Network Topology

Summary

This session explores various network topologies, including bus, star, ring, mesh, and hybrid. It explains the physical and logical aspects of topology, emphasizing how nodes are arranged for communication. Each topology's advantages and disadvantages are discussed, such as cost-effectiveness and fault tolerance. The session concludes with a hybrid topology example, combining different topologies for enhanced network design.

Takeaways

• 🌐 **Network Topology Definition**: The arrangement of nodes in a computer network to establish communication among them.
• 🔵 **Physical vs. Logical Topology**: Physical topology refers to the physical placement of network nodes, while logical topology concerns the data flow between nodes.
• 🚌 **Bus Topology**: Nodes are connected to a common transmission medium, with data transmission being bidirectional and all nodes receiving the data.
• 🔄 **Ring Topology**: A closed loop version of bus topology where nodes are connected in a circular manner, requiring a token for data transmission in a unidirectional manner.
• 🌟 **Star Topology**: Nodes are connected to a central node, such as a hub or switch, which manages all communication, providing security and a single point of administration.
• 🔗 **Mesh Topology**: Each node is connected to every other node, offering high fault tolerance and reliability but at a higher cost due to the extensive cabling.
• 💡 **Advantages of Bus Topology**: Cost-effective due to fewer cables and suitable for temporary setups; nodes are not affected by other node failures.
• ⚠️ **Disadvantages of Bus Topology**: Lacks fault tolerance, as a single cable failure can disrupt the entire network, and there's no security as all nodes receive all data.
• 🔑 **Token Ring Mechanism**: In ring topology, a token is passed around the network to allow nodes to transmit data, ensuring orderly data flow.
• 💼 **Star Topology Scalability**: Easy to expand by adding more switches or hubs, making it a scalable option for growing networks.
• 💬 **Hybrid Topology**: A combination of two or more topologies, such as bus, star, and mesh, to leverage the advantages of each while mitigating their disadvantages.

Q & A

What is network topology?

Network topology refers to the arrangement of nodes in a computer network, which can be viewed as both a physical layout and a logical layout that dictates how data flows between nodes.

What are the two types of topologies mentioned in the script?

The two types of topologies mentioned are physical topology, which refers to the physical placement of network nodes, and logical topology, which concerns the data flow between nodes.

How does data transmission work in a bus topology?

In a bus topology, all nodes are connected to a common transmission medium. Data sent by one node is transmitted over this medium, and all nodes receive the data, but only the intended recipient node accepts it.

What are the advantages of bus topology?

The advantages of bus topology include lower cost due to fewer cables, suitability for temporary networks, and the ability for individual node failures to not affect the entire network.

What are the disadvantages of bus topology?

Disadvantages of bus topology include a lack of fault tolerance, limited cable length, and a lack of security since all nodes receive copies of the data signal.

How does communication in a ring topology differ from bus topology?

In a ring topology, communication is unidirectional and involves passing data along a closed loop from node to node until it reaches the intended recipient, unlike bus topology where data is broadcast to all nodes.

What is a token in the context of ring topology?

A token in ring topology is a signal that indicates which node has the permission to send data. The node holding the token is allowed to transmit data to the network.

What are the advantages of ring topology?

Advantages of ring topology include better performance due to the closed loop and equal access for all nodes, which can help prevent bottlenecks.

What are the disadvantages of ring topology?

Disadvantages of ring topology include the risk of a single point of failure, unidirectional communication which can slow down data transfer, and potential security issues due to data passing through multiple nodes.

How does star topology differ from bus and ring topologies?

In star topology, each node is connected to a central node, such as a hub or switch, rather than being connected to a common transmission medium or in a closed loop like in bus and ring topologies.

What are the advantages of star topology?

Advantages of star topology include ease of design and implementation, centralized administration, and scalability by adding more hubs or switches to the network.

What are the disadvantages of star topology?

Disadvantages of star topology include a single point of failure at the central node, potential bottlenecks due to high traffic, and increased cost for purchasing hubs or switches.

What is a mesh topology and how does it provide fault tolerance?

A mesh topology is where each node is directly connected to every other node, providing multiple paths for data to reach its destination, thus offering high fault tolerance and reliability even in the event of link failures.

What are the advantages of mesh topology?

Advantages of mesh topology include high fault tolerance and reliability, as there are multiple paths for data to reach its destination, ensuring data transmission even in the case of link failures.

What are the disadvantages of mesh topology?

Disadvantages of mesh topology include high cost due to the need for many connections, impracticality for very large networks, and potential issues with broadcasting messages that need to be managed carefully.

What is a hybrid topology and how does it differ from other topologies?

A hybrid topology combines two or more different network topologies, such as bus, star, and mesh, into a single network. It allows for the utilization of the advantages of each topology while mitigating some of their disadvantages.