Network Topologies

Network topology refers to the arrangement of elements in a communication network such as links, nodes, and so on. The term network topology refers to the arrangement of various types of telecommunication networks, such as command and control radio networks, industrial field buses, and computer networks. Local area networks, a common computer network installation, contain examples of network topologies.

Network topologies are classified into two types: physical and logical. While logical topology emphasizes the pattern of data transfer between network nodes, physical topology emphasizes the physical layout of the connected devices and nodes

Computer Network Topology

Types of Network Topologies

In computer networks, there are primarily six types of physical topology. They are as follows:

• Bus Topology

• Ring Topology

• Star Topology

• Mesh Topology

• Tree Topology

• Hybrid Topology

Different Types of Network Topologies 

Let us now go over these topologies one by one:

1. Bus Topology: The simplest type of topology is called a bus topology, in which network communication takes place over a single bus or channel. There are numerous taps and drop lines connected to the bus. Drop Lines are cables that connect the bus to the computer, and taps are connectors. In other words, each node is connected to a single transmission line.

The following are the benefits of Bus topology:

• Easy to install and use.

• Other nodes won't be impacted if one node fails.

• Less wiring is needed.

• Economical to implement.

The following are Bus topology drawbacks:

• Efficiency decreases as nodes increase (strength of signal decreases).

• A bus failure will result in network failure.

• The bus's limited length means that only a certain number of nodes can connect to it.

• As messages are broadcast to all nodes, there are more security concerns and risks.

Bus Topology

2. Ring Topology: When two computers are connected to form a ring, the topology is known as a ring topology. The message passing is circular and unidirectional. A fixed amount of time is allotted for each computer to access the network for transmission in this deterministic network topology. Each node is a part of a closed loop.

Ring topology has the advantages listed below:

• Simple installation

• Fewer Cables are needed.

• Minimizes the possibility of data collision.

• An easy problem to solve.

• The access time is the same for every node.       

The following are some drawbacks to ring topology:

•  The network as a whole will collapse if one node fails.

•  Slow data transfer rate as each message has to go through the ring path.

•  Getting more difficult to reconfigure.

Ring Topology

3. Star Topology: A computer network topology known as a star topology connects each node to a central hub. The hub or switch acts as a bridge between the nodes. Any node making a service request or offering a service must first get in touch with the hub. The other connected devices function as clients in a star topology, while the hub and switch serve as a server.

The benefits of the star topology are as follows:

• Less costly.

• Centralized management.

• Simple to scale.

• Other nodes won't be impacted if one node fails.

• Easy to upgrade and reconfigure.

The following are some drawbacks of the star topology:

• The network will collapse if the primary device faults occur.

• There are a limited number of devices in the network.

Star Topology

4. Mesh Topology: Mesh technology is a network configuration in which computers are linked to one another by numerous redundant connections. There are numerous methods for transferring from one computer to another. It lacks a switch, hub, or any other central computer that acts as a communication hub.

Mesh topology has the benefits listed below:

• Direct communication is facilitated by dedicated links.

• There are no channel traffic issues.

• Due to each node having its own dedicated path, fault tolerance is good.

• Quick communication.

• Maintains security and privacy thanks to a separate communication channel.

• There are backup options in the network in case a node fails.

Mesh topology has the following drawbacks:

• Extremely high cabling is required.

• Implementation is expensive.

• The network is difficult to install and takes up a lot of space.

• Installation and regular maintenance are extremely difficult.

Mesh Topology

5. Tree Topology: A computer network topology known as a "tree topology" is one in which all nodes are either directly or indirectly connected to the main bus cable. Bus and Star topologies are combined to create tree topology. With a tree topology, the network is split up into manageable segments that can be easily maintained.

The following are the benefits of Tree topology:

• Network coverage over a long distance.

• Checking each hierarchy makes fault finding simple.

• There should be little or no data loss.

• A large number of nodes can be directly or indirectly connected.

• If one of the hierarchical networks fails, the others are unaffected.

    The following are the drawbacks of Tree topology:

• The cost of cabling and hardware is high.

• Implementation is difficult.

• Hub cabling is also necessary.

• A large network with a tree topology is difficult to manage.

• It necessitates a lot of maintenance.

• The network will fail if the main bus fails.

Tree Topology

6. Hybrid Topology: A hybrid topology is a computer topology made up of two or more topologies. All topologies in this topology are interconnected based on their needs to form a hybrid. 

The following are the benefits of hybrid topology:

• It can support a large number of nodes.

• It allows us to modify the network to meet our specific requirements.

• Very Dependable.

The following are the drawbacks of hybrid topology:

• The design is complicated.

• Implementation is costly.

• MSAL (Multistation Access Unit) is required.

Hybrid Topology

Summary

As a result of learning about the various computer network topologies, we can conclude that the following factors must be considered when choosing a physical topology:

• Installation is simple.

• Tolerance for Errors.

• The cost of implementation.

• Cabling is needed.

• Regular maintenance is required.

• Reconfiguration and upgrade are simple.

Learning by Doing

Choose the Correct Answer:

1. If a star topology is used, the network will fail if..

1. the switch/hub breaks

2. one of the numerous computers system failures

3. the printer break

4. All of the above

2. The entire setup will be affected by a bus defect.

1. True

2. False

3. Tree topology combines the features of ______________topology.

1. Ring and Star

2. Star and Bus

3. Mesh and Bus

4. None of the above

Solved Questions

1. Identify the category of topology in which all nodes are linked to a central system.

Ans: Star Topology

2. The single backbone connects all computers. What kind of topology is that?

1. Star Topology

2. Bus Topology

3. Ring Topology 

4. All of the above

Ans: B) Bus Topology

3. Describe a node.

Ans: A node on a network is any computer or other device that can communicate with other devices.