What Is Bus Topology And What Are Its Types?

What Is Bus Topology And What Are Its Types?

Short : In this article, you’ll know what is bus topology, what are its types, how communication and data packet happens on a bus topology. We’ll also tell you what are the advantages and disadvantages of using a bus topology.

In my previous post, I told you about network topology and its different types. In this article, we are going to take a look at the different types of topologies that exist —

What is Point-to-point topology ?

When we connect two network nodes end-to-end, it forms a point-to-point topology. For example, if I am the network administrator of the network of my institution and while troubleshooting I connect my laptop to a wireless router, this will form a case of Point-to-point topology. This also implies that if either node in the coupling gets down, my Point-to-point topology also gets down.

What is Bus topology ?

In a network, when all the nodes are connected by a single physical cable and the central cable becomes the backbone of the network then, it is called as a Bus topology.

For illustration, remember the old fashioned computer labs. There, a common copper wire used to run across the lab and all the computers were tapped to the wire. So, the wire formed the backbone of the network while computers formed different nodes of the topology.

In a bus topology, when a data is sent from one to another through the central cable, the data travels in the form of a packet. The data packet contains the address of the destination machine.

Curious Case of Alex & Christina :

Let’s say, there are five machines in a Bus topology namely A, B, C, D & E connected to a central cable serially. Let’s say, Machine A is owned by Alex and Machine C is owned by Christina. Alex wants to send a message to Christina. So when a data packet is sent from Alex to Christina, that means from machine A to machine C, at first, machine B owned by Bob, checks the destination address inside the packet. Since the packet was not meant for Bob, it is forwarded on and reaches Christina.

Machine C owned by Christina matches the address of the packet with its own machine address and bingo! the message is for Christina, and hence, the machine C decides to receive the message. And that’s how machine A and Machine C communicates on a bus topology.

But there is a glitch. Now Bob, who owns the machine B, is jealous of Alex and Christina and he decides to read the message. So, he spoofs his machine address as Christina’s machine address and is successfully able to receive the data packet and the message inside that. This is called spoofing. However, we will talk about spoofing later in this series. Let’s first focus on the basics.

Advantage of Bus topology:

• Minimal use of the physical resources

Disadvantage of the Bus topology:

• A Single point of failure

Imagine if the cable breaks down, none of the nodes will be able to communicate with each other.

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