Quiz 7 Communications and Networks

1. Discuss the components required for successful communications.

Computer communications describes a process in which one computer transfers data, instructions and information to another computer or computers. Successful communications require a sending device that initiates an instruction to transmit data, instructions or information, a communications device that converts or formats the data, instructions or information from the sending device into signals carried by a communications channel, and a communications channel or path on which the signals travel. Also required are a communications device that receives signals from the communications channel and converts or formats them so the receiving device can understand the signals, and a receiving device that accepts the data, instructions or information.

2. Identify various sending and receiving devices.

A sending device initiates the transmission of data, instructions, and information while a receiving device accepts the items transmitted.

Microcomputers, minicomputers, and mainframes all can serve as sending and receiving devices.

Besides, Internet appliances and Web enabled handheld computers and devices (e.g. cellular telephones and pagers) can also serve sending and receiving devices.

3. Describe uses of computer communications.

Today most computers are capable (through either a phone line or a cable connection) of exchanging information over the Internet. Your child can send a message from his or her computer to the computer of a neighbor or a friend on the other side of the planet. Students might use computers to communicate with their classmates about homework assignments, group projects, or other school-related activities. They may also use them to submit homework assignments and presentations to their teachers.

4. List advantages of using a network.

A network is a collection of computers and devices connected by communications channels that facilitates communications among users and allows users to share resources with each other. Resources may include data, information, hardware and software.

By using a network, people can communicate efficiently and easily via email, instant messaging, chat rooms, telephony, videophone calls and videoconferencing. In a networked environment, each computer on the network can access and use hardware on the network, such as printers or scanners. Authorised computers on a network can also access data and information stored on other computers in the network. Users connected to a network can access software (programs) on the network.

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

Network architecture is the logical design of the components of a network, including the number and type of servers, workstations and network resources. It includes the communications devices and the type of physical transmission media used to connect components.

A peer-to-peer LAN is a simple, inexpensive network that typically connects less than 10 computers together. Each computer on a peer-to-peer network can share hardware (such as a printer), data or information located on any other computer in the network. Each computer stores files on its own storage devices, and contains both the network operating system and application software. Peer-to-peer networks are ideal for very small businesses and home users. Another use of peer-to-peer, called P2P, describes an Internet network that enables users with the same networking software to connect to each other's hard disks and exchange files directly.

A client/server LAN is a network in which one or more computers acts as a server and the other computers on the network can request services from the server. A server, sometimes called the host computer, controls access to the hardware and software on the network and provides a centralised storage area for programs, data and information. The other computers on the network, called clients, rely on the server for these resources. The major difference between the server computer and the client computer is that the server has more storage space and power. Dedicated servers perform a specific task - a file server stores and manages files, a print server manages printers and print jobs, a database server stores and provides access to a database and a network server manages network traffic. A client/server network provides an efficient means to connect 10 or more computers together, but can be used to connect a smaller number of computers. A network administrator is the operations person in charge of the network.

6. Describe the various network communications standards.

Network standards defines:

•  Way devices access the medium
•  Speed on different types of networks
•  Types of network technology (cable / wireless)

Protocols

•  Rules on how devices communicate with each other
•  Data format used
•  Coding Scheme
•  Error Handling
•  Sequencing techniques etc.
•  Hardware / Software Vendors try to meet these guidelines

ANSI, IEEE

Standardizing Organization

7. Explain the purpose of communications software.

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.

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

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.

Dial-up modem

• 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.

Setting up a home network

Before you start: To decide what type of network to set up or to find out what hardware and cables you need, see What you need to set up a home network. That topic has information about the different types of networks (also known as network technologies), as well as hardware requirements for each type.

Once you know what type of network you want and have the necessary hardware, there are four possible steps to take (two of these are not always required):

1.       Install any necessary hardware.

2.       Set up an Internet connection (optional).

3.       Connect the computers.

4.       Run the Set Up a Wireless Router or Access Point wizard (wireless only).

Each of these steps is described in detail later in this article.

Start by setting up one computer. Once you set up the network and you are sure that the first computer is working correctly, you can add additional computers or devices.

Install the hardware

Install network adapters in any computers that need them. (Follow the installation instructions in the information that came with each adapter.)

Set up or verify an Internet connection (optional)

You don't need an Internet connection to set up a network, although most people want to use their network to share an Internet connection. To set up an Internet connection, you need a cable or DSL modem and an account with an Internet service provider (ISP). Then open the Connect to the Internet wizard and follow the instructions.

If you already have an Internet connection, you just need to verify that the connection is working. To do that, open your web browser and go to a website that you don't usually visit. (If you go to a website that you visit often, some of its webpages might be stored on your computer and will display correctly even if your connection is faulty.) If the website opens and you don't get any error messages, your connection is working.

Connect the computers

There are several ways to connect computers—the configuration depends on the type of network adapters, modem, and Internet connection that you have. It also depends on whether or not you want to share an Internet connection among all the computers on the network. The following sections briefly describe some connection methods.

Turn on all computers or devices, such as printers, that you want to be part of your network. If your network is wired Ethernet or HPNA, it should be set up and ready to use. You should test your network (see below) to make sure that all computers and devices are connected correctly.

Run the Set Up a Wireless Router or Access Point wizard

If your network is wireless, run the Set up a Wireless Router or Access Point wizard on the computer attached to the router.

·         Open Set Up a Wireless Router or Access Point by clicking the Start button, clicking Control Panel, clicking Network and Internet, and then clicking Network and Sharing Center. In the left pane, click Set up a connection or network, and then click Set up a wireless router or access point.

The wizard will walk you through the process of adding other computers and devices to the network. For more information, see Add a device or computer to a network.

Test your network

It's a good idea to test your network to make sure that all of the computers and devices are connected and working properly. To test your network, do the following on each network computer: Click the Start button, and then click Network. You should be able to see icons for the computer you are on and all of the other computers and devices that you have added to the network. If the computer you are checking has a printer attached, the printer icon might not be visible on other computers until you enable printer sharing. (Printer sharing is not available on Windows Vista Starter.)

Changing TCP/IP settings

If you need to adjust TCP/IP settings for your network, see Change TCP/IP settings.

Connecting your mobile PC from work to your home network

To connect the mobile PC that you use at work to the Internet or to your work network from your home network, you must have a network connection set up at home. For information about using your mobile PC on your home network, see Switching between your home and workplace networks.

11. Identify various physical and wireless transmission media.