NETWORKING BASICS

Chapter 1

OBJECTIVES Upon completion of this chapter, you

should be able to:Define & identify different types of

networksDescribe the advantages & disadvantages

of network typesDescribe & identify topologies Identify the OSI model, why it’s used, and

what happens at each layerDescribe various protocolsCompare and contrast TCP and UDPConvert binary to decimal to hexadecimal

NETWORKING OVERVIEW

1.1

INTRO TO NETWORKS What is a network?

Group of interconnected devices able to share info with each other

Networks consist of:Hosts/NodesConnecting MediaNetwork interfaceProtocols (standards)

NETWORK BENEFITS Share peripherals Consolidate storage Group collaboration/communication

File sharing, email, social media, VoIP, websites

NETWORK TYPES:PEER TO PEER Hosts don’t have a specific role

Can provide & consume network services

NETWORK TYPES:PEER TO PEER

ADVANTAGES DISADVANTAGES

Easy to implement Inexpensive to

implement No special software

to buy; use PC’s OS Easy to configure to

share storage & printing

Not scalable Bigger = difficult to

manage Usually limited to 10

No centralized controls

Decentralized storage

Possible slower performance

NETWORK TYPES:CLIENT-SERVER Server

Provides a resource/service, like email or web pages Email server/web

server

Client Consumes network

services Requests & displays

info from a server PC with web browser to

display pages from web server

NETWORK TYPES:CLIENT-SERVER

ADVANTAGES DISADVANTAGES

Very scalable Easy to support

Centralized management

Data protection Backup shared data

on server

More expensive! Advanced planning

to setup

NETWORKING TERMS Addressing Subnet LAN MAN WAN Internet Intranet Extranet

Test Out 1.1.3Watch video &

take notes10:58

REVIEW- 3Q What type of network uses each device

to share files with other devices on the network?Peer to peer

What type of network do you assign specific hosts a role such as file storage and other hosts just access those resources?Client-server

What connects a client PC to the network’s medium?Network interface

NETWORK TOPOLOGIES

1.2

TOPOLOGY Graphical layout of the network

Two types:Physical topology

Layout of how devices are physically connected

Logical topology How devices communicate/data transmitted Shows IP addresses & groups

LOGICAL TOPOLOGIES Bus/Broadcast

Data sent to ALL devices connected to the cable

Each device looks at the data to see if it is addressed to it or not

RingData is passed from computer to computer

StarData sent only to destination device

BUS & RING PHYSICAL TOPOLOGY Bus

All connected to same cable, terminated at end

Broken cable= no one communicates Ring

Each device connected to each other

STAR TOPOLOGY Has a central connecting device Most common

MESH TOPOLOGY Each device connects to every other

device Redundancy Used in backbone; not with PCs

PROJECT Physical & logical topology ID handout

REVIEW- 4Q The physical layout of nodes on a network

is known as the networks: Topology

Which physical topology is most common today? Star

How does data get passed in a logical ring topology? Sent from one device to the next

How does data get passed in a logical bus topology? Sent to all devices in network

OSI MODEL

1.3

OSI MODEL Before 1983, network devices were

proprietaryHad to buy all from same vendor or it

wouldn’t work

OSI model created standards to follow

OSI model layers break down the communication process between devices

OSI MODEL

OSI MODELLayer # Layer Name Description

7 Application Provides network access to applicationsSMTP; HTTP; DHCP; FTP; Telnet

6 Presentation Transforms data to a format

5 Session Establishes, manages, terminates sessions

4 TransportReliable transport; flow control; retransmission; TCP; port numbers; segments

3 Network Routing; Logical (IP) addressing; packet

2 Data Link Physical (MAC) addressing; access to media frame

1 Physical Bits; electricity

ACTIVITY The OSI Communications Process Go to Test Out

View 1.3.3 & 1.3.4Review 1.3.5 OSI Model Facts1.3.6 Exam Questions

ACTIVITY

ACTIVITY

NETWORK SIGNALING

1.4

INFO CONVERTED INTO SIGNALS Encoding

Converting info for travel on mediaEx: bits into electricity, light, radio waves

Types of Signals:Digital (bits)

0 volts= 0 +5 volts= 1

Analog Doesn’t represent bits But can be converted…

MODULATION Converting digital signal to analog

Connect via phone line FM (Frequency Modulation)

Varies the frequency (or hertz) AM (Amplitude Modulation)

Adjusts the strength

DEMODULATION Converting analog to digital

Modem (modulate-demodulate)Baud- # time per second signal changesBit Rate- # of bits per second

HOW THAT DATA IS TRANSMITTED- BROADBAND Analog signals over multiple frequencies Uses Multiplexing

Mixing multiple signals over a cable’s bandwidth Usually outside of your network

HOW THAT DATA IS TRANSMITTED- BASEBAND Sends data in single channel using all

bandwidth of the cable (one at a time) Uses Time-Division Multiplexing

Each signal gets a specific time to send Ethernet is baseband

Send/receive using all of the frequency

REVIEW- 3Q 1.4.4 Quiz What is the process for converting

digital signals for travel on media?Encoding

What is the process of converting signals on media to digital?Decoding

What process allows multiple signals to be mixed over a cable’s bandwidth?Multiplexing

NETWORK PROTOCOLS

1.5

TCP/IP PROTOCOL SUITE What is a protocol?

Set of rules for communication

Protocol SuiteSet of protocols that work togetherTCP/IP

TCP Connection-oriented Sends acknowledgements

Like tracking a FedEx delivery Breaks messages into small segments

If sender doesn’t get an ACK of message received, it retransmits

Only portion lost is resent On receiving host, TCP reassembles

data

FTP & HTTP are examples of protocols using TCP

UDP Connectionless Used for faster transmissions Low overhead “Best effort delivery”

Regular mail / no guarantee of delivery No ACK or retransmission No error checking* Used for streaming audio, video, VoIP

DNS, DHCP, TFTP, VoIP, Gaming, SNMP are examples of protocols that use UDP

TCP VS. UDP

TCP UDP

Guaranteed delivery

Connection-oriented

Acknowledgements Slower bc of

establishing a connection & acknowledging

Email, web, file transfer

Best effort delivery Connectionless No

acknowledgements Faster bc of no

connection or acknowledgements

Audio/video streams

ACTIVITY 1

PROTOCOLS

Protocol

Information

HTTP Connection to transfer web pages- TCP

HTTPS Secure connection for web pages transmission- TCPSecurity created by SSL or TSL

FTP File transfer- TCP

TFTP File transfer- UDP

Telnet Remote login- TCP

SSH Secure remote login- TCP

POP3 Transfer of email from email server to you; then deleted

IMAP Transfer of email from email server to you; kept on server

SMTP Used to send email between email servers

PROTOCOLS

Protocol

Information

SFTP & SCP

Secure file transfer

DHCP Automatically assign IP/SM/DG/DNS server addresses- UDP

DNS Translates names to IP addresses- TCP/UDP

NTP Allows devices to sync their clocks through network- TCP/UDP

SNMP Create alerts to monitor the network- UDP

ICMP Can detect other devices & verify connectivity- PING

TCP/UDP ACTIVITY

ACTIVITY Review all protocols on 1.5.4

Take Quiz on 1.5.5

COMMON NETWORK SERVICES Web server FTP server DNS server DHCP server Directory Services

Directory of users on a network, resources, and access control

SSH ServerFrom client, you can connect remotely &

securely to a device

Review1.5.21.5.31.5.4

REVIEW- 3Q What type of network has centralized

resources, such as central file storage?Client-server

What type of network shares resources located on local computer hard drives?Peer to peer

You type www.gcit.org into your web browser. A DNS request is created and then a we request is sent. What type of network is this?Client-server

REVIEW- 4Q Which protocol is used for web page

transmission? HTTP

You have a network of 100 devices. Which process will easily allow all computers to automatically be able to communicate on a network by assigning IP addresses? DHCP

Which utility/protocol can test connectivity? Ping/ICMP

Which protocol allows remote login, but is not secure? Telnet

NUMBERING SYSTEMS

1.6

CONVERT BINARY TO DECIMAL Add up the values of the binary 1’s

156

11100101229

128 64 32 16 8 4 2 1

1 0 0 1 1 1 0 0

BINARY/DECIMAL CONVERSIONS Binary to Decimal Conversions

Add up the bit values to come up with the decimal answer

Decimal to Binary ConversionsConvert the decimal number to bits

Binary GamePlay Now

BINARY/DECIMAL/HEX CONVERSIONS Hex= MAC address 0-9, A-F (10-15) Convert Hex to

Binary, then to Decimal

Convert backwards too

AB

ACTIVITY TestOut Quiz 1.6.3

Conversion Handout/Quiz

REVIEW & STUDY Complete the study guide handout

Take all quizzes on TestOut

Jeopardy review

NETWORKING BASICS

Chapter 1