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ICTL NETWORKS Activity 1: (a)

Introduction to Networks

Networks Definition

A network consists of two or more computers that are linked in order to share resources (such as printers and CD-ROMs), exchange files, and allow electronic communications. The computers on a network may be linked through cables, telephone lines, radio waves, satellites or infrared light beams.

(b)

Benefits of Computer Networks

1. File Sharing - Network file sharing between computers gives you more flexibility rather than using floppy drives or Zip drives. you can use the network to save copies of your important data on a different computer, examples share photos, music files and documents. 2. Sharing Devices. Sharing devices is another benefit in which a network exceeds stand-alone computers. For example laser printers, fax machines, modems, scanners and CD-ROM players, when these peripherals are added to a network, they can be shared by many users. 3. Sharing Internet Access. In computer network, students can access the internet simultaneously. 4. Speed. Using a network is faster way for sharing and transferring files. Without a network, files are shared by copying them to floppy disk. 5. Cost. Networkable versions of many popular software programmes are available at considerable savings compared to buying individual licensed copies. Its easier upgrading of the program.

allows


6. Security. Files and programmes on a network are more secure as the users do not have to worry about illegal copying of programmes. Passwords can be applied for specific directories to restrict access to unauthorized users. 7. Centralized Software Management. One of the greatest benefits of installing a school network is the fact that all of the software can be loaded on one computer (the server). This saves time and energy when installing updates and tracking files. 8. Electronic Mail. A network that provides the hardware necessary to install an e-mail system. E-mail’s help in personal and professional communication for all school personnel as it enables the spread of general information to the entire school staff. Example, electronic mail on LAN (Local Area Network) enables students to communicate with teachers and peers at their own school when connected to the Internet, it enables users to communicate with others. 9. Flexible Access. School networks allow students to access their files from computers throughout the school. Some schools provide public access to students to begin an assignment in the computer lab and save then access the file when they are at a cyber cafÊ or home.

(c)

Devices Needed in Computer Networks.

Hub A central device that provides a common connection point for nodes on a network. Network Interface Card A NIC (network interface card) is a piece of computer hardware designed to allow computers to communicate over a computer network.


Router A device that forwards data packets along networks. A router is connected to at least, two networks, commonly two LANs or WANs or a LAN and its ISP’s network. Connector Short for Registered Jack-45, an eight-wire connector used commonly to connect computers onto a local-area network (LAN), especially Ethernets. RJ-45 connectors look similar to RJ-11 connectors used for connecting telephone equipment. Modem Short for modulator-demodulator. A modem is a device or program that enables a computer to transmit data over telephone or cable lines. Computer information are stored digitally, whereas information transmitted over telephone lines are transmitted in a form of analogue waves. A modem converts between these two forms. Activity 2:

(a)

Types of Computer Networks:

Local Area Network (LAN)

Local Area Network are groups of computers and network devices connected together, usually within the same building. The simplest form of LAN is to connect two computers together.


(b)

Metropolitan Area Network (MAN)

MAN is a network that interconnect users with computer resources in a geographic area or region larger than that covered by a local area network (LAN) but smaller than the area covered by wide area network (WAN)

(c)

Wide Area Network (WAN)

Wide Area Network is defined as a group of computers and network devices connected across a large physical areas such as states or countries. Computers connected to a Wide Area Network are often connected through the telephone system. They can also be connected through leased lines or satellites. The largest WAN in existence is the Internet.


Differences between Types of Computer Networks Criteria

LAN

MAN

WAN

Cost Network Size Speed Transmission

Low Small Fastest

High Larger Faster Twisted-Pair and

Higher Largest Fast Fibre-Optic, radio

Fibre-Optic

wave and satellite

Large

Largest

Media Type Number of computer

Activity 3:

(a)

Twisted-Pair Smallest

Types Of Network Topology :

Star Network

A star network is also known as star topology. A star network is designed with each node (file server, workstations, and peripherals) connected directly to a central network hub. The hub will control the flow of communication in the network. If one of the nodes fails, the star network will still function as long as the hub is working.

Nodes

Star Network


(b)

Ring Network

Ring network is also known as ring topology. A ring network consists of all computers and other devices that are connected in a loop. In a ring network, each node connects directly to the neighbouring nodes. If the device on a ring network fails, all the devices before the failed device are unaffected but those after the failed device will not function.

Ring Network (c)

Bus Network

A bus network is also known as a bus topology. A bus network consists of a single cable to which all the computers and other devices are connected. It must have a common backbone (the central cable) to connect all the devices. If one of the nodes fails, the bus network will still function.

Bus Network


Activity 4:

Current Technology in Computer Networks

(a) Wi-Fi

Official Wi-Fi logo Wi-Fi (wireless fidelity) is a set of standards that refers to the Wireless Local Area Network (WLAN) that applies IEEE 802.11 specification. Currently in Some of the advantages of using Wi-Fi are as follows: •

Simplicity. You can connect computers anywhere in your home or school without the use for wires. Computers connected to the network using radio signals and computers can be up to 30 meters or so apart.

Cost Wireless Networks are easy to set up and are inexpensive.

Easy Access

Wi-Fi supports 1roaming by moving your computers from one access

point to another as you move around a 2hot spot. Wi-Fi works like a two-way radio communication. A computer’s wireless adapter translates data into a radio signal and transmits it using an 3

antenna. A wireless router receives the signal and 4decodes it. It sends the information to the

internet using a physical, wired Ethernet connection. To receive the signal, the router will receive data from the Internet, translating it into a radio signal and sending it back to the wireless adapter.


(b) Bluetooth

Bluetooth logo

Bluetooth Headset

Bluetooth is a network standard, specifically a protocol that defines how two Bluetooth devices use short-range radio waves to transmit data. The data transfers between the devices at a rate of up to 2 Mbps. To communicate with each other, Bluetooth devices must be within 10 metres but can be extended to 100 metres with additional equipment. A Bluetooth device contains a small chip that allows it to communicate with another Bluetooth device. Examples of Bluetooth-enabled devices are desktop computers, notebook computers, handheld computers, PDAs, smart phones, headset, microphones, digital cameras, fax machines and printers.


For computers and devices that are not Bluetooth-enabled, you can purchase a Bluetooth wireless port adapter that will convert an existing USB port or serial port into a Bluetooth port. For example, Windows XP has a built-in Bluetooth support that allows users to easily configure Bluetooth communications. Are Wi-Fi and Bluetooth competing technologies? Bluetooth is designed for limited data transfer between two devices, one of which is usually a mobile device (e.g. a notebook computer and a printer, a digital camera and a desktop computer and between two PDAs). However Wi-Fi which supports data transfer at faster rates allow users to network many computers and devices together wirelessly.


SHARE DOCUMENT Activity 1 : Sharing a folder on the network Notes: This activity is only to show how to allow users to share a folder on the network.

1. Click Start then, click My Documents.

Click here

Figure 1 2. Right click the folder that you want to share then click Sharing and Security.

Click here

Figure 2


3. The Properties dialog box appears, tick Share this folder on the network and allow network users to change my files. Then click OK.

Tick here

Figure 3 4. Now you can see the difference between shared and unshared drive.

Unshared

Shared

Figure 4


Activity 2 : Receiving documents through LAN Notes: a. To achieve this activity, more than one computer in the network must be active at the same time. b. This activity can be done only if the person who will receive/transfer file or document enabled his/her folder sharing first. c. The example shown in this activity is different from your computer interface. You may use any suitable file or folder.

1. Right click on Start Menu, then click My Network Places as shown in Figure 1.

Figure 1


2. Double click on My Network Places as shown in Figure 2.

Figure 2 3. Click Microsoft Window Network then click workgroup to see entire computer. ( Figure 3 )


Figure 3 4. The following steps show how to copy a document from the computer named PC1. ( Figure 4 )

Double click here

Figure 4


5. Double click PC1. Then click BAHAN. ( Figure 5 )

Figure 5 6. Click document named Activity 1. ( Figure 6 )


Figure 6 7. Right click and choose copy

copy

Figure 7 8. Close the window.


9. The following step will show how to paste the copied file into your own folder. 10. Click on Start Menu, then click My Documents as shown in Figure 8.

Figure 8 11. Double click My Document. Right click folder TUGASAN then click open.

Figure 9


12. Right click anywhere in the folder, click Paste. ( Figure 10 )

Figure 10 13. Now you can see the document Activity 1 in the designated folder (Figure 11).


Figure 11 Activity 3 : Transferring documents through LAN Notes: a. More than one computer in the network must be active at the same time to achieve this activity. b. This activity can be done only if the person who will receive/transfer file or document enabled his/her folder sharing first. c. The example shown in this activity is different from your computer interface. You may use any suitable file or folder.

1. Right click on Start Menu then, click My Documents ( Figure 1 ).


Click here

Figure 1

2. Right click bill then click copy. Minimize the window.( Figure 2 )


Figure 2 3. Right click on Start Menu then, double click Explore . ( Figure 3 )

Figure 3


4. Click My Network Places . ( Figure 4 )

Figure 4 5. Double click folder BAHAN on PC1 (pc1). ( Figure 5 )

Click here


Figure 5 6. All the content inside folder BAHAN will be displayed. ( Figure 6 )

Figure 6 7. Right click anywhere in BAHAN folder, then click paste.


paste

Figure 7 8. Now bill file is displayed in the BAHAN folder.

Figure 8


noteict  

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