Chapter 1 Introduction to Networking Mohammad Mahbobor Rahaman Lecturer, MIS, Dept. of Business Administration, Leading University (LU) , Sylhet, Bangladesh

Objectives The connection to the Internet Networking math

Requirements for Internet Connection Connection to the Internet can be broken down into the following: Physical connection Used to transfer signals between PCs within the local network and to remote devices on the Internet Logical connection Uses standards called protocols. A protocol is a formal description of a set of rules and conventions that govern how devices on a network communicate. The application Interprets the data and displays the information in an understandable form

PC Basics Electronic components Personal computer subsystems Connector, IC, LED, resistor, transistor Personal computer subsystems Bus, CD-ROM drive, CPU, disk drives, microprocessor, motherboard, RAM, ROM Back plane components Mouse port, network card, parallel port

All Computers Have a CPU, Memory, Storage, and Interfaces

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

NIC and Modem Installation Connectivity to the Internet requires an adapter card, which may be a modem or NIC. Notebook computers may have a built-in interface or use a Personal Computer Memory Card International Association (PCMCIA) card. Desktop systems may use an internal or external NIC.

Modem A modem, or modulator-demodulator, is a device that provides the computer with connectivity to a telephone line A modem converts data from a digital signal to an analog signal that is compatible with a standard phone line The modem at the receiving end demodulates the signal, which converts it back to digital.

High-Speed and Dialup Connectivity

TCP/IP Description and Configuration Transmission Control Protocol/Internet Protocol (TCP/IP) is a set of protocols or rules developed to allow cooperating computers to share resources across a network. To enable TCP/IP on the workstation, it must be configured using the operating system tools.

Testing Connectivity with Ping Ping is a program that is useful for verifying a successful TCP/IP installation. It works by sending multiple IP packets to a specified destination. Each packet sent is a request for a reply. Each reply contains the success ratio and round-trip time to the destination.

Web Browser and Plug-Ins 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

Number Systems Knowing what base someone refers to Base conventions 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 103 = 10 X 10 X 10 = 1000 24 = 2 x 2 x 2 x 2 = 16 Binary numbers Use principle of place value just as decimal numbers do

Binary Number System

Bits and Bytes Bits are binary digits. They are either 0s or 1s. In a computer, they are represented by On/Off switches or the presence or absence of electrical charges, light pulses, or radio waves.

Bits and Bytes

Base 10 Numbers

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.

Base 2 Table 27 26 25 24 23 22 21 20 128 64 32 16 8 4 2 1

Base 2 (Binary) Numbers

Base 2 Calculations 8-Bit Values Binary Value: 10101010 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). Binary Value: 11101001

Converting Decimal to Binary Example: 35 = 32 + 2 + 1 = 00100011 27 26 25 24 23 22 21 20 128 64 32 16 8 4 2 1

Converting Decimal to Binary Start by dividing the decimal by the largest number in the Value row that will go.

Looking At the Table Relationships The table will work with larger numbers, such as this 12-bit example. For any number in the value row, the sum of all numbers to the right is the current value minus 1 (64 - 1 = 63). Sometimes its easier to subtract the 0 values from 255 (largest 8-bit value). -

Powers of 2 Powers of 2 are used extensively in networking. One solution: Start with 2 (which is 21). Double the number to get the next value. If you need 26, continue until you have 6 values. Look over the example to the right. The second column is included only for reference.

Converting 8-Bit Binary to Decimal Binary numbers are converted to decimal numbers by multiplying the binary digits by the base number of the system, which is base 2, and raised to the exponent of its position.

Four-Octet Dotted-decimal Representation of 32-Bit Binary Numbers Split the binary number into four groups of eight binary digits. Then convert each group of eight bits, also known as an octet into its decimal equivalent.

Hexadecimal The base 16, or hexadecimal (hex), number system is used frequently when working with computers, because it can be used to represent binary numbers in a more readable form.

Boolean or Binary Logic Boolean logic is based on digital circuitry that accepts one or two incoming voltages. Boolean logic is a binary logic that allows two numbers to be compared and generate a choice based on the two numbers.

IP Addresses and Network Masks When IP addresses are assigned to computers, use a portion of the bits on the left side of the 32-bit IP number to represent a network. The bits left over in the 32- bit IP address identify a particular computer on the network. The IP address of a computer usually consists of a network, and a host part that represents a particular computer on a particular network.