Architecture of Networks

A computer network is basically a set of technologies, that can be either hardware, software or media, used to connect computers together, building a communication bridge between them, so that they can exchange information and share resources. The basics of networking are discussed in the article. Here we will learn about other major characteristics of networks like topology and size.

Topology

Network topology is the configuration or arrangement of how connections, devices, and nodes are arranged with respect to each other. Their logical and physical arrangements come under this characteristic. Major techniques involved in network topology are:

• Bus Topology:

A network consisting of a central linear transmission cable to which all network devices are attached along the length. The data travels in both directions along the bus. When the destination terminal sees the data, it copies it to the local disk. The main advantage of this topology is that it requires the least amount of cables.

• Ring Networks

In the ring topology, each terminal is connected to exactly two nodes, giving the network a circular shape. Data travels in only one predetermined direction. If the ring is broken the entire network is unable to communicate.

• Star Networks

A network that uses a central device called the server or central node, connected directly to several other devices. Any exchange of data between two nodes must take place through the server.

• Tree Networks

Tree topology has a group of star networks connected to a linear bus backbone cable. It incorporates features of both star and bus topologies. Tree topology is also called hierarchical topology.

• Mesh Networks

A network in which there are multiple connections between the devices on the network so that messages can take any one of several paths.

Network size and coverage area

Networks can be categorized depending on size, complexity, level of security, or geographical range. Some of the most popular topologies based on geographical spread include:

• PAN (Personal Area Network)

It connects an individual’s personal devices that are located close together. PAN is the interconnection between devices within the range of a person’s private space, typically within a range of 10 meters. If you have transferred images or songs from your laptop to mobile or from mobile to your friend’s mobile using Bluetooth, this is an example of setting up and using a personal area network. A person can connect her laptop, smartphone, personal digital assistant, and portable printer in a network at home. This network could be fully Wi-Fi or a combination of wired and wireless.

• LAN (Local Area Network)

It connects devices located in a small geographic area. It is spread over a single site like an office, building, or manufacturing unit. LAN is set up when team members need to share software and hardware resources with each other but not with the outside world. Typical software resources include official documents, user manuals, employee handbooks, etc. Hardware resources that can be easily shared over the network include the printer, fax machines, modems, memory space, etc. This decreases infrastructure costs for the organization drastically. A LAN may be set up using wired or wireless connections. A LAN that is completely wireless is called Wireless LAN or WLAN.

WAN (Wide Area Network)

Wide Area Network is spread over a country or many countries, thus it covers large geographical area. WAN is typically a network of many LANs, MANs and WANs. Network is set up using wired or wireless connections, depending on availability and reliability. • The most common example of WAN is the Internet.

MAN (Metropolitan Area Network)

It serves the metropolitan areas. It is a network spread over a city, college campus, or a small region. MAN is larger than a LAN and typically spread over several kilometers. The objective of MAN is to share hardware and software resources, thereby decreasing infrastructure costs. MAN can be built by connecting several LANs. The most common example of MAN is a cable TV network.

CAN (Campus Area Network)

It follows the same principle as the local area network, but it is a larger and more diversified scale. In this type of network offices or organizations are linked together. For example, an office or university use campus are networks withing their space.