Network Topologies

This is the physical wiring of the network (ie: the ethernet connections, WIFI connections, etc.). There's also a logic topology where we dictate what happens logically when there are tears in the topology.

Bus

A common wire that everyone can see when many devices talk on the same wire:

This forces only one device to be able to talk at a time on the network. Notice this happens in WiFi between cell towers.

Ring

Some benefits of this is that:

• Redundancy (having multiple vertices to travel along allows for multiple viable paths)

Star

A device with many connections specifically to it. For example, a router follows a star topology.

Tree/Hierarchical

The benefit is that you can address requests pretty easy (the path is pretty clear). However, adjacent nodes in the tree (in-order traversal) may have to take considerably longer.

What does ethernet do? The network we physically wire is a tree structure with loops near the bottom, using a Spanning Tree Protocol to logically take links down such that we get that tree structure back:

This helps get us the advantage of loops (see that section) when we need it.

Ad-hoc

Whenever any topology isn't conforming to one of the above, then it is ad-hoc. For example, the added connection in the figure above makes it an ad-hoc connection.