The act of transferring data and information at a far distance for communication is called telecommunication.
The transmission of data from a place to another using computer technology is called data communication.
The interconnection of two or more computers by means of transmission media like cable or without cables in order to communicate and share resources data, application software, and hardware is known as a computer network. Its advantages are:
A computer network is the interconnection of computers to share the data, files, hardware, software, and so on. It also makes the communication and transmission reliable In the offices, the files should be transferred from one to other branches very often. Also, the software and hardware can be shared which reduces the cost of buying many items of hardware, software, and so on. So, computer network reduces expenses of offices.
The reasons for keeping the computers on the network are:
In a network of computers, many computers are connected to each other at a distance for the sharing of information, data, software, hardware and so on. Computer network has made the communication and transmission easier, faster, reliable and secure. The information in one corner of world can spread whole over the world in short period through computer network. We feel like working in a room though we are working a kilometers away to each other in a computer network. So, computer network make the world a small place.
The essential components of simple network are:
- Network Interface unit.
- Communication Channel on Transmission Media.
The differences between server and workstation are:
|It is the main component of the computer network that controls, store and distribute the data, programs, etc.||It is the computer besides server in a network that uses the available resources in a network.|
|It provides the facilities of sharing hardware, data, software and so on.||It shares and transfers the data, programs, etc. among clients and servers under servers permission.|
The differences between dedicated server and non-dedicated server are:
|Dedicated server||Non-dedicated server|
|It can be used as server and workstation both.||It can only be used as server.|
|It is designed as server of simple and small computer network.||It is designed as a server of specific and advanced network.|
The path through which data, information and other various form of files transfers on a network in the form of electromagnetic wave is called communication channels.
Its types are:
- Bounded transmission media.
- Unbounded transmission media.
The bounded transmission media used in computer network are:
- Twisted Pair Cable:
i. Unshielded Twisted pair.
ii. Shielded Toasted pair.
- Coaxial cable.
- Fiber optic cable.
The importances of modem in computer network are:
- It enables to transmit data, information and files.
- It converts digital signal into analog form and also its vice versa.
- It requests and loads the internet facilities.
- It enables to share hardware and software resources.
The different types of computer network based on range are:
- LAN (within a building or room)
- MAN (within metropolitial area)
- WAN (within global or wide area)
The interconnection of few computers with cables or small wireless media within a building viz small territory for the sharing of hardware and software resources is called LAN.
It is the basic unit of computer network. It is connected with cables within a small area. So, it has high data transmission speed. Also, wireless media is also used in LAN.
The computer network that connects two or more LAN in the metropolitial area with wireless communication channel for the sharing of hardware and software resources is called MAN.
There are large number of LAN connected to each other under MAN. It is owned by single of multiple organizations. It is the network bigger than LAN but smaller than WAN.
The global computer network that spreads over a large geographic area with unguided or wireless media for the purpose of communication, transmission and share is called MAN.
It connects the many groups of LANS and MANs. It uses the wireless transmission media like microwave, radio save or satellite links. Data can be transmitted at the speed of 10 giga bits per second ( Gbps ) in these network.
The differences between LAN & WAN are:
|It is interconnection of computers within a small area.||It is interconnection of LANs and MANs within a global area.|
|Both wired and wireless media is used as transmission media.||Highly powerful wireless media is used as transmission media.|
We all know that, WAN is the networks that spreads over the global world. There are many small computer networks in the world. LAN is the smallest and unit computer network. MAN spreads over metropolitial area and connects multiple LANs. And finally, many MANs in the world are connected to each other and WAN is formed. So, a WAN is composed of LANS and MANs.
The difference between client-server model and peer-to-peer model are:
|It is also called domain model.||It is also called workgroup model.|
|It has a server and the workstations.||All the computers in network works as server and workstation both.|
|Server decides for sharing of resources.||Each computer uses decide for sharing of resources.|
The manner in which the computers on a network are connected with the help of transmission media is called network topology.
It's basic types are:
- Bus topology.
- Ring topology.
- Star topology.
- Mesh topology.
The topology in which computer are arranged in a linear format and the nodes (computer) are connected directly to the common cable with the help of T-connectors is called bus topology.
The common cable is also known as a network bus or trunk that acts as a backbone to a network. Many different lengths of co-axial cables are used in this type of topology. When any nodes sends data, the data passes on both directions in the form of packets through the bus and reach to all the nodes.
The advantages of bus topology are:
- It is easy to setup the nodes.
- It requires less amount of cables.
- It uses the co-axial cables which is cheap & easy to setup.
- Failure of any nodes doesn't effect other nodes on the network.
The disadvantages of Bus topology are:
- If the bus has problem, whole network fails to function.
- It provide limited flexibility to change the position of nodes.
- It will be more weaker with the increment of nodes.
- This topology doesn't works for huge network.
Ring topology in a computer network is the pattern of nodes where the nodes are arranged in the shape of ring (circle).
In this topology, both ends of cable is connected to the nodes which removes the necessities of terminator. Co-axial cables are connected among the node in circle shape. Every nodes acts as a repeater on the network that boasts the signals before passing it to other.
The advantages of ring topology are:
- Network signals are strong as every nodes acts as repeater.
- It supports high data transmission rate.
- It is easy to setup
- It requires less cables for setup.
The disadvantages of ring topology are:
- Failure of any node breaks the whole function.
- The diagnosis of the fault is difficult.
- Data transmission is slow in case of huge network.
- It is uneasy to add and remove the nodes.
Hub is a networking device having the series of connecting ports which joins multiple nodes or other network devices together to form the segment of computer network.
The difference of switch and hub are:
|It transmits the shared resources to assigned MAC address on a network.||It transmits the shared resources to all the node on the network.|
|It has better performance than hub as it follow only the assigned path.||It has weaker performance than switch as it flow the data in every path.|
The topology in which all the nodes are connected through a centrally located device in the form of star is called star topology.
However, the nodes are not under compulsion to be arranged in the form of star but should be directly connected with the network connecting device. It is connected by either switch or hub. The sent data from any nodes first reach to the switch or hub and to the assigned MAC address (nodes).
The advantages of stars topology are:
- Its easy to remove and add the nodes.
- Failure of any nodes doesn't affect other nodes.
- Fault detection is easy.
- It is suitable for a huge network which is also reliable.
The disadvantages of stars topology are:
- It requires more cables for installation.
- Failure of hub or switch creates entire network failure.
- It is expansive to arrange this topology.
- It has the chance of data loss.
Communication protocol is a program that controls and manages the transferring of data or message from one computer to other on a network.
Any four of them are:
- TCP/IP (Transmission control Protocol/Internet Protocol)
- SMTP (simple Mail Transfer Protocol)
- FTP (File Transfer Protocol)
- HTTP (Hyper text transfer Protocol)
- POP (Post office protocol)
- IPX/SPX (Internet Package Exchange/Sequential Packet Exchange)
- NETBEUI (Net Bios Extended User Interface)
FTP: File Transfer Protocol
SMIP: Simple Mail Transfer Protocol
TCP/IP: Transmission Control Protocol/Internet Protocol
ISP: Internet Service Provider
POP: Post Office Protocol
UPT: Unshielded Twisted Pair
STP: Shielded Twisted Pair
NetBEUI: Net BIOS Extended User Interface
DARPA: Defense Advanced Research Projects Agencies
HTTP: Hyper Text Transfer Protocol
MODEM: Modulator and Demodulator
WLAN: Wireless Local Area Network
a. A group of interconnected computer.
- Computer network.
b. A computer on a network.
c. The physical path through which data and information flow on the network.
- Transmission media.
d. The data handling capacity of communication system.
e. The amount of data transmitted per second through the communication channel.
f. A computer which provides resources to other computer on a network.
g. A computer which uses the services on the network.
h. An operation system of server computer.
- Novell net ware server.
i. A computer in a network that provides resources but doesn't allows client to use it as a workstation.
- Dedicated server.
j. A computer in a network that provides resources and allows client to use it as a workstation.
- Non dedicated server.
k. A computer which uses bounded media.
- Wired network.
l. Transmission media through data are transmitted in the form of light.
- Fiber optic cables.
m. A network that uses unbounded transmission media.
- Wireless network.
n. A network model having at least one server and multiple clients.
- Client/server network.
o. A network model where all nodes have equal right.
- Peer-to-peer network.
p. Network within a room.
q. Network within a city or neighboring cities.
r. A device that converts digital signal into analog and vice-versa.
s. A card that connects a computer with a networking cable.
t. Network spreaded over the world.
u. The physical layout of cabling for connecting computers on a network.
- Network topology.
v. A network structure where all computers on a network are connected through a centrally located device.
- Star topology.
w. A set of rules that each computers on a network has to follow.
- Communication protocol.
x. A multi port repeater.
- Hub (active).
y. A network device that joins segments of a network.
z. A network devices that regenerates or amplifies signals.
aa. A network device that makes communication between two different protocols.