A Wide Area Network (WAN) is a communication network that spans a large geographical area. It can connect cities, states and parts of a country or even countries. The devices in a WAN are connected through public infrastructure such as a telephone system or through leased lines or even satellites. The Internet may be called as the largest WAN. Various, Local Area Networks (LANs) or Metropolitan Area Networks (MANs) are interconnected in a variety of ways and at different levels and accesses to form a WAN. Larger corporations or organisations which have their facilities located all over the world uses WAN.
In a Wide Area Network (WAN) the user or organisation does not own the communication links or infrastructure that connects the remote computer system; instead such a service is provided by a telecom/internet service provider. WANs transmit data at slower speeds than LANs. WANs are similar in their structure to a MAN, but its range of services cover distances greater than fifty kilometres.
WANs are used for data and image transmission and also for voice services. Due to the rapid progress of technology in the recent years and additions to the LAN connections over the years, there has been a significant surge in WAN usage. So, government entities, businesses, educational institutions, students, clients, buyers and suppliers are using WANs from various locations across the world at an unprecedented scale. WANs thus ensure that the connecting parties effectively carry out their daily functions regardless of their location thereby reducing distances and making the world a relatively smaller place.
(The above figure is a simplified diagram to represent a Wide Area Network (WAN). Various LANs situated in different cities are connected via the WAN).
How does a WAN work ?
A WAN may transmit data over long distances to connect various LANs, MANs or other computer networking architecture. But such LANs or MANs cannot transmit data over tens, hundreds or thousands of kilometres and herein WANs as they overcome this difficulty of covering distance ranges.
Since a WAN covers large distances as compared to LANs, Virtual Private Network (VPN) can help connect its various parts. VPN uses the public infrastructure over the internet and a variety of specialised protocol which support private communications. In simple terms, a VPN uses public telecommunication network to conduct private data communications by using authentication and data encryption. This helps in providing protected communication between sites over the internet.
Technologies used in implementing WAN
In the beginning, in the 1980s, technology standards such as X.25 were used. These kind of networks supported the credit card systems, automated teller machines (ATM) and some early online information systems. X.25 networks used 56 Kbps dial up modem connection. A modem being a device which helps a computer transmit or receive its digital data over telephone or cable lines.
Later on in the 1990s, Frame Relay technology came into existence. This simplified the X.25 protocol thereby providing higher speeds in lesser the costs. Frame Relay is a network protocol technology designed to connect LAN and transfer data across WAN.
Multiprotocol Label switching (MPLS) then replaced Frame Relay technology. This MLPS improved protocol support for handling voice and video traffic along with the normal data traffic. With increasing popularity in the 2000s MLPS eventually replaced Frame Relay.
Nowadays, households are connected to the WAN using Dial-Up, ADSL (Asymmetric Digital Subscriber Line) which commonly uses a Gateway to make a connection, Cable, 4G or fibre optic. ATM (Asynchronous Transfer Mode), ISDN (Integrated Services Digital Network) are some other standards/technology to for WAN implementation.
Speeds ranging from 28 kilo-bits/second to speeds as high as 100 Giga-bits/second (using a Ethernet 100GBaseY connection) have are being used by the people to connect to the internet. Trials were recently conducted in 2017 for business use of 400 gigabit Ethernet. An Ethernet simply helps in connecting computers together in a LAN using some protocol or a set of rules in order to facilitate data transmission.
Advantages of a WAN
WAN offers privacy and security. As a WAN provides dedicated, direct and encrypted connection for data transmission, it increases the security of the system.
Update files and data are available on the servers of various software companies. So, all the users and administrators get updated version of data or files within a few seconds.
Sharing of software and resources can happen over long distances just like in a LAN.
High bandwidth is ensured due to the Network Performance Consistency as our data doesn’t compete with other internet data due to dedicated bandwidth. Leased lines could be allotted to achieve this.
Businesses have become global or their geographical reach has increased due to the access to the WANs anywhere.
Disadvantages of a WAN
We need secure connections over a WAN. Thus our computers/networks need firewalls and anti-virus software. Such requirements needs upgrade regularly as the threats become more pernicious.
Disconnection and server connection issues are also frequent, especially in remote areas.
The setup cost for WANs are high as it requires purchase of routers, switches and extra security software. Such setups also have a high maintenance costs.
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