Computer Networks: Current Concepts, Topologies, and Technologies

Types of Networks by Scale

Local Area Network (LAN)

A Local Area Network (LAN) is a network that is limited to a relatively small area, such as an office, school, or apartment. LANs allow devices within the region to communicate and share resources.

Application:

1. Office: LANs are widely used in offices to share files, printers, and applications.
2. Schools: LANs help students and teachers share resources and information.
3. Apartments: LANs allow apartment residents to share the internet and other resources.

Wide Area Network (WAN)

A Wide Area Network (WAN) is a network that covers a wider area, such as a city, country, or even the world. WAN allows devices in different locations to communicate and share resources.

Application:

1. Large Enterprises: WANs are used by large companies to connect branch offices in various locations.
2. Government: The WAN assists the government in managing information and resources across various departments.
3. Internet Services: WANs are used by Internet service providers to provide Internet access to customers around the world.

Metropolitan Area Network (MAN)

Metropolitan Area Network (MAN) is a network that covers metropolitan areas, such as large cities. MAN enables devices within the metropolitan area to communicate and share resources.

Application:

1. Big Cities: MAN is used by big cities to connect public facilities such as train stations, shopping malls, and healthcare facilities.
2. Education: MAN assists educational institutions in managing information and resources across various campuses.
3. Large Corporations: MAN is used by large companies to connect offices within large cities.

Network Model

Peer-to-Peer

Peer-to-peer (P2P) is a networking model in which each device functions as a client and server simultaneously. Each device can send and receive data, as well as share resources with other devices.

Excess:

1. Simple: P2P installation and use is relatively simple as it does not require a central server.
2. Easy Sharing: P2P allows users to share files and resources easily.
3. No Server Required: There is no need to have an expensive and complex central server.

Deficiency:

1. Capacity Limitations: P2P has capacity limitations because each device has to share bandwidth simultaneously.
2. Interference: If one of the devices fails, then the entire network will be disrupted.
3. Security: P2P is vulnerable to cyberattacks because data can move freely between devices.

Client-Server

Client-server is a network model in which each device functions as a client accessing resources from a central server. Servers store and manage resources, while clients access and use those resources.

Excess:

1. Stable Performance: Client-server provides stable performance as data does not need to share bandwidth simultaneously.
2. Fail Resistant: If one of the clients fails, then the data is still accessible through the server.
3. Security: Client servers are more secure because data is stored and managed by servers that have tighter controls.

Deficiency:

1. Complex: Client-server installation and deployment are more complex because they require expensive and complex central servers.
2. High Cost: It costs a lot to buy and maintain a central server.
3. Server Dependency: The network depends on the performance of the server, so if the server fails, then the entire network will be disrupted.

Conclusion

Computer networks play a crucial role in connecting devices and enabling communication and resource sharing. The selection of the right topology, technology, network type, and network model depends largely on the specific needs and scale of the desired network. By understanding these various aspects, we can design and manage an efficient, secure, and reliable network.