Wide Area Networks (WAN)
Introduction
A Wide Area Network (WAN) is a telecommunications network that extends over a large geographical area for the purpose of computer networking. Wide Area Networks are often established with leased telecommunication circuits.
History
The development of WAN technologies was driven by the increasing need to connect local area networks (LANs) and individual computers to larger networks, such as the internet. The earliest types of WANs were established in the late 1960s and early 1970s, including the Advanced Research Projects Agency Network and the X.25 network protocol.
Design and Function
WANs are designed to connect networks across large geographical areas, including cities, states, provinces, countries, or even worldwide. They are used to connect schools, businesses, and government entities. WANs are often interconnected with Local Area Networks, which are smaller networks located in a specific geographical area, such as an office building or school.
Technologies
Various technologies are used in wide area networks, including circuit switching, packet switching, and leased lines. Circuit switching, such as Integrated Services Digital Network (ISDN), involves dedicating a specific path in the network for the duration of the transmission. Packet switching, such as Internet Protocol (IP), involves breaking down data into packets and sending them individually over the network. Leased lines are dedicated lines that provide constant connectivity between two network points.
WAN Protocols
There are several key protocols used in a WAN, including IP, Point-to-Point Protocol, and Multiprotocol Label Switching. IP is the primary protocol used in the internet. PPP is a data link protocol commonly used to establish a direct connection between two networking nodes. MPLS is a protocol for speeding up and shaping network traffic flows.
WAN Services
WAN services include leased line services, Frame Relay, Asynchronous Transfer Mode, and Multiprotocol Label Switching. Leased line services provide a constant, dedicated capacity between two points. Frame Relay is a telecommunication service designed for cost-efficient data transmission. ATM is a network protocol that encodes data into small fixed-sized cells. MPLS is a scalable, protocol-independent transport for data transfer.
Advantages and Disadvantages
The main advantage of a WAN is its size. By connecting a large number of devices and networks over a large area, a WAN enables more comprehensive and efficient communication. However, WANs are complex and can be costly to establish and maintain. They also require a high level of technical skill to manage.
Future of WANs
The future of WANs lies in the integration of cloud services, software-defined networking, and virtualization technologies. These technologies will enable more flexible, scalable, and efficient WANs, capable of meeting the demands of modern businesses and organizations.