If you want to learn about network topology, then you reach the right place. This article is all about network topologies, different types of network topologies, their configuration, functions, applications as well as advantages and disadvantages. Let’s read about it.
What is Network topology?
The physical design or the procedure that are followed to construct network connections is called topology. It relates especially to the position of the computers and how the cable travels between them. It is also important to select the right topology for proper use of computer networks.
Important network topologies are:
- Bus Topology
- Star Topology
- Ring Topology
- Tree Topology
- Mesh Topology
The simplest type of network is the bus topology. In a bus network topology, all computers or network nodes are connected to a common communication medium. In a local network, this channel is usually a central cable called a bus.
Working of Bus Network
If a computer wants to send data to another computer in the network, it sends the data and destination address via the bus. This data and address move from one end of the network to the other. Each computer checks this address and, if it matches with this computer, the computer keeps the data. Otherwise, the data moves to the nest computer.
The electrical signal from a computer travels the whole length of the cable. When the signal reaches the end of the wire, it bounces back and travels back up the wire. It is called ringing. To avoid the signals form ringing, you have to connect terminators at either end of the segment. The terminators digest the electrical energy and end the reflections also.
- It is simple, easy to use, and suitable for very small networks
- Least amount of cable is required to connect the computers so it is less expensive
- It is easy to extend a bus. Two ables use a connector to join each other
- Also allows more computers to join the network
- Heavy network traffic can slow a bus considerably
- Each connector reduces the strength of the electrical signal
- A cable crack or untied connector will results reflections and entire network will also stop
- Increase in the number of computers will also decrease the speed of the network.
A star network topology is one in which all the cables travel from the computers to a central point, where they are all attached to a device called a hub.
Working of Star Network
If two computers desire to share data, the sender computer sends data to the hub and hub sends it to the receiving computer. Every computer on a star network communicates with a central hub. A hub provides a middle connection point so that all computers can correspond across the network.
- It is simple to amend and add new computers to a star network without disturbing the remaining network
- Hub can accommodate multiple cable types
- Finding faults becomes very simple
- If a Single computer stops working, it does not affect the whole network
- Star topology is more elastic among the remaining topologies.
- If middle hub breakdown, the complete network will also crash
- It is more costly because all network wires must be travel to one midpoint
In this network topology, each computer is connected to the next computer with the last one connected to the first.
Working of Ring Network
Every computer is connected to the next computer in the ring. Each retransmits what it receivers from the previous computer. The messages flow in one direction. Since each computer retransmits what it receives, there is no signal loss problems and termination requirement like bus topology because there is no end to the ring.
- Every computer has an equal reach to the token, so no one computer has the monopoly over the network.
- Failure of one computer on the ring can affect the whole network
- Difficult to troubleshoot
- Adding or removing computers disrupts the network
A tree network topology is the combination of the characteristics of both bus and star topologies. It is based on groups of computers in the shape of star topology; then these groups use a bus backbone cable/wire to join together. The use of tree topology is to expand an existing network.
- It imparts point-to-point wiring for every single segment
- Different hardware and software vendors support tree topology
- The type of cable limits the overall length of each segment
- If the backbone cable cracks, the whole segment shuts down
- It is extra complicated to build up and wire than other topologies
In a mesh network topology, every device on the network is physically connected to every other device on the network. Various possible ways are available to send a message from the source to destination. Mesh topology provides enhanced performance and consistency.
The use of mesh topology is very rare. The wide area networks mostly use mesh topology where reliability is important.
- The use of dedicated link makes it sure that each connection can hold its own data load. It reduces the traffic issues
- If one link becomes useless, it does not damage the full system.
- It is simple to detect and correct errors
- The cost of a complete mesh network is very high
- It is complex to set up and reconfigure