Notes on Networking Concepts By Tanuja Banerjee, Computer teacher St. Anne’s Girls” High School
Notes on Networking Concepts
A group of computers and other peripheral devices that are linked together for the purpose of sharing data and hardware resources is called computer network.
Wireless– Wireless is a means of communication that uses low powered radio waves to transmit data between devices.
Wireless Networking– Wireless Networking allows networks to be deployed without cabling. Spaces such as outdoor areas where cables cannot be put:, can have wireless network
Advantages of Network
- Sharing of hardware- Network shares expensive resources and reduces the operational and maintenance cost.
- Sharing of software- Sharing of software saves cost of licensing on each machine.
- Fast and efficient communication- Network offers a fast and reliable communication channel among the users.
- Security- As the server of the organization is fully secured against unauthorized access. The relevant data and files are fully protected and only accessible to authorized users
- Reducing redundancy- A network reduces the need for hard copies of all documents. By sharing files over the network, the need to share paper copies of reports or any other information can be eliminated or greatly reduced.
- Saving time and cost- Sharing of data and information through network saves both time as well as cost of paper.
- Efficiency- Deletion, modification or upgradation of software or data at a single point brings more efficiency and effectiveness into a working system.
Server- It is a powerful computer or a set of computers with high speed and great processing capability. It can link many electronic devices together and provide important network services to private and public users.
Client- Client is a computer or device which uses the network to access any service from the server. A client is also called a Node.
Network Interface Card (NIC)- It is a hardware component which connects a computer to a network. It also provides a unique physical address known as Media Access Control (MAC) address to each computer connected to the network. There are two types of NICs-Wired NIC &Wireless NIC
Medium of connection- The interconnection between individual devices can be established in two ways- Through wires/cables OR Through wireless medium
Ethernet Twisted Pair- It is most common and widely used wire in Local Area Network. Modern Ethernet networks use twisted pair cable containing eight wires. these wires are arranged in special order, and an RJ-45 connector is crimped at both the ends of the cable.
Coaxial Cable- It is also known as Coax started being induced in around 1920s in the telephony networks. It contains a copper wire also cable.
Optical Fiber- It is a flexible and transparent strand of glass which is capable of transmitting light between two ends of the fiber. It uses light pulses instead of electrical pulses for information transmission.
Switch and Router- When a network has more than two computers, then we need a central point of connection through which all the computers are connected on a network.
- Switch- In wired networking computers are connected by switches.
- Router- In wireless networking Routers are used to transmit radio signals.
Modem- MODEM stands for Modulator Demodulator. It modulates the digital data into analog signal and demodulates analog signal back into digital signal. In simple words we can say that modem is used to connect computer via telephone lines.-
Types of Network
Personal Area Network-
PAN generally covers a range within 10 meters (about 30 feet) organized around an individual person. It can be created via cables, Bluetooth or infrared rays. .PANs created by using Bluetooth is also called PICONETS.
Local Area Network-
LAN is used when two or more computers are connected within a small area like a room, building, house or a campus. LAN is a low cost , high speed and secured network.. It can cover an area within 10 kilometers. Example- Networking in school lab.
Metropolitan Area Network-
MAN is a computer network in a geographic area larger than LAN generally spread in a city. The maximum range of MAN can be 50 kilometers.. Example of MAN is Cable Television Network.
Wide Area Network- This kind of network connects two or more computers located at far away places. They are linked by communication facilities like telecommunication or satellite signals Example of WAN are- Internet, Automated Teller Machine (ATM) etc.
Pattern or way of arranging computers and other peripheral devices to form a network is known as Network Topology.
Bus Topology- In this topology , each node is attached directly to a central cable which is the common communication medium for all the attached nodes.
Ring Topology- In ring topology, the devices are connected to each other in a circular shape forming a loop. Each node is connected to only two other nodes, one on each side of the node
Star Topology- In star topology, each node is connected to a central node directly by a single path.
Network architecture is an overall design of a computer network that describes how a computer network is configured and what strategies are being used. Computer networks are of two types-
It is a network where several computers called clients or workstations are connected to the main computer called the server.
Server- A server is a computer that provides services to clients and controls access to hardware, software and other resources.
Clients- Clients are the computers which request services like data retrieval, storage etc. from the server.
Peer To Peer Network-
Peer-to-Peer is a network where a few computers having equal capacity and capabilities are connected together to use the resources available on the network. In Peer-to-Peer network , there is no central server. Each computer can act as a server as well as client.
Network security means protecting data and resources from access by unauthorized persons. Some of security measures are-
1. Login & password- All authorized users are given with a Login ID and password by a network manager/ administrator for authentication purposes.
2. Access levels- Different rights and privileges are given to different users. Some users may be able to use a few applications and devices whereas others can use more applications and devices on network.
3.. Encryption- Encryption is the process of changing data into an unreadable and non-understandable code. To make it readable again , the key is used to unscramble the file and decrypt it.
4. Firewall- A firewall is a software/hardware tool that protects a server, a network or an individual computer from attacks by unauthorized users. It protects both the inflow and outflow of data and information.
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