Computer Networking

Two wireless modes that can be used are:

1. Bluetooth
2. WiFi

Personal Area Network

MAN (Metropolitan Area Network) is most suitable for communication between both the units.

WAN (Wide Area Network)

Raman will use Microwave as the wireless communication media since Microwave communication is extensively used in 3G/4G and WiMax networks.

Wide Area network

The Network Interface Card (NIC) identifies every single node in a network by providing a unique physical address to it.

An Intranet refers to a computer network within an organization.

An Extranet refers to a computer network that allows controlled access from outside for specific business or educational purpose.

A cable modem connects to the Internet using a Broadband access through a telephone line.

The maximum range of LAN can be 10 Km.

WAN (Wide Area Network) is a type of network that requires a telecommunication media or satellite signals to transfer data.

The actual protocols of TCP/IP model are called TCP/IP suite.

Bluetooth technology sends information within its personal space called the Personal Area Network (PAN).

Cross over cable is basically designed for connecting to computers without a hub or a router.

Infrared Wireless technology requires a line-of-sight connection between transmitter and receiver.

There are four types of computer networks:

1. LAN (Local Area Network) — LAN is used when two or more computers or peripheral devices are connected within a small area, like a room, office building, or a campus. The maximum range of LAN can be 10 Kilometers. The number of computers in a LAN varies from 2 to 1000. The hardware as well as software resources are shared through LAN.
2. MAN (Metropolitan Area Network) — MAN is much larger than a LAN setup and is spread across a city. The most common example of a MAN type network is Cable Television Network. The main purpose of a MAN is to share hardware and software resources. The maximum range of MAN can be 50 Km.
3. WAN (Wide Area Network) — WAN is used when we have two or more computers located at far away places, linked by communication facilities, like telecommunication or satellite signals. The most common example of a WAN network is the Internet which is generally used in houses, schools, banks and private and public sector. The main characteristic of a WAN is that it requires a public telecommunication media to transfer data.
4. PAN (Personal Area Network) — PAN is mainly created for an individual person. It consists of a desktop/laptop computer, a mobile phone, and/or a handheld computing device, such as a PDA or a Smartphone. We can use these networks to transfer files including e-mail, calendar appointments, digital photos, and music. Personal area networks generally cover a range of less than 10 meters.

Modems are available in two categories:

1. Internal modem — These are attached to the internal slot of the motherboard. These are categorised as full duplex and half duplex which are used for fax and internet communications. They can also be used for data and voice communication.
2. External modem — It is a small box connected to the communication port of the computer. It works similar to the internal modem. The only difference is that it is placed outside the CPU box.

The four advantages of networking are:

1. Hardware Sharing — In a network, we can share almost every peripheral device, such as a printer, scanner, modem, CD writer, etc., among several computers. All these devices are attached to a remote server, which is shared among multiple computers. This reduces the cost of hardware.
2. Software Sharing — Every application software can be installed on the main server rather than installing it on every computer individually. Computers in a network can use the required software from the server. This technique saves cost as well as time.
3. Efficiency of Hardware and Software Resources — In a network, modifications in software or hardware are done at a single point. Since the resources are installed at a single point, all modifications are done at that point rather than in individual computers.
4. Reduces Redundancy — Since people use the same data in a common workplace, they can share it over a network by saving and storing it centrally. This also reduces the redundancy of the same data.

Internet is a computer-based world wide information network. It is composed of a large number of smaller interconnected networks.

Five uses of the Internet are:

1. Businesses use the Internet to provide access to complex databases, such as financial databases.
2. Companies carry out electronic commerce (commerce on internet) including advertising, selling, buying, distributing products, and providing after sales services.
3. Businesses and institutions use the Internet for voice and video conferencing and other forms of communication that enable people to telecommute, or work from a distance.
4. The use of electronic mail (e-mail) over the Internet has greatly speeded communication between companies among coworkers, and between other individuals.
5. Individuals use the Internet for communication, entertainment, finding information and to buy and sell goods and services.

The advantages of Infrared wireless technology are as follows:

1. It has low power consumption.
2. Infrared components are less expensive.
3. It is more secure than radio-frequency signals.
4. Direct line of sight requirement of Infrared enhances its security and minimizes interference, making it suitable for short-range, point-to-point communication.

The disadvantages of Infrared wireless technology are as follows:

1. It has limited range of approx 5 meters and it cannot penetrate walls or other obstacles.
2. It works only in direct line of sight between the transmitter and receiver. Even the smallest obstruction will disrupt communication.
3. Infrared communication can take place only between two devices at a time limiting its use to control multiple devices.
4. It has relatively low data transfer speeds compared to technologies like Bluetooth or Wi-Fi.
5. Bright ambient light, including sunlight and strong artificial lighting, can interfere with infrared signals and degrade the quality of communication.

Wi-Fi stands for Wireless Fidelity. It creates a Wireless Local Area Network that uses radio waves to send the information. A secure, reliable, and fast wireless connection is established between the electronic devices and the Internet by using this technology. The devices require a wireless adapter connected to them to capture the Wi-Fi signals.

Wi-Fi offers the following advantages:

1. Wi-Fi has replaced the wired medium completely and can be used to connect to the Internet anywhere, at any time.
2. It is relatively inexpensive and can also be accessed at places where cables cannot be installed.
3. One can connect multiple devices through Wi-Fi.

Wi-Fi faces the following challenges:

1. It has high power consumption.
2. It is slower than the wired medium.
3. The transmission breaks or slows down when there is noise interference.

Data is different from information in the following ways:

A computer network is a group of computers and peripheral devices, connected through a data communication system to facilitate the sharing of hardware and software resources among different users working on different computers.

A computer network is required for the following reasons:

1. A computer network enables the sharing of hardware and software resources.
2. Data can be shared over a network by saving and storing it centrally reducing redundancy of the same data.
3. It helps in saving of paper and time by reducing the need for generating multiple hard copies of the same document.
4. It enables Internet sharing among the computers in the network thus, reducing internet usage cost.

Cloud Computing refers to manipulating, configuring, and accessing the applications online. It offers online data storage, infrastructure, and applications.

The different types of cloud services are:

1. Public cloud — A public cloud is provisioned for open use by the general public. It has no boundaries and the cloud infrastructure can be used by anyone, anywhere over the Internet.
2. Private Cloud — A private cloud is owned and used by a single organization over a private network. It centralizes the resources of the organization so that they can be accessed easily by its various departments and offices at different locations.
3. Hybrid Cloud — A hybrid cloud is a combination of both private and public cloud. This type of cloud offers benefits of multiple deployment models such as the controlled environment in private clouds and rapid elasticity of public clouds.
4. Community Cloud — The community cloud is provisioned for use by a group of consumers from different organizations who share the same concerns. It may be owned, managed, and operated by one or more of the organizations in the community or a third party.

The various long distance communication mediums used in networking are:

1. Coaxial Cables — A Coaxial cable consists of central copper wire surrounded by insulation and then a shield of braided wire.
   1. It is relatively inexpensive and can transmit data at higher rates.
   2. It also provides better immunity against electromagnetic disturbances.
   3. It is mainly used by the cable television industry to connect TVs to a cable TV service.
   4. The two main types of Coaxial cable are:
      1. Baseband Coaxial cable — It supports quick transmission of a single signal at a time. It is mainly used for LANs.
      2. Broadband Coaxial cable — It transmits multiple signals at the same time and is used for longer distances.
2. Fibre optics — A Fibre optic cable consists of a central glass core containing a bundle of glass threads, surrounded by several layers of protective materials. The glass threads are capable of transmitting data converted into light signals at extremely high speed.
   1. A Fibre optic cable is highly resistant to signal interference and provides better data transmission by providing high bandwidth.
   2. It is fragile and the maintenance cost is high.
3. Satellite — Satellites create a communication channel between a source transmitter and a receiver at different locations on the Earth. The ground station with the help of a dish antenna sends signal to the satellite, it amplifies the received signal and sends it back to the ground station for relay.
4. Wimax — WiMax stands for Worldwide Interoperability for Microwave Access. It is a telecommunication protocol that provides fixed and mobile internet services.
   1. WiMax requires a tower called WiMax Base Station, that is connected to the Internet using a standard wired high-speed connection.
   2. The connectivity between the tower and the end user is provided through microwave link.
   3. WiMax technology provides high speed connection upto 75 Mbps over an area of 30 miles for fixed stations and 3-10 miles for mobile stations.
5. Microwave — Microwave is a wireless communication technology that uses high frequency beams of radio waves to provide high speed signal transmission that can send and receive voice, video, and data information.
   1. The transmission is fast but is limited to line-of-sight transmission, in which signal travels in a straight line with no obstructions between microwave antennas.
   2. Microwave signals are used for both satellite and ground-based communications.
   3. Many TV and telephone communications in the world are transmitted over long distances using microwave signals.
   4. Microwave signals are widely used in radar technology.
6. Radio wave — Radio waves is a wireless transmission medium that distributes radio signals through the air.
   1. Radio waves are widely used as signals on radio communication.
   2. A transmitter is used to send the broadcast signal and a receiver is needed to accept the signal.
   3. Radio waves have lower frequencies and longer wavelength.
   4. Radio waves can have a frequency range from 300 gigahertz (GHz) to as low as 30 hertz (Hz).

The advantages of cloud computing are as follows:

1. Cost saving — Cloud Computing can significantly lower the company's IT expenses and requirements as it provides access to numerous storage facilities and applications.
2. Reliability — It is much more reliable, when it comes to data management, backup, and recovery from failures.
3. Unlimited Free Storage — Cloud provides unlimited free and secure storage space to store large amounts of information.
4. Accessibility — Cloud allows easy access to cloud-based services and applications through Internet-enabled devices.

The disadvantages of cloud computing are as follows:

1. Technical Issues — There are times when cloud system encounters serious technical problems, which may lead to the entire business processes being temporarily suspended.
2. Security — Storing the company's sensitive data and important files on third-party cloud providers, always opens up security risks.
3. Vendor Lock-in — Switching from one cloud service to another may lead to portability and support issues.
4. Limited Control — The consumer has very little control over the applications, data, and services of cloud.

Telecommunication

Reason — The computers which are located at far away locations use the Telecommunication system for data communication.

Dependence on electricity

Reason — Dependence on electricity is not an advantage of networking as the networking equipments require electricity to work.

Node

Reason — A computer system, which can access a remote service from a server using a network is called a node.

ISP

Reason — An ISP (Internet Service Provider) is an organisation that provides the facility of availing internet services against a fee. It is not a basic hardware component which connects the nodes in a network.

Intranet

Reason — Intranet is a computer network within an organisation, used to share files and resources of the organisation securely.

Modem

Reason — A Modem converts digital signal to analog signal and vice versa.

PAN

Reason — A computer network, which is used for communication among computers and their peripherals close to each other is called PAN (Personal Area network).

1000

Reason — The maximum number of computers in a LAN can be 1000.

50

Reason — The maximum range of MAN can be 50 km.

Yahoo

Reason — Yahoo is not a web browser.

Data

Reason — Data refers to a collection of numbers, characters, symbols, and images.

Light rays

Reason — Optical Fiber is a networking medium that transmits light rays instead of electronic signals to send data.

Guided media

Reason — Optical Fibre cable and Coaxial cables are the categories of Guided media.

Twisted Pair

Reason — Twisted Pair cable transmits multiple signals at the same time and is used for longer distances.

Optical Fiber

Reason — Optical Fiber is an example of guided media and not wireless media.

Optical Fiber cable

Reason — Optical Fiber cable is the most widely used form of wiring medium that transmits transmission over longer distances and at higher bandwidth.

Bluetooth technology

Reason — Bluetooth technology is an example of wireless media while Ethernet Cables, Optical Fiber and Coaxial cable are examples of guided media.

Reddit

Reason — Reddit provides free or low cost online storage for the users.

Hybrid

Reason — A cloud which is accessible to both private and public users is called Hybrid cloud.

FTP

Reason — FTP (File Transfer Protocol) is used for exchanging files between computers.

IMAP/POP

Reason — IMAP/POP are the two most popular Internet standard protocols for retrieving e-mails.

Micro wave

Reason — Micro wave is a communication technology that uses low power radio waves to connect electronic devices wirelessly.

Repeater

Reason — Repeater is used to regenerate a signal.

mpg

Reason — Video stored in MPEG format have the extension mpg.

Intranet is a computer network within an organisation, used to share files and resources of the organisation securely.

Extranet refers to a computer network that allows controlled access from the outside for specific business or educational purposes.

1. NIC — Network Interface Card
2. ISP — Internet Service Provider
3. LAN — Local Area Network
4. MAN — Metropolitan Area Network
5. WAN — Wide Area Network
6. PAN — Personal Area Network

The File Transfer Protocol (FTP) was originally designed by Abhay Bhushan and published in 1971.

WiMax stands for Worldwide Interoperability for Microwave Access. It is a telecommunication protocol that provides fixed and mobile internet services. WiMax requires a tower called WiMax Base Station, that is connected to the Internet using a standard wired high-speed connection. The connectivity between the tower and the end user is provided through microwave link. WiMax technology provides high speed connection upto 75 Mbps over an area of 30 miles for fixed stations and 3-10 miles for mobile stations.

1. Modem — Internal modem, External modem.
2. Transmission — Wired Transmission, Wireless Transmission
3. Coaxial cable — Baseband Coaxial Cable, Broadband Coaxial Cable
4. Wireless Networking Technology — Bluetooth, Wi-Fi

The maximum data transmission range of bluetooth technology is 240 metres.

Radio waves are a wireless medium for broadcasting radio signals through the air. They have lower frequencies and longer wavelengths. Their frequency ranges from 300 GHz to 30 Hz.

Three network components are:

1. Server
2. Client
3. Network Interface Card (NIC)

The three types of cables used in wired networking technology are:

1. Ethernet Cables
2. Coaxial cables
3. Optical Fibre Cables

A Coaxial cable is used by the cable television industry to connect TVs to a cable TV service.

Coaxial cable is called coaxial cable because the two conductors are concentric. This means that the two conductors share the same axis.

False

Reason — Data communication means sending data electronically from one computer to another using a transmission medium. The medium can be guided or unguided.

True

Reason — Networking of computers reduces the redundancy of the same data.

False

Reason — In a network, internet facility can be installed on a server and all the computers connected to the server can access the internet service.

False

Reason — The maximum range of LAN can be 10 Kms while a MAN can cover a range of about 50 kms. Thus, MAN is larger than LAN.

False

Reason — The maximum range of LAN can be 10 km.

False

Reason — A Private Cloud is defined as a set of services available to private individual / organization only.

True

Reason — A Gateway is a network point that acts as an entrance to another network.

True

Reason — IP or Internet Protocol provides a sequence number to each of the packet so that they might reach their destination in the correct order.

True

Reason — Internet browsers have an in-built feature to make FTP requests to other servers.

False

Reason — In case of unguided media, there is no physical path for data transmission.

False

Reason — Wireless media is the most common medium for communication.

True

Reason — Oliver Heaviside, an English physicist, engineer, and mathematician patented the coaxial cable in 1880.

False

Reason — Fiber Optic cable transmits data converted into light signals.

False

Reason — A node is a computer system which uses a network to access a remote service from the server.

True

Reason — Transmission of computerized data from one location to another is called communication.

True

Reason — Picture formats are recognized by the extension like .gif and .jpg

False

Reason — Sounds stored in AU format have the extension .au.