Welcome to Cisco Academy

Chapter 1

Introduction to Networking

Objectives

• Understand Safety Rules• Provide common knowledge base

– PC Hardware

• Build bridge between understanding of PC hardware and Networks similarities

• Develop understanding of Boot Process• Appreciate importance of Networks• Identify network characteristics• Introduce Binary Numbering System• Appreciate importance of Bandwidth

Specific Objectives & Tasks

• Identify four primary components of PC architecture• Identify PC subsystem components• Install a NIC• Configure PC for different network types• Develop understanding of Binary Number System• Convert Decimal to Binary & Binary to Decimal• Identify units of Information• Be able to discuss need for Networks• Be able to identify Network Devices• Use analogies to understand bandwidth

PC Components

• Transistor – amplifies or opens/closes circuit• IC – does specific task; contains transistors• Capacitor – stores energy in electrostatic field• Connector – plugs into a port or interface• LED – semiconductor device that emits light

PC Components

B u s B u s

K eyb oard /M ou seS eria l/P ara lle l P ort

N ICM on ito r

In te rfaces

B u s

R A MR O M

F L A S HE P R O M

M em ory

B u s

A L UO /S S u p erviso r

C P U

B u s B u s

H ard D iskD iske tte

C D -R O MZ IP

S to rag e

Boot Processes

• Boot Instructions – stored in ROM until used• Software Applications – stored in RAM after

loading• RAM and ROM – talk to CPU through the bus• Saved Information – flows from RAM to storage

device• Exported Information – flows from RAM through

bus to external device such as the printer

Web Browsers and Plug-Ins

• IE– Integrated with other MS products– Takes up more disk space– Uses, does e-mail, file transfers

• Communicator– First popular browser– Takes less disk space– Same as IE

Popular Plug-Ins

• Flash/Shockwave Player

• Adobe Acrobat Reader

• Windows Media Player

• Quicktime

• Real Player

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NIC

• Network Interface Card– printed circuit board that provides network

communication capabilities to and from a personal computer

• A.K.A. LAN Adapter– Can be designed for Ethernet, Token Ring, FDDI

(IMPORTANT)

• Requires:– IRQ, I/O Address, Upper Memory address in Win 95,98,

NT

Network Card Selection Criteria

• Type of Network– Ethernet, FDDI, Token Ring

• Type of Media– Twisted Pair, Fiber Optic, Coaxial Cable

• Type of Bus– PSI or ISA or PCMCIA (lap top)

• Half duplex or full duplexing• 10 mbs or 100 mbs

TCP/IP Configuration

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Binary

• Decimal System– Base 10 0 1 2 3 4 5 6 7 8 9

• Binary System– Base 2 0 1

• Computer works in Binary– Two states - On/Off; Current/No Current– Computer translates from decimal to binary and from

binary to decimal• NOTE: ASCII is a binary code

Units of InformationB= bytes; b = bits

Bit (0,1)

b

Binary Digit

1 bit 1 bit On/Off

Op/Clos

Byte

B

8 bits 1 byte 8 bits Letter or number

Kilobyte

KB

1,024 bytes

Approx

1000 bytes

Approx

8000 bits

10-page report = 10 KB

Megabyte

MB

1,024 KB 1 million bytes

8 million bits

Floppy = 1.4 MB

Gigabyte

GB

1,024 MB 1 billion bytes

8 billion bits

Hard drive = 8 GB

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Binary

10 9 8 7 6 5 4 3 2 1

2**9 2**8 2**7 2**6 2**5 2**4 2**3 2**2 2**1 2**0

512 256 128 64 32 16 8 4 2 1

Decimal

10 9 8 7 6 5 4 3 2 1

10**9 10**8 10**7 10**6 10**5 10**4 10**3 10**2 10**1 10**0

1 B 100 M 10 M 1 M 100000 10000 1000 100 10 1

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Terms to Know

• Bit a 0 or 1 – a Binary digiT

• Byte 8 bits – approximately 1 character

• KB, MB, GB, TB, kbps, kBps, Mbps– All measures of storage

• Hz, MHz, GHz– All measures of computer operation - cycles

Networks

• A network is an entity - an intricately connected system of objects or people.

• Networks are all around us, even inside us.

• Your own nervous system and cardiovascular system are networks.

• There can several types of networks

• Think of some

Networks Accomplish Many Tasks

• Avoid duplication of equipment and resources

• Allow us to communicate efficiently

• Enable us to manage computing resources

• Support shared resources

Network Types

• LAN– Building, Campus (group of building)

• MAN– Metropolitan Area

• WAN– Entire world – can even include outer space

IP Addressing

• IP address is used to identify PC to network (at layer 3 of OSI model)

• IP address is used to send traffic over WAN• IP address is usually in dotted decimal format

(does not have to be)– 123.122.234.255

– In binary 01111011.01111010.11101010.11111111

– In hex 7B 7A EA FF

Subnet Masking

• Used with IP address to determine which LAN to use to send packet on its way

• Takes form of– 255.255.0.0– 11111111.11111111.00000000.00000000

• Router uses ANDING to determine which LAN is associated with the IP address– ANDING is a BOOLEAN Algebra process

ANDING

• IP address is 10.10.0.26• Subnet mask is 255.255.0.240• Anding

– 00001010.00001010.00000000.00011010

– 11111111.11111111.00000000.11110000

– 00001010.00001010.00000000.00010000

– 10.10.0.16

• Host 10.10.0.26 is a member of LAN 10.10.0.16

LAN Characteristics

• Operate within a limited geographic area

• Allow multiple access to high bandwidth media

• Control private (autonomous) networks

• Provide full-time connectivity to local services

• Connect physically adjacent devices

WANS

• Operate over wide geographic areas

• Allow access over serial interfaces operating at lower speeds

• Provide full-time and part-time connectivity

• Connect devices located over wide geographic areas

• WANS connect LANS

Bandwidth

• Measure of how much information can flow from one place to another in a given amount of time

• Two types – digital and analog

• Cisco course deals with digital bandwidth

• Measured in BITS (b) per second

Analogies for Bandwidth

• Pipe line– Bandwidth is pipes– Network devices are valves; fittings; packet is water

• Highway– Bandwidth is lanes– Packets are vehicles; network devices are signals, on

ramps, etc.

• Audio Systems– Network devices are telephones, CD-ROMS– Packets are music

Bandwidth is Important

• It is finite

• It can save money

• It is key measure of network design and performance

• It is key to understanding Internet

• The demand for it increases constantly

Throughput

• The formula is Estimated Time = Size of File / Bandwidth

• Throughput is always less than Bandwidth

• Bandwidth is used to design networks

• Throughput is used to evaluate network performance

Media

• Coaxial Cable– 50 ohm and 75 ohm

• Twisted Pairs– Shielded and Unshielded

• Fiber Optics– Single Mode and Multi Mode (62.5/125)

• Wireless