Computer Network Topologies - MetaTutorials
Here, we will learn about the topologies of the computer network in detail with their advantages and disadvantages.

## What is Topology?

The topology shows the geometric representation of the network of how the various computer devices and nodes are linked to each other.

Following are the Six different types of Topology in the computer network:
1. Bus Topology
2. Ring Topology
3. Star Topology
4. Tree Topology
5. Mesh Topology
6. Hybrid Topology
Now, let's discuss all the above-mentioned topologies one by one in detail with advantages and disadvantages.

## Bus Topology

Bus Topology is a network topology which is constructed in such a way that all the devices share the same transmission cable.
The common transmission cable in this topology is called Bus. A bus carries the data and information from one endpoint to another endpoint.
Data sent by a computer or device moves only in one direction. When the data reaches the end then the terminator removes the data from the transmission cable.
There is a dropline which connects each node or device to the transmission cable.

In this topology, the transmission line acts as a spine, if it fails then all the devices connected to it stop their functioning or the complete network automatically breaks down.

Following are the advantages of Bus Topology:
1. It is the simplest topology of a computer network for connecting the devices or nodes in a linear way.
2. This topology is easy to set up and maintain.
3. As compared to Star and Mesh network topologies, this topology requires less amount of cabling. So, its cost is less.
4. It works well when the network is small, simple, and temporary.
5. In this topology, we can easily connect and remove the node without affecting other nodes in a network.

Following are the disadvantages of Bus Topology:
1. The main disadvantage of this topology is that if the spine (transmission cable) fails then the whole system automatically breaks down or fails.
2. Requirement of a terminator is necessary for both ends of the transmission cable.
3. This topology is not the best solution for big and huge networks.
4. If we add extra devices to the network then the performance of the network slows down.
5. As compared to other network topologies its performance is very slow.

## Ring Topology

Ring Topology is a network topology which is constructed in such a way that each device is connected with two neighboring devices for data communication and sharing resources.
This topology is actually formed like a ring, i.e., the last device of the network is connected with the first device of the same network. Here, the data is transferred in a circular way.

In this topology, tokens are used to transmit the data from the sender node to the destination node. They hold the address of the destination node and pass the data from one node to each node until the destination device is reached.

Following are the advantages of Ring Topology:
1. We can easily manage the ring topology and easily track the faults that occurred.
2. As we know that the data is moved in a single direction, so the chances of packet collision is very low.
3. As compared to other network topologies, the speed of data transferring is fast in this topology.
4. This network topology is best for those applications which require low latency.
5. We can add extra nodes to this topology without affecting its performance.

Following are the disadvantages of Ring Topology:
1. The main disadvantage of this topology is that if one node fails or shutdowns then it affects the whole network.
2. As compared to the bus topology, the performance of this topology is slow.
3. It is difficult to add or remove the node during the data transmission. If we do so, then it may affect the network.
4. It is expensive because there is a requirement of hardware for connecting each device to the network.

## Star Topology

Star Topology is a network topology which is designed in such a way that all the devices/nodes are connected to the central device.
In this topology, the central device acts as a server and the other connected devices/nodes act as the client. The name of the central device is hub or switch which uses a point-to-point connection. If the central device is a hub then it broadcasts the message and if the central device is switch then it unicasts the message.

In this topology, if one device wants to send the data to another device, then the hub (central device) works as an intermediary device. Firstly, the hub receives the data sent from the sender device and after that passes the data to the destination device.

Following are the advantages of Star Topology:
1. The main advantages of star topology is that other devices not get affected if one device connected to the hub fails or shutdowns. So, its reliability is high.
2. This topology can be upgraded and reconfigured easily.
3. It is best for large and huge networks.
4. We can easily add and remove the device from the network without creating any disturbance to the network.

Following are the disadvantages of Star Topology:
1. The main disadvantage of this topology is that if the hub or switch fails or shutdowns then the whole network automatically goes down.
2. The cost of implementation is high because of the requirement of a hub or switch as the central device in this topology.

## Tree Topology

Tree Topology is a network topology which is designed in such a way that all the devices/nodes are connected in a hierarchical structure.
It inherits the features of bus and star topology. Sometimes, it is also known as Star-bus topology.
In this topology, various star topologies are connected to the single bus.

Following are the advantages of Tree Topology:
1. We can easily maintain the tree topology and track the faults.
2. Other devices of this network do not get affected if one device fails or shutdowns. So, its reliability is good.
3. If one hierarchy network fails or damaged then other hierarchy networks are not affected.

Following are the disadvantages of Tree Topology:
1. As compared to the other network topologies, its configuration is hard.
2. The performance of this network topology is a bit slow because of the presence of the huge number of nodes in the network.
3. If we add a maximum number of nodes/devices to the network, then the network becomes complex. So, it is difficult to manage.

## Mesh Topology

Mesh Topology is a network topology which is designed in such a way that all the devices/nodes are connected with each other via a point-to-point connection.
Let's suppose, if there are N number of devices in this network topology, then each device is connected with (N-1) devices and the number of cables used would be (N(N-1)/2).
Mesh Topology is categorized into two categories:
1. Full Mesh Topology
2. Partial Mesh Topology

Following are the advantages of Mesh Topology:
1. Each node has multiple connections to reach the destination node, if one path is blocked then the other path can be used for transmitting data and sharing resources.
2. There are no traffic issues in this network because a point-to-point connection is established between the two devices.
3. We can easily detect the faults of this network topology.
4. Communication is very fast in this topology because the devices/nodes are directly connected to each other.

Following are the disadvantages of Mesh Topology:
1. This topology requires a large number of cables and input/output ports.
2. As we know that each device connected to all the devices. So, its setup is very complex and difficult.
3. Due to the use of a large number of cables, it is quite expensive.

## Hybrid Topology

Hybrid Topology is a network topology which is designed when two or more network topologies are connected with each other.
The hybrid topology inherits the characteristics of mesh topology, bus topology, star topology, tree topology, and ring topology.

Following are the advantages of Hybrid Topology:
1. This topology is very flexible because it can be constructed on the basis of organization requirements.
2. Hybrid topology is reliable and scalable. It is scalable because the network size can be increased by adding the nodes or topology.
3. This topology is used for designing extremely large networks.