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Fundamentals of Computer Networks 2010 1 Table of Contents Introduction............................................................................................................................................. 3 Requirements: ......................................................................................................................................... 5 Question 1: .......................................................................................................................................... 5 Technology Involved: ........................................................................................................................... 5 Definition and usage: ....................................................................................................................... 5 Methods of high Internet Connection: .................................................................................................. 6 Type of Networks: ........................................................................................................................... 6 Cable, DSL, Satellite & Wireless Internet connection ........................................................................ 11 Cable: ............................................................................................................................................ 11 DSL:.............................................................................................................................................. 12 Type of DSL: ................................................................................................................................... 13 Advantages and disadvantages of DSL .............................................................................................. 15 Satellite connection:....................................................................................................................... 16 Wireless Internet: ........................................................................................................................... 17 Advantages of Wi-Fi:..................................................................................................................... 18 Question 2: ............................................................................................................................................ 20 Access Speed:.................................................................................................................................... 20 Advantages........................................................................................................................................ 21 Disadvantages ................................................................................................................................... 21 Suitability.......................................................................................................................................... 21 ISDN................................................................................................................................................. 21 -Advantages................................................................................................................................... 22 -Disadvantages .............................................................................................................................. 22 Suitability: ..................................................................................................................................... 22 DSL or Broadband............................................................................................................................. 23 DSL comes in two forms: .............................................................................................................. 23 Advantages .................................................................................................................................... 23 Disadvantages................................................................................................................................ 23 Suitability ...................................................................................................................................... 24

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Fundamentals of Computer Networks

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  • 1. Fundamentals of Computer Networks 2010 Table of Contents Introduction............................................................................................................................................. 3 Requirements: ......................................................................................................................................... 5 Question 1: .......................................................................................................................................... 5 Technology Involved: ........................................................................................................................... 5 Definition and usage: ....................................................................................................................... 5 Methods of high Internet Connection: .................................................................................................. 6 Type of Networks: ........................................................................................................................... 6 Cable, DSL, Satellite & Wireless Internet connection ........................................................................ 11 Cable: ............................................................................................................................................ 11 DSL:.............................................................................................................................................. 12 Type of DSL: ................................................................................................................................... 13 Advantages and disadvantages of DSL .............................................................................................. 15 Satellite connection:....................................................................................................................... 16 Wireless Internet: ........................................................................................................................... 17 Advantages of Wi-Fi:..................................................................................................................... 18 Question 2: ............................................................................................................................................ 20 Access Speed:.................................................................................................................................... 20 Advantages........................................................................................................................................ 21 Disadvantages ................................................................................................................................... 21 Suitability .......................................................................................................................................... 21 ISDN ................................................................................................................................................. 21 -Advantages................................................................................................................................... 22 -Disadvantages .............................................................................................................................. 22 Suitability: ..................................................................................................................................... 22 DSL or Broadband............................................................................................................................. 23 DSL comes in two forms: .............................................................................................................. 23 Advantages .................................................................................................................................... 23 Disadvantages................................................................................................................................ 23 Suitability ...................................................................................................................................... 24 1
  • 2. Fundamentals of Computer Networks 2010 The best service that provides the best service:................................................................................... 24 Question 3 ............................................................................................................................................. 25 The bright side of Wi-Fi Technology ................................................................................................... 25 The bad side of WI-Fi Technology..................................................................................................... 26 Question 4 ............................................................................................................................................. 27 Environment: ..................................................................................................................................... 27 Client devices: ................................................................................................................................... 27 Hardware Requirements .................................................................................................................... 27 Minimum Hardware Requirements ................................................................................................ 28 Minimum Software Requirements:................................................................................................. 29 Security: ........................................................................................................................................ 29 Cost: .............................................................................................................................................. 30 Question 5 ............................................................................................................................................. 31 DSL safety and security: .................................................................................................................... 31 Regulation: ........................................................................................................................................ 31 Question 6 ............................................................................................................................................. 32 Question 7 ............................................................................................................................................. 33 Advantages and disadvantages of Wi-Fi............................................................................................. 33 Question 8 ............................................................................................................................................. 35 Conclusion: ........................................................................................................................................... 36 Reference: ............................................................................................................................................. 37 2
  • 3. Fundamentals of Computer Networks 2010 Introduction Is a computer network, mostly get back or referred as a network, it contain a lot of computers, devices connect together through a channels that simplification the connection between the users, and allow to share data or information with users. Networks may be classified according to a wide variety of characteristics. Network nowadays can provide to the people many and more things that can be useful to the whole world like sharing information specific details and business and this kind of network can be easily to use and work with, later we will explain to people how can implement a network . A computer network allows sharing of resources and information among devices connected to the network. The Advanced Research Projects Agency ARPA funded the design of the Advanced Research Projects Agency Network ARPANET for the United States Department of Defense. It was the first operational computer network in the world. Development of the network began in 1969, based on designs developed during the 1960s. For a history see ARPANET, the first network. Purpose: Facilitating communications. Using a network, people can communicate efficiently and easily via e-mail, instant messaging, chat rooms, telephony, video telephone calls, and video conferencing. Sharing hardware. In a networked environment, each computer on a network can access and use hardware on the network. Suppose several personal computers on a network each require the use of a laser printer. If the personal computers and a laser printer are connected to a network, each user can then access the laser printer on the network, as they need it. 3
  • 4. Fundamentals of Computer Networks 2010 Sharing files, data, and information. In a network environment, any authorized user can access data and information stored on other computers on the network. The capability of providing access to data and information on shared storage devices is an important feature of many networks. Sharing software. Users connected to a network can access application programs on the network. 4
  • 5. Fundamentals of Computer Networks 2010 Requirements: Question 1: Describe the technology involved, giving a clear indication of methods of high-speed Internet access that is available. Technology Involved: Definition and usage: The phrase technology derive from a Latina word is originally contain 2 words the first word is techno that is mean ART or ACCOPATION second the LOGY which mean STUDY or SCIENC. Hence the expression of Technology means or applies for Scientific and knowledge in every field. There are two reasons to follow scientific knowledge: for the sake of the knowledge itself and for the practical uses of that knowledge. Because this second aspect of science affects the lives of most people, it is more familiar than the first. Knowledge must be gained, however, before it can be applied, and often the most important technological advances arise from research pursued for its own sake. Traditionally, new technology has been concerned with the construction of machines, structures, and tools on a relatively large scale. The development of materials for building bridges or skyscrapers is an example of this, as is the development of the internal-combustion engine and the nuclear reactor. While such activities involve all the sciences, from chemistry to nuclear physics, the overriding goal has been the same to improve the human condition by finding better ways to deal with the macroscopic world. Figure 1: things that related to human technology 5
  • 6. Fundamentals of Computer Networks 2010 The dividing line between what we include in the following list as technology and what we call science elsewhere in this volume is somewhat arbitrary. In general, what we have done is this: if a term is essential to understanding a particular branch of science, it appears in the list for that science. Thus, atom appears with the physical sciences, even though an understanding of atoms is clearly important to the new technology. If, however, the term involves something that is likely to affect an individual's life, even though it is not a central concept of a particular branch of science, it is listed under Technology. Methods of high Internet Connection: Type of Networks: Local-Area networks (LANs): The computers are geographically close together that is, in the same building. A computer network that spans a relatively small area. Most LANs are confined to a single building or group of buildings. However, one LAN can be connected to other LANs over any distance via telephone lines and radio waves. A system of LANs connected in this way is called a wide-area network WAN. Most LANs connect workstations and personal computers. Each node individual computer in a LAN has its own CPU with which it executes programs, but it also is able to access data and devices anywhere on the LAN. This means that many users can share expensive devices, such as laser printers, as well as data. Users can also use the LAN to communicate with each other, by sending e-mail or engaging in chat sessions. Figure 2: Local-area networks (LANs) 6
  • 7. Fundamentals of Computer Networks 2010 Wide-area networks (WANs): The computers are farther apart and are connected by telephone lines or radio waves. A computer network that spans a relatively large geographical area. Typically, a WAN consists of two or more local-area networks LANs. Computers connected to a wide-area network are often connected through public networks, such as the telephone system. They can also be connected through leased lines or satellites. The largest WAN in existence is the Internet. Figure 3: Wide-area networks (WANs) 7
  • 8. Fundamentals of Computer Networks 2010 Campus-Area networks (CANs): The computers are within a limited geographic area, such as a campus or military base. Acronym for campus-area network. An interconnection of local-area networks within a limited geographical space, such as a school campus or a military base. Figure 4: Campus-area networks (CANs) 8
  • 9. Fundamentals of Computer Networks 2010 Metropolitan-area networks (MANs): A data network designed for a town or city. Short for Metropolitan Area Network, a data network designed for a town or city. In terms of geographic breadth, MANs are larger than localarea networks LANs, but smaller than wide-area networks WANs. MANs are usually characterized by very high-speed connections using fiber optical cable or other digital media. Figure 5: Metropolitan-area networks (MANs) 9
  • 10. Fundamentals of Computer Networks 2010 Home-area networks (HANs): A network contained within a user's home that connects a person's digital devices. Short for home area network. A HAN is a network contained within a user's home that connects a person's digital devices, from multiple computers and their peripheral devices to telephones, VCRs, televisions, video games, home security systems, smart appliances, fax machines and other digital devices that are wired into the network. Figure 6: Home-area networks (HANs) 10
  • 11. Fundamentals of Computer Networks 2010 Cable, DSL, Satellite & Wireless Internet connection Cable: A cable modem is a device that enables you to hook up your PC to a local cable TV line and receive data at about 1.5 Mbps. This data rate far exceeds that of the prevalent 28.8 and 56 Kbps telephone modems and the up to 128 Kbps of Integrated Services Digital Network ISDN and is about the data rate available to subscribers of Digital Subscriber Line DSL telephone service. A cable modem can be added to or integrated with a set-top box that provides your TV set with channels for Internet access. In most cases, cable modems are furnished as part of the cable access service and are not purchased directly and installed by the subscriber. A cable modem has two connections: one to the cable wall outlet and the other to a PC or to a set-top box for a TV set. Although a cable modem does modulation between analog and digital signals, it is a much more complex device than a telephone modem. It can be an external device or it can be integrated within a computer or set-top box. Typically, the cable modem attaches to a standard 10BASE-T Ethernet card in the computer. All of the cable modems attached to a cable TV company coaxial cable line communicate with a Cable Modem Termination System CMTS at the local cable TV company office. All cable modems can receive from and send signals only to the CMTS, but not to other cable modems on the line. Some services have the upstream signals returned by telephone rather than cable, in which case the cable modem is known as a Telco-return cable modem. The actual bandwidth for Internet service over a cable TV line is up to 27 Mbps on the download path to the subscriber with about 2.5 Mbps of bandwidth for interactive responses in the other direction. However, since the local provider may not be connected to the Internet on a line faster than a T-carrier system at 1.5 Mpbs, a more likely data rate will be close to 1.5 Mpbs. 11
  • 12. Fundamentals of Computer Networks 2010 DSL: Digital Subscriber Line DSL is a family of technologies that provides digital data transmission over the wires of a local telephone network. DSL originally stood for digital subscriber loop. In telecommunications marketing, the term Digital Subscriber Line is widely understood to mean Asymmetric Digital Subscriber Line ADSL, the most commonly installed technical varieties of DSL. DSL service is delivered simultaneously with regular telephone on the same telephone line as it uses a higher frequency band that is separated by filtering. The data throughput of consumer DSL services typically ranges from 384 KB/s to 20 MB/s in the direction to the customer, depending on DSL technology, line conditions, and service-level implementation. Typically, the data throughput in the reverse direction, i.e. in the direction to the service provider is lower, hence the designation of asymmetric service, but the two are equal for the Symmetric Digital Subscriber Line SDSL service. Figure 7: Kind of DSL 12
  • 13. Fundamentals of Computer Networks 2010 Type of DSL: ADSL: ADSL uses standard telephone lines to transmit upstream and downstream data on a digital frequency, which sets these data streams apart from the analog signals telephones and fax machines use. Because the ADSL signal is operating on a different frequency, the telephone can be used normally, even when surfing the Web with ADSL service. The only requirement will probably be inexpensive DSL filters on each phone or fax line, to remove any white noise on the line that might be generated from ADSL service. The asymmetric in ADSL refers to the fact that the downstream data rate, or the data coming to your computer from the Internet, is traveling faster than upstream data, or the data traveling from your computer to the Internet. Upstream data rates are slower because Web page requests are fairly miniscule data strings that do not require much bandwidth to handle efficiently. HDSL: High bit-rate Digital Subscriber Line, one of the earliest forms of DSL, is used for wideband digital transmission within a corporate site and between the telephone company and a customer. The main characteristic of HDSL is that it is symmetrical: an equal amount of bandwidth is available in both directions. HDSL can carry as much on a single wire of twistedpair cable as can be carried on a T1 line up to 1.544 Mbps in North America or an E1 line up to 2.048 Mbps in Europe over a somewhat longer range and is considered an alternative to a T1 or E1 connection. 13
  • 14. Fundamentals of Computer Networks 2010 IDSL: IDSL is a system in which digital data is transmitted at 128 Kbps on a regular copper telephone line twisted pair from a user to a destination using digital rather than analog or voice transmission, bypassing the telephone company's central office equipment that handles analog signals. IDSL uses the Integrated Services Digital Network Integrated Services Digital Network Basic Rate Interface in ISDN transmission code. IDSL is a technology developed by Ascend Communications now part of Lucent Technologies. IDSL is only one possible technology in the Digital Subscriber Line approach of which Asymmetric Digital Subscriber Line or Asymmetric Digital Subscriber Line is best known and an expedient approach that allows use of existing ISDN card technology for data-only use. The differences between IDSL and ISDN are: ISDN passes through the phone company's central office voice network; IDSL bypasses it by plugging into a special router at the phone company end. ISDN requires call setup; IDSL is a dedicated service. ISDN may involve per-call fees; IDSL may be billed at a flat rate with no usage charges. VDSL: Very High Speed Digital Subscriber Line transmits data in the 13 Mbps - 55 Mbps range over short distances, usually between 1000 and 4500 feet 300 - 1500 meters, of twisted pair copper wire. The shorter the distance, the faster the connection rate. As the final length of cable into the home or office, VDSL connects to neighborhood Optical Network Units ONUs, which connects to the central office's main fiber network backbone. This architecture will allow VDSL users to access the maximum bandwidth available through normal phone lines. 14
  • 15. Fundamentals of Computer Networks 2010 VDSL is currently going through a standards issue, so it isn't widely deployed yet. The VDSL alliance favors a line coding scheme based on Discrete Multitone DMT, a multi-carrier system that is more compatible with existing ADSL technology. The VDSL coalition favors a line coding scheme based on Quadature Amplitude Modulation QAM, a single-carrier system that is less expensive and consumes less power. Advantages and disadvantages of DSL Advantages: Sometimes we are always online and can still use the phone line for usual calls. Your Internet rate is much faster than an ordinary modem 1.5 Mbps vs. 56 Kbps. Mainly DSL installation does not need new wiring, so it uses your vacant phone line. It is Up to 25x Times faster than the Dial-up Modem. The Cost efficient. No eventful Signals. No Dropped links. Faster to downloads documents. Games are faster to engage in recreation it online. Devoted Connection & Speed. 15
  • 16. Fundamentals of Computer Networks 2010 Disadvantages: The DSL connection it works faster if you are existing closer to provider central office. Data being received is faster than data being sent over the Internet. DSL accessibility is limited to certain cities, not each person can get this service. -Access: Is the most service for using the inter connection for private users and can be use for the villatic places where cable or DSL is not available there and cant be implement. And more over satellite is the best connection for these kinds of places. Satellite connection: Satellite connection cannot be work by phone line or cable other by dish. The computer is connecting to a satellite modem which is correlated to the satellite dish antenna and can be accusatively on the home roof. When you browse a webpage, your request is sent to the satellite. The satellite then transmits a signal to the operation center of satellite internet provider. The webpage information is then beamed back to your computer through the same path. Figure 8: Type of Satellite Figure 9: How Satellite Works 16
  • 17. Fundamentals of Computer Networks 2010 Advantages of Satellite Internet Access: High speed internet access in rural / remote areas where cable and DSL are not available. Does not tie up with local phone service or cable TV subscription. Connection speed is not affected by phone or cable wiring. Disadvantages of Satellite Internet Access: More expensive than DSL and cable. Large setup fee. Expensive equipment upfront. Has to be set up by trained technician. Short delay of signal transmission may affect real time applications. Fair access policy limits the ability to download large files in reasonable amount of time. Connection speed is slower than DSL and cable. Wireless Internet: Wireless networks utilize radio waves and/or microwaves to maintain communication channels between computers. Wireless networking is a more modern alternative to wired networking that relies on copper and/or fiber optic cabling between network devices. Wireless is rapidly gaining in popularity for both home and business networking. Wireless technology continues to improve, and the cost of wireless products continues to decrease. Popular wireless local area networking WLAN products conform to the 802.11 Wi-Fi standards. The gear a person needs to build wireless networks include network adapters NICs, access points APs, and routers. 17
  • 18. Fundamentals of Computer Networks 2010 Advantages of Wi-Fi: Flexible Working: Access the Internet, do File Transfers, even Print from anywhere within 100 meters of the Wi-Fi Access Point. Reduce Cable Clutter: Reduce the clutter of wires and cables behind your Desktop/ Notebook. Reduce Setup Cost: If you are setting up a new office, you can reduce the IT setup cost by implementing Wi-Fi - you can save the cost of cabling and the cost on Network sockets. Avoid Deterioration with Time: Network Cables and Sockets tend to deteriorate over time, while Wi-Fi does not have this disadvantage. Eliminate Re-configuring Computers: If you have more than one office location and your staff travel between offices, installing Wi-Fi Networks at each location makes good sense. Your staff can then access the Internet and Network at all locations, without having to re-configure their Internet settings each time. 18
  • 19. Fundamentals of Computer Networks 2010 Disadvantages of Wi-Fi: Password and Security: It is important to secure your Wi-Fi connection at home or the office. Otherwise, anyone with a Wi-Fi-enabled computer can access your data and Internet connection Password-protecting your Wi-Fi connection is an easy process and once you set up all your Computers and devices to access your Wi-Fi network, you do not need to type in passwords each time thereafter. Signal Strength Sensitivity: Wi-Fi Networks are sensitive to signal strength. To ensure good connectivity, you must ensure that all computers and gadgets receive adequate signal strength at all times. Effect of Climatic Conditions: Wi-Fi signals are likely to be adversely affected by climatic conditions such as thunderstorms. Figure 10: DSL Modem Increased number of Network Devices: You are increasing the number of devices on your Network, by incorporating a Wi-Fi Access point this is a must, for Wi-Fi access. Also, you will need a power socket to plug in and power the Wi-Fi Access Point. 19
  • 20. Fundamentals of Computer Networks 2010 Question 2: Which service provides the best service? Which is the cheapest? Justify your answer. Today an Internet connection is essential not only for surfing the Internet but for email, music and video downloads and also for uploading content to your website. Here we will look at how to choose an Internet connection that's right for your needs. An Internet connection is provided by an ISP Internet service provider. There are many ISPs to choose from and a number of different connection methods. When choosing your internet connection you need to take into account: Access speed Access type Always on - broadband, cable and wireless Access Speed: This varies from 28kbits/sec dial up to 4000 Kbits/sec cable broadband. If you are just viewing web pages then 28k is acceptable for downloading or uploading large files like video, music or pictures then it will be very slow and you need to consider alternatives. With an always on connection broadband/cable the connection is always established and it never disconnects. This means that an email sent to you arrives straight in your inbox without you having to connect to the Internet and check. Not only does such a connection provide instant access, it is also faster and easier to share with a large group of users. I do however mean that your computer/network is permanently exposed to the Internet and you need to take extra precautions. Dial-Up Analogue Connection -56K Monthly Cost: Varies from 1p per minute to 60RM per month unlimited access. Speed: Up to 56Kbps Hardware Requirements: 56k modem included in most modern PCs approx. 106-215RM. 20
  • 21. Fundamentals of Computer Networks 2010 Advantages Inexpensive. Wide availability. Disadvantages Using a modem ties up a phone line. Connection is not always on. Slowest access method. Suitability Basic Internet browsing and email. Not suitable if regularly downloading or uploading large files like music, video or pictures. If your web site is mainly text based then this type of connection is ok. If you have a music Website or similar and need to make music files available then you first need to upload them to the Internet, then this type of connection is not suitable. ISDN Similar to dial-up, ISDN establishes a connection to your service provider when you access the Internet. However, ISDN circuits are 64-128K and fully digital. ISDN is not easy to install and troubleshoot and requires you to have an ISDN box installed by your telephone company. It is frequently used by small businesses as in addition to the ISDN line you can also use a normal telephone line at the same time. This means you can access the Internet as well as talking on the telephone. Monthly Cost: As Analogue dial up. Speed: 64Kbps - 128Kbps. Hardware Requirements: ISDN card 30-190 RM or router 200-300. 21
  • 22. Fundamentals of Computer Networks 2010 -Advantages Lets you talk and surf simultaneously. Faster than 56kbps analogue. Suitable for attaching more than 1 PC to the Internet 2-6 light users. -Disadvantages Difficult to setup. Available only in limited areas. Requires special termination equipment to be fitted by the telecom company at both ends of the telephone line. Outdated being replaced by DSL. Not practical for more than 6 computers depending on usage. Suitability: Basic Internet browsing and email and connection sharing. Not suitable if regularly downloading or uploading very large files like music, video or pictures. If your web site is mainly text based then this type of connection is ok. If you have a music Website and need to make many music files available then you first need to upload them to the Internet, then this type of connection is not suitable. Cable Cable connects you to the Internet through a coaxial cable usually using the same line as your TV service. Cable connections offer very high connection speeds, 1 to 4 Mbps, but the connection may be shared with other users. This means that you can experience much slower speeds due to congestion. Hardware Requirements: Cable Modem Usually included. If you have multiple computers then you might need cable router to share connection. Speed: 500 Kbps to 2 Mbps. 22
  • 23. Fundamentals of Computer Networks 2010 DSL or Broadband DSL Digital Subscriber Line Broadband is a relatively new technology, which brings high connection speeds to normal analogue telephone users. It is basically the telecom answer to cable. DSL comes in two forms: Asymmetrical Digital Subscriber Line ADSL provides different upload and download speeds most common. Symmetrical Digital Subscriber Line SDSL provides the same speed in both directions Monthly Cost: Starts at approx. Speed: 128Kbps - 1Mbps Hardware Requirements: DSL modem often included. If you want to connect multiple computers: one DSL router. Advantages Always on connection. Can use a telephone and Internet simultaneously. Wide variety of speeds and prices. Large choice of service providers ISPs. Disadvantages Available only in limited areas Speed vary widely Some providers have monthly download limits1GB per month is typical. Requires special termination equipment to be fitted by the telecom company at both ends of the telephone line. Exposes computer to Internet so you need to install firewall software. Windows XP has a built in firewall. 23
  • 24. Fundamentals of Computer Networks 2010 Suitability Broadband is suitable for very heavy Internet users and multiple computers small office or home network. If you regularly download or upload large files like music, video or pictures then this type of connection is the one you need. The best service that provides the best service: So, from all the details that mention upper can say that the all types of service got positive and negative points. But the best service that users can use is the DSL because is more faster and can be named under the high-speed category than the other connection, easy to call while using the internet, and much cheaper and available that can find it in MALAYSIA and the other thing about the DSL is easy and cheaper for implement in many places such as houses, buildings, offices, hospitals, universities, government buildings, and even under the ground. That what gives DSL the ability to be the best service that can be providing fast, secure, cheap, and easy connection for many users to use. 24
  • 25. Fundamentals of Computer Networks 2010 Question 3 Describe with examples the importance of Wi-Fi technology (i.e. how the technology has or will affect human beings at work and social life). WIFI gives you an extremely large amount of freedom because you can basically use it from anywhere. From your couch to your local shopping mall, wireless reliability can always lend a helping hand. Also, WIFI is not restricted to certain groups. No matter who you are, you can use it. WIFI is fast, reliable, and easy to use. Wireless Fidelity is important to the wireless LAN world, because it is securely tested to assure ability of equipment of the same frequency band and feature. The bright side of Wi-Fi Technology Technology with its rapid growing speed is influencing old ways of doing daily affairs. We don't need any more to move around to handle different tasks and chores since all of them will be done in a matter of pushing a button located on a remote control. Nobody can deny that technology has brought comfort to our lives, but almost all of us confess this fact that technology by itself has got a lot of deficits that in long term will cause a lot of side effects either physically or emotionally. This is a fact that through the multi-media and the wide spread range of webs Internet the concept of time and distance have been vanished and people can keep in touch with each other by means of such facilities. The negative view is the fact that they keep in touch in a virtual world not natural. Via the webs and mail the emotional feelings and thoughts cant be transferred. People can convey their attitudes and thoughts much more effectively when they are close to each other. 25
  • 26. Fundamentals of Computer Networks 2010 The bad side of WI-Fi Technology One bad effect of technology on life is that with more technology placing barriers between people, face to face meetings happen less. This small, simple change leads to a whole host of very serious problems with society in general. People are becoming lazier; choosing to stay at home and play video games than go to a basketball game or get together with friends. On top of that, the new barriers that are made because of technology gives those who are most affected by them a decaying sense of pride in their country. In fact, it is this lack of pride that has spurred many of the anti-American feelings that are felt and publicized by people of this very country. Not all technology is bad or evil, but we do need to be careful that we don't become slaves meaning obsessed with, not actual slaves to our own creations. Newspapers and local agencies and music stores have been forced to shut down since items are available online. 26
  • 27. Fundamentals of Computer Networks 2010 Question 4 Describe the criteria required for the successful implementation of the Wi-Fi technology (i.e. the basic requirements such as hardware, software, skills, cost, etc.). Environment: Provide a description of the environment where the wireless network will operate. For buildings, include the floor plan, type of construction, and possible locations for mounting access points. For outdoor areas, include satellite images, aerial photographs, or drawings. Walk through the areas to verify accuracy of these items. Take lots of photos. In addition to a visible inspection, consider performing an RF site survey. All of this will capture the environment in a way that will help designers choose the right technical elements. Client devices: You should specify the client devices and existing client radios to ensure the solution accommodates them in the most effective manner. For example, you could specify that users will have laptops running Microsoft Vista with integrated 802.11b/g radios. This provides a basis for deciding on the type of client radios to specify for other client devices during the design and whether theres a need to support legacy devices 802.11b/g. Hardware Requirements If you simply want to connect your laptop to someone else's 802.11b network, you will need only client card and driver software at this point, compatible cards cost between 95rm and 319rm. Like most equipment, the price typically goes up with added features, such as an external antenna connector, higher output power, a more sensitive radio, and the usual bells and whistles. Once you select a card, find out what the network settings are for the network you want to connect to and hop on. If you need more range, a small Omni directional antenna typically 160RM-319RM can significantly extend the roaming range of your laptop. 27
  • 28. Fundamentals of Computer Networks 2010 Minimum Hardware Requirements Wireless routers are network routers that can join several wireless networks together and also works as a wireless access point. The most common routers are DSL or cable modem broadband routers, which connect the local home networks to the internet. Significance: Wireless routers are useful tools for homes and businesses. They are popular, in large part, because of the issues that having a large amount of cables can provide. They are relatively inexpensive and can be easy to configure, which only adds to their popularity. Function: Wireless routers can easily connect computers sharing a network. All that is required for wireless routers to work is a network and wireless network adapter cards for the computers. After the wireless router is installed, the wireless adapter card picks up on the access point and allows the computer to connect to that network. Types: There are different types of wireless routers. Routers have different frequencies, including Wireless-B, which has a maximum raw data of 11 Mbits/s; Wireless-A and -G, which both have a maximum raw data rate of 54 Mbits/s, but operate on different frequency bands; and Wireless-N, which has a maximum raw data rate of 300 Mbits/s. Benefits: Due to the lack of wires, wireless routers can easily connect several computers without the fear of tangled wires, giving the user more freedom. Furthermore, holes are often drilled in walls and floors to connect the wires from a computer to a wired router, which is a hassle that isn't necessary for wireless routers. 28
  • 29. Fundamentals of Computer Networks 2010 Warning: Although wireless routers provide users with the freedom to move, the signal fades the farther away the user travels from the router. Also, wireless routers aren't as secure as wired routers, since any individual with a wireless network adapter can connect to the access point. 1.0 GHz CPU. 256 MB RAM. 20 GB hard drive. 24X CDROM reader. 14 XGA color LCD display. 1024 x 768 pixel resolution. VGA output to drive LCD projectors, monitors, displays. 10/100 - base -T Ethernet, for network/Internet access. Minimum Software Requirements: Microsoft Windows XP SP2 operating system. Microsoft Internet Explorer v6.0. Antivirus software up to date virus definitions. Firewall software. Security: Describe the sensitivity of the information that will traverse the wireless network. If possible, cite existing corporate wireless security policies. Youll likely need to require encryption and authentication of all client devices. Be sure to give security requirements plenty of thought so that you design a solution that will protect the companys valuable resources. 29
  • 30. Fundamentals of Computer Networks 2010 Cost: The price of set up wireless network depending on the category of design what the user want and the range of the area what like to cover. Wireless network less costly way to access internet than cell phone network. Set up wireless association it almost require router and wireless card for desktop barely, but the notebook need the wireless card because the notebook that already has. This is the major important the user need to purchase it. For that reason if the user wants to expand the range of wireless network, than he needs to buy range extender. According to computers shops the price for router and wireless card is not crossing than 500RM, the wireless card 100-200 RM and the typical router around 100-25 RM. 30
  • 31. Fundamentals of Computer Networks 2010 Question 5 -Describe under what circumstances the technology can be implemented i.e. any special considerations or pre-requisites such as safety, security, regulation, etc. DSL safety and security: DSL wire safety got a lot of arrangement to do before using the connection itself and these are: The users have to be aware to make the wire apparent to everyone or bare to the sun light. The DSL wire must be cover with certain warp and not to be bare to any kind of factor denudation. The most important point in safety is that user has to be very organized with the wire to be cling on the wall if the wire is coming from far access point. For a small office with a network, the most effective and easily maintained solution is to use unroutable private IP addresses within the network and access the Internet through a masq, or NAT router. The users can get the Internet service by simply plugging into a network jack provided by the office building's Internet service; they may be providing a private IP address that provides good protection except from people in the same building. There are certain programs can protect the network and this kind of program like the firewall and its especially for the DSL can protect and make the line secured as well. Regulation: Line can continue even in the presence for the DSL signals. These asymmetric data rates are suitable for switched video. Home entertainment and internet browsing application, making ADSL the target product for the residential and home worker market segments and the most widespread flavor of DSL. For more information about the regulation you can visit this website and the link is below: http://books.google.com.my/books?id=G9v6u9weUNgC&pg=PA159&dq=Digital+Subscriber+L ine+regulation&hl=en&ei=bTDLSqmMs6vrAey9LHaCw&sa=X&oi=book_result&ct=result&resnum=2&ved=0CDwQ6AEwAQ# v=onepage&q=Digital%20Subscriber%20Line%20regulation&f=false 31
  • 32. Fundamentals of Computer Networks 2010 Question 6 -Describe where such technology is best suited for implementation (i.e. for specific industry and locality). The best technology can be suited and implement in the industry places will be the DSL connection because its fast and cheap to apply it. And the DSL can be connect to specific place in the industry places because there will be a problem while implement the DSL inside the factory or working place so, the perfect idea is to apply the DSL wires to specific points inside the industry like to the main offices and head section then from that point we can use another type of network like Wi-Fi because some of the experts need to use the internet for some experiments during their work. Unlike the locality the implement of the DSL will easy to apply inside the buildings because with the basic of the structure of the building the implement of the DSL will be easier to apply in different ways and will be more secure and safety. The most useful thing in DSL in the building especially in company that its too fast to share information and files between each other and can create a private network using only by the company. For the home use the DSL is furthermore great because its cheap to buy and easy to apply and popular in the whole world and become a very public. The problem that might face the DSL connection in the industry is the factory or building which is not for employers and not organize well, sometime the DSL network need to setup very well because if there is a problem in send or receiving data the technical can found the damage point very fast by making a sign after each point or length thats make fixing the DSL not that hard. Figure 11: Industry Figure 11: Locality 32
  • 33. Fundamentals of Computer Networks 2010 Question 7 -Describe the advantages / strengths for implementing Wi-Fi technology. -Describe the disadvantages / problems for implementing Wi-Fi technology. Advantages and disadvantages of Wi-Fi Advantages: Wi-Fi products are extensively available in the market. There are different brands of access points and user's network interfaces are able to inter-operate at a very basic service level. The users in Wi-Fi unlicensed radio spectrum and they are not require regulatory approval for individual department. The local area network to be setup with cabling. Prices are considerably lower as competition amongst vendors' increases. Wi-Fi networks can support roaming. This allows mobile users with laptop computer to be able to move from one access point to another. Wi-Fi has a set of global standards, it is not like the cellular but the users can work in different countries around the world at the same time. Disadvantages: The spectrum assignments and operational limitations are not consistent worldwide. Power consumption is fairly high compared to some other standards, making the battery life and heat a concern to some users. Wi-Fi uses the unlicensed 2.4GHz spectrum, which often crowded with other devices such as Bluetooth, microwave ovens, cordless phones, or video sender devices, and among many others. This may cause degradation in performance. Wi-Fi networks have limited range. A typical Wi-Fi home router might have a range of 45m 150ft indoors and 90m 300ft outdoors. Ranges may also vary as Wi-Fi is no exception to the physics of radio wave propagation with frequency band. 33
  • 34. Fundamentals of Computer Networks 2010 The most common wireless encryption standard, wired equivalent privacy or WEP has been shown to be breakable even when it has been correctly configured. Access points could be used to steal personal and confidential information transmitted from Wi-Fi consumers. Intervention of a closed or encrypted access point with other open access points on the same or a nearby channel can prevent access to the open access points by others in the area. It poses a high problem in high-density areas such as large apartment blocks where many residents are operating Wi-Fi access points 34
  • 35. Fundamentals of Computer Networks 2010 Question 8 Based on the information you gather, write a plan for subscribing to a high-speed Internet connection service using relevant diagrams, figures and provide a simple illustration of the implementation of the chosen standard. This figure or diagram below show to the user or person how the network connection build by the formal way. As you can see in the diagram below the main line its comes from the main server building which provide the internet service, inside the main building there is a server which offer the line which is the server next point will be the central office public phone network between this two build the user can see that there is a ATM Switch Asynchronous Transfer Mode, after this two main points the line will be going to the home or to the destination point inside the destination point there must be a splitter which can equip two line in the home one is for the phone as shown below and the other for the modem. Main building ATM Switch Phone building Server Destination Splitter DSL Modem HUB 35
  • 36. Fundamentals of Computer Networks 2010 In this condition the user can choose the wireless modem to offer a wireless connection network inside the home and for laptops or desktop which got wireless card, and there is another way if the desktop pc doesnt have wireless card the user can apply a HUB to connect a LAN network to the desktop pc as show below as many as the HUB contain of ports. This kind of connection allows the user to spend little money and its effective for using the internet, browsing, and downloading anything from the World Wide Web. And this type can be found in MALAYSIA as well. Conclusion: Nowadays the internet is almost in every home and every where in the whole world for this reason the network can be found in every where and by the time the people can understand the importance of network and how the internet and the information transformed. By the time people can recongnize how the network works and what are the equipment that being used for implement the set of connection. Moreover the people are looking for using the internet and network with low cost and fast transforming details. And the what are the suitable connection for specific place can be used be powerful without any problem by arrange this matter verycarefully. 36
  • 37. Fundamentals of Computer Networks 2010 Reference: http://www.answers.com/topic/technology http://images.google.com.my/images?hl=en&q=technology&oq=technology&um=1&ie=UTF8&sa=N&tab=wi http://insan87.files.wordpress.com/2008/04/wan.gif http://searchsecurity.techtarget.com/sDefinition/0,,sid14_gci211726,00.html http://images.google.com.my/images?hl=en&gbv=2&tbs=isch%3A1&sa=1&q=-+widearea+networks+%28WANs&btnG=Search&aq=f&oq=&start=0 http://www.webopedia.com/TERM/n/network.html http://images.google.com.my/images?hl=en&gbv=2&tbs=isch:1&q=Homearea+networks&sa=N&start=18&ndsp=18 http://www.high-speed-internet-access-guide.com/wireless/ http://www.isp-reviews.org/satellite.htm http://www.howstuffworks.com/dsl.htm http://www.howstuffworks.com/question606.htm http://mason.gmu.edu/~dcruz/importance.html http://wireless.ictp.it/school_2005/lectures/sebastian/wifi_hardware.pdf http://www.topbits.com/wi-fi-software-tools.html http://computer.howstuffworks.com/wimax3.htm http://web.princeton.edu/sites/ehs/radiation/nirad.htm http://www.inventum.cc/news/dot-wifi http://www.google.com.my/url?sa=t&source=web&ct=res&cd=2&ved=0CAoQFjAB&url=http%3A%2F%2 Fwww.northumbria.ac.uk%2Fstatic%2F5007%2Faccpdf%2Fspectrum.pdf&rct=j&q=wifi+hardware+requi rements&ei=4MfJS7X3NZSwrAeJ3JzkBQ&usg=AFQjCNHrKrdinexeMuF6mV9XOkc8ngG6ig 37
  • 38. Fundamentals of Computer Networks 2010 http://compnetworking.about.com/cs/wireless/f/whatiswireless.htm http://welloiledpc.com/wifi.htm http://www.webopedia.com/TERM/W/Wi_Fi.html http://www.google.com.my/images?client=firefox-a&channel=s&rls=org.mozilla%3AenUS%3Aofficial&hl=en&source=imghp&q=satellite+internet+access&gbv=2&aq=0&aqi=g2&aql=&oq=+Satellite+Internet+&gs_rfai= 38
  • 39. Fundamentals of Computer Networks 2010 Date of working: Q1, 2, 3 18-4-2010 Q4, 5 19-4-2010 Q6, 7, 8 21-4-2010 Q9 23-4-2010 39