Copyright 2002Cisco Press: CCNA Instructor’s Manual Year 1 - Chapter 1/Cisco 1 - Module 1 Computer Basics By Robert M. Cannistra
Copyright 2002Cisco Press: CCNA Instructor’s Manual Objectives Describe the basic computer hardware components Understand computer software basics Understand the binary numbering system Define networks and networking Define digital bandwidth
Copyright 2002Cisco Press: CCNA Instructor’s Manual Computer Hardware Components Electronic Components –Connector, IC, LED, resistor, transistor Personal Computer Subsystems –Bus, CD-ROM drive, CPU, disk drives, microprocessor, motherboard, RAM, ROM Backplane Components –Mouse port, network card, parallel port
Copyright 2002Cisco Press: CCNA Instructor’s Manual All Computers Have a CPU, Memory, Storage, and Interfaces.
Copyright 2002Cisco Press: CCNA Instructor’s Manual Network Interface Cards When you select a network card, consider the following three factors: –Type of network –Type of media –Type of system bus Installing a NIC in a PC
Copyright 2002Cisco Press: CCNA Instructor’s Manual Computer Software Web Browsers –A Web browser acts on behalf of a user by Contacting a Web server Requesting information Receiving information Displaying the results on a screen Plug-Ins –Flash/Shockwave, QuickTime, Real Audio
Copyright 2002Cisco Press: CCNA Instructor’s Manual Number Systems Knowing What Base Someone Refers To –Decimal uses 10 digits: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9. –Binary uses 2 digits: 0 and 1. Base Conventions –101 in Base 2 is spoken as one zero one. Working with Exponents –10 3 = 10 X 10 X 10 = 1000 –2 4 = 2 x 2 x 2 x 2 = 16 Binary Numbers –Use principle of place value just as decimal numbers do
Copyright 2002Cisco Press: CCNA Instructor’s Manual Base 10 (Decimal) Numbers
Copyright 2002Cisco Press: CCNA Instructor’s Manual Base 10 Calculations The upper table shows the actual math. The lower table is a simplified version that requires the following: –Start the value row and position row with 1 in the rightmost box. –Each subsequent value is current value times the base (10 in this case) –Value to be calculated is entered in the digit row. –Multiply digit amount times value entry above.
Copyright 2002Cisco Press: CCNA Instructor’s Manual Base 2 Table
Copyright 2002Cisco Press: CCNA Instructor’s Manual Base 2 (Binary) Numbers
Copyright 2002Cisco Press: CCNA Instructor’s Manual Base 2 Calculations 8-Bit Values Binary Value: Binary Value: Start the value row and position row with 1 in the rightmost box. Each subsequent value is the current value times the base (2 in this case).
Copyright 2002Cisco Press: CCNA Instructor’s Manual Binary Number System Even and Odd –A binary number is a multiple of 2 (even number) if the rightmost digit is a 0. –A binary number is odd if the rightmost digit is 1.
Copyright 2002Cisco Press: CCNA Instructor’s Manual Converting Decimal to Binary Example: 35 = =
Copyright 2002Cisco Press: CCNA Instructor’s Manual Converting Decimal to Binary Start by dividing the decimal by the largest number in the Value row that will go.
Copyright 2002Cisco Press: CCNA Instructor’s Manual Looking at the Table Relationships The table will work with larger numbers, such as this 12-bit example. Sometimes its easier to subtract the 0 values from 255 (largest 8-bit value). - For any number in the value row, the sum of all numbers to the right is the current value minus 1 ( = 63).
Copyright 2002Cisco Press: CCNA Instructor’s Manual Powers of 2 for Non-Math Majors Powers of 2 are used extensively in networking. One solution: 1.Start with 2 (which is 2 1 ). 2.Double the number to get the next value. 3.If you need 2 6, continue until you have 6 values. Look over the example to the right. The second column is included only for reference.
Copyright 2002Cisco Press: CCNA Instructor’s Manual Binary Number System Exercises 1.Convert the binary number 1010 to Base Convert the Base 2 number to decimal notation. 3.Convert the decimal number 1111 to binary notation. 4.Convert the decimal number 198 to binary notation.
Copyright 2002Cisco Press: CCNA Instructor’s Manual Network and Networking Data Networks Data Networking Solutions –Local-area networks –Wide-area networks
Copyright 2002Cisco Press: CCNA Instructor’s Manual LANS Are Designed To: Operate within a limited geographic area Allow many users to access high-bandwidth media Provide full-time connectivity to local services Connect physically adjacent devices
Copyright 2002Cisco Press: CCNA Instructor’s Manual LAN Devices
Copyright 2002Cisco Press: CCNA Instructor’s Manual WAN Technologies Include Analog modems Integrated Services Digital Network (ISDN) Digital Subscriber Line (DSL) Frame Relay Asynchronous Transfer Mode (ATM) T (US) and E (Europe) Carrier Series: T1, E1, T3, E3 Synchronous Optical Network (SONET)
Copyright 2002Cisco Press: CCNA Instructor’s Manual WAN Devices
Copyright 2002Cisco Press: CCNA Instructor’s Manual Bandwidth Measurements
Copyright 2002Cisco Press: CCNA Instructor’s Manual Digital Bandwidth Two Analogies That Describe Digital Bandwidth –Width of a pipe –Number of lanes on a highway Media Bandwidth Differences –Category 5 UTP – 100 meters maximum physical distance –Multimode (62.5/125um) optical fiber – 2000 meters –Modem – 56 Kbps = Mbps –T1 – Mbps
Copyright 2002Cisco Press: CCNA Instructor’s Manual Bandwidth Pipe Analogy
Copyright 2002Cisco Press: CCNA Instructor’s Manual Bandwidth Highway Analogy
Copyright 2002Cisco Press: CCNA Instructor’s Manual Digital Bandwidth (cont.) Data Throughput in Relation to Digital Bandwidth –Factors that determine: internetworking devices, type of date being transferred, topology, number of users, user’s computer Data Transfer Calculation –Estimated time = size of file / bandwidth Why Is Bandwidth Important? –Bandwidth is finite!
Copyright 2002Cisco Press: CCNA Instructor’s Manual Media Bandwidth
Copyright 2002Cisco Press: CCNA Instructor’s Manual Importance of Bandwidth