Computer Network:
An interconnection of multiple devices, also known as hosts, that are connected using multiple paths for the purpose of sending/receiving data or media. Computer networks can also include multiple devices/mediums which help in the communication between two different devices; these are known as Network devices and include things such as routers, switches, hubs, and bridges.The arrangement of a network that comprises nodes and connecting lines via sender and receiver is referred to as network topology. The various network topologies are:
a) Mesh Topology :
In a mesh topology, every device is connected to another device via a particular channel.
Figure 1: Every device is connected with another via dedicated channels. These channels are known as links.
Advantages of this topology :
1.It is robust.
2.The fault is diagnosed easily. Data is reliable because data is transferred among the devices through dedicated channels or links.
3.Provides security and privacy.
4.Problems with this topology :
5.Installation and configuration are difficult.
6.The cost of cables is high as bulk wiring is required, hence suitable for less number of devices.
The cost of maintenance is high.
Star Topology :
In star topology, all the devices are connected to a single hub through a cable. This hub is the central node and all other nodes are connected to the central node. The hub can be passive in nature i.e., not an intelligent hub such as broadcasting devices, at the same time the hub can be intelligent known as an active hub. Active hubs have repeaters in them.
start topology
A Advantages of this topology :
If N devices are connected to each other in a star topology, then the number of cables required to connect them is N. So, it is easy to set up.
Each device requires only 1 port i.e. to connect to the hub, therefore the total number of ports required is N.
Problems with this topology :
If the concentrator (hub) on which the whole topology relies fails, the whole system will crash down.
The cost of installation is high.
Performance is based on the single concentrator i.e. hub.
c) Bus Topology :
Bus topology is a network type in which every computer and network device is connected to a single cable. It transmits the data from one end to another in a single direction. No bi-directional feature is in bus topology. It is a multi-point connection and a non-robust topology because if the backbone fails the topology crashes.
bus topology
Figure 3: A bus topology with shared backbone cable. The nodes are connected to the channel via drop lines.
Advantages of this topology :
If N devices are connected to each other in a bus topology, then the number of cables required to connect them is 1, which is known as backbone cable, and N drop lines are required.
The cost of the cable is less as compared to other topologies, but it is used to build small networks.
Problems with this topology :
If the common cable fails, then the whole system will crash down.
If the network traffic is heavy, it increases collisions in the network. To avoid this, various protocols are used in the MAC layer known as Pure Aloha, Slotted Aloha, CSMA/CD, etc.
Security is very low.
Ring Topology :
In this topology, it forms a ring connecting devices with its exactly two neighboring devices.
A number of repeaters are used for Ring topology with a large number of nodes, because if someone wants to send some data to the last node in the ring topology with 100 nodes, then the data will have to pass through 99 nodes to reach the 100th node. Hence to prevent data loss repeaters are used in the network.
The transmission is unidirectional, but it can be made bidirectional by having 2 connections between each Network Node, it is called Dual Ring Topology.
 |
| ring topology |
The following operations take place in ring topology are :
Advantages of this topology :
The possibility of collision is minimum in this type of topology.
Cheap to install and expand.
Problems with this topology :
Troubleshooting is difficult in this topology.
The addition of stations in between or removal of stations can disturb the whole topology.
Less secure.
Tree Topology :
This topology is the variation of Star topology. This topology has a hierarchical flow of data.
 |
| tree topology |
Advantages of this topology :
It allows more devices to be attached to a single central hub thus it decreases the distance that is traveled by the signal to come to the devices.
It allows the network to get isolate and also prioritize from different computers.
Problems with this topology :
If the central hub gets fails the entire system fails.
The cost is high because of cabling
Computer Network Types:
A computer network is a group of computers linked to each other that enables the computer to communicate with another computer and share their resources, data, and applications.
A computer network can be categorized by their size. A computer network is mainly of four types:
LAN(Local Area Network)
PAN(Personal Area Network)
MAN(Metropolitan Area Network)
WAN(Wide Area Network)
LAN(Local Area Network)
Local Area Network is a group of computers connected to each other in a small area such as building, office.
LAN is used for connecting two or more personal computers through a communication medium such as twisted pair, coaxial cable, etc.
It is less costly as it is built with inexpensive hardware such as hubs, network adapters, and ethernet cables.
The data is transferred at an extremely faster rate in Local Area Network.
Local Area Network provides higher security.
Personal Area Network is a network arranged within an individual person, typically within a range of 10 meters.
Personal Area Network is used for connecting the computer devices of personal use is known as Personal Area Network.
Thomas Zimmerman was the first research scientist to bring the idea of the Personal Area Network.
Personal Area Network covers an area of 30 feet.
Personal computer devices that are used to develop the personal area network are the laptop, mobile phones, media player and play stations.
Wireless Personal Area Network:
Wireless Personal Area Network is developed by simply using wireless technologies such as WiFi, Bluetooth. It is a low range network.
Wired Personal Area Network: Wired Personal Area Network is created by using the USB.
MAN(Metropolitan Area Network):
A metropolitan area network is a network that covers a larger geographic area by interconnecting a different LAN to form a larger network.
Government agencies use MAN to connect to the citizens and private industries.
In MAN, various LANs are connected to each other through a telephone exchange line.
WAN(Wide Area Network):
A Wide Area Network is a network that extends over a large geographical area such as states or countries.
A Wide Area Network is quite bigger network than the LAN.
A Wide Area Network is not limited to a single location, but it spans over a large geographical area through a telephone line, fibre optic cable or satellite links.
The internet is one of the biggest WAN in the world.
A Wide Area Network is widely used in the field of Business, government, and education.
Internet:
The Internet is a vast network that connects computers all over the world. Through the Internet, people can share information and communicate from anywhere with an Internet connection.
Features of Internet:
Features of Internet Accessibility. An Internet is a global service and accessible to all. ...
Easy to Use. ...
Interaction with Other Media. ...
Low Cost. ...
Extension of Existing IT Technology. ...
Flexibility of Communication. ...
Security.
Working Of Internet:
It works by using a packet routing network that follows Internet Protocol (IP) and Transport Control Protocol (TCP) . TCP and IP work together to ensure that data transmission across the internet is consistent and reliable, no matter which device you're using or where you're using it.
Benifits of Internet:
1.Information, knowledge, and learning. ...
2.Connectivity, communication, and sharing. ...
3.Address, mapping, and contact information. ...
4.Banking, bills, and shopping. ...
5.Selling and making money. ...
6.Collaboration, work from home, and access to a global workforce. ...
7.Entertainment.
Comments
Post a Comment