6 Main Network Topology Types

Computer Network Topologies

Network Topology refers to layout of a network. How different nodes in a network are connected to each other and how they communicate is determined by the network's topology. They can be either physical or logical. There are many types of Network Topologies. I have explained basic and the most famous network topologies below.

Bus Network Topology 

In the bus topology every computer is connected to a main cable called the backbone or trunk. Therefore in effect every computer is directly connected to every other computer in the network. The back bone is made out of coaxial cable. There are NIC cards with BNC ports in each computer to connect with main cable. As you can see in the above picture we also use T-connectors and Terminators. This is an outdated network topology.

Advantages	Disadvantages
Easy to setup	If something happens to the main cable the entire network goes down
Low cost	Need terminators in each end
Works well in small networks	Not recommended for large networks
Requires only less cable length	Outdated
	Hard to troubleshoot

Ring Network Topology

In the Ring topology, the computers are connected in a closed loop configuration. Adjacent of computers are directly connected. Other pairs of computer are indirectly connected. The data or communication travels in clockwise. In here we also use coaxial cable with T-connectors, but we do not need any terminators.

Advantages	Disadvantages
All data travels in clock wise, so the collisions are reduced	Network depends on the wire. If something happens to that wire whole network goes down
Better than Bus topology	Data packet must past through all the nodes
No need any network servers. No need of terminators	If one workstation shutdowns it will effect for whole network
Each computer has equal access to the resources	Some components are more expensive
Additional components do not affect for the performance of the network

Mesh Network Topology

Mesh is a network topology which devices are connected with many redundant interconnections between network nodes. In here we need to use many NIC cards for a pc. There are fully connected mesh topologies and also partially connected mesh topologies. 

Advantages	Disadvantages
No need any servers	Hard to manage and Troubleshoot
Robustness	Very expensive
Scalability	Higher redundancy
A broken node won’t distract the transmission of data in a mesh network.
Expansion and modification can be done without disrupting other nodes
Data can be transmitted from different devices simultaneously. This topology can withstand high traffic.

Star Network Topology 

In star topology there is a central hub or switch which all the computers are directly connected. Every computer indirectly connected to every other computers through the central hub or switch.

Advantages	Disadvantages
Easy to implement	Expensive
Easy to expand	If switch or hub fails the whole network goes down
Can troubleshoot easily	Number of the computers in the network depends on hub or switch
Failure of a computer does not effect for the whole network

Tree Network Topology (Star Bus Topology)

The tree topology uses two or more star networks connected together. The central hub or switch of the star networks are connected to a main cable. Tree topology can be describe as a combination of Star and Bus topologies. This is one of the popular topology nowadays. The purpose of this network is to have bunch of networks. 

Advantages	Disadvantages
Can expand the network easily	If something happen to main cable communication between other networks will stop
Can easily manage and maintain	Expensive
Easy to troubleshoot	Difficult to maintain when the network getting larger
If one segment is damaged, other segments are not effected	Scalability depends on the type of the cable
Can apply in the places where Bus and Star topology cannot be used

Hybrid Network Topology

This topology contains more than one of the previously illustrated network topologies connected to each other. E.g.:- Connecting a star network topology to a ring network topology.

Comparison of Star, Ring and Bus Topologies

BASIS	STAR TOPOLOGY	RING TOPOLOGY	BUS TOPOLOGY
Architecture structure	All the clients and peripherals connected to a switch or hub.	Every node has two branches connected to a node either side of it.	All the PCs and peripherals are connected to a single Coaxial cable known as backbone or trunk.
Cabling required	Larger	Less	Less
Point of failure	Switch/Hub	Every node in the ring	Every node in the bus network and the backbone.
Data traversal	All data passes through the central network connection.	Data moves clockwise until it reaches destination.	Data moves both directions until it reaches destination.
Network expansion	Can easily add another device by using Ethernet cables without breaking the existing Network.	Network has to break in order To add a new device to the Network.	Network has to break in order To add a new device to the Network.
Fault isolation	Easy	Difficult	Difficult
Troubleshooting	If there is a Switch/Hub failure, other nodes are affected. Failure of a single node does not affect whole network The other nodes are affected only in the case of a hub failure.	If a node goes down data can only travel up to that damaged node.	If a node goes down data can only travel up to that damaged node.
Cost	High	Low	Low

Advantages of Star Topology for Enterprise Networks

In star topology all the client devices and other peripherals are isolated. So a failure of one or more of those devices do not affect the whole company network. This is very important for company environment because it helps to keep the network up and maintain the productivity. And also this helps for troubleshooting (can easily identify the troubled device). It very easy to understand, implement and navigate through star topology. Non-technical users can easily understand what is going on with network, so it is very easy to train them to use networked system. A company growth can’t be limited, number of the employees can increase so the network should fulfil their needs also. Star topology provide grate support for network extending. You just need to add a PC and connect Ethernet cable for the pc and switch and set up IPs. By using different servers with star topology network a company can easily manage user accounts, passwords, policies, restrictions etc.