What are the Types of Network Topologies?

What is Network Topology?

                             Network topology is the arrangement of the elements (links, nodes, etc.) of a communication network.  It is the topological structure of a network and may be depicted physically or logically. It is an application of graph theory wherein communicating devices are modeled as nodes and the connections between the devices are modeled as links or lines between the nodes.

There are 5 types of network topologies:

1.) Linear bus topology 

                             -is a type of network topology in which each device is connected one after the other in a sequential chain. In this case, the bus is the network connection between the devices, and if any link in the network chain is severed, all network transmission is halted. It works well for small networks because it is simple to set up and utilizes shorter cables since each device is connected to the next. It is a poor solution for larger networks, however since the entire network relies on each connection, and network speed is reduced as more devices are added.

2.) Star topology

                              

                       -Alternatively referred to as a star network, star topology is one of the most common network setups. In this configuration, every node connects to a central network device, like a hub, switch, or computer. The central network device acts as a server and the peripheral devices act as clients. Depending on the type of network card used in each computer of the star topology, a coaxial cable or a RJ-45 network cable is used to connect computers together.

RJ-45 network cable

3.) Mesh topology

                                                                                                                                                     -A network setup where each computer and network device is interconnected with one another, allowing for most transmissions to be distributed, even if one of the connections go down. It is a topology commonly used for wireless networks. Below is a visual example of a simple computer setup on a network using a mesh topology. Mesh topology may be contrasted with conventional star/tree local network topologies in which the bridges/switches are directly linked to only a small subset of other bridges/switches, and the links between these infrastructure neighbours are hierarchical. 

A mesh topology can be a full mesh topology or a partially connected mesh topology.

In a full mesh topology, every computer in the network has a connection to each of the other computers in that network. The number of connections in this network can be calculated using the following formula (n is the number of computers in the network): n(n-1)/2

In a partially connected mesh topology, at least two of the computers in the network have connections to multiple other computers in that network. It is an inexpensive way to implement redundancy in a network. In the event that one of the primary computers or connections in the network fails, the rest of the network continues to operate normally.

4.) Ring topology

                    -A ring topology is a network configuration in which device connections create a circular data path. Each networked device is connected to two others, like points on a circle. Together, devices in a ring topology are referred to as a ring network.

In a ring network, packets of data travel from one device to the next until they reach their destination. Most ring topologies allow packets to travel only in one direction, called a unidirectional ring network. Others permit data to move in either direction, called bidirectional.



The major disadvantage of a ring topology is that if any individual connection in the ring is broken, the entire network is affected.

Ring topologies may be used in either local area networks (LANs) or wide area networks (WANs). Depending on the type of network card used in each computer of the ring topology, a coaxial cable or a RJ-45 network cable is used to connect computers together.

5.) Hybrid topology

-A hybrid topology is a type of network topology that uses two or more differing network topologies. These topologies include a mix of bus topology, mesh topology, ring topology, star topology, and tree topology. It is an interconnection of two or more basic network topologies, each of which contains its own nodes.

The resulting interconnection 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.

Advantages of a hybrid network includes increased flexibility as new basic topologies can easily be added or existing ones removed and increased fault tolerance.

Sources: computerhope.com
                 study.com
                 Wikipedia