Hardware and Networking Servicing Level III Past Paper PDF 2020

Hardware and Networking Servicing Level III Based on August, 2011 Version 3 Occupational standards Module Title: Determining Best Fit Topology LG Code: EIS HNS3 M05 LO (1-3) LG (17-19) TTLM Code: EIS HNS3 TTLM 1220v1 December 2020 Bishoftu, Ethiopia Version -1 Federal TVET Agency Page i Hardware and Network Servicing Level -III Author/Copyright December 2020 Table of Contents page LO #1- Identify key information sources...................................................................................... 1 Information Sheet 1.1 Identifying information repositories..................................................... 2 Self-Check 1............................................................................................................................... 4 Information Sheet 1.2 Review current organizational documentation.................................... 5 Self-Check 2............................................................................................................................... 9 Information Sheet 1.3 Developing critical questions............................................................ 10 Self-Check 3............................................................................................................................. 13 Information Sheet 1.4 Ensuring information gathering techniques....................................... 14 Self-Check 4............................................................................................................................. 21 LO #2- Determine user needs................................................................................................... 23 Information Sheet 2.1 Identifying different segments of network based on business requirements 24 Self-Check 1............................................................................................................................. 35 Information Sheet 2.2. Determining segment needs using network functional analysis............. 37 Self-Check 2............................................................................................................................. 50 Self-Check 3............................................................................................................................. 53 LO #3- Develop best topology.................................................................................................. 54 Information sheet 3.1 Determining resource requirements for each network segment......... 55 Self-Check 1............................................................................................................................. 83 Information sheet 3.2. Analyzing features of the physical environment on network design 84 Self-Check 2........................................................................................................................... 108 Information sheet 3.3. Conducting costing process for possible topology.......................... 109 Self-Check 3........................................................................................................................... 112 Information sheet3.4. Selecting and documenting appropriate network topology............... 113 Self-Check 4........................................................................................................................... 131 References............................................................................................................................. 132 Answer Key Module Title: Best fit topology............................................................................ 133 Version -1 Federal TVET Agency Page ii Hardware and Network Servicing Level -III Author/Copyright December 2020 LG#17 LO #1- Identify key information sources Instruction sheet This learning guide is developed to provide you the necessary information regarding the following content coverage and topics:  Identifying information repositories  Reviewing current organizational documentation  Developing critical questions  Ensuring information gathering techniques This guide will also assist you to attain the learning outcomes stated in the cover page. Specifically, upon completion of this learning guide, you will be able to:  Identify information repositories  Review current organizational documentation  Develop critical questions  Ensure information gathering techniques Learning Instructions: Read the specific objectives of this Learning Guide. 1. Follow the instructions described below. 2. Read the information written in the “Information Sheets”. Try to understand what are being discussed. Ask your trainer for assistance if you have hard time understanding them. 3. Accomplish the “Self-checks” which are placed following all information sheets. 4. Ask from your trainer the key to correction (key answers) or you can request your trainer to correct your work. (You are to get the key answer only after you finished answering the Self-checks). 5. If you earned a satisfactory evaluation proceed to the next information sheet 6. If your self-check test is satisfactory proceed to the next learning guide, 7. If your self-check test is unsatisfactory, see your trainer for further instructions or go back to “information sheets”. Version -1 Federal TVET Agency Page 1 Hardware and Network Servicing Level -III Author/Copyright December 2020 Information Sheet 1.1 Identifying information repositories 1.1. Identify information repositories across the business Defining information So what is information? What is the relationship between information, data and knowledge? When information is entered and stored in a computer, it is generally referred to as “data.” After processing (such as formatting and printing), output data can again be perceived as “information.” When information is packaged or used for understanding or doing something, it is known as "knowledge". An information repository is a collection of interrelated information maintained across a network on multiple servers. It creates a unified resource for anyone connected with the system to access when they need information. In general, there are three types of resources or sources of information: primary, secondary, and tertiary. It is important to understand these types and to know what type is appropriate for your coursework prior to searching for information. In information technology, a repository is "a central place in which an aggregation of data is kept and maintained in an organized way, usually in computer storage. It "may be just the aggregation of data itself into some accessible place of storage or it may also imply some ability to selectively extract data. The repositories constitute information systems that aim to organize, preserve and disseminate in the Open Access mode scientific and academic resources of the institutions. A Business Process Repository is a central location for storing information about how an enterprise operates. This information may be contained in various media including paper, film or electronic form with a storage mechanism appropriate to the medium. Electronic repositories range from passive containers which store process artifacts (also referred to as process objects) to sophisticated tools that serve as active participants in monitoring, executing, managing and reporting on business processes. They come in the form of Document Management Systems, Process Modeling Tools and Business Process Management Systems. Administration of a Version -1 Federal TVET Agency Page 2 Hardware and Network Servicing Level -III Author/Copyright December 2020 Business Process Repository includes activities such as storing, managing and changing process knowledge (objects, relationships. Data or information may be collected from within the organisation (internal) or it may be sourced from external organisations. In order to collect the right information, you may need to read many documents and interview many people. Types and sources of information 1. Primary sources are original materials on which other research is based, including: o original written works – poems, diaries, court records, interviews, surveys, and original research/fieldwork, and o research published in scholarly/academic journals. 2. Secondary sources are those that describe or analyze primary sources, including: o reference materials – dictionaries, encyclopedias, textbooks, and o books and articles that interpret, review, or synthesize original research/fieldwork. 3. Tertiary sources are those used to organize and locate secondary and primary sources. o Indexes – provide citations that fully identify a work with information such as author, titles of a book, article, and/or journal, publisher and publication date, volume and issue number and page numbers. o Abstracts – summarize the primary or secondary sources, o Databases – are online indexes that usually include abstracts for each primary or secondary resource, and may also include a digital copy of the resource. Version -1 Federal TVET Agency Page 3 Hardware and Network Servicing Level -III Author/Copyright December 2020 Self-Check 1 Written Test Directions: Answer all the questions listed below. Use the Answer sheet provided in the next page: Part I: Choose the best answer from the given alternatives. (Each 2 point) 1. Understanding of an information could be: A. Data C. Repository B. Wisdom D. Knowledge 2. ________________is a central place in which an aggregation of data is kept and maintained in an organized way, usually in computer storage. A. Wisdom B. Knowledge C. Data D. Repository 3. Reference material is the best examples of ________________________sources of information. A. Tertiary Primary C. Secondary D. All of the above Part II: Fill the blank spaces 1. When information is entered and stored in a computer, it is generally referred to as _________(1%). 2. List sources of information (3%) 3. Write down at least 4 examples of primary sources of information. (4%). Note: Satisfactory rating 100% Score = ___________ You can ask you teacher for the copy of the correct answers. Version -1 Federal TVET Agency Page 4 Hardware and Network Servicing Level -III Author/Copyright December 2020 Information Sheet 1.2 Review current organizational documentation 1.2 Reviewing the current organizational documentation Documents and information Documentation is any communicable material that is used to describe, explain or instruct regarding some attributes of an object, system or procedure, such as its parts, assembly, installation, maintenance and use. Documentation can be provided on paper, online, or on digital or analog media, such as audio tape or CDs. Nearly everyone agrees that good documentation is important to the success of software projects, and yet very few projects actually have good documentation. Even successful projects often have barely adequate documentation. Organizational documentation is the practical and formal reflection of the organizational structure. Described in the documentation are relationships between system and elements, which constitute the formal organizational structure of the company. Organizational documentation is the practical and formal reflection of the organizational structure. Described in the documentation are relationships between system and elements, which constitute the formal organizational structure of the company. For the proper functioning of any organization it is necessary to develop the documentation containing the overall description of the system. Documentation should facilitate the work of the personnel, as well as assist the leadership in the efficient management of the company. The good news is that both these problems can be solved by understanding how documentation works, and that there are four distinct kinds of documentation - with four distinct functions. Version -1 Federal TVET Agency Page 5 Hardware and Network Servicing Level -III Author/Copyright December 2020 The four kinds of documentation are:  Learning-oriented tutorials  goal-oriented how-to guides  understanding-oriented discussions  information-oriented reference material An organisation stores a large number of documents such as policy documents, finance statements, annual reports and mission statements. These documents can provide valuable information when analysing user requirements. For example, mission statements may provide information regarding organisational goals. You may be required to review these documents to identify the kind of information they contain. The contents may be useful in the business requirements analysis. Organizational Documentation may include the following tips. 1. The organizational documents of a business generally include the documents used to form or organize the business (registration documents) and the operational documents used to control activity within the business (operational documents) 2. The basic financial statements of an enterprise include the 1) balance sheet (or statement of financial position), 2) income statement, 3) cash flow statement, and 4) statement of changes in owners' equity or stockholders' equity. The balance sheet provides a snapshot of an entity as of a particular date. 3. Performance reports show the stakeholders the status of the project and its performance against the planned baselines. Examples of work performance reports include status reports, progress reports, trends report, earned value report, forecasting report, variance report, etc. 4. An organizational security policy is a set of rules or procedures that is imposed by an organization on its operations to protect its sensitive data. Sources of information When conducting a business user-requirements analysis, it is important to identify the sources of information. You will need to select different sources of information in order to gather complete and accurate information. Version -1 Federal TVET Agency Page 6 Hardware and Network Servicing Level -III Author/Copyright December 2020 Table 1: Information sources Repository/source Information required Management To establish objectives, boundaries, constraints, policies, information requirements, involvement in the project, potential problems. Clerical/operational staff To establish actual procedures carried out, documents used, volume of work, job satisfaction, morale. Statements of company policy These will provide information on overall objectives and likely including changes. Organization charts Identify reporting responsibilities and staff names/positions. Administrative procedure QA documents, instruction and procedure manuals which provide manuals a statement of the way in which tasks are supposed to be performed. Document blanks or data entry These are forms that are filled in and passed between forms departments or stored for reference. This gives the analyst an indication of the formal data flows and data stores. Completed documents or data These are forms that have been filled in and passed between entry forms departments or stored for reference. These give the analyst an indication of the 'actual' data that is currently required. Training manuals To identify processes and procedures. Sales and promotional literature To identify products; company image; marketing style; target market. Job descriptions and These should define the responsibilities of personnel. specifications Reports for decision making Reports may include: sales; inventory; production; costing. Performance reports Identify gaps between actual performance and intended performance. Intranet and website Examine for metaphors, design features (such as colour). The intranet will be a valuable resource that can be searched for electronic copies of documents. Memos and letters May provide background for your problem statement and ultimate solution. Version -1 Federal TVET Agency Page 7 Hardware and Network Servicing Level -III Author/Copyright December 2020 Organisational documents provide invaluable sources of information for analysing business needs. When gathering data for business needs, it is common to review organisational documents and categorise them according to the type of information they provide. Version -1 Federal TVET Agency Page 8 Hardware and Network Servicing Level -III Author/Copyright December 2020 Self-Check 2 Written Test Directions: Answer all the questions listed below. Use the Answer sheet provided in the next page: Part I: Choose the best answer from the given alternatives.(1 point each). 1. Documentation can be provided on: A. Paper B. Audio C. CD D. DVD E. All are correct 2. Organizational Documentation may include the following tips. A. Financial statement B. An organizational security policy C. Performance reports D. All of the above Part II: fill in the blank spaces.  The four kinds of documentation are:- (4 point). ____________________________________________________________________________ ____________________________________________________________________________ ____________________________________________________________________________ __________________________  What is documentation?(1 point). ______________________________________________________________ Note: Satisfactory rating 100% Score = ___________ You can ask you teacher for the copy of the correct answers. Version -1 Federal TVET Agency Page 9 Hardware and Network Servicing Level -III Author/Copyright December 2020 Information Sheet 1.3 Developing critical questions 1.3 Developing critical questions Introduction When conducting usability studies or field studies, it’s a great idea to ask lots of open-ended questions. Typically, researchers ask questions before, during, and after research sessions. It’s easy to focus on what you want to know rather than on how you ask, but the way you ask questions matters a lot in terms of what and how much you can discover. You can learn unexpected and important things with this easy technique. Definition Open-ended questions are questions that allow someone to give a free-form answer. Closed-ended questions can be answered with “Yes” or “No,” or they have a limited set of possible answers (such as: A, B, C, or All of the above). Closed-ended questions are often good for surveys, because you get higher response rates when users don’t have to type so much. Also, answers to closed-ended questions can easily be analyzed statistically, which is what you usually want to do with survey data. However, in one-on-one usability testing, you want to get richer data than what’s provided from simple yes/no answers. If you test with 5 users, it’s not interesting to report that, say, 60% of users answered “yes” to a certain question. No statistical significance, whatsoever. If you can get users to talk in depth about a question, however, you can absolutely derive valid information from 5 users. Not statistical insights, but qualitative insights. Critical Questions Version -1 Federal TVET Agency Page 10 Hardware and Network Servicing Level -III Author/Copyright December 2020 Steps to developing a research question: Choose an interesting general topic. Most professional researchers focus on topics they are genuinely interested in studying  Do some preliminary research on your general topic  Consider your audience  Start asking questions  Evaluate your question  Begin your research. Here are some questions to guide you through the process of critical evaluation of information sources: Authority: Who created the information?  Who is the creator/author/source/publisher of the information? What are the author's credentials or affiliations?  Is the author's expertise related to the subject? Are they an authority on the topic through education, experience, or expertise in the field?  Whose voices/viewpoints are not being heard? Accuracy: How accurate is the information?  Was the information reviewed by others before being published? Does it contain spelling mistakes and grammatical errors?  What citations or references support the author's claims?  Is it fact or opinion? Do the authors leave out important facts or alternative perspectives? Argument: What are the author's claims?  What is the author's position?  What reasons does the author give to support their position?  Are there any flaws in the author's logic?  Do you agree or disagree with the author's argument or perspective? Why?  What is your position on this topic? Version -1 Federal TVET Agency Page 11 Hardware and Network Servicing Level -III Author/Copyright December 2020  What evidence (i.e. research) can you provide to support your position? Self-Awareness: Check yourself  Examine your own perspective and ensure you are seeking out information that represents alternative perspectives and worldviews.  Ensure you are not seeking or favoring sources that only confirm your existing beliefs (avoid confirmation bias).  Get uncomfortable. Read from sources across the spectrum (even if you do not agree with such sources); this will help ensure you are aware of the various sides of a debate/issue. Relevance: Does the source satisfy your information need?  Is the information related to your topic? Does it help you better understand your topic?  Is the information at an appropriate depth or level for your assignment? Timeliness: How current is the information?  When the information was created, published or updated?  Is it recent enough to be relevant to your topic or discipline? Sometimes you are required to use recently published material; sometimes you must use historical documents. Version -1 Federal TVET Agency Page 12 Hardware and Network Servicing Level -III Author/Copyright December 2020 Self-Check 3 Written Test Directions: Answer all the questions listed below. Use the Answer sheet provided in the next page: Part I: Choose the best answer from the given alternatives. (Each 1 point) 1. ________________questions are questions that allow someone to give a free-form answer. A. Close-ended B. Open-ended 2. _______________________________ Questions are often good for surveys. A. Close-ended B. open-ended Part II: Fill the blank spaces 1. Write down at least 3 examples of closed ended questions. (4%) 3. Write down at least 3 examples of open-ended questions. (3%). _________________________________________________________________________ _________ Note: Satisfactory rating 100% You can ask you teacher for the copy of the correct answers. Score = ___________ Version -1 Federal TVET Agency Page 13 Hardware and Network Servicing Level -III Author/Copyright December 2020 Information Sheet 1.4 Ensuring information gathering techniques Assess methods Data gathering methods and budget constraints There are a variety of different data gathering methods, and each have their own advantages and disadvantages. You will need to research the advantages and disadvantages of these methods. While you are undertaking your research, take notice of the relative costs associated with each method. Your research should highlight that questionnaires are an effective method of capturing data from a large group of people at a relatively low cost; however, if the sample group is small, sometimes the questionnaire development costs outweigh the benefits. In the past, questionnaires have often been paper-based. A cost associated with paper-based surveys is the coding and transcribing of the responses into a computer for analysis. Using computer-based questionnaires reduces costs associated with coding and transcribing data. You may find through your research that some authors refer to workshops as activities that last several days, involve high-level management and are conducted at remote locations using high- tech equipment. But this need not be the case. Given this insight, workshops are sometimes classified as an expensive method. This is due to costs associated with the venue, computing infrastructure, facilitator and management wages. However, if done correctly, workshops can return significant results in a short period of time because issues can be explored from a variety of perspectives, and resolutions can be arranged from a team perspective. When determining requirements, the most common method of gathering data is the interview. The interview is usually a cost-effective method of gathering goal-focused information associated with the business requirements. Version -1 Federal TVET Agency Page 14 Hardware and Network Servicing Level -III Author/Copyright December 2020 Reviewing documents Reviewing documents is the process of searching, finding and extracting information from documents which have been created by authors. A listing of documents can be found in Table 1: Information sources. If you are developing a website with e-commerce facilities, it may be worthwhile reviewing customer order forms and documents identifying sales processes and procedures. If you are interested in identifying the number of items per order or the number of incorrect orders received from customers, you may need to sample records kept by the organisation. b. Interviews An interview is a planned meeting during which you obtain information from another person. The personal interview is often the preferred information gathering technique when developing business and user requirements. The interviewer can contextualise the response by observing body language. Body language is all of the non-verbal information being communicated by an individual. Part of body language is facial disclosure. Facial disclosure can sometimes enable you to understand how people feel by watching the expressions on their faces. Many common emotions have easily recognizable facial expressions. Now let’s look at the most common steps that take place during the interviewing process. 1. Determining the people to interview You need to determine the people that can best satisfy the answers to your questions. Organisational charts and job specifications can help to identify appropriate people to interview. Table 1: Information sources, provides a list of information sources that may be useful in determining the right people with which to speak. 2. Establishing objectives for the interview You need to be clear about what your objectives are for the interview. To do this, you should determine the general areas to be discussed, then list the facts that you want to gather. The Version -1 Federal TVET Agency Page 15 Hardware and Network Servicing Level -III Author/Copyright December 2020 objectives of the interview will depend on the role of the person being interviewed. Upper management provides a "big picture" or overview which will help you understand the system as a whole. Specific details about operations and business processes are best learned from people who actually work with the system on a daily basis. Examples of goals can be found in the topic “Gather data through formal processes.” 3. Developing the interview questions Creating a list of questions helps you keep on track during the interview. It is appropriate to include open and closed questions during the body of the interview. Extended discussion on questions can be found in the topic “Gather data through formal processes.” 4. Preparing for the interview Preparation is the key to a successful interview. It is often easy to detect an unprepared interviewer. The interviewee is providing their valuable time, so you, as the interviewer, must be prepared. The interviewer should book and confirm their appointment times and venue. In addition, the goals or subject matter of the interview should be communicated to the interviewee. 5. Conducting the interview An interview can be characterised as having three phases: the opening, the body and the conclusion. During the interview opening, the interviewer should explain the reason for the interview, what the interviewer expects to get out of the interview, and motivate the interviewee to contribute to the interview. The interview body represents the most time-consuming phase where you obtain the interviewee's responses to your questions and focus on your well-defined objectives. Most interviewees will expect or at least permit you to take notes. Some interviewers use audio note-takers. While this can capture the entire interview, some interviewees may be hesitant to Version -1 Federal TVET Agency Page 16 Hardware and Network Servicing Level -III Author/Copyright December 2020 express their opinions if they know that they have been recorded on tape. Typing on laptop computers can also be distracting during the interview process. The interview conclusion allows you to summarise your understanding of the data gathered during the interview. You should express your appreciation for the interviewee's valuable time and instil a sense of value for the interviewee. You may need to follow-up with more questions, so the conclusion is an important time to develop rapport and trust with the interviewee. 6. Documenting the interview It is important that you transcribe your notes into a format that allows you to understand the information gained at the interview. Sometimes, inexperienced interviewers do not capture the interview in writing until sometime after the interview. In these cases, the interviewer may lose many of the valuable facts gained in the interview. Some interviewees request copies of the interview transcript. This can be helpful in prompting the interviewee to volunteer information inadvertently omitted in the interview. 7. Evaluating the interview It is important to review your notes and transcript to identify any areas of problem, bias or errors. The review may prompt further questions that need to be answered. c. Questionnaires Questionnaires are sometimes called surveys. A questionnaire involves questions written onto a form. The respondent provides their response in the form. Two common formats for questionnaires are free-format and fixed-format. A single questionnaire often includes both formats.  Free-format questionnaires offer the respondent greater latitude in their answer. A question is asked, and the respondent records the answer in the space provided after the question. Version -1 Federal TVET Agency Page 17 Hardware and Network Servicing Level -III Author/Copyright December 2020  Fixed-format questionnaires contain questions that quire the selection of predefined responses from individuals. A typical questionnaire starts with a heading or title. This is usually followed by a brief statement of purpose and contact details for the person distributing the questionnaire. Often an introductory paragraph includes the deadline date for completion, as well as how and where to return the form. Instructions should be provided to give clear guidance on how to complete the form. Headings can be used to separate sections of the questionnaire. Your questionnaire may request the name and/or job role of the respondent; however, it has been found that anonymous responses often provide better information. Questionnaires do not have to be paper-based. You may choose to distribute electronic questionnaires via e-mail, or you may request that respondents access a website and complete a questionnaire online. d. Observation Observation is a technique that enables the analyst to view how processes and activities are being done in the context of the business. This additional perspective can give a better understanding of system procedures. It is sometimes worthwhile to read procedure manuals to find out how things should be done. Then interview people to find out how they believe it is being done. Finally, observe processes to find out how it is actually being done. e. Brainstorming Brainstorming is a workshop or meeting where ideas are expressed and captured for later consideration. The three common rules of brainstorming are:  Be spontaneous. Call out ideas as they occur.  No criticism, analysis, or evaluation is permitted while the ideas are being generated. Any idea may be useful, if only to generate another idea.  Focus on the quantity of ideas, rather than the quality of the ideas. Version -1 Federal TVET Agency Page 18 Hardware and Network Servicing Level -III Author/Copyright December 2020 Categories of data Quantitative vs. qualitative data You may need to source quantitative data or qualitative data. Quantitative data can be measured. Sources include reports for decision making, performance reports, data capture forms, and numeric results from surveys and statistical research. Quantitative data can be analysed using mathematical equations and computation. Care needs to be taken to ensure that quantitative data is current and reliable - you may want to investigate the method of data capture and processing. Qualitative data is a record of thoughts, observations, opinions or words. Qualitative data often comes from asking open-ended questions to which the answers are not limited by a set of choices or a scale. Qualitative data is important to capture; it may be in the form of memos, procedure manuals, survey responses, workshop results or policy guidelines. Care needs to be taken when analysing qualitative data to ensure that the information or data has not been authored in a way to bias or politically motivate receivers of information. Sampling When determining requirements, it is likely that you will have to collect information from a number of people. If the organisation is small, you may choose to collect information from all people - this is called a census. Alternatively, you may choose to collect information from only nominated specialists. This is known as judgement sampling or convenience sampling. Not all organisations are small and localised: consider determining requirements for an organisation with over 2000 computer users spread across 4 continents. In this situation, it is prudent to survey a sample of users. Two commonly used sampling techniques are randomisation and systematic sampling.  Randomisation is a sampling technique characterised as having no predetermined pattern or plan for selecting sample data.  Systematic sampling is a technique that attempts to reduce the variance of the estimates by spreading out the sampling. One example would be choosing documents or records by formula which avoids very high or low estimates. The use of sampling is much more time efficient, and that is why sampling is so commonly used. Unfortunately, the improper use of sampling can lead to methodological disaster. Version -1 Federal TVET Agency Page 19 Hardware and Network Servicing Level -III Author/Copyright December 2020 Summary In this resource you have identified the difference between data, information and knowledge. You are aware that there are different sources of information. These include internal or external, documents or people and the data you collect may be qualitative or quantitative data. When selecting samples, you may choose a census, a judgment sample/convenience sample, randomised sample or a systematic sample. From each of the nominated information sources you can expect to get a variety of information. Version -1 Federal TVET Agency Page 20 Hardware and Network Servicing Level -III Author/Copyright December 2020 Self-Check 4 Written Test Directions: Answer all the questions listed below. Use the Answer sheet provided in the next page: Part I: Choose the best answer from the given alternatives. (Each 1 point) 1. According to your readings, qualitative data can be defined as follows: “Qualitative data is a record of thoughts, observations, opinions or words.” A. True B. False 2. Collecting information from only nominated specialists is called: A. convenience sampling B. judgment sampling C. All of the above. 3. Which of the following is NOT usually regarded as a step of the interview process? A. determine the people to interview B. develop interview questions C. close the interview D. conduct the interview E. None of the above 4. Which of the following is can NOT be a data gathering method? A. Observation B. Interview C. Questionnaires D. None of the above Part II: Fill the blank spaces 1. ______________________is a technique that enables the analyst to view how processes and activities are being done in the context of the business. (1%) 2. An_____________________________________ is a planned meeting during which you obtain information from another person. (1%). Version -1 Federal TVET Agency Page 21 Hardware and Network Servicing Level -III Author/Copyright December 2020 3. The most common steps that take place during the interviewing process are: (7%). __________________________________________________________________________ __________________________________________________________________________ __________________________________________________________________________ __________________________________________________________________________ __________________________________________________________________________ __________________________________________________________________________ __________________________________________________________________________ ___________________________ Note: Satisfactory rating 100% Score = ___________ You can ask you teacher for the copy of the correct answers. Version -1 Federal TVET Agency Page 22 Hardware and Network Servicing Level -III Author/Copyright December 2020 LG #18 LO #2- Determine user needs Instruction sheet This learning guide is developed to provide you the necessary information regarding the following content coverage and topics:  Identifying different segments of network based on business requirements  Determining segment needs using network functional analysis  Estimating traffic content and volumes This guide will also assist you to attain the learning outcomes stated in the cover page. Specifically, upon completion of this learning guide, you will be able to:  Identify different segments of network based on business requirements  Determine segment needs using network functional analysis  Estimate traffic content and volumes Learning Instructions: Read the specific objectives of this Learning Guide. 1. Follow the instructions described below. 2. Read the information written in the “Information Sheets”. Try to understand what are being discussed. Ask your trainer for assistance if you have hard time understanding them. 3. Accomplish the “Self-checks” which are placed following all information sheets. 4. Ask from your trainer the key to correction (key answers) or you can request your trainer to correct your work. (You are to get the key answer only after you finished answering the Self-checks). 5. If you earned a satisfactory evaluation proceed to the next information sheet 6. If your self-check test is satisfactory proceed to the next learning guide, 7. If your self-check test is unsatisfactory, see your trainer for further instructions or go back to “information sheets”. Version -1 Federal TVET Agency Page 23 Hardware and Network Servicing Level -III Author/Copyright December 2020 Information Sheet 2.1 Identifying different segments of network based on business requirements 2.1. Identifying different segments of network based on business requirements A computer network or data network is a telecommunications network which allows computers to exchange data. In computer networks, networked computing devices exchange data with each other using a data link. The connections between nodes are established using either cable media or wireless media. The best-known computer network is the Internet. Network computer devices that originate, route and terminate the data are called network nodes.Nodes can include hosts such as personal computers, phones, servers as well as networking hardware. Two such devices can be said to be networked together when one device is able to exchange information with the other device, whether or not they have a direct connection to each other. Computer networks differ in the transmission medium used to carry their signals, the communications protocols to organize network traffic, the network’s size, topology and organizational intent. Computer networks support an enormous number of applications and services such as access to the World Wide Web, digital video, digital audio, shared use of application and storage servers, printers, and fax machines, and use of email and instant messaging applications as well as many others. In most cases, application-specific communications protocols are layered (i.e. carried as payload) over other more general communications protocols. User Requirements From the model of system components in our generic system, the user component is at the highest layer. The term user represents primarily the end users of the system, but it can be expanded to include everyone involved in the system, such as network and system administrators and management. User requirements is the set of requirements gathered or derived from user input and is what is needed by users to successfully accomplish their tasks on the system. Typically, Version -1 Federal TVET Agency Page 24 Hardware and Network Servicing Level -III Author/Copyright December 2020 When gathering requirements, everyone involved with that network is considered a potential user. Figure 1. Types of user requirements. We begin describing requirements at this layer, which will lead to the development of more specific requirements as we work through each of the components. From the user perspective, we can ask, "What does it take to get the job done?" This will usually result in a set of qualitative, not quantitative, requirements. Part of our job in gathering and deriving user requirements is to make them quantitative whenever possible. In general, the system should adapt to users and their environments, provide quick and reliable information access and transfer, and offer quality service to the user. This indicates the following general requirements:  Timeliness  Interactivity  Reliability  Presentation quality  Adaptability  Security Version -1 Federal TVET Agency Page 25 Hardware and Network Servicing Level -III Author/Copyright December 2020  Affordability  Functionality  Supportability  Future growth User requirements are the least technical and are also the most subjective. As shown in Figure 2.3, requirements become more technical as they move from users to the network. All of these requirements will be developed in more detail as we proceed through the application, device, and network components. Figure 2. User requirements Requirements are presented as a guide for you to use in developing requirements for your network, and they may change depending on the user's environment. Timeliness is a requirement that the user is able to access, transfer, or modify information within a tolerable time frame. What a "tolerable" time frame is, of course, depends on the user's perception of delay in the system. It is this perception that we want to quantify. For example, a user may want to download files from a server and complete each transfer within 10 minutes. Or the user may need to receive video frames every 30 ms. Each one of these times indicates a delay that the network will need to provide. For timeliness, end-to-end or round-trip delay can be a useful measurement. Interactivity is similar to timeliness but focuses on a response time from the system (as well as the network) that is on the order of the response times of users. In the preceding example, we could consider the 10 minutes needed to download a file as the response time for the system. Version -1 Federal TVET Agency Page 26 Hardware and Network Servicing Level -III Author/Copyright December 2020 We further say that the file transfer is interacting with the user (which it is), but the degree of interactivity in this example is very low and not of much interest from an architectural or design perspective. What is interesting is when the system and network response times are close to the response times of users, for then changes that are made in the network architecture and design to optimize response times can have a direct impact on users' perception of interactivity. Therefore, interactivity is a measure of the response times of the system and network when they are required to actively interact with users. Delay, here the round-trip delay, is a measure of interactivity. Using these descriptions of timeliness and interactivity, timeliness is more likely to be associated with bulk file or image transfer, whereas interactivity is likely to be associated with remote device access (e.g., telnet), Web use, or visualization. Reliability, that is, availability from the user's perspective, is a requirement for consistently available service. Not only must the user be able to have access to system resources a very high percentage of the time, but the level of service to the user (in terms of application usage or information delivery) must be consistent. Thus, reliability is closely related to the performance characteristic reliability (discussed in Chapter 1 as part of RMA), but delay and capacity are also important. It is likely that a combination of all performance characteristics would be used to describe reliability. Presentation quality refers to the quality of the presentation to the user. This may be the user's perception of audio, video, and/or data displays. As examples, consider the current Internet capabilities of video conferencing, video feeds (live or delayed), and telephony. Although it is possible to do all of these on the Internet, there are other mechanisms that currently provide much better presentation quality. It is often not sufficient to provide a capability over a network—that capability must be as good as or better than other mechanisms, or the user will be disappointed. Network architects and designers often miss this concept. Measures of quality include all of the performance characteristics. Adaptability is the ability of the system to adapt to users' changing needs. Some examples of this are in distance-independence and mobility. As users rely more and more on the network, they are becoming coupled to logical services and decoupled from physical servers. Version -1 Federal TVET Agency Page 27 Hardware and Network Servicing Level -III Author/Copyright December 2020 This decoupling means that users do not have to care where servers are located, as long as they can get the services they need. A result of this is distance-independent computing, where the user loses all knowledge of where jobs are being executed, or where data are sourced, stored, or migrated through the network. Mobility refers to mobile or nomadic computing, where the user can access services and resources from any location, using portable devices and wireless access to the network. Adaptability to such user needs forces requirements on the system architecture and design. Security from the user perspective is a requirement to guarantee the confidentiality, integrity, and authenticity of a user's information and physical resources, as well as access to user and system resources. Security is probably closest to the performance characteristic reliability, but it will affect capacity and delay as well. Affordability is the requirement that purchases fit within a budget. Although this requirement is not technical, it will affect the architecture and design. Our goal in this requirement is to determine what users or management can afford to purchase for the network so that our architecture and design do not cost too much to implement. As a user requirement, we are looking for how costs and funding are tied to users, groups of users, and management. We will also discuss funding as a system-wide requirement, from an overall budget perspective. Functionality encompasses any functional requirement that the user will have for the system. Functions that the system will perform are often tied to applications that are used on the system. Understanding functionality is important in that it will lead into application requirements (covered in the next section). Part of understanding functionality is determining which applications users actually want or apply in their daily work. We do not want to analyze applications that no one is planning to use. Supportability is a set of characteristics that describe how well the customer can keep the network operating at designed performance through the full range of mission scenarios described by the customer during the requirements analysis process. This includes how users want or need to be supported by their network operations staff and any interfaces they will have with a network operations center (NOC). Version -1 Federal TVET Agency Page 28 Hardware and Network Servicing Level -III Author/Copyright December 2020 For example, will the network need to be reconfigured to meet different or changing user needs? What applications will the network operations staff and/or NOC need to provide support to users and to identify and troubleshoot problems on the network? Information such as this will be used later as input to the network management architecture. Types of Computer Network Based on the area coverage of the network, computer networks can be divides into two 1. Local Area Network (LAN) 2. Wide area Network (WAN) 3. Metropolitan area Network (MAN) LANs  Local area networks are used to interconnect distributed communities of computers located within a single building or localized group of buildings.  Since all equipment is located within a single establishment, LAN’s are normally installed and maintained by the organization. Hence, they are also referred to as private data networks.  Example: network in your class MAN:  Is a larger network that usually spans several buildings in the same city or town.  Example: networks among Addis Ababa sub city administrations (Kifle Ketemas) WANs  When data communication is necessary or desired beyond the reach of a MAN, a wide area network (WAN) over public carrier networks is established.  Institutions transferring large amounts of data between offices often decide to lease dedicated transmission lines from public carriers, in what is termed an enterprise-wide private network.  Example: network among news agency offices in different region of Ethiopia. VPN (Virtual Private Network: is an encrypted connection over the Internet from a device to a network. The encrypted connection helps ensure that sensitive data is safely transmitted. It prevents unauthorized people from eavesdropping on the traffic and allows the user to conduct work remotely. Version -1 Federal TVET Agency Page 29 Hardware and Network Servicing Level -III Author/Copyright December 2020 Explanation: A Virtual Private Network i.e. VPN is a technique used in networking or other intermediate networks for connecting computers and making them isolated remote computer networks, maintaining a tunnel of security and privacy. A virtual LAN (VLAN) is any broadcast domain that is partitioned and isolated in a computer network at the data link layer (OSI layer 2). LAN is the abbreviation for local area network and in this context virtual refers to a physical object recreated and altered by additional logic. A Virtual Local Area Network (VLAN) is a logical division of computer systems in a LAN (Local Area Network) that are connected to a switch, based on their functionalities. VLANs are implemented for enhancing security between various departments and also for easy configuration. Wireless Local Area Network (WLAN) – a network that connects two or more devices using a wireless distribution method and provides access to the public Internet. Most WLANs are based on Institute of Electrical and Electronic Engineers (IEEE) 802.11 standards, otherwise known as Wi-Fi. PSTN (public standard telephone network) uses an old technology whereby circuit-switched copper phone lines are used to transmit analogue voice data. It is the basic service that you have at home and in a small business. As a dedicated service, a PSTN line cannot be used for any other purpose while a call is being made. Types of networks based on configuration (Node Relationship) Terms to be familiar  Servers—Computers that provide shared resources to network users.  Clients—Computers that access shared network resources provided by a server.  Media—the wires that make the physical connections.  Shared data—Files provided to clients by servers across the network.  Shared printers and other peripherals—Additional resources provided by servers.  Resources—any service or device, such as files, printers, or other items, made available for use by members of the network. Based on the computers relationship on the network, computer networks can be categorized as Peer to Peer and Server based network Version -1 Federal TVET Agency Page 30 Hardware and Network Servicing Level -III Author/Copyright December 2020 Peer-to-Peer Networks In a peer-to-peer network, there are no dedicated servers, and there is no hierarchy among the computers. All the computers are equal and therefore are known as peers. Each computer functions as both a client and a server, and there is no administrator responsible for the entire network. The user at each computer determines what data on that computer is shared on the network. Peer to peer network are also called Workgroup Where a Peer-to-Peer Network Is Appropriate Peer-to-peer networks are good choices for environments where:  There are 10 users or fewer.  Users share resources, such as files and printers, but no specialized servers exist.  Security is not an issue.  The organization and the network will experience only limited growth within the foreseeable future. Where these factors apply, a peer-to-peer network will probably be a better choice than a server- based network. Advantages of peer to peer network  Easy to install and configure  The cost of installation and operation is less  A full time network administrator is not required Disadvantages of peer to peer network  Shared resources can be accessed by everyone  Backup has to be performed on each computer separately  No centralized security Server Based network (client/server network) In an environment with more than 10 users, a peer-to-peer network—with computers acting as both servers and clients—will probably not be adequate. Therefore, most networks have dedicated servers. A dedicated server is one that functions only as a server and is not used as a client or workstation. Version -1 Federal TVET Agency Page 31 Hardware and Network Servicing Level -III Author/Copyright December 2020 Servers are described as "dedicated" because they are not themselves clients, and because they are optimized to service requests from network clients quickly and to ensure the security of files and directories. Server based network is also known as Domain. Advantages of server based network  Centralized resources  Easier to backup files  Easier to find files  Efficient  Security  One machine can secure entire network  One central login  Scalability Disadvantage of client server  If the server goes down, it takes part or the whole network with it  It is more expensive to install  Needs to be maintained by staff with high IT skills Specialized servers Servers must perform varied and complex tasks. Servers for large networks have become specialized to accommodate the expanding needs of users. Following are examples of different types of servers included on many large networks File and Print Servers File and print servers manage user access and use of file and printer resources. Application Servers Application servers make the server side of client/server applications, as well as the data, available to clients. Mail Servers Mail servers operate like application servers in that there are separate server and client applications, with data selectively downloaded from the server to the client. Fax Servers Fax servers manage fax traffic into and out of the network by sharing one or more fax modem boards. Version -1 Federal TVET Agency Page 32 Hardware and Network Servicing Level -III Author/Copyright December 2020 Communications Servers Communications servers handle data flow and e-mail messages between the servers' own networks and other networks, mainframe computers, or remote users who dial in to the servers over modems and telephone lines. Directory Services Servers Directory services servers enable users to locate, store, and secure information on the network Business requirements for network system Identifying Business Requirements Business requirements describe why the organization is undertaking the project. They state some benefits that the developing organization or its customers expect to receive from the product. Business requirements may be delineated in several documents such as a project charter, business case, or in a project vision and scope statements. Business requirements bring the project owner, stakeholders and the project team on the same song sheet. But you can’t build software from such high-level information. In the Enforces Requirement Suite, ™ we consider the following business requirements.  Problem Statement  Project Vision  Project Constraints (Budget, Schedule, and Resources)  Project Objectives  Project Scope Statements  Business Process Analysis  Stakeholder Analysis The results from the business process analysis and stakeholder analysis activities are also considered business requirements. The purpose of the business process analysis is to determine how the business process will work. It is often necessary to resolve deficiencies in the business process before trying to automate it. Not dealing with the business process design first is like trying to pave a cow path; it might get you there, but it certainly won’t be the straightest most direct path. The stakeholder analysis is needed to determine who will be impacted by the system and how to engage the impacted people to get their user requirements. Version -1 Federal TVET Agency Page 33 Hardware and Network Servicing Level -III Author/Copyright December 2020 As the organization's network grows, so does the organization's dependency on the network and the applications that use it. Network-accessible organizational data and mission-critical applications that are essential to the organization's operations depend on network availability. To design a network that meets customers' needs, the organizational goals, organizational constraints, technical goals, and technical constraints must be identified. This section describes the process of determining which applications and network services already exist and which ones are planned, along with associated organizational and technical goals and constraints. We begin by explaining how to assess the scope of the design project. After gathering all customer requirements, the designer must identify and obtain any missing information and reassess the scope of the design project to develop a comprehensive understanding of the customer's needs. 4 Key Factors to Consider When Creating an IT Network  Understand your network goals. Surprisingly, not all businesses consider what the actual goal of their IT network is.  Create a budget and acquire components.  Training, security, and scalability.  IT maintenance. Version -1 Federal TVET Agency Page 34 Hardware and Network Servicing Level -III Author/Copyright December 2020 Self-Check 1 Written Test Directions: Answer all the questions listed below. Use the Answer sheet provided in the next page: Part I: Choose the best answer from the given alternatives. (Each 1 point) 1. If Ambo University main Campus wants to develop a network for main branch that linked with Woliso FBE Campus, what network type is applicable for this situation in order to share information between the two Campuses? A. MAN B. WAN C. LAN D. All of the above 2. One of the following is not the main advantages of computer networking? A. Sharing of hardware B. Sharing of software C. Sharing of hardware and software D. Sharing of powers 3. Which of the following is the Disadvantages of peer to peer network A. Shared resources can be accessed by everyone B. Backup has to be performed on each computer separately C. No centralized security D. All of the above 4. ______________________is the wire that make the physical connections. A. Media B. Resource C. Client D. Server 5. VPN stands for __________________________________. A. Very poor network B. Virtual private network C. Virtual local area network D. None of the above Version -1 Federal TVET Agency Page 35 Hardware and Network Servicing Level -III Author/Copyright December 2020 Part II: Fill the blank spaces 1. What is the main difference between LAN, MAN and WAN? (3%) ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ ___________________________ 2. Write down the advantages of server based network (4%). ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ ________ Note: Satisfactory rating 6 and 12 points You can ask you teacher for the copy of the correct answers. Score = ___________ Version -1 Federal TVET Agency Page 36 Hardware and Network Servicing Level -III Author/Copyright December 2020 Information Sheet 2.2. Determining segment needs using network functional analysis 2.2. Determining segment needs using network functional analysis Network segmentation, which involves splitting the larger network into smaller network segments, can be accomplished through firewalls, virtual local area networks, and other separation techniques. Determine best-fit topology for a local network What evidence can you provide to prove your understanding of each of the following citeria? Determine user needs 1. Identify the different segments of the proposed network based on business requirements 2. Determine segment needs, using network functional analysis 3. Estimate traffic content and volumes based on business requirements 4. Develop a prioritized organizational network functional matrix Determine the resource requirements for each network segment on the basis of functional analysis Develop local area network specification 1. Determine the resource requirements for each network segment on the basis of functional analysis 2. Analyse features of the physical environment for the effect on network design 3. Conduct a costing process for possible topology options 4. Consider topology options with reference to available resources and network functional matrix 5. Select and document appropriate network topology based on business requirements and functional analysis Version -1 Federal TVET Agency Page 37 Hardware and Network Servicing Level -III Author/Copyright December 2020 Introducing Network Analysis A network analyzer is a combination of hardware and software. Although there are differences in each product, a network analyzer is composed of five basic parts: Hardware Most network analyzers are software-based and work with standard operating systems and network interface cards (NICs). However, some hardware network analyzers offer additional benefits such as analyzing hardware faults (e.g., cyclic redundancy check (CRC) errors, voltage problems, cable problems, jitter, jabber, negotiation errors, and so on). Some network analyzers only support Ethernet or wireless adapters, while others support multiple adapters and allow users to customize their configurations. Depending on the situation, you may also need a hub or a cable tap to connect to the existing cable. Capture Driver This is the part of the network analyzer that is responsible for capturing raw network traffic from the cable. It filters out the traffic that you want to keep and stores the captured data in a buffer. This is the core of a network analyzer—you cannot capture data without it. Buffer This component stores the captured data. Data can be stored in a buffer until it is full or in a rotation method (e.g., a round robin”) where the newest data replaces the oldest data. Buffers can be disk-based or memory-based. Real-time Analysis This feature analyzes the data as it comes off the cable. Some network analyzers use it to find network performance issues, and network intrusion detection systems use it to look for signs of intruder activity. Decode This component displays the contents (with descriptions) of the network traffic so that it is readable. Decodes are specific to each protocol, thus network analyzers vary in the number of decodes they currently support. However, new decodes are constantly being added to network analyzers. Notice: Jitter is the term that is used to describe the random variation of signal timing (e.g., electromagnetic interference and crosstalk with other signals can cause jitter). Jabber is the term that is used to describe when a device is improperly handling electrical signals, thus affecting the rest of the network (e.g., faulty NICs can cause jabber). Version -1 Federal TVET Agency Page 38 Hardware and Network Servicing Level -III Author/Copyright December 2020 Who Uses Network Analysis System administrators, network engineers, security engineers, system operators, and programmers all use network analyzers, which are invaluable tools for diagnosing and troubleshooting network problems, system configuration issues, and application difficulties. Historically, network analyzers were dedicated hardware devices that were expensive and difficult to use. However, new advances in technology have allowed for the development of software-based network analyzers, which make it more convenient and affordable for administrators to effectively troubleshoot a network. It also brings the capability of network analysis. The art of network analysis is a double-edged sword. While network, system, and security professionals use it for troubleshooting and monitoring the network, intruders use network analysis for harmful purposes. A network analyzer is a tool, and like all tools, it can be used for both good and bad purposes. A network analyzer is used for:  converting the binary data in packets to readable format  Troubleshooting problems on the network  analyzing the performance of a network to discover bottlenecks  Network intrusion detection  Logging network traffic for forensics and evidence  analyzing the operations of applications  discovering faulty network cards  discovering the origin of virus outbreaks or Denial of Service (DoS) attacks  Detecting spyware  Network programming to debug in the development stage  detecting a compromised computer  Validating compliance with company policy  As an educational resource when learning about protocols Version -1 Federal TVET Agency Page 39 Hardware and Network Servicing Level -III Author/Copyright December 2020 Common Network Analyzers A simple search on Security Focus (www.securityfocus.org/tools/category/4) shows the diversity and number of sniffers available. Some of the most prominent are: Wireshark is one of the best sniffers available and is being developed as a free, commercial- quality sniffer. It has numerous features, a nice graphical user interface (GUI), decodes over 400 protocols, and is actively being developed and maintained. It runs on UNIX-based systems, Mac OS X, and Windows.This is a great sniffer to use in a production environment, and is available at www.wireshark.org. WinDump is the Windows version of tcpdump, and is available at www.winpcap.org/windump. It uses the WinPcap library and runs on Windows 95, 98, ME, NT, 2000, and XP. Network General Sniffer A Network General Sniffer is one of the most popular commercial sniffers available. Now a suite of enterprise network capture tools, there is an entire Sniffer product line at www.networkgeneral.com. Windows 2000 and 2003 Server Network Monitor Both the Windows 2000 Server and the Windows 2003 Server have a built-in program to perform network analysis. It is located in the “Administrative Tools” folder, but is not installed by default; therefore, you have to add it from the installation CD. Ether Peek is a commercial network analyzer developed by WildPackets.Versions for both Windows and Mac, and other network analysis products can be found at www.wildpackets.com. Tcpdump is the oldest and most commonly used network sniffer, and was developed by the Network Research Group (NRG) of the Information and Computing Sciences Division (ICSD) at Lawrence Berkeley National Laboratory (LBNL). It is command line-based and runs on UNIX- based systems, including Mac OS X. It is actively developed and maintained at www.tcpdump.org. Snoop Snoop is a command-line network sniffer that is included with the Sun Solaris OS. Snort Snort is a network IDS that uses network sniffing, and is actively developed and maintained at www.snort.org. For more information, refer to Nessus, Snort, & Ethereal Power Tools: Customizing Open Source Security Applications (Syngress Publishing: 1597490202) and Snort Intrusion Detection and Prevention Toolkit (Syngress, ISBN: 1597490997). Dsniff Dsniff is a very popular network-sniffing package. It is a collection of programs that are used to specifically sniff for interesting data (e.g., passwords) and to facilitate the sniffing process (e.g., evading switches). It is actively maintained at www.monkey.org/~dugsong/dsniff. Version -1 Federal TVET Agency Page 40 Hardware and Network Servicing Level -III Author/Copyright December 2020 Ettercap was specifically designed to sniff a switched network. It has built-in features such as password collecting, OS fingerprinting, and character injection, and runs on several platforms including Linux, Windows, and Solaris. It is actively maintained at ettercap.sourceforge.net. Analyzer is a free sniffer that is used for the Windows OS. It is being actively developed by the makers of WinPcap and WinDump at Politecnico di Torino, and can be downloaded from analyzer.polito.it. Packetyzer is a free sniffer (used for the Windows OS ) that uses Wireshark’s core logic. It tends to run a version or two behind the current release of Wireshark. It is actively maintained by Network Chemistry at www.networkchemistry.com/products/packetyzer.php. MacSniffer MacSniffer is specifically designed for the Mac OS environment. It is built as a front- end for tcpdump.The software is shareware and can be downloaded from personalpages.tds.net/~brian_hill/macsniffer.html. Network Standards Ethernet This lesson introduces the Ethernet network architecture. Over the years, Ethernet has become the most popular media access method to the desktop computer and is used in both small and large network environments. Ethernet is a nonproprietary industry standard that has found wide acceptance by network hardware manufacturers. Problems related to using Ethernet hardware products from different hardware manufacturers in a single network are nearly nonexistent. This lesson presents an overview of the major Ethernet components, features, and functions. Ethernet Features Ethernet is currently the most popular network architecture. Notice that the cable is terminated at both ends. This baseband architecture uses a bus topology, usually transmits at 10 Mbps, and relies on CSMA/CD to regulate traffic on the main cable segment. The Ethernet media is passive, which means it requires no power source of its own and thus will not fail unless the media is physically cut or improperly terminated. Version -1 Federal TVET Agency Page 41 Hardware and Network Servicing Level -III Author/Copyright December 2020 The Ethernet Frame Format Ethernet breaks data down into packages in a format that is different from the packets used in other networks: Ethernet breaks data down into frames. (Remember that the terms "packet" and "frame" can be used interchangeably; in the context of Ethernet, the term "frame" is used.) A frame is a package of information transmitted as a single unit. An Ethernet frame can be between 64 and 1518 bytes long, but the Ethernet frame itself uses at least 18 bytes; therefore, the data in an Ethernet frame can be between 46 and 1500 bytes long. Every frame contains control information and follows the same basic organization. Ethernet specifications The 10-Mbps IEEE Standards This section looks at four 10 Mbps Ethernet topologies:  10BaseT  10Base2  10Base5  10BaseFL 10BaseT Standard  10 Mbps, baseband, over twisted-pair cable  Mostly uses UTP but can also use STP  Has a physical star and logical bus topology  The maximum length of a 10BaseT segment is 100 meters (328 feet). Repeaters can be used to extend this maximum cable length. The minimum cable length between computers is 2.5 meters (about 8 feet). A 10BaseT LAN will serve 1024 computers Figure 3. A patch panel makes moving computers easy Version -1 Federal TVET Agency Page 42 Hardware and Network Servicing Level -III Author/Copyright December 2020 Table 3.10 BaseT Specifications Summary Category Notes Cable Category 3, 4, or 5 UTP. Connectors RJ-45 at cable ends. Transceiver Each computer needs one; some cards have built in transceivers. Transceiver to hub distance 100 meters (328 feet) maximum. Backbones for hubs Coaxial or fiber-optic cable to join a larger LAN or to carry major traffic between smaller networks. Total number of computers per LAN 1024 by specification. without connectivity components 10Base2 Standard Another topology is 10Base2, given this name in the IEEE 802.3 specification because it transmits at 10 Mbps over a baseband wire and can carry a signal about two times 100 meters (the actual distance is 185 meters, or 607 feet). This type of network uses thin coaxial cable, or thinnet, which has a maximum segment length of 185 meters (607 feet) and a minimum cable length of at least 0.5 meters (20 inches) between workstations. There is also a 30-computer maximum per 185-meter segment. A single thinnet network can support a maximum of 30 nodes (computers and repeaters) per cable segment, as per the IEEE 802.3 specification. Version -1 Federal TVET Agency Page 43 Hardware and Network Servicing Level -III Author/Copyright December 2020 Table4: 10Base2 Specifications Summary Category Notes Maximum segment length 185 meters (607 feet). Connection to network interface card BNC T connector. Trunk segments and repeaters Five segments can be joined using four repeaters. Computers per segment 30 computers per segment by specification. Segments that can have computers Three of the five segments can be populated. Maximum total network length 925 meters (3035 feet). 10Base5 Standard The IEEE specification for this topology is 10 Mbps, baseband, and 500-meter (five 100-meters) segments. It is also called standard Ethernet. This topology makes use of thick coaxial cable , also known as thicknet. Thicknet generally uses a bus topology and can support as many as 100 nodes (stations, repeaters, and so on) per backbone segment. The distances and tolerances for thicknet are greater than those for thinnet: a thicknet segment can be 500 meters (1640 feet) long for a total network length of 2500 meters (8200 feet). Figure 4. Thicknet cable composition The thicknet cabling components include:  Transceivers These are devices that can both transmit and receive, provide communications between the computer and the main LAN cable, and are located in the vampire taps attached to the cable. Version -1 Federal TVET Agency Page 44 Hardware and Network Servicing Level -III Author/Copyright December 2020  Transceiver cables the transceiver cable (drop cable) connects the transceiver to the NIC.  DIX (or AUI) connectors these are the connectors on the transceiver cable.  N-series connectors, including N-series barrel connectors, and N-series terminators The thicknet components work in the same way as the thinnet components. It also shows the DIX or AUI connector on the transceiver cable. NOTE "AUI," an acronym for attachment unit interface, is a 15-pin (DB-15) connector commonly used to connect a NIC to an Ethernet cable; Figure 5. Thicknet backbone with attached transceiver and cable Table 5. 10Base5 Specifications Summary Category Notes Maximum segment length 500 meters (1640 feet). Transceivers Connected to the segment (in the tap). Maximum computer-to-transceiver distanc

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