a. What is communication? From which word is it derived?
ans : Communications is the exchange of information between two or more
things, such as people, devices, governments, organizations, or
businesses. In digital communication, data is exchanged between two or more computing devices. This data communication (datacom) occurs over a communication medium, such as a telephone line, fiber optic cable, or wireless radio signal. The collection of digital devices and their connection media is a computer network and is what allows devices to "talk" to each other.
The word communication is derived from communis (Latin) which means
common. Communis is noun word, which means common, communiality or
sharing. Similarly, communicare is a verb, which means 'make something
common'.
b. What is data transmission mode? List different types of data transmission modes.
ans : Data communication is the transmission of electronic data and information between two points, either via an analogue(electrical) signal or digital (binary) signal.
The different types of data transmission modes are :
i. Simplex mode of data transmission
ii. Half Duplex mode of data transmission
iii. Full Duplex mode of data transmission
c. List the elements of data communication.
ans : The basic elements of data communication are :
i. Sender
ii. Medium
iii. Receiver and
iv. Protocol
d. Distinguish between simplex and duplex mode of communication.
Simplex Mode of data communication
- In Simplex mode, the communication is unidirectional, i.e., the data flow in one direction.
- A device can only send the data but cannot receive it or it can receive the data but cannot send the data.
- This transmission mode is not very popular as mainly communications
require the two-way exchange of data. The simplex mode is used in the
business field as in sales that do not require any corresponding reply.
- The radio station is a simplex channel as it transmits the signal to the listeners but never allows them to transmit back.
- Keyboard and Monitor are the examples of the simplex mode as a
keyboard can only accept the data from the user and monitor can only be
used to display the data on the screen.
- The main advantage of the simplex mode is that the full capacity of
the communication channel can be utilized during transmission.
Full Duplex Mode of data communication
- In Full duplex mode, the communication is bi-directional, i.e., the data flow in both the directions.
- Both the stations can send and receive the message simultaneously.
- Full-duplex mode has two simplex channels. One channel has traffic
moving in one direction, and another channel has traffic flowing in the
opposite direction.
- The Full-duplex mode is the fastest mode of communication between devices.
- The most common example of the full-duplex mode is a telephone
network. When two people are communicating with each other by a
telephone line, both can talk and listen at the same time.
e. Write down the difference between guided and unguided media with example.
ans : The difference between guided and unguided media is as follows:
f. Define computer Network and justify that, how does it reduces operation cost?
ans : A computer network is a set of computers sharing resources located on or provided by network nodes. The computers use common communication protocols over digital interconnections to communicate with each other. These interconnections are made up of telecommunication network technologies, based on physically wired, optical, and wireless radio-frequency methods that may be arranged in a variety of network topologies .
Computer Networks can allow businesses to reduce expenses and improve efficiency by sharing data and common equipment, such as printers,
among many different computers. At the same time, the network may be
connected by cables, telephone lines, infrared beams etc, which is
cheaper and helps to reduce the expenses.
g. List out any two advantages and disadvantages of computer network.
ans: Any two advantages of computer network are:
- Faster Problem-solving –
Since an extensive
procedure is disintegrated into a few littler procedures and each is
taken care of by all the associated gadgets, an explicit issue can be
settled in lesser time.
- Reliability –
Reliability
implies backing up information. Due to some reason equipment crashes,
and so on, the information gets undermined or inaccessible on one PC,
another duplicate of similar information is accessible on another
workstation for future use, which prompts smooth working and further
handling without interruption.
Similarly besides its advantages, there are some disadvantages of computer network too. They are:
- It lacks robustness –
If a PC system’s
principal server separates, the whole framework would end up futile.
Also, if it has a bridging device or a central linking server that
fails, the entire network would also come to a standstill. To manage
these issues, gigantic systems ought to have a ground-breaking PC to
fill in as a document server to influence setting up and keeping up the
system less demanding.
- It lacks independence –
PC
organizing includes a procedure that is worked utilizing PCs, so
individuals will depend on a greater amount of PC work, rather than
applying an exertion for their jobs that needs to be done. Besides this,
they will be subject to the primary document server, which implies
that, in the event that it separates, the framework would end up futile,
making clients inactive.
h. What is Local Area Network? Write its importance.
ans : The computer network which is limited to a small area such as a room, a building or a school and connects limited number of computer is called Local Area Network(LAN). We can use a large number of computers in a LAN but it is restricted to a small geographical area. Local Area Networks are limited by distance. In order to keep the signal at a quality transmission level, it must be boosted by repeaters along the way.
The importance of Local Area Network are :
- Reduced Costs: LANs apresent a significant reduction in Local Area Network hardware costs and efficient resource pooling.
- Increased Storage Capacity:
By pooling all data into a central data storage server, the number of
storage servers required is decreased and the efficiency of operations
is increased.
- Optimized Flexibility: Data can be accessed by any device from anywhere via Internet connection.
- Streamlined Communication: Files and messages can be transferred in real time and accessed easily from anywhere on any device.
i. What is Metropolitan Area Network? Write its features.
ans : The medium sized network that covers the area larger than a LAN but smaller than a WAN is called Metropolitan Area Network. It covers a larger geographical area such as : an university, an entire city, a valley, a district or a zone. This type of network is prepared by connecting several LANs in different locations.
Features of MAN:
- It covers a larger geographical area than LAN and connects larger number of computer.
- It uses cable or wireless communication media to connect computers.
- It connects multiple LANs in different locations by using Ethernet technology.
- It is owned by a single or multiple organizations.
- It offers a number of network services compatible with bandwidths from 128 kbps to 1 Gbps.
j. What is Wide Area Network? Mention its characteristics.
ans : The communication networks, that spans globally and connects large number of computer around the world is called Wide Area Network. It is the largest network in the world. It is not restricted to a geographical location. The Internet is an example of a WAN.
The characteristics of WAN are :
- It is not restricted to a geographical location. It covers whole world.
- It uses satellite links or microwave system to connect several LANs and MANs.
- It is owned by multiple organizations.
- This technology is of high speed and very expensive to setup.
- Data Transmission in WAN is slower than LANs and WANs.
k. List the different services provided by computer Network.
ans : Network services are the thing that a network can do. The major networking services are as follows :
i. File Services : This includes file transfer, storage, data migration, file update, synchronization and achieving.
ii. Printing Services : This service produces shared access to valuable printing devices.
iii. Message Services : This service facilitates email, voice mails and coordinate object oriented applications.
iv. Application Services : This services allow to centralize high profile applications to increase performance and scalability(ability).
v. Database Services : This involves coordination of distributed data and replication.
L. What is Networking architecture or model? List its types.
ans: Network architecture describes how the computers on the network interact and communicate with each other. It is the combined form of network topologies and mode of data transmission between the computers in the network.
Generally, network architecture can be classified into two types:
i. Client-Server network architecture
ii. Peer to Peer network architecture
M. What is protocol ? List any four types of common protocols.
ans : Certain rules are needed for sending and receiving information between the computers in the network. Such rules are called protocols. A protocol is a set of rules that governs data communications. A protocol defines what is communicated, how it is communicated and when it is communicated.
Some of the common protocols used in the Network are
1. TCP/IP(Transmission Control Protocol/Internet Protocol)
2. FTP(File Transfer Protocol)
3. HTTP(HyperText Transfer Protocol)
4. IMAP(Internet Message Access Protocol)
5. NNTP(Network News Transfer Protocol)
6. POP(Post Office Protocol)
7. SMTP(Simple Mail Transfer Protocol)
8. TFTP(Trivial File Transfer Protocol)
9. PPP(Point to Point Protocol)
10. IPX/SPX(Internetwork Packet eXchange/Sequence Packet eXchange)
11. Net BEUI(Network Bios extended User Interface)
M. Sketch and explain about Star Topology.
