inc. ISBN 0-7821-4406-3.
  3. ^ Forouzan, Behrouz. Data Communications and Networking. McGraw-Hill. p. 14. ISBN 9780073376226.
  4. ^ "Campus Area Networks (CAN). Computer and Network Examples". conceptdraw.com.
  5. ^ "Frame relay". techtarget.com.
  6. ^ "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.
  7. ^ 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. doi:10.1038/srep21278. PMC 4750034. PMID 26864633.
  8. ^ "A New Laser for a Faster Internet - Caltech". Cal Tech.

External links

Arbitrary code execution

In computer security, arbitrary code execution (ACE) is used to describe an attacker's ability to execute arbitrary commands or code on a target machine or in a target process. An arbitrary code execution vulnerability is a security flaw in software or hardware allowing arbitrary code execution. A program that is designed to exploit such a vulnerability is called an arbitrary code execution exploit. The ability to trigger arbitrary code execution over a network (especially via a wide-area network such as the Internet) is often referred to as remote code execution (RCE).

Campus network

A campus network, campus area network, corporate area network or CAN is a computer network made up of an interconnection of local area networks (LANs) within a limited geographical area. The networking equipments (switches, routers) and transmission media (optical fiber, copper plant, Cat5 cabling etc.) are almost entirely owned by the campus tenant / owner: an enterprise, university, government etc. A campus area network is larger than a local area network but smaller than a metropolitan area network (MAN) or wide area network (WAN).

DWANGO

The Dial-up Wide-Area Network Game Operation, better known by the acronym DWANGO, was an early online gaming service based in the United States. Launched in 1994, it was originally known for its compatibility with Doom, for which it functioned as a matchmaking service for online multiplayer. The service also supported various other titles, including other id Software games such as Doom II and Heretic as well as titles from other companies like Duke Nukem 3D, Blood, and Shadow Warrior from 3D Realms.To use the service, players would pay a fee and run the DWANGO client software which would dial into a DWANGO server. Initially, a phone number in Houston, Texas had to be dialed, but soon a number of servers in other cities were also set up. However, DWANGO's dial in approach was soon overshadowed by online multiplayer through the increasingly popular Internet and the service ceased operation in October 1998. Its Japanese division has continued to flourish, evolving into the telecommunications/media company which now operates the Niconico video hosting service.

Dwango (company)

DWANGO Co., Ltd. (株式会社ドワンゴ, Kabushiki gaisha Dowango) is a telecommunications and media company based in Japan, headed by Nobuo Kawakami. The company is now a wholly owned subsidiary of Kadokawa Dwango Corporation. The company was spun off from a U.S.-based service offering online multiplayer for video games, DWANGO (Dial-up Wide-Area Network Game Operation), which was shut down in 1998. Dwango's majority shareholders until its merger with Kadokawa Corporation included Kawakami himself, Kadokawa Corporation, and Avex Group. Dwango runs the popular Japanese video sharing site Niconico. The company also is the 100% owner of the game developer Spike Chunsoft. In November 2013, it was confirmed Nintendo purchased 612,200 or 1.5% shares of the company at the request of Nobuo Kawakami.On May 14, 2014, it was announced that Dwango and Kadokawa Corporation would merge on October 1, 2014, and form the new holding company Kadokawa Dwango Corporation. Both Kadokawa and Dwango became subsidiaries of the new company.In February 2019, Kadokawa Dwango announced that Dwango would stop being their subsidiary to be a direct subsidiary of Kadokawa Corporation in a reorganization of the company.

Frame Relay

Frame Relay is a standardized wide area network technology that specifies the physical and data link layers of digital telecommunications channels using a packet switching methodology. Originally designed for transport across Integrated Services Digital Network (ISDN) infrastructure, it may be used today in the context of many other network interfaces.

Network providers commonly implement Frame Relay for voice (VoFR) and data as an encapsulation technique used between local area networks (LANs) over a wide area network (WAN). Each end-user gets a private line (or leased line) to a Frame Relay node. The Frame Relay network handles the transmission over a frequently changing path transparent to all end-user extensively used WAN protocols. It is less expensive than leased lines and that is one reason for its popularity. The extreme simplicity of configuring user equipment in a Frame Relay network offers another reason for Frame Relay's popularity.

With the advent of Ethernet over fiber optics, MPLS, VPN and dedicated broadband services such as cable modem and DSL, the end may loom for the Frame Relay protocol and encapsulation. However many rural areas remain lacking DSL and cable modem services. In such cases, the least expensive type of non-dial-up connection remains a 64-kbit/s Frame Relay line. Thus a retail chain, for instance, may use Frame Relay for connecting rural stores into their corporate WAN.

Gujarat State Wide Area Network

Gujarat State Wide Area Network (GSWAN) is an end-to-end IP based network designed for the service convergence (Voice, video and Data) on a single backbone, for the state Government of Gujarat, India. The GSWAN was implemented in the year 2001-02.GSWAN is based on open standards, is scalable and has high capacity Network to carry Voice, Data and Video traffic between designated Government of Gujarat offices at State, District and Taluka levels via a dedicated E1 leased line.The connectivity to end-user is based on standard leased circuits dial-up circuits or using Ethernet ports as appropriate for the individual offices. Single point Gateway with adequate capacity for Internet and provision for connecting other existing Networks have also been set up.

First tierSecretariat Center at state capital, Gandhinagar. Various departments and hundreds of subordinate offices located at the state capital are connected to SC horizontally through SCAN (Secretariat Campus Area Network). SCAN had about 7000 Ethernet I/O’s at Gandhinagar and all these I/Os are interconnected with GSWAN for information exchange. 300 GSWAN phone connections provided to various offices at Secretariat for direct voice communication to any GSWAN node in the state.

Second TierConstitutes District Centers, located at district collector’s office and multiple district level other offices connected with DC horizontally. All the 24 districts, except Gandhinagar, are connected on 2 Mbit/s (E1) leased lines with the Secretariat Center. The dialup access is given to all those Government offices in district, Taluka, that are not considered for direct integration on Ethernet / leased / OFC / Wireless.

Third TierConstitutes Talukas Centers, located at Taluka Mamlatdar’s office and Taluka Development Office provision are kept for connecting Taluka level other offices horizontally. All 225 Talukas are connected to District Centers. (211 on 64 Kb leased lines, and rest of 14 Talukas on Ethernet).

IEEE 802.3

IEEE 802.3 is a working group and a collection of Institute of Electrical and Electronics Engineers (IEEE) standards produced by the working group defining the physical layer and data link layer's media access control (MAC) of wired Ethernet. This is generally a local area network (LAN) technology with some wide area network (WAN) applications. Physical connections are made between nodes and/or infrastructure devices (hubs, switches, routers) by various types of copper or fiber cable.

802.3 is a technology that supports the IEEE 802.1 network architecture.

802.3 also defines LAN access method using CSMA/CD.

LPWAN

A low-power wide-area network (LPWAN) or low-power wide-area (LPWA) network or low-power network (LPN) is a type of wireless telecommunication wide area network designed to allow long range communications at a low bit rate among things (connected objects), such as sensors operated on a battery.

The low power, low bit rate and intended use distinguish this type of network from a wireless WAN that is designed to connect users or businesses, and carry more data, using more power. The LPWAN data rate ranges from 0.3 kbit/s to 50 kbit/s per

channel.A LPWAN may be used to create a private wireless sensor network, but may also be a service or infrastructure offered by a third party, allowing the owners of sensors to deploy them in the field without investing in gateway technology.

LTE-M

LTE-M (LTE-MTC [Machine Type Communication]), which includes eMTC (enhanced Machine Type Communication), is a type of low power wide area network (LPWAN) radio technology standard developed by 3GPP to enable a wide range of cellular devices and services (specifically, for machine-to-machine and Internet of Things applications). The specification for eMTC (LTE Cat-M1) was frozen in 3GPP Release 13 (LTE Advanced Pro), in June 2016. Other 3GPP IoT technologies include NB-IoT and EC-GSM-IoT.The advantage of LTE-M over NB-IoT is its comparatively higher data rate, mobility, and voice over the network, but it requires more bandwidth, is more costly, and cannot be put into guard band frequency band for now.. In March 2019, the Global Mobile Suppliers Association reported that over 100 operators had deployed/launched either NB-IoT or LTE-M networks.

Link Access Procedure for Frame Relay

In wide area network computing, Link Access Procedure for Frame Relay (or LAPF) is part of the network's communications protocol which ensures that frames are error free and executed in the right sequence.

LAPF is formally defined in the International Telecommunication Union standard Q.922. It was derived from IBM's Synchronous Data Link Control protocol, which is the layer 2 protocol for IBM's Systems Network Architecture developed around 1975. ITU used SDLC as a basis to develop LAPF for the frame relay environment, along with other equivalents: LAPB for the X.25 protocol stack, LAPM for the V.42 protocol, and LAPD for the ISDN protocol stack.

In Frame Relay Local Management Interface (LMI) messages are carried in a variant of LAPF frames.

LAPF corresponds to the OSI model Data Link layer.

Local area network

A local area network (LAN) is a computer network that interconnects computers within a limited area such as a residence, school, laboratory, university campus or office building. By contrast, a wide area network (WAN) not only covers a larger geographic distance, but also generally involves leased telecommunication circuits.

Ethernet and Wi-Fi are the two most common technologies in use for local area networks. Historical technologies include ARCNET, Token ring, and AppleTalk.

Metropolitan area network

A metropolitan area network (MAN) is a computer network that interconnects users with computer resources in a geographic region of the size of a metropolitan area. The term MAN is applied to the interconnection of local area networks (LANs) in a city into a single larger network which may then also offer efficient connection to a wide area network. The term is also used to describe the interconnection of several local area networks in a metropolitan area through the use of point-to-point connections between them .

NATO CRONOS

Crisis Response Operations in NATO Operating Systems (CRONOS) is a system of interconnected computer networks used by NATO to transmit classified information. It provides NATO Secret level operations, with access to NATO intelligence applications and databases. As of 1999, a wide area network of NT computers used in NATO in Europe.

CRONOS provides e-mail, the Microsoft Office Suite, etc.

It provides informal messaging (e-mail) and information sharing within the NATO community.

There is no connectivity between CRONOS and any US network or with the coalition wide area network.

Narrowband IoT

Narrowband Internet of Things (NB-IoT) is a Low Power Wide Area Network (LPWAN) radio technology standard developed by 3GPP to enable a wide range of cellular devices and services. The specification was frozen in 3GPP Release 13 (LTE Advanced Pro), in June 2016. Other 3GPP IoT technologies include eMTC (enhanced Machine-Type Communication) and EC-GSM-IoT.NB-IoT focuses specifically on indoor coverage, low cost, long battery life, and high connection density. NB-IoT uses a subset of the LTE standard, but limits the bandwidth to a single narrow-band of 200kHz. It uses OFDM modulation for downlink communication and SC-FDMA for uplink communications. In March 2019, the Global Mobile Suppliers Association announced that over 100 operators have deployed/launched either NB-IoT or LTE-M networks.

Residential gateway

A residential gateway is a small consumer-grade router which provides network access between local area network (LAN) hosts to a wide area network (WAN) via a modem. The modem may or may not be integrated into the hardware of the residential gateway. The WAN is a larger computer network, generally operated by an Internet service provider.

SD-WAN

SD-WAN is an acronym for software-defined networking in a wide area network (WAN). SD-WAN simplifies the management and operation of a WAN by decoupling (separating) the networking hardware from its control mechanism. This concept is similar to how software-defined networking implements virtualization technology to improve data center management and operation.A key application of SD-WAN is to allow companies to build higher-performance WANs using lower-cost and commercially available Internet access, enabling businesses to partially or wholly replace more expensive private WAN connection technologies such as MPLS.American marketing research firm Gartner predicted in 2015 that by the end of 2019 30% of enterprises will deploy SD-WAN technology in their branches.

State Wide Area Network

A State Wide Area Network (SWAN) is one of the core infrastructure components under the National e-Governance Plan of the Government of India. The main purpose of this network is to create a dedicated Closed User Group (CUG) network and provide a secured and high speed connectivity for Government functioning and connecting State Headquarters, District Headquarters, Blocks Headquarters. The SWAN project, which forms a strategic component of the National eGovernance Plan, was approved in March 2005.

Wireless WAN

Wireless wide area network (WWAN), is a form of wireless network.

The larger size of a wide area network compared to a local area network requires differences in technology.

Wireless networks of different sizes deliver data in the form of telephone calls, web pages, and streaming video.

A WWAN often differs from wireless local area network (WLAN) by using mobile telecommunication cellular network technologies such as LTE, WiMAX (often called a wireless metropolitan area network or WMAN), UMTS, CDMA2000, GSM, cellular digital packet data (CDPD) and Mobitex to transfer data. It can also use Local Multipoint Distribution Service (LMDS) or Wi-Fi to provide Internet access. These technologies are offered regionally, nationwide, or even globally and are provided by a wireless service provider. WWAN connectivity allows a user with a laptop and a WWAN card to surf the web, check email, or connect to a virtual private network (VPN) from anywhere within the regional boundaries of cellular service. Various computers can have integrated WWAN capabilities.

A WWAN may also be a closed network that covers a large geographic area. For example, a mesh network or MANET with nodes on buildings, towers, trucks, and planes could also be considered a WWAN.

A WWAN may also be a low-power, low-bit-rate wireless WAN, (LPWAN), intended to carry small packets of information between things, often in the form of battery operated sensors.

Since radio communications systems do not provide a physically secure connection path, WWANs typically incorporate encryption and authentication methods to make them more secure. Some of the early GSM encryption techniques were flawed, and security experts have issued warnings that cellular communication, including WWAN, is no longer secure. UMTS (3G) encryption was developed later and has yet to be broken.

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