Question

What are common network topologies of star, mesh, bus, ring, point to point, point to multipoint and hybrid?   What are advantages and disadvantages of each?   When are each used?

Answer 1

Star topology : A star topology is a topology for a Local Area Network (LAN) in which all nodes are individually connected to a central connection point, like a hub or a switch. A hub sends every packet of data to every device, whereas a switch only sends a packet of data to the destination device.

Advantages:

• it has  high-performing as no data collisions occur
• if one cable or device fails then all the others will continue to work
• it is very reliable

Disadvantages :

• if a hub or switch fails, all the devices connected to it will have no network connection.
• required of extra hardware

Use: when there is a failure in cable then only one computer might get affected and not the entire network.

Mesh topology : Mesh topology is a type of network topology in which each computer is connected to every other computer in the network.Each node is capable of sending messages to and receiving messages from other nodes.

Advantages:

• Fault detection is easy.
• Mesh topology is reliable and robust as failure of one node doesn’t affect other nodes

Disadvantages :

• require a lot of maintenance
• Amount of wires required to connected each system

Use: mesh topologies to avoid breakdowns in communication

Bus topology : A bus topology is a topology for a Local Area Network (LAN) in which all the nodes are connected to a single cable.

Advantages:

• Less cables required
• it is cheap and easy to install

Disadvantages :

• if the main cable fails or gets damaged the whole network will fail
• Difficultly in fault detection.

Use: Small workgroup local area networks (LANs) whose computers are connected using a cable.

Ring topology : each device is connected with the two devices on either side of it. There are two dedicated point to point links a device has with the devices on the either side of it. Token passing is used in this topology

Advantages:

• Token passing makes ring topology perform better than bus topology
• Easy to install.

Disadvantages :

• Data traffic issues, since all the data is circulating in a ring.

Use: In wide area networks (WAN) and meteropolitan area networks (MAN), a ring topology is used to as the topology

Point to Point topology : simplest topology that connects two nodes directly together with a common link.Point to point is a one to one type of connection.

Advantages:

• Very simple connectivity
• Easy to handle and maintain
• high bandwidth because of having two node connected

Disadvantages :

• if any of the node stops working, data cannot be transfer across the network.

Use: only used for small areas where nodes are closely located

Point to multipoint topology : The Point-to-Multipoint topology is a common network architecture for outdoor wireless networks to connect multiple locations to one single central location. one-to-many connection

Advantages:

• easy to intall
• low cost
• reliability

Disadvantages :

• if shared communication link fails then the entire network fails.
• multipoint connection needs more than two end points.

Use: when two device uses same connected device

Hybrid topology : A combination of two or more topology is known as hybrid topology. For example a combination of star and mesh topology is known as hybrid topology.

Advantages: ​​​​​​​

• effective
• reliable
• scalable
• It is extremely flexible.

Disadvantages :

• Installation is difficult.
• . Design is complex so maintenance is high thus expensive.

Use: allows the nodes in a given basic topology to communicate with other nodes in the same basic topology as well as those in other basic topologies within the hybrid topology.