LAN, WAN and MAN

The Network allows computers to connect and communicate with different computers via any medium. LAN, MAN, and WAN are the three major types of networks designed to operate over the area they cover. There are some similarities and dissimilarities between them.

Types of Networks

The different types of networks can be categorised based on the area they cover, the type of communication they use, and their architectural design.

Division Based on Area Covered

Networks can be divided based on the area they cover, ranging from personal connections to global networks:

1. Personal Area Network (PAN)

PAN is a personal area network having an interconnection of personal technology devices to communicate over a short distance. It covers less than 10 meters or 33 feet of area. PAN has fewer users as compared to other networks such as LAN, WAN, etc. PAN typically uses some form of wireless technology. PAN involves the transmission of data between information devices such as smartphones, personal computers, tablet computers, etc.

Advantages:

• Allows for easy communication between personal devices in close proximity.
• Can be set up easily and quickly.
• Uses wireless technology, which eliminates the need for wires and cables.
• PANs are designed to be energy efficient, which means that devices can communicate with each other without draining their batteries quickly.
• PANs are typically secured using encryption and authentication protocols, which helps to prevent unauthorized access to data and resources.

Disadvantages:

• Limited coverage area.
• May not be suitable for large-scale data transfer or communication.PANs typically have limited bandwidth, which means that they may not be able to handle large amounts of data or high-speed communication.
• May experience interference from other wireless devices.

2. Local Area Network (LAN)

LAN or Local Area Network connects network devices in such a way that personal computers and workstations can share data, tools, and programs.

The group of computers and devices are connected together by a switch, or stack of switches, using a private addressing scheme as defined by the TCP/IP protocol. Private addresses are unique in relation to other computers on the local network. Routers are found at the boundary of a LAN, connecting them to the larger WAN.

Data transmits at a very fast rate as the number of computers linked is limited. By definition, the connections must be high-speed and relatively inexpensive hardware (Such as hubs, network adapters, and Ethernet cables). LANs cover a smaller geographical area (Size is limited to a few kilometres) and are privately owned. One can use it for an office building, home, hospital, school, etc. LAN is easy to design and maintain. A Communication medium used for LAN has twisted-pair cables and coaxial cables. It covers a short distance, and so the error and noise are minimized.

Early LANs had data rates in the 4 to 16 Mbps range. Today, speeds are normally 100 or 1000 Mbps. Propagation delay is very short in a LAN. The smallest LAN may only use two computers, while larger LANs can accommodate thousands of computers. LAN has a range up to 2km. A LAN typically relies mostly on wired connections for increased speed and security, but wireless connections can also be part of a LAN. The fault tolerance of a LAN is more and there is less congestion in this network. For example A bunch of students playing Counter-Strike in the same room (without internet).

Advantages:

• Provides fast data transfer rates and high-speed communication.
• Easy to set up and manage.
• Can be used to share peripheral devices such as printers and scanners.
• Provides increased security and fault tolerance compared to WANs.

Disadvantages:

• Limited geographical coverage.
• Limited scalability and may require significant infrastructure upgrades to accommodate growth.
• May experience congestion and network performance issues with increased usage.

3. Metropolitan Area Network (MAN)

MAN or Metropolitan area Network covers a larger area than that covered by a LAN and a smaller area as compared to WAN. MAN has a range of 5-50km. It connects two or more computers that are apart but reside in the same or different cities. It covers a large geographical area and may serve as an ISP (Internet Service Provider). MAN is designed for customers who need high-speed connectivity. Speeds of MAN range in terms of Mbps. It’s hard to design and maintain a Metropolitan Area Network.

The fault tolerance of a MAN is less and also there is more congestion in the network. It is costly and may or may not be owned by a single organization. The data transfer rate and the propagation delay of MAN are moderate. Devices used for transmission of data through MAN are Modem and Wire/Cable. Examples of a MAN are part of the telephone company network that can provide a high-speed DSL line to the customer or the cable TV network in a city.

Advantages:

• Provides high-speed connectivity over a larger geographical area than LAN.
• Can be used as an ISP for multiple customers.
• Offers higher data transfer rates than WAN in some cases.

Disadvantages:

• Can be expensive to set up and maintain.
• May experience congestion and network performance issues with increased usage.
• May have limited fault tolerance and security compared to LANs.

4. Wide Area Network (WAN)

WAN or Wide Area Network is a computer network that extends over a large geographical area, although it might be confined within the bounds of a state or country. WAN has a range of above 50 km. A WAN could be a connection of LAN connecting to other LANs via telephone lines and radio waves and may be limited to an enterprise (a corporation or an organization) or accessible to the public. The technology is high-speed and relatively expensive.

There are two types of WAN: Switched WAN and Point-to-Point WAN. WAN is difficult to design and maintain. Similar to a MAN, the fault tolerance of a WAN is less and there is more congestion in the network. A Communication medium used for WAN is PSTN(Public Switched Telephone Network) or Satellite Link. Due to long-distance transmission, the noise and error tend to be more in WAN.

WAN’s data rate is slow about a 10th LAN’s speed since it involves increased distance and increased number of servers and terminals etc. The speed of WAN ranges from a few kilobits per second (Kbps) to megabits per second (Mbps). Propagation delay is one of the biggest problems faced here. Devices used for the transmission of data through WAN are Optic wires, Microwaves, and Satellites. An example of a Switched WAN is the asynchronous transfer mode (ATM) network and Point-to-Point WAN is a dial-up line that connects a home computer to the Internet.

Advantages:

• Covers large geographical areas and can connect remote locations.
• Provides connectivity to the internet.
• Offers remote access to resources and applications.
• Can be used to support multiple users and applications simultaneously.

Disadvantages:

• Can be expensive to set up and maintain.
• Offers slower data transfer rates than LAN or MAN.
• May experience higher latency and longer propagation delays due to longer distances and multiple network hops.
• May have lower fault tolerance and security compared to LANs.

There are other types of Computer Networks also, like :

• SAN (Storage Area Network)
• VPN (Virtual Private Network)

Based on Types of Communication

Networks can also be divided based on the types of communication they use:

1. Point-to-Point Networks

Point-to-Point networking establishes a direct link between two networking nodes, such as a computer and a printer. This type of network ensures that data is transmitted directly from one device to another without intermediaries. It is commonly used for simple, dedicated connections where only two devices need to communicate. The communication medium can be wired, such as a cable, or wireless, such as infrared or radio signals. Examples include a computer connected to a printer or a direct dial-up connection between two computers.

Advantages:

• Provides a dedicated and direct connection, ensuring reliable communication between two devices.
• Simple to set up and configure due to the limited number of devices involved.
• Offers low latency as there are no intermediate devices or complex routing.
• Secure communication as data travels directly between the two nodes without passing through other devices.

Disadvantages:

• Limited to only two devices, making it unsuitable for networks requiring multiple device connections.
• Not scalable, as adding more devices requires additional dedicated links.
• May require physical cables for wired connections, which can limit flexibility.
• Lacks fault tolerance; if the direct link fails, communication is disrupted.

2. Multipoint Networks

Multipoint networks involve more than two devices sharing a single communication link. The capacity of the channel is shared either spatially (multiple devices use the link simultaneously) or temporally (devices take turns using the link). This type of network is used in scenarios where multiple devices need to communicate over a shared medium, such as in bus or ring topologies. An example is a Wi-Fi network where multiple devices connect to a single access point.

Advantages:

• Allows multiple devices to share a single communication channel, reducing the need for multiple dedicated links.
• More cost-effective than point-to-point networks for connecting multiple devices.
• Supports dynamic communication, where devices can join or leave the network easily.
• Suitable for environments like offices or homes where multiple devices need to communicate.

Disadvantages:

• Shared bandwidth can lead to congestion and reduced performance when many devices are active.
• Complex to manage compared to point-to-point networks due to multiple devices sharing the link.
• Potential for interference or collisions in spatially shared connections.
• Security risks may increase as multiple devices access the same communication medium.

3. Broadcast Networks

Broadcast networks use a single communication channel where one sender transmits data that can be received by multiple parties simultaneously. In this setup, data travels in one direction, from the sender to all potential receivers. A common example is a radio station, where the station broadcasts signals that can be picked up by any radio receiver within range. Another example is a television network broadcasting to multiple viewers.

Advantages:

• Efficient for distributing data to a large number of recipients simultaneously.
• Simple to implement for one-to-many communication scenarios.
• Reduces the need for individual connections to each receiver, saving resources.
• Ideal for applications like broadcasting news, updates, or streaming media.

Disadvantages:

• Data is sent in one direction, limiting two-way communication.
• No guarantee that all intended recipients receive the data reliably.
• Can lead to bandwidth wastage if not all receivers need the transmitted data.
• Security concerns, as broadcasted data can potentially be intercepted by unauthorized parties.

Based on Type of Architecture

Networks can be divided based on their type of architecture:

1. Peer-to-Peer (P2P) Networks

Peer-to-Peer networks consist of computers with similar capabilities and configurations, referred to as peers, connected over the Internet. In a P2P network, each peer acts as both a client and a server, allowing direct file sharing and communication without relying on a central server. This architecture is commonly used for file-sharing applications like BitTorrent, where peers share resources directly with each other.

Advantages:

• No need for a central server, reducing setup and maintenance costs.
• Highly scalable, as adding more peers increases the network’s resource-sharing capacity.
• Resilient to failures, as there is no single point of failure; peers can continue sharing even if some nodes go offline.
• Efficient for decentralized applications like file sharing or distributed computing.

Disadvantages:

• Security risks, as peers directly share files, which may expose systems to malware or unauthorized access.
• Performance can vary depending on the number and reliability of peers in the network.
• Difficult to manage and monitor due to the lack of centralized control.
• May face legal issues in cases of unauthorized file sharing or copyrighted content.

2. Client-Server Networks

In a Client-Server network, each computer or process on the network is either a client or a server. Clients request services or resources, while servers provide those services. Servers are typically high-performance computers managing resources like files (file servers), printers (print servers), or network traffic (network servers). This architecture is widely used in web applications, where clients (e.g., web browsers) request data from servers (e.g., websites).

Advantages:

• Centralized management makes it easier to control, secure, and maintain the network.
• Efficient resource allocation, as servers are dedicated to providing specific services.
• Scalable, as additional servers can be added to handle increased demand.
• Enhanced security through centralized authentication and access control mechanisms.

Disadvantages:

• High setup and maintenance costs due to the need for dedicated server hardware and software.
• Single point of failure; if the server goes down, clients lose access to services.
• Can experience performance bottlenecks if the server is overloaded with requests.
• Requires skilled administration to manage and secure the server effectively.

3. Hybrid Networks

Hybrid networks combine elements of both client-server and peer-to-peer architectures. They leverage the centralized control of client-server networks and the decentralized resource sharing of P2P networks. An example is a torrent network, where a central tracker (server) coordinates peers, but file sharing occurs directly between peers. Hybrid networks are used in applications requiring both centralized management and distributed resource sharing.

Advantages:

• Combines the benefits of centralized control and decentralized resource sharing.
• Flexible, allowing adaptation to different use cases and requirements.
• Can provide redundancy and fault tolerance by distributing tasks across peers and servers.
• Efficient for applications requiring both centralized coordination and direct peer communication.

Disadvantages:

• Complex to design and maintain due to the combination of two architectures.
• May face security challenges from both client-server and P2P components.
• Higher costs compared to pure P2P networks due to the need for server infrastructure.
• Performance may vary depending on the balance between client-server and P2P operations.