What is Network Topology? Types of Network Topology ? (Lession – 21)

Network Topology

When it comes to computer networks, there are many different methods in which separate components may be linked to one another. The Network Topology is the manner in which the structure is defined, as well as the manner in which the components are linked to one another.

Types of Network Topology :

Network topology is the layout of a network that includes nodes and connecting lines via sender and receiver. This arrangement is referred to as the network topology framework. The various network topologies are:

• Point to Point Topology
• Mesh Topology
• Star Topology
• Bus Topology
• Ring Topology
• Tree Topology
• Hybrid Topology

1. Point to Point Topology

The Point-to-Point Method Topology is a sort of topology that focuses on the functioning of both the sender and the receiver. This is the most basic kind of communication that may take place between two nodes, with one of the nodes acting as the transmitter and the other as the receiver. There is a high bandwidth provided by point-to-point.

2. Mesh Topology

A mesh topology is a network architecture in which every device is linked to another device over a specific channel. The protocols that are used in Mesh Topology include and are not limited to Ad Hoc Configuration Protocols (AHCP), Dynamic Host Configuration Protocol (DHCP), and others.

Advantages of Mesh Topology :

• The nodes are able to communicate with one another extremely quickly.
• The Mesh Topology is a reliable system.
• Identifying the problem is not difficult. The reliability of the data is ensured by the fact that it is sent between the devices by means of specialized channels or connections.
• Gives protection and privacy to the user.

Drawbacks of Mesh Topology :

• The process of installation and setup is challenging.
• Due to the fact that bulk wiring is necessary, the cost of cables is significant; thus, they are ideal for a smaller number of devices.
• The expense of upkeep is rather significant.

The internet backbone is a typical example of a mesh architecture. In this configuration, different internet service providers are linked to each other via dedicated channels. Additionally, this topology is used in the communication systems of the military as well as the navigation systems of airplanes.

3. Star Topology

The Star Topology configuration involves all of the devices being linked to a single hub by means of a wire. All other nodes are linked to this hub, which serves as the central node. This hub is the connected node. It is possible for the hub to be passive in nature, which means that it is not an intelligent hub like broadcasting devices. On the other hand, the hub may also be intelligent, which is referred to as an active hub.

It is common for active hubs to have repeaters. When it comes to connecting the computers, either coaxial cables or RJ-45 cables are used. A wide variety of well-known Ethernet local area network protocols, such as CD (Collision Detection), CSMA (Carrier Sense Multiple Access), and others, are used in Star Topology.

Advantages of Star Topology :

• In a star topology, the number of cables that are necessary to connect N devices to one other is equal to the number of devices that are linked to each other. In this way, it is simple to set up.
• In order to connect to the hub, each device only needs one port, which means that the total number of ports that are necessary is N.
• It has a robustness. Only one particular link will be affected if it fails; the other links will remain unaffected.
• defect detection and fault isolation are both simple processes.
• The utilization of cheap coaxial cable makes star topology a cost-effective network architecture.

Drawbacks of Star Topology :

• The whole system will come to a halt in the event that the concentrator, also known as the hub, on which the entire topology is dependent fails.
• The installation process comes at a considerable expense.
• The single concentrator, also known as the hub, is the basis for performance.

4. Bus Topology

Every computer and other network device is linked to a single cable in a bus topology network, which is a sort of network configuration. It may go in both directions. Due to the fact that the topology will fail in the event that the backbone fails, it is a multi-point connection and that it is not a resilient topology. There are several different MAC (Media Access Control) protocols that are followed by LAN ethernet connections in Bus Topology. These protocols include TDMA, Pure Aloha, CDMA, Slotted Aloha, and others.

Advantages of Bus Topology :

• In the event where N devices are linked to one another in a bus topology, the number of cables that are necessary to connect them is one, which is referred to as the backbone cable. Additionally, N drop lines are needed.
• In bus-based networks that are capable of supporting up to 10 Mbps, the most common kind of cable utilized is either coaxial or twisted pair.
• The cable is used to construct smaller networks, despite the fact that its cost is lower in comparison to that of other topologies.
• Because the methods for installation and troubleshooting are generally known, bus topology is a technology that is considered to be familiar.
• CSMA is the approach that is used the most often for this kind of topology.

 Drawbacks of  Bus Topology :

• Although a bus topology is a lot less complicated, it still calls for a significant amount of cabling.
• Whenever the common wire breaks, the whole system will come to a complete and utter halt.
• When there is a lot of traffic on the network, there is a greater likelihood of collisions occurring. The MAC layer makes use of a number of different protocols, such as Pure Aloha, Slotted Aloha, CSMA/CD, and others, in order to circumvent this issue.
• Network speeds would be slowed down if more devices were added to the network.
• There is virtually little security.

5. Ring Topology

In a Ring Topology, it creates a ring that connects devices with precisely two connected devices that are next to one other. In a Ring topology with a high number of nodes, a lot of repeaters are used. This is due to the fact that if someone wishes to transmit some data to the last node in the ring topology with 100 nodes, then the data will have to go via 99 nodes in order to get at the 100th node. Therefore, repeaters are used in the network in order to avoid the loss of data.

The data travels in just one way, which is referred to as unidirectional. However, it is possible to have the data flow in both directions by establishing two connections between each Network Node. This configuration is known as Dual Ring Topology. For the purpose of data transmission, the workstations in the Ring Topology make use of the Token Ring Passing protocol.

Advantages of Ring Topology :

• A high-speed data transfer is being carried out.
• When using this form of topology, the likelihood of a collision occurring is quite low.
• Installing and expanding at a low cost.
• Compared to a star topology, it is more cost-effective.

Drawbacks of Ring Topology :

• The failure of a single node in the network has the potential to bring about the failure of the whole network.
• Within this structure, troubleshooting is a challenging endeavor.
• Any change to the topology, whether it is the addition of stations in between or the removal of stations, might cause disruption.
• less safe to use.

6. Tree Topology

This topology is a variant of the Star topology for the Star topology. The data flows in a hierarchical fashion across this structure. DHCP and SAC, which stands for “Standard Automatic Configuration,” are examples of protocols that are used in Tree Topology.

Advantages of Tree Topology :

• Consequently, it reduces the distance that the signal must travel in order to reach the devices since it enables a greater number of devices to be connected to a single central hub simultaneously.
• This enables the network to be prioritized and insulated from the many machines that are connected to it.
• New devices may be added to the network that is already in place.
• When using a tree topology, error detection and error repair are both fairly simple processes.

Drawbacks of Tree Topology :

• The whole system will fail if the central hub fails to function properly.
• Cables are the reason for the high cost of the project.
• The process of reconfiguring gets more challenging once more devices are added.

7. Hybrid Topology

This particular topological technology is the culmination of all of the other kinds of topologies that we have discussed in the previous section. It is possible to employ hybrid topology when the nodes are allowed to assume whatever shape they want. This indicates that they may be unique topologies, such as the Ring or Star topology, or they can be a blend of the numerous sorts of topologies that were discussed before. Additionally, the protocol that was explained previously is used by each and every separate topology.

Advantages of Hybrid Topology :

• These topologies are very adaptable.
• If more devices are added, it will not be difficult to increase the size of the network.

Drawbacks of Hybrid Topology :

• There are several obstacles to overcome while designing the architecture of the hybrid network.
• The hubs that are used in this architecture are quite costly.
• Due to the fact that a hybrid network needs a significant amount of cabling and network equipment, the infrastructure cost is quite expensive.

Read more – What is Computer Network? Advantages, and Disadvantages Of Computer Network, Types Of Computer Network (Lession- 20)