Network Topologies

 What is Network Topology?

Network topology refers to the manner in which the links and nodes of a network are arranged to relate to each other. Topologies are categorized as either physical network topology, which is the physical signal transmission medium, or logical network topology, which refers to the manner in which data travels through the network between devices, independent of physical connection of the devices. Logical network topology examples include twisted pair Ethernet, which is categorized as a logical bus topology, and token ring, which is categorized as a logical ring topology.

Physical network topology examples include star, mesh, tree, ring, point-to-point, circular, hybrid, and bus topology networks, each consisting of different configurations of nodes and links. The ideal network topology depends on each business’s size, scale, goals, and budget. A network topology diagram helps visualize the communicating devices, which are modeled as nodes, and the connections between the devices, which are modeled as links between the nodes.

 Bus Topology: Every computer and network device is connected to a single cable in a bus topology network. Linear Bus topology is defined as having exactly two terminals.

Advantages: 

• Installation is simple.
• Compared to mesh, star, and tree topologies, the bus utilizes less cabling.

Disadvantages: 

• Difficulty in reconfiguring and isolating faults. 
• A bus cable malfunction or break interrupts all communication.

2. Ring Topology: The topology is named ring topology because one computer is connected to another, with the final one being connected to the first. Exactly two neighbors for each device.

Advantages: 

• Data transmission is relatively straightforward because packets only move in one direction.
• There is no requirement for a central controller to manage communication between nodes.

Disadvantages: 

• In a Unidirectional Ring, a data packet must traverse through all nodes.
• All computers must be turned on in order for them to connect with one another.

3. Star Topology: Each device in a star topology has a dedicated point-to-point link to a central controller, which is commonly referred to as the HUB. There is no direct connection between the devices. Traffic between the devices is not allowed in this topology. As an exchange, the controller is used.

Advantages: 

• When attaching or disconnecting devices, there are no network interruptions.
• It’s simple to set up and configure.
• Identifying and isolating faults is simple.

Disadvantages:

• Nodes attached to the hub, switch, or concentrator is failed if they fail.
• Because of the expense of the hubs, it is more expensive than linear bus topologies.

4. Mesh Topology: Every device in a mesh topology has dedicated point-to-point connectivity to every other device. The term “dedicated” refers to the fact that the link exclusively transports data between the two devices it links. To connect n devices, a fully connected mesh network contains n *(n-1)/2 physical channels.

Advantages:

• Data can be sent from multiple devices at the same time. This topology can handle a lot of traffic.
• Even if one of the connections fails, a backup is always available. As a result, data transit is unaffected.

Disadvantages:

• The amount of cabling and the number of I/O ports that are necessary.
• It is difficult to install and reconfigure.

5. Tree Topology: The topology of a tree is similar to that of a star. Nodes in a tree, like those in a star, are connected to a central hub that manages network traffic. It has a root node, which is connected to all other nodes, producing a hierarchy. Hierarchical topology is another name for it. The number of Star networks is connected via Bus in Tree Topology.

Advantages:

• Network expansion is both possible and simple.
• We partition the entire network into pieces (star networks) that are easier to manage and maintain.
• Other segments are unaffected if one segment is damaged.

Disadvantages:

• Tree topology relies largely on the main bus cable because of its basic structure, and if it fails, the entire network is handicapped.
• Maintenance becomes more challenging when more nodes and segments are added.