Network Topology

Network Topology is a diagram or map which shows about the layout of network.

In computer network, network topology is the brief description of arrangement of the devices (Router, Switch, Hub, PC's, etc) and cables which are connecting these devices with each other in the network.

Network Topology is defined into two major parts

Physical Network Topology
Logical Network Topology

Logical Network Topology

Logical Network Topology is a type of topology in which only the over view of devices is show which means that how many devices are connected in the network and what type of those devices are.

Physical Network Topology

Physical Network Topology is a type of topology in which all the devices and cables are show completely with their complete locations and paths.

There are different types of Physical Typologies

Point to Point Topology
Ring Topology
Star Topology
Bus Topology
Mesh Topology
Tree Topology

Point to Point Topology

In this topology two devices connect with each other with the direct link without any dedicated device or any third party.

Examples of Point to Point Topology are

Telephone Connections

Network Topology - point to point topology

Advantages of Point to Point Topology

Very low cost to setup
Very easy to setup connection
Suitable for networks which are temporary
Used to connect two areas using high speed link

Disadvantages of Point to Point Topology

Growth is limited in these networks
There is no centralized administration
Compromising and very week security

Ring Topology

Ring Topology is a type of topology in which all the devices or nodes are connected with each other and forms a close circle. If any cable or device fails whole network will shutdown. All the packets should have to pass from each node to reach their destination.

Advantages of Ring Topology

All packets travel in same direction and data travel speed is very high
Packet transmission is simple because all packets travel in same direction
New node consume very low bandwidth due to which networks speed remains better
Collision domain does not occurs because nodes transmit data only when the link is free
Only one node can transmit data at same time

Disadvantages of Ring Topology

If one node or link fails all the network will shutdown
If changes are made in the networks it effects the whole network
Packets sent from sender should have to pass from all the nodes to reach the destination
All nodes are completely dependent on the link between them

Star Topology

Star Topology is used mostly. In this topology all the nodes are connected with central devices which may be switch or hub. If that central device fails then the whole network will shutdown.

Advantages of Star Topology

Star Topology is easy to set
it gives much better performance than other typologies
If organization wants to expand their network then this topology allows easy method to expand
If any node fails it does not effects or shutdown the networks
Administrator can easily add or remove any node form that network
If any failure occurs it can be easily detected due to centralized administration
It is more secure than other typologies because analysis of traffic is easy in this topology

Disadvantages of Star Topology

Star Topology is very expensive because dedicated devices are required to establish this topology
huge amount of hardware is required
All the operations performed in this topology are completely dependent on central device and if that device fails then whole network will shutdown
Addition of new nodes is dependent upon the capacity and bandwidth of central device

Bus Topology

Bus topology is a topology in which all the devices are connected with central cable or backbone cable. Bus topology is reliable topology and if any one node fails it does not effect the network and data transmission stay active.

Advantages of Bus Topology

Implementation of bus topology is very easy
In small networks it is suitable
Mostly used in temporary networks
Much less expensive than other

Disadvantages of Bus Topology

Length of cable is limited due to which limited number of nodes can be added to that topology
If number of nodes are less then it's performance is better
If number of nodes increases then performance and speed of network decreases
This topology is used in the networks having less traffic
All the devices are dependent on the central cable and if that cable fails whole network will shutdown
All nodes can see the packets travelling through bus due to which security of network compromises
It is very difficult for administrator to troubleshoot problem in the network

Mesh Topology

In mesh topology each node and network device is directly connected with each other and form multiple links so that if one link or node is down then data will travel from other node or link.

Data can take more than one paths to reach the destination form the source.

Advantages of Mesh Topology

All the nodes and devices are connected in such a way that at the same time data can be sent to more than one nodes
If one node or links fails it will not stops the transmission. Transmission occurs from the other nodes and links
Mesh topology can handle heavy network traffic due to multiple links
Point to Point connections can also be established and they will help to identify the problems in the network
This topology does not affect by the number of nodes

Disadvantages of Mesh Topology

It need continuous observation and maintenance
Very expensive to install
Complex cabling is required

Tree Topology

Tree topology is a three level topology. Tree topology is the combination of two typologies which are star and bus typologies. It is also called Hybrid Topology.

Advantages of Tree Topology

Easily expandable
Troubleshooting is easy
Each level is connected directly with the root node with point to point connection
If one level fails remaining levels doesn't effected

Disadvantages of Tree Topology

Dependent on main cable
Expansive to install and maintain
Addition of new nodes depend upon the bandwidth of the main cable

Basic Networking

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