Chapter 1 Introduction to Networking

Chapter 1 Introduction to Networking
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
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
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.
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
Base 2 (Binary) Numbers
Base 2 Calculations 8-Bit Values
Converting Decimal to Binary
Example: 35 = 32 + 2 + 1 = 00100011
Converting Decimal to Binary
Looking At the Table Relationships
Powers of 2
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.