What is LAN, WAN and MAN

With the continuous development of computer network technology, computer, printer and other network equipment can achieve information transfer and resource sharing based on specific network technology, computer network has become an essential part of our life. Depending on the scope of coverage, computer networks can be classified into LAN, MAN, and WAN.

What is LAN

LAN (short for Local Area Network) is the most common and widely used network. It refers to a computer network in which two or more computer devices (such as servers and workstations) are connected by cables (such as coaxial cables, twisted-pair cables, and optical cables) within a range of 1 to 5 kilometers to realize resource sharing, such as homes, offices, schools, or buildings with computers, servers, and peripherals such as printers, scanners, projectors, and other storage. 

At present, Ethernet (IEEE 802.3 standard) is the most common LAN networking mode. In recent years, with the formulation of 802.11 standard, IEEE802.11A/B/G/N and other wireless protocols have been widely used, and the application of wireless LAN has been popularized.

What is MAN

MAN (short for Metropolitan Area Network) refers to the computer network established within the same city area, with its range covering up to 60 kilometers. MAN transmission is small in delay and fast in speed, it can be regarded as a backbone network. High-speed connection network can be established by connecting hosts, s and LANs at different s within the same city through optical cable. Common protocols of MAN include ATM (Asynchronous Transfer Mode), DQDB (Distributed Queue Dual Bus), SMDS (Switched Multi-Megabit Data Service ) and so on.

What is WAN

WAN (short for Wide Area Network) refers to a computer network that connects local area networks or metropolitan area networks in different areas. It has a wide coverage of up to thousands of kilometers, and can connect multiple regions, cities and countries, and even achieve long-range communication across several continents. Compared with LAN (Local area network) and MAN (metropolitan area network), WAN (wide area network) involves more diversified devices, such as routers, switches and firewalls. Each branch of an enterprise can establish WAN connection to realize communication through microwave and satellite channels. At present, the commonly used WAN protocols include Frame-Relay, point-to-point protocol (PPP), Advanced Data Link Control Protocol (HDLC) and Synchronous Data Link Control Protocol (SDLC).

Differences between LAN, MAN and WAN

LAN, MAN, and WAN are all computer networks. Although the nature of communication is the same, the three network types still differ in terms of coverage, application and so on. 

Coverage

The coverage of the three types from small to large is LAN (Local Area Network), MAN (Metropolitan Area Network), WAN (Wide Area Network).

Transmission Media

Typically, LAN uses wireless WiFi or 100/1000Mbps network cables for communication. MAN uses 100Mbps cable or modem. WAN is different from the communication between users. It generally uses telephone lines, high-speed data lines, satellites, microwave and other ways to communicate, and its transmission rate is relatively low compared with LAN.

Applications

LAN can effectively deny access from unauthorized users and ensure service security, which is sui for enterprise intranet. As for MAN, the most common is the household cable television network in every city. in addition, various government agencies or enterprises can rely on MAN to connect its department offices located in different regions. For some military services, railway reservations, airlines and others with high security requirements for its network, high security communication can be achieved by establishing WAN.

Establishment and Maintenance

Compared with MAN and WAN, LAN is easier to set up and maintain because there are fewer network nodes.