...be summarized as a result of technical, political and economic reasons: The reasons for the popularity of TCP/ IP over the OSI are : * TCP/IP answers an immediate, almost desperate need - data communications in heterogeneous networks - very well. * It is relatively simple and robust compared to other alternatives. * TCP/IP is bundled into the Berkeley Software Distribution (BSD) Unix. Hence, TCP/IP became the minimum networking capability for any vendor entering the market for scientific and engineering graphics workstations. * Its available on virtually every hardware and operating system platform and It is often free as its open source. * Thus, it’s the lingua franca of the Internet. * It’s more credible than OSI, making greater utilization of bandwidth at a lower cost. * It supports multiplexing and being connectionless, supports more communication devices. * Existence of Internet layer reduces error handling overhead on the transport layer with the help of intelligent hosts, thus increasing throughput and efficiency at the transport layer. (b) List the major disadvantages with the layered approach to protocols. The disadvantages are : 1. Associated with layered protocols is that often higher layers of the protocol stack are unable to optimize data transfers based on the characteristics of underlying layers. 2. Each layer potentially imposes overhead both in terms of processing time and control information stored in protocol headers. ...
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...COMP2330 Data Communications and Networking Written Assignment 1 Sample Solutions 1. Which of the OSI layers handles each of the following: (a) Dividing the transmitted bit stream into frames. (b) Determining which route through the subnet to use. (10 marks) Ans: a) Data Link Layer b) Network Layer 2. An image is 1024x768 pixels with 3 bytes/pixel. Assume the image is uncompressed. How long does it take to transmit it over a 56-kbps modem channel? Over a 1-Mbps cable modem? Over a 10-Mbps Ethernet? Over 100-Mbps Ethernet? (10 marks) Ans: The size of the image is 1024 x 768 x 3 x 8 = 18874368 bits. For a 56-kbps modem, it takes 18874368/56000 [pic] 337 seconds. For a 1-Mbps cable modem, it takes 18864368/106 [pic] 18.9 seconds. For a 10-Mbps Ethernet, it takes around 1.89 seconds. For a 100-Mbps Ethernet, it takes around 0.19 seconds. 3. A digital signaling system is required to operate at 9600bps. (10 marks) (a) If a signal element encodes a 4-bit word, what is the minimum required bandwidth of the channel if we assume a noise free system? (b) Repeat part (a) for the case of 8-bit words. Ans: Because we assume noise free, we can use Nyquist’s equation: C = 2B log2M. We have C = 9600 bps (a) log2M = 4, because a signal element...
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...What is Data Communications? The distance over which data moves within a computer may vary from a few thousandths of an inch, as is the case within a single IC chip, to as much as several feet along the backplane of the main circuit board. Over such small distances, digital data may be transmitted as direct, two-level electrical signals over simple copper conductors. Except for the fastest computers, circuit designers are not very concerned about the shape of the conductor or the analog characteristics of signal transmission. Frequently, however, data must be sent beyond the local circuitry that constitutes a computer. In many cases, the distances involved may be enormous. Unfortunately, as the distance between the source of a message and its destination increases, accurate transmission becomes increasingly difficult. This results from the electrical distortion of signals traveling through long conductors, and from noise added to the signal as it propagates through a transmission medium. Although some precautions must be taken for data exchange within a computer, the biggest problems occur when data is transferred to devices outside the computer's circuitry. In this case, distortion and noise can become so severe that information is lost. Data Communications concerns the transmission of digital messages to devices external to the message source. "External" devices are generally thought of as being independently powered circuitry that exists beyond the chassis of a computer...
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...Business Data Communications and Networking 9th Edition Jerry Fitzgerald and Alan Dennis 1-1 Introduction to Data Communications 1-2 Outline • Brief history of Data Communications – Communications, Information Systems and the Internet • Data Communications Networks – Network components, network types • Network Models – OSI model, Internet model, transmission via “layers” • Network Standards – Standards making, common standards • Future Trends – Pervasive networking, integration of voice, video, and data, new information services 1-3 Information Age • First Industrial Revolution – Introduction of machinery – New organizational methods – Changed the way people worked • Second Industrial Revolution – Information Age – Introduction of computers – Introduction of networking and data communication – Changed the way people worked again • Faster communication Collapsing Information lag • Brought people together Globalization 1-4 The Collapsing Information Lag Historical developments in electronic communications telegraph sped up the rate and volume of transmission of information 1850 Information took days or weeks to be transmitted 1900 Information transmitted in minutes or hours 1950 2007 large quantities of information transmitted in a fraction of a second growth of telecommunications and especially computer networks Globalization of networks 1-5 Advances in Phone Technology Phone invented 1876 first...
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...resources! Instructors and students using Data Communications and Networking, Fourth Edition by Behrouz A. Forouzan will find a wide variety of resources available at the Online Learning Center, www.mhhe.comlforouzan Instructor Resources Instructors can access the following resources by contacting their McGraw-Hill Representative for a secure password. PowerPoint Slides. Contain figures, tables, highlighted points, and brief descriptions of each section. Complete Solutions Manual. Password-protected solutions to all end-of-chapter problems are provided. a Pageout. A free tool that helps you create your own course website. D Instructor Message Board. Allows you to share ideas with other instructors using the text. a o Student Resources The student resources are available to those students using the book. Once you have accessed the Online Learning Center, click on "Student Resources," then select a chapter from the drop down menu that appears. Each chapter has a wealth of materials to help you review communications and networking concepts. Included are: Chapter Summaries. Bulleted summary points provide an essential review of major ideas and concepts covered in each chapter. a Student Solutions Manual. Contains answers for odd-numbered problems. Glossary. Defines key terms presented in the book. Flashcards. Facilitate learning through practice and review. a Animated Figures. Visual representations model key networking concepts, bringing them to life. D Automated...
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...choose the tiered topology WAN, where the sites connected in star or ring formations are interconnected at different levels, with the interconnection points being organized into layers to form hierarchical groupings. Variations on this topology abound. Indeed, flexibility makes the tiered approach quite practical. A network architect can determine the best placement of top-level routers based on traffic patterns or critical data paths. In addition, tiered systems allow for easy expansion and inclusion of redundant links to support growth. On the other hand, their enormous flexibility means that creation of tiered WANs requires careful consideration of geography, usage patterns, and growth potential. As a Wan transmission I would choose the T-Carrier. T-carrier standards specify a method of signaling, which means they belong to the Physical layer of the OSI model. A T-carrier uses TDM (time division multiplexing) over two wire pairs (one for transmitting and one for receiving) to divide a single channel into multiple channels. Each channel may carry data, voice, or video signals. The medium used for T-carrier signaling can be ordinary copper wire, fiber-optic cable, or wireless links. So in this case I am going to use both - T1 and T3 transmissions to connect the central office with regional offices. To connect the 150 home offices with the regional offices I am would use the DSL (digital subscriber line) Connection. DSL is a WAN connection and it operates over the PSTN...
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...DATA COMMUNICATIONS First Semester 2012-2013 CMSC 137 Data Communications and Networking ICS-UPLB JAC Hermocilla Data Communications ● Communication involves information sharing : local or remote Telecommunication – communication at a distance – ● telephony, telegraphy, television ● Data communications – the exchange of data between devices via some form of transmission medium such as wire cable – data - information presented in whatever form agreed upon by parties creating and using data ● Devices must be part of a data communications system (DCS) , a combination of hardware and software First Semester 2012-2013 CMSC 137 Data Communications and Networking ICS-UPLB JAC Hermocilla Effective DCS ● Delivery – Must deliver data to the correct destination Must deliver data accurately Must deliver data in a timely manner Must consider variations in the packet arrival time CMSC 137 Data Communications and Networking ICS-UPLB JAC Hermocilla ● Accuracy – ● Timeliness – ● Jitter – First Semester 2012-2013 Components of a DCS (1) ● Message – Information to be communicated Device that sends the message: computer, phone Device that receives the message: computer, phone Physical path by which a message travels from sender to receiver: twisted-pair wire, coaxial cable, fiber optics, radio waves A set of rules that govern data communications An agreement between the communicating devices ● ...
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...ĐỒNG QUỐC TIẾN The Impact of Social Networking in Traveling Websites Introduction As has been noted by different authors, the advent of information technology and the internet has gave way to different changes on the way how business, marketing and other transaction or social networking is done. Since, different industries and business wanted to gain competitive advantage through the use of information technology, most of these enterprises are considering changes. There is a notion that users surf the internet, there are many enterprises that have their own website and thousands of advertisement are open with just a blink of an eye (Donthu & Garcia, 1999). The use of websites is available for any enterprise who wants to make each and every target consumer aware of their existence. In addition website development may enable the enterprise to be known worldwide since more and more users are being independent on the internet as a tool to get essential information. It is considered today as the most significant part of the travel marketing strategy in the world where competition is very stiff, and that is the market environment. In today’s generation, travelers or visitors are not only visiting a specific place or events, simply just for fun. Most of them are looking for excitement, and more importantly learning process and tourists and travelers are looking for new products and services that would satisfy their needs. This is one of the reasons why, more and more countries...
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...into the student website to view this document. • Instructor policies: This document is posted in the Course Materials forum. University policies are subject to change. Be sure to read the policies at the beginning of each class. Policies may be slightly different depending on the modality in which you attend class. If you have recently changed modalities, read the policies governing your current class modality. Course Materials Fitzgerald, J. & Dennis, A. (2009). Business data communications & networking (10th ed.). Hoboken, NJ: Wiley. Iniewski, K., McCrosky, C., & Minoli, D. (2008). Network infrastructure and architecture: Designing high-availability networks. Hoboken, NJ: Wiley-Interscience. Turban, E. & Volonino, L. (2009). Information technology for management: Improving performance in the digital economy (7th ed.). Hoboken, NJ: Wiley. Supplemental Resources Element K. (2010). Fundamentals of Data Communication: Level 1. Element K. (2010). Fundamentals of Data Communication: Level 2. Element K. (2010). Network Security Fundamentals. Article References Aird, C. L. & Sappenfield, D. (2009, June). IT the 'enabler' of global outsourcing. Financial Executive, 25(5), 62. Chtioui, T. (2009,...
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...our daily lives. Describe the role of data networking in the human network. Identify the key components of any data network. Identify the opportunities and challenges posed by converged networks. Describe the characteristics of network architectures: fault tolerance, scalability, quality of service and security. Install and use IRC clients and a Wiki server. • How Networks Impact Daily Life • Explain the benefits of instantaneous communication and how it supports and improves our lives. How Networks Impact Daily Life • Describe the characteristics and purpose of popular communication media such as, IM, Wikis , Blogs, Podcasting, and Collaboration Tools –Instant messaging • Real time communication - between 2 or more - people based on typed text –Weblogs (Blogs) • Web pages created - by an individual –Podcasting • Website that contains - audio files available - for downloading How Networks Impact Daily Life • Explain ways that using information networks to share and collaborate improves teaching and learning How Networks Impact Daily Life • Describe ways communication over a network changes the way we work How Networks Impact Daily Life • Describe ways communication over a network supports the way we play Data Networking Role, Components, and Challenges • Basic characteristics of communication –Rules or agreements are 1st established –Important information may need to be repeated –Various modes of communication may impact the effectiveness of getting...
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...CHAPTER 8: NETWORKING AND DIGITAL COMMUNICATION Multiple Choice: 1. A basic computer network can be described as: A. a minimum of five computers linked together. B. a number of palmtop computers. C. two or more computers that are linked together. D. the use of satellites linking computers together. Answer: C 2. Reference: Basic Network Anatomy Difficulty: Easy The three essential components of every computer system include all of the following EXCEPT: A. software. B. hardware. C. people. D. cables. Answer: D 3. Reference: Basic Network Anatomy Difficulty: Easy All of the following are advantages of using a computer network EXCEPT that it: A. reduces costs when hardware is shared. B. promotes independence so users have exclusive control over their own data and applications. C. saves money when software is shared. D. enables data sharing, increasing efficiency and productivity. Answer: B Reference: Basic Network Anatomy Difficulty: Easy Copyright © 2008 Prentice-Hall. All rights reserved. Chapter 8: Networking and Digital Communication 4. All of the following statements are true EXCEPT: A. Wireless networks are convenient. B. Wireless networks are generally slower than wired LANs. C. Wireless networks use radio transmitters. D. Wireless networks are generally faster than wired networks. Answer: D 5. Reference: Networks Near and Far Difficulty: Moderate A(n) ____________ broadcasts messages to all devices connected to a LAN. A. switch...
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...CS065 – Data Communications Course Description This course provides a broad introduction to the fundamentals of data communications and network technology. Emphasis is on more complex aspects of data communications from the perspective of the computer science and information technology in the communication of data, and the interaction of remote systems. Course Objectives ← The objectives of the course are to enable students to: ← Understand and describe time, space, and frequency domains and their applications ← Understand and apply the abstract ISO 7 layer OSI reference model ← Understand and describe other networking models such as TCP/IP, N-ISDN, and ATM. ← Understand and describe circuit, packet switching, frame/cell relay, ATM, WDM, optical networking and newer networking technologies ← Apply mathematical/ analytical skills in basic performance evaluation such as utilization throughput and delay. Course Structure and Contents Module 1: Introduction to Data Communication • Understand and describe time, space, frequency domains application. Module 2: ISO 7 layer OSI reference model • Understand and apply the abstract ISO 7 layer OSI reference model Module3: Other Networking models • Understand and describe other networking models such as TCP/IP, N-ISDN, and ATM. Module4: Network Technologies • Understand and describe circuit, packet switching, frame/cell relay, ATM, WDM, optical networking and newer...
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...Title |Advance Computer Networking | Question 1. What does computer networking accomplish? 2. How does networking improve the usefulness of computers? 3. What are the drawbacks of networking computers? 4. What is the future of networking computers? 5. Is computer networking still at infancy, Discuss? Question 1: What does computer networking accomplish? Computer networking is the interconnection of two or more computers to share resources. Computer networking has evolved beyond the sharing of resources; it allows people and machines to communicate, using some of the advanced features or services. Computer networking has brought about increased productivity, cost reduction and synergy between users. Other accomplishments of the computer networks include: • File sharing and management: One of the major accomplishments of computer networking is file sharing, which includes remote file accessing. Organizations or individuals can share documents irrespective of their location provided their PCs are interconnected. It saves time, and provides a more efficient means of transferring data, rather than using storage device to copy and transport data to the other user. • Resource sharing and management: Another important achievement of computer networking is resource sharing. All computers in a network can...
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...theorem have to do with communications? The Nyquist theorem will define “the theoretical maximum bit rate” for the noiseless channel through the Nyquist bit rate formula as following: BitRate=2×bandwidth×log_2 L[3] Q3-8. What does the Shannon capacity have to do with communications? The Shannon capacity has to determine the theoretical highest data rate for a noisy channel through the following formula: Capacity=bandwidth×log_2 (1+SNR)[4] 3.8.3 Problems: P3-7. What is the bit rate for each of the following signals? a. A signal in which 1 bit lasts 0.001 s Basically, bit rate is donated as r_b and we can found it by using the following formula: r_b=n/T Whereas n measured in bits, and T measured in second. [5] So, in such a case: r_b=1/0.001=1000bps b. A signal in which 1 bit lasts 2 ms First, we need to convert 2 ms to second. 2 ms=2×〖10〗^(-3)=0.002 s r_b=1/0.002=500bps c. A signal in which 10 bits last 20...
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...Tiffany’s Networking Request for Proposal for a Technology Network Infrastructure May 6, 2011 1 Purpose The purpose of this Request for Proposal (RFP) is to invite prospective vendors to submit a proposal to supply a Structured Cabling solution to Tiffany’s networking. The RFP provides vendors with the relevant operational, performance, and architectural requirements for the solution. 2 Coverage & Participation The intended coverage of this RFP, and any agreement resulting from this solicitation, shall be for the use of all departments at Tiffany’s networking along with any satellite offices. Tiffany’s networking reserves the right to add and/or delete elements, or to change any element of the coverage and participation at any time without prior notification and without any liability or obligation of any kind or amount. General Information The Enterprise Insert Enterprise Description Here Describe the enterprise in a few brief paragraphs. State the core business of the enterprise, the number of employees and the general size of the IT infrastructure: number of workstations, servers, etc. Include a description of the business and location including any satellite offices that will be involved in the project. Describe the overall objectives of the Structured Cabling solution purchase. Focus on larger business goals, not technical specifications. For example, most enterprises put the purchase of a Structured Cabling solution...
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