1.2 Basics of Computer Networks

In previous tutorial, we answered some basic questions regarding computer networks. Now we will learn about the categories of networks and structures in which they exist. There are various types of networks that exist today. Depending upon range and extensiveness, they are broadly classified into these categories:

  1. Personal Area Networks (PANs):

    PANs have a range of about 1 meter. It is used in assembling of machines and personal devices. A simple example includes attaching the computer peripherals to it’s CPU.

  2. Local Area Networks (LANs)

    LANs have ranges from 10 to 1000 meters. It is mostly used in assembling machines inside a building or a campus. Examples of such networks are networks used in offices, schools etc.

  3. Metropolitan Area Networks (MANs)

    MANs range over a whole town/city. It’s example is the local TV cable networks or the local telephone cables that reach your home.

  4. Wide Area Networks (WANs)

    The WANs’ range is over a country or even a continent. A WAN can be as complex as the backbones that connect the Internet or as simple as a dial-up line that connects a home computer to the Internet. They can further be classified into switched and point to point WANs. They are basically used to provide internet access.

    Source

These are the types of networks based on extensiveness of their application. But, they should not be confused with the Physical Topology of network i.e. the structure of network, which is defined as the organization of network. The topology is made up of two or more links. The types of topology are Mesh, Star, Bus and Ring.

  1. Mesh Topology

    Here, every node is connected to another node. There are no traffic problems as each connection can carry its own data load. Using separate links for each connection makes mesh topology robust. Therefore if a link becomes unusable, it does not effects the entire system. This system also provides an advantage of privacy and security. The only disadvantage is that it uses a large amount of cables and ports, making it bulky and expensive.

  2. Star Topology

    Each node has a direct dedicated point-to-point link to a central hub. Here, The devices are not directly linked to one another. This is comparatively cheaper than mesh as it requires less number of ports and cables. Also, Installing or Repairing such system is quite easy. Though ,it is robust in terms that when one station fails, it doesn’t affect others. Still, the problem arises if the hub fails. In such a case the whole system ha to suffer.

  3. Bus Topology

    This system is multipoint. One long cable acts as a backbone to link all the peripheral devices in a network system. This system is cheaper and provides an optimum way of connectivity through the backbone cable. But, it has its own disadvantages. As the length of backbone increases, the signal gets weaker. It’s installation is usually designed to be optimally best. Therefore, the addition or removal of any device may have adverse effects on the whole system. Also, a fault in backbone will halt the functioning of complete system.

  4. Ring Topology

    Each node is connected to two adjacent nodes. Signal unidirectionally travel through each node until it reaches its destination in a ring like structure. It’s easy to install and reconfigure. Usually, the signal is flowing at all times, so it also easy to detect the error (if any). An alarm can be used to detect if signal isn’t reaching correctly on time. But, a single fault in any component will stop the entire system.

These are some basics that every Computer networking student must know. These type of networks and systems are found in our day-to-day lives also. Mostly, the hybrid of these topologies are brought in practice.

The power of networking and connectivity has had its significance from the very beginning if our existence. The biggest example of WAN is the Internet, which has revolutionized our civilization.  The applications are countless and we are still moving indefinitely in the direction of progress and development in networking and data communications. In the next tutorial, we will see and explore various networking models and go technically deep in transfer of data bits from one node to another.

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