Transcript Chapter 1 Networking Basics

Chapter 1
 Upon
completion of this chapter, you should
be able to:
 Define & identify different types of networks
 Describe the advantages & disadvantages of
network types
 Describe & identify topologies
 Identify the OSI model, why it’s used, and
what happens at each layer
 Describe various protocols
 Compare and contrast TCP and UDP
 Convert binary to decimal to hexadecimal
1.1
 What

is a network?
Group of interconnected devices able to share
info with each other
 Networks




consist of:
Hosts/Nodes
Connecting Media
Network interface
Protocols (standards)
 Share
peripherals
 Consolidate storage
 Group collaboration/communication

File sharing, email, social media, VoIP, websites
 Hosts

don’t have a specific role
Can provide & consume network services
Easy to implement
 Inexpensive to
implement
 No special software to
buy; use PC’s OS
 Easy to configure to
share storage &
printing

ADVANTAGES

Not scalable


Bigger = difficult to
manage
Usually limited to 10
No centralized
controls
 Decentralized storage
 Possible slower
performance

DISADVANTAGES
 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
Very scalable
 Easy to support



Centralized
management
More expensive!
 Advanced planning to
setup

Data protection

Backup shared data on
server
ADVANTAGES
DISADVANTAGES
 Addressing
 Subnet
 LAN
 MAN
 WAN
 Internet
 Intranet
 Extranet
Test Out 1.1.3
Watch video &
take notes
10:58
 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
1.2
 Graphical
 Two

types:
Physical topology


layout of the network
Layout of how devices are physically connected
Logical topology


How devices communicate/data transmitted
Shows IP addresses & groups
 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
 Ring

Data is passed from computer to computer
 Star

Data sent only to destination device
 Bus


All connected to same cable, terminated at end
Broken cable= no one communicates
 Ring

Each device connected to each other
 Has
a central connecting device
 Most common
 Each
device connects to every other device
 Redundancy
 Used in backbone; not with PCs
 Physical
& logical topology ID handout
 The
physical layout of nodes on a network is
known as the networks:

Topology
 Which
today?

physical topology is most common
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
1.3
 Before
1983, network devices were
proprietary

Had to buy all from same vendor or it wouldn’t
work
 OSI
 OSI
model created standards to follow
model layers break down the
communication process between devices
Layer # Layer Name
Description
7
Application
Provides network access to applications
SMTP; HTTP; DHCP; FTP; Telnet
6
Presentation
Transforms data to a format
5
Session
Establishes, manages, terminates sessions
4
Transport
Reliable 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
 The
OSI Communications Process
 Go to Test Out



View 1.3.3 & 1.3.4
Review 1.3.5 OSI Model Facts
1.3.6 Exam Questions
1.4
 Encoding


Converting info for travel on media
Ex: bits into electricity, light, radio waves
 Types

Digital (bits)



of Signals:
0 volts= 0
+5 volts= 1
Analog


Doesn’t represent bits
But can be converted…
 Converting

Connect via phone line
 FM

(Frequency Modulation)
Varies the frequency (or hertz)
 AM

digital signal to analog
(Amplitude Modulation)
Adjusts the strength
 Converting
 Modem


analog to digital
(modulate-demodulate)
Baud- # time per second signal changes
Bit Rate- # of bits per second
 Analog
signals over multiple frequencies
 Uses Multiplexing


Mixing multiple signals over a cable’s bandwidth
Usually outside of your network
 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
 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
1.5
 What

is a protocol?
Set of rules for communication
 Protocol


Suite
Set of protocols that work together
TCP/IP
 Connection-oriented
 Sends

Like tracking a FedEx delivery
 Breaks


acknowledgements
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
 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
Guaranteed delivery
 Connection-oriented
 Acknowledgements
 Slower bc of
establishing a
connection &
acknowledging
 Email, web, file
transfer

TCP
Best effort delivery
 Connectionless
 No acknowledgements
 Faster bc of no
connection or
acknowledgements


Audio/video streams
UDP
Protocol
Information
HTTP
Connection to transfer web pages- TCP
HTTPS
Secure connection for web pages transmission- TCP
Security 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
Protocol
Information
SFTP & SCP Secure file transfer
DHCP
Automatically assign IP/SM/DG/DNS server addressesUDP
DNS
Translates names to IP addresses- TCP/UDP
NTP
Allows devices to sync their clocks through networkTCP/UDP
SNMP
Create alerts to monitor the network- UDP
ICMP
Can detect other devices & verify connectivity- PING
 Review
 Take
all protocols on 1.5.4
Quiz on 1.5.5
 Web
server
 FTP server
 DNS server
 DHCP server
 Directory Services

Directory of users on a network, resources, and
access control
 SSH

Review
1.5.2
1.5.3
1.5.4
Server
From client, you can connect remotely &
securely to a device
 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

Which protocol is used for web page
transmission?


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?


HTTP
Ping/ICMP
Which protocol allows remote login, but is not
secure?

Telnet
1.6
 Add

up the values of the binary 1’s
128
64
32
16
8
4
2
1
1
0
0
1
1
1
0
0
156
 11100101

229
 Binary

to Decimal Conversions
Add up the bit values to come up with the
decimal answer
 Decimal

Convert the decimal number to bits
 Binary

to Binary Conversions
Game
Play Now
 Hex=
MAC address
 0-9, A-F (10-15)
 Convert Hex to
Binary, then to
Decimal
 Convert backwards
too
 AB
 TestOut
Quiz 1.6.3
 Conversion
Handout/Quiz
 Complete
 Take
the study guide handout
all quizzes on TestOut
 Jeopardy
review
Chapter 1