Quiz 7

Quiz 7 Communications and Networks

1. Discuss the components required for successful communications.

answer:

Sending device — initiates instruction to transmit data, instructions, or information
Communications device — connects the sending device to the communications channel
Communications channel — media on which data, instructions, or information travel
Communications device — connects the communications channel to the receiving device
 Receiving device — accepts transmission of data, instructions, or information

2. Identify various sending and receiving devices.

answer: 

A sending device initiates the transmission of data, instructions, and information while a receiving device accepts the items transmitted. All types of computers and mobile devices serve as sending and receiving devices in a communications system. This includes mainframe computers, servers, desktop computers, notebook computers, Tablet PCs, smart phones, portable media players, and GPS receivers.

3. Describe uses of computer communications.

answer:

Computers can be instructed to perform a variety of individual functions. A set of instructions that tells a computer what to do is called a program. Today, more than 10,000 application programs are available for use on personal computers. They include such popular programs as word processing programs, spreadsheet programs, database programs, and communication programs.
Word processing programs are used to type, correct, rearrange, or delete text in letters, memos, reports, and school assignments. Spreadsheet programs enable individuals to prepare tables easily. The users of such programs establish rules for handling large groups of numbers. For example, using a spreadsheet program, a person can enter some numbers into a table and the program will calculate and fill in the rest of the table.

Spreadsheets may be used for preparing budgets and financial plans, balancing a cheque book, or keeping track of personal investments.
Database programs allow a computer to store large amounts of data (information) in a systematic way. Such data might include the name, address, telephone number, salary, and starting date of every employee in a company. The computer could then be asked to produce a list of all employees who receive a certain salary.  

Communication programs connect a personal computer to other computers. People can thereby exchange information with one another via their personal computers. In addition, communication programs enable people to link their personal computers with databanks. Databanks are huge collections of information stored in large centralized computers. News, financial and travel information, and other data of interest to many users can be obtained from a databank.

4. List advantages of using a network.

answer:

• share software
• share information with others on networks
• share peripherals
• speed of sharing software and information files
• cheaper than buying individual software and hardware for each standalone especially if for a school, network software often offers deals for amount being purchased
• security, files can be copy inhibit mode
• centralized software management- software being loaded onto one computer but also this loads software to entire network at one time
• electronic mail(e-mail) between network users, ideal for office memos
• flexible access- access you files from any computer on the network unlike standalone which would mean only being able to access your data from the one computer you uploaded data onto.

5. Differentiate among client/server, peer-to-peer, and P2P networks.

answer:  
client - server model => One or more computers act as server and other computers or clients access server.

The client–server model of computing is a distributed application structure that partitions tasks or workloads between the providers of a resource or service, called servers, and service requesters, called clients. A server machine is a host that is running one or more server programs which share their resources with clients. A client does not share any of its resources, but requests a server's content or service function. 

peer - to - peer (P2P) => Simple network that connects fewer than 10 computers.Each computer, or peer, has equal capabilities.

Peer-to-peer (P2P) computing or networking is a distributed application architecture that partitions tasks or workloads between peers.Peers make a portion of their resources, such as processing power, disk storage or network bandwidth, directly available to other network participants, without the need for central coordination by servers or stable hosts. Peers are both suppliers and consumers of resources, in contrast to the traditional client–server model where only servers supply (send), and clients consume (receive).

6. Describe the various network communications standards.

answer:

Network communication standards are certain rules and specifications framed by standard organisations for manufacturing network hardware and developing network software.

7. Explain the purpose of communications software.

answer:
The purpose of communication software is used to provide remote access to systems and is also    used to exchange messages in text, audio and video format for the purpose of communication. This software sends and receives data over telephone lines through modems. The communication software allows computers in different geographical regions to communicate with each other through terminal emulators, file transfer programs, chat and instant messaging programs.

• Programs that help users establish connection to Internet, other network, or another computer.

• Programs that help users manage transmission of data, instruction, and information.

• Programs that provide an interface for users to communicate with one another.

8. Describe various types of lines for communications over the telephone network.
answer: 

A telephone network is a telecommunications network used for telephone calls between two or more parties.

There are a number of different types of telephone network:

• A fixed line network where the telephones must be directly wired into a single telephone exchange. This is known as the public switched telephone network or PSTN.
• A wireless network where the telephones are mobile and can move around anywhere within the coverage area.
• A private network where a closed group of telephones are connected primarily to each other and use a gateway to reach the outside world. This is usually used inside companies and call centres and is called a private branch exchange (PBX).

9. Describe commonly used communications devices.
answer:

• A dial-up modem converts digital signals to analog signals and vice versa
• Usually in the form of an adapter card

                                                     DSL Modem / ISDN Modem-Cable Modem

• Send and receive digital data from DSL(Digital Subscriber Line) / ISDN

         

                                                              Cable Modem

•  Sends and receives data over cable television (CATV) network
•  Much faster than dial-up modem or ISDN
•  Sometimes called a broadband modem

                                                                  Wireless Modem

• Allows access to the Web wirelessly from a notebook computer, a smart phone, or other mobile device. 

                                                                  Hub or Switch

• Device that provides central point for cables in network. 

                                                                       Router

• Connects computers and transmits data to correct destination on network.

10. Discuss different ways to set up a home network.
answer: 
 A home network can be enabled in a Windows XP system through various ways.In wired connections, the user can enable the home network option through the use of various physical media. The computers should be connected through wires with the help of a router. A wireless connection can be established without any physical medium and thus the user can stay at any position within the wireless range. For wireless connections, wireless-enabled devices are required to connect the system to the network. Configuring a Virtual Private Network is another method that is used to set up or access a home network. Home network connections can also be enabled through local area connections.

11. Identify various physical and wireless transmission media.

answer:

Physical Wireless transmission media  =>  Wire, cable and other tangible materials used to send communication signals.Used when inconvenient, impractical or impossible to install cables. It includes Bluetooth and IrDA.