The process by which computers are connected to each other in a computer network is called network topology.
How the computers are connected in the network, how the cables are connected to each other, this is the main topic of topology.
There are six types of network topologies.
These are discussed below:
1. Bus Topology:
In a typical bus network, a single cable is usually used without any type of electronic device such as a repeater or amplifier so that the signal from one computer can be transmitted directly to another computer.
So this topology is called Passive topology.
This terminator depletes the electrical signal, so it cannot be reflected.
There will be problems if Terminator is not used at the end.
If there is a problem with your bus topology network, you need to check first.
If there is a problem with your bus topology network, first check if the two ends of the bus are terminated properly.
The advantages of the bus topology
- This is a very simple, low cost, easy to use and easy to understand topology for small networks.
- The bus network takes the shortest length of cable, resulting in lower costs.
- The bus network can be expanded by connecting the backbone or the bus to another bus using the BNC barrel connector. As a result, more computers can join the network.
- Repeaters can be used to extend the bus further and improve signal performance.
The repeater amplifies the electric signal.
If any computer in the bus network is damaged, there is no difficulty in working on another computer. It is possible to easily disconnect from a computer network.
- Adding or removing a node (computer, printer, or other device) to a bus network does not use the entire network.
Disadvantages of using bus topology:
- Performance can be very poor if the network is overused. Only one computer can send a message at a time. Others have to wait until he has finished sending his message. If the number of computers increases, this problem may become widespread.
- Each barrel weakens the electrical signal. Therefore, if the diameter is expanded using a large number of barrel connectors, the network performance will be poor.
- Troubleshooting the bus network is difficult. If the cable breaks somewhere in the bus, it cannot be easily removed. The whole network becomes useless as a result of bus breakdown. Then one computer cannot communicate with another. To remove this cable brake, you have to test from one end of the bus to the other end with cable tester or any other device.
- There is no coordination for data transmission in this topology. Any computer can transmit data at any time. As a result, a lot of network bandwidth is lost. This system wastes more time on computers interrupting each other than on data transmission.
Each computer that connects through a central device to create a network structure is called a star topology.
In Star Topology, all the computers in the network simply come out and connect to a central location.
If a computer wants to transfer data, it first sends a hub or a switch.
The hub or switch then sends the signal to the target.
Advantages of Star Topology
- A large number of computers can be easily added to the network. The number of computers in the star topology depends on how many ports there are. This network can be expanded if all the ports of a hub are used by adding another hub to that hub. By increasing the number of hubs here, more computers can be added to the network. By increasing the number of hubs here, more computers can be added to the network.
- If there is a problem in the network, it is easy to start the problem search from the central location i.e. hub. Intelligent hubs can also be used for network monitoring.
- If a computer breaks down in the network, it does not affect the network. Other computers can communicate with each other properly. Any computer problem can be easily found out.
- If the hub supports different types of cables, it is possible to use several types of cables at the same time.
The disadvantage of star topology
- When the hub of the center becomes useless, the whole network becomes crippled.
- This topology requires more cable. Because the cable from each computer has to be taken to the central hub. The more cable, the higher the cost.
Such topologies are used to create high-powered networks. The great advantage of this type of network is that every computer gets equal rights here and if the performance of the network decreases due to more computers then it is applicable to everyone. Ring topology is called active topology. In this topology, if a computer wants to send a message to another computer, it will go to the nearest computer. The computer will see if the message is for him. If it is not for him, he will send the message to the next computer, thus it will go to the destination. Each computer amplifies that signal and sends it to the next computer. And in topology data packets always flow in the same direction (usually clockwise). Unlike the bus network, there is no need to use a terminator, as there is no open end.
Advantages of ring topology
- Each computer gets equal access to the network, because the token goes to each computer. That is why no computer can dominate the whole network.
- Although the number of computers has increased, its efficiency has not been affected much.
- No server computer is required on the network.
Disadvantages of ring topology
- When a computer in the ring becomes useless, the network becomes useless. If there is a problem in the ring network, it becomes difficult to find the fault.
- Adding or removing a computer from the network ring disrupts the entire network.
- As the number of computers in this network increases, the time of data transmission also increases.
- Complex control software is used for ring topology.
The tree topology is basically an extension of the star topology. In this topology, all the computers are connected to a special place using multiple hubs called root. There they are connected to the server computer by a high speed connection to increase the speed of sending their signals.
Advantages of tree topology
- Expanding the network of tree topologies by creating new branches is quite convenient.
- The structure of this network is more suitable for office management.
- Connecting or removing new nodes is easy.
- This does not disrupt the normal functioning of the network.
Disadvantages of tree topology
- If an error occurs on the root or server computer, the tree becomes inoperable in the network.
- Not relatively complex compared to other topologies.
5.Mesh or interconnected topology
In mesh topology, every computer under the network is directly connected to all other computers. It has a separate link or bus between each workstation. So each workstation can exchange data directly with any workstation.
Advantages of mesh topology
- Signals can be exchanged very fast between any two nodes.
- There is no problem if any computer or connection line is damaged. This means that the network does not easily cause a big problem.
- It has a lot more certainty in data communication.
- Problems on the network can be solved very easily.
Disadvantages of mesh topology
- Network installation and configuration in this topology is quite complex.
- The longer the connection lines, the higher the cost.
- Moreover the cost increases further as additional links have to be placed in the network.
A network that is made up of a network of different topologies, namely, star, ring, bus, etc., is called a hybrid network. The Internet is a hybrid network, because it connects almost all types of networks. The advantages and disadvantages of a hybrid network depend on the topologies used in that network.
Advantages of hybrid topology
- This topology allows you to expand the network as needed.
- If any problem occurs, it can be easily diagnosed.
- If any one part is lost, the whole network is not lost but the part is lost.
Disadvantages of hybrid topology
- The hubs used in this topology have to be kept active at all times.