Network Topology

Defined

Network topology refers to the physical or logical arrangement of computers, cables, and other components on a network. It essentially shows how different nodes and links are organised to ensure smooth network communication.

Bus topology involves each computer or server being connected to a single main cable or bus.
The main advantage is simplicity and ease of setup.
However, if the main cable fails, the entire network suffers.

Ring topology involves connecting each node to exactly two other nodes, forming a ring for the data signals to travel around.
It can handle high traffic and can also be fairly reliable – as data will automatically switch to the reverse path if one segment is down.
Its main disadvantage comes from having a slow reaction to changes or failures in the network.

Star topology has all nodes connected to one central hub or switch. Communication is only possible through this central node.
It’s the most widely used network topology today due to its high performance, it’s easy to troubleshoot and extend or modify.
Drawbacks include dependency on the central hub and high maintenance costs due to the need for more cabling.

Mesh topology connects each node to every other. There are two types: full-mesh where every device has a direct connection to each other, and partial-mesh where some devices are organized in a mesh while others rely on a bus topology, for example.
This provides high fault tolerance and excellent performance.
The main downside is that it requires a lot of cabling and resources, making it expensive and complex to install and manage.

Tree topology is a hybrid topology that combines characteristics of bus and star topologies. It’s organised in a hierarchy.
It’s scalable and allows for easy expansion of the network.
It relies heavily on the top tier nodes – if these fail, all under them will suffer.

Cost: Different topologies require different amounts of cabling, hardware, and maintenance. This impacts the total cost of setting up and maintaining the network.
Performance: Topologies affect how data flows in a network. This can impact performance — how fast data travels, how effectively it handles traffic, and its reliability.
Fault Tolerance: Some topologies can better handle network hardware failure. For example, in a star topology, if one node fails, only that node is affected. In contrast, a bus topology can fail entirely if there’s a break in the main cable.
Scalability: This is about how easy it is to add (or remove) devices from the network.