data comm chapter 4.pptx
TRANSCRIPT
-
7/27/2019 DATA COMM CHAPTER 4.pptx
1/156
Prepared by :
Puan Nora Binti Abas
Edited by:
Noor Azura Osman
JKE, POLIMAS (2013)
CHAPTER 4DATA COMMUNICATION
-
7/27/2019 DATA COMM CHAPTER 4.pptx
2/156
OBJECTIVE
At the end of the unit you will be able to:
Understand the principle of datacommunication.
Know the history of data communication.
Understand data communication circuitarrangement.
Know network topology.
Understand network classification.
-
7/27/2019 DATA COMM CHAPTER 4.pptx
3/156
PRINCIPLE OF DATA COMMUNICATION
Not to be confused withtelecommunication
Any process that permitsthe passage from a senderto one or more receivers ofinformation of any nature,delivered in any easy to
use form by anyelectromagnetic system.
Data communication-
Defined as a subset oftelecommunication involving the
transmission of data to and fromcomputers and components ofcomputer systems.
More specifically data communication istransmitted via mediums such as wires,coaxial cables, fiber optics, or radiated
electromagnetic waves such asbroadcast radio, infrared light,
microwaves, and satellites.
Information that has been
processed, organized, andstored is call data.
Data communications simply meanthe transferring of digital information(usually in binary form) between twoor more points (terminals). At both the
source and destination, data are indigital form; however, during
transmission, they can be in digital oranalog form.
-
7/27/2019 DATA COMM CHAPTER 4.pptx
4/156
APPLICATION OF DATA COMMUNICATION
Electronic Mail (e-mail or Email).
Videotext. Teleconferencing.
AutomatedBanking
Machines.
Electronic BulletinBoards (BBS -Bulletin Board
Services).
-
7/27/2019 DATA COMM CHAPTER 4.pptx
5/156
SYNCHRONOUS DIGITAL HIERARCHY
SDH
This synchronoussystem has been
speciallydesigned in
order to providea simple and
flexible networkinfrastructure
The SDH is an internationalstandard that is highly popular
and used for its high speed datatransfer of the
telecommunication and digital
signals.
-
7/27/2019 DATA COMM CHAPTER 4.pptx
6/156
PLESIOCHRONOUS DIGITAL HIERARCHY
Digital hierarchy is a
popular technology that iswidely used in the networksof telecommunication in order
to transport the hugeamounts of data over thedigital equipment fortransportation
Ex:
microwave radio or fiber
optic systems.PDH
These groups of signals
can be transmitted as an
electrical signal over a
coaxial cable, as radio
signals, or optically via
fiber-optic systems
-
7/27/2019 DATA COMM CHAPTER 4.pptx
7/156
Uplink
Downlink
Transponder
Earth Station Microwave
-
7/27/2019 DATA COMM CHAPTER 4.pptx
8/156
Fibre Optic
-
7/27/2019 DATA COMM CHAPTER 4.pptx
9/156
Coaxial cable
Consists of an inner
conductor wire
surrounded by insulation,
called the dielectric
The dielectric issurrounded by a
conductive shield, which
is surrounded by a non-
conductive jacket. Coaxial
cable has better datatransmission rate than
twisted pair
-
7/27/2019 DATA COMM CHAPTER 4.pptx
10/156
No. Features SDH PDH
1. Interleaving Byte Interleaving Bit Interleaving
2. Management capability of powerful management Limited management available
3. Standard digital format world standard in digital format No world standard on digital format(three incompatible regional standards -European, North American and Japanese)
4. Optical interfaces optical Interfaces No world standard for optical interfaces.Networking is impossible at the opticallevel.
5. Multiplexing Structure Flexible synchronous multiplexing
structure .
Rigid asynchronous multiplexing structure.
6. Cost cost effective and easy traffic crossconnection capacity and add and dropfacility
Cost-effective support for access networks
COMPARISON BETWEEN SDH AND PDH
-
7/27/2019 DATA COMM CHAPTER 4.pptx
11/156
The History Of Data Communication
.
HISTORY OF DATA COMMUNICATION
-
7/27/2019 DATA COMM CHAPTER 4.pptx
12/156
Samuel Morse's 1837
exhibition of a telegraph system.
General Telecom, LLC
points to a telegraph patent .
Great Western Railway
telegraph service.
EARLY HISTORY
-
7/27/2019 DATA COMM CHAPTER 4.pptx
13/156
Alexander Graham Bell, 1876introduced the telephone.
Guglielmo Marconi, 1895
developments in communication technology .
1947
Bell Labs introduced the transistor, a device that found integration insubsequent electronic products.
1958
launching of a communications-oriented satellite, and the first facsimiletransmission over standard telephone lines occurred four years later.
HISTORY OF TELECOMMUNICATION
-
7/27/2019 DATA COMM CHAPTER 4.pptx
14/156
1962; First fax transmission in themodulation of data into sound fortransmission across telephonelines.
20th century; Modem technologycontinued to carry slower datatraffic.
1969; Development of InternetProtocol (IP) marked a significantmilestone in data communication.
By 1991, more than 1 million servershad used online using Internet
Protocol technology.
COMPUTER CONNECTION
-
7/27/2019 DATA COMM CHAPTER 4.pptx
15/156
1921,
the first commercial radio voices broadcast, acommunication channel that transmitted data inthe form of modulated radio waves and policedispatchers had adopted the technology .
1974,
the Federal Communication Commission (FCC)began allocating wireless spectrums for wirelesscommunication, and wireless companies beganintegrating radio packet data.
WIRELESS
-
7/27/2019 DATA COMM CHAPTER 4.pptx
16/156
DATA COMMUNICATION CIRCUIT ARRANGEMENT
-
7/27/2019 DATA COMM CHAPTER 4.pptx
17/156
Primary source -usually a
mainframecomputer with itsown set of localterminals and
peripheralequipment.
transmissionmedium - digital
information istransferred.
Data terminalequipment (DTE) -
the interfaceequipment used at
the station(between the host
and modem).
Datacommunicationsequipment (DCE) -
the equipment thatconverts digitalsignals to the
analog signals andinterfaces the data
terminal.
DATA COMMUNICATION CIRCUIT ARRANGEMENT
-
7/27/2019 DATA COMM CHAPTER 4.pptx
18/156
-
7/27/2019 DATA COMM CHAPTER 4.pptx
19/156
Graham Betts
Sender transmitted
Data is transmitted, on a single channel, one bit at a timeone after another
- Much faster than parallel because of way bits processed(e.g. USB and SATA drives)
Receiver received
Serial Transmission
101 0 0 1 1 0
-
7/27/2019 DATA COMM CHAPTER 4.pptx
20/156
Receiverreceive
d
-each bit has its own piece of wire along which it travels
- often used to send data to a printer
Parallel Transmission
Sen
dertransm
itted
All bits are sent simultaneously
1
0
0
1
1
0
01
-
7/27/2019 DATA COMM CHAPTER 4.pptx
21/156
Why Not use Parallel Instead of serial?
Due to inconsistencies on channelsdata arrives at different times
Because of the way it is transmittedpacket switching cannot be used
The above two points makes parallelslower than serial and requires higher
bandwidth.
Parallel transmissions are rarely usedanymore
-
7/27/2019 DATA COMM CHAPTER 4.pptx
22/156
Synchronous Transmissionall data sent at once and no packet switching
Asynchronous TransmissionUses stop/ start bits
most common type of serial data transfer
Allows packet switching
Allows sharing of bandwidth (i.e. talk on phone
while another person is using internet)
Synchronous VS
AsynchronousTransmissions
-
7/27/2019 DATA COMM CHAPTER 4.pptx
23/156
Graham Betts
- simplex: One direction only
Transmission Direction
-
7/27/2019 DATA COMM CHAPTER 4.pptx
24/156
Graham Betts
Half Duplex Transmission
half duplex:
Both directions
but only onedirection at a
time
-
7/27/2019 DATA COMM CHAPTER 4.pptx
25/156
Graham Betts
Full Duplex Transmission
fullduplex:
send andreceive
bothdirectionsat once
-
7/27/2019 DATA COMM CHAPTER 4.pptx
26/156
There are three basicconfigurations used to
connect computers theyare the
Bus
Ring
Star
NETWORK TOPOLOGIES
-
7/27/2019 DATA COMM CHAPTER 4.pptx
27/156
Graham Betts
Uses an empty data packet
called a token and a special
protocol called token ring.
Packets travel around the ring
in a clockwise direction.
Clients require an empty
token to transmit data.
Advantages
- no collisions because all
data travels in same direction.
Disadvantages
- fails if an individual node in
the network fails
Ring
http://bettscomputers.com/moodle/course/view.php?id=10 -
7/27/2019 DATA COMM CHAPTER 4.pptx
28/156
Graham Betts
A bus is a form of Ethernet. Nodes linked by a cable known as the bus. Bus transmits in
both directions and uses CSMA/CD protocol
BUS TOPOLOGY
Advantages
- Easy to set up and maintain
failure of one node does not affect
network
Disadvantages
-Higher rate of data collision thanwith a bus network
-fails if there is any damage to the
bus
-
7/27/2019 DATA COMM CHAPTER 4.pptx
29/156
Graham Betts
All data is sent from one client
to another through the server.
Advantages
- If one client fails no other
clients are affected.
Disadvantages- If central file server fails the
network fails.
Star
-
7/27/2019 DATA COMM CHAPTER 4.pptx
30/156
Network Hardware
-
7/27/2019 DATA COMM CHAPTER 4.pptx
31/156
Graham Betts
A network is a number of computers andperipheral devices connected together so
as to be able to communicate (i.e. transfer
data)Each device in a network is called a
node.
Terminals are data entry points whichcan also display.
What is a Network?
-
7/27/2019 DATA COMM CHAPTER 4.pptx
32/156
Graham Betts
LAN a network that connects computers in a limitedgeographical area.
MAN a backbone that connects LANs in a metropolitanarea such as a city and handles the bulk of communications
activity across that region.
WAN covers a large geographical area such as a city orcountry. Communication channels include telephone lines,Microwave, satellites, etc.
NETWORKS: categorized by size
NETWORK TOPOLOGIES
-
7/27/2019 DATA COMM CHAPTER 4.pptx
33/156
NETWORK TOPOLOGIES
(categorizing by shape)
-
7/27/2019 DATA COMM CHAPTER 4.pptx
34/156
Graham Betts
Large networks can be separated into two or more smaller networks using a bridge.
This is done to increase speed and efficiency. This type of network is called a segmented
LAN and has largely been superseded by the use of switches which can transfer data
straight to a computer and thus avoid bottleneck jams which bridges were designed to
fix.
Bridge
Bridge
-
7/27/2019 DATA COMM CHAPTER 4.pptx
35/156
Graham Betts
Often used to connect a LAN with a WAN. Gateways join two or
More different networks together.
Gateway
Gateway
-
7/27/2019 DATA COMM CHAPTER 4.pptx
36/156
Graham Betts
Internetpublic/international network which is used to access information, e-shopping, e-
banking, email
Intranetprivate network (LAN or WAN) used to share resources in secure environment
uses web pages (HTML to view) and TCP/IP protocols (to make connection)
Extranetintranet that has been extended to include access to or from selected external organizations
such as customers, but not general public.
Note: Connections via leased lines, or network interconnections.
Internet, Intranet, Extranet
-
7/27/2019 DATA COMM CHAPTER 4.pptx
37/156
Graham Betts
Transmission Media
twisted pair telephone cable
coaxial cableThick black cable used for higher
bandwidth communications than twisted pair
(i.e. Optus cable)
fibre optic data transferred through pulses of
light. Extremely fast.
Non cable methods such as satelite,
microwave, wireless and bluetooth
More on internet
http://www.bettscomputers.com/transmissionmedia.htmhttp://www.bettscomputers.com/transmissionmedia.htm -
7/27/2019 DATA COMM CHAPTER 4.pptx
38/156
Graham Betts
SERVERS: Help to manage the network and the resources of that network.On larger networks servers commonly have specialised tasks such as: File Servers:stores and manages files, Print Servers: manages printers and print jobs, MailServer: Manages email, Web Server: manages web access.
Routers: connects multiple networks and are protocol independent. can be
used in place of a switch or bridge.Switches: smart hubs which transmit packets to the destination port onlyHubs: like double adapters /power boards in the home except instead ofplugging in extension cords we are plugging in computers to allow them tocommunicate.
Network HardwareMore on Internet
http://bettscomputers.com/moodle/course/view.php?id=61http://bettscomputers.com/moodle/course/view.php?id=61 -
7/27/2019 DATA COMM CHAPTER 4.pptx
39/156
Graham Betts
- adding/removing users
- assigning users to printers
- giving users file access rights
- installation of software and sharing with users
- client installation and protocol assignment
- logon and logoff procedures
- network based applications
Some Network Administration Tasks
-
7/27/2019 DATA COMM CHAPTER 4.pptx
40/156
Graham Betts
Other Information Processesin Communication Systems
Collecting: phone as collection device with voice mail,EFTPOS terminal as a collection device for electronicbanking
processing: sending of attachments with e-mail, encoding
and decoding methods, including: analog data to analogsignal, digital data to analog signal, digital data to digitalsignal, analog data to digital signal, client-serverarchitecture: the client controls the user interface and theapplication logic server controls access to the database
-
7/27/2019 DATA COMM CHAPTER 4.pptx
41/156
Graham Betts
Collecting: The following are collection devices:ATMs for internetbanking, EFTPOS for stores, microphone and video camera for videoconferencing. Data can be analog or digital
Collecting
-
7/27/2019 DATA COMM CHAPTER 4.pptx
42/156
Graham Betts
Processing
Processing: Is the manipulation or changing
the data into a more useable format. The
processing may include changing the
appearance of the data, the file type orstorage options.
-
7/27/2019 DATA COMM CHAPTER 4.pptx
43/156
Graham Betts
Displaying
Displaying: How the information ismade available for the user to see
-
7/27/2019 DATA COMM CHAPTER 4.pptx
44/156
Graham Betts
Issues related toCommunication Systems
Messaging Systems (social context, Danger of Misinterpretation, PowerRelationships, Privacy and confidentiality, power relationships, electronic junkmail, information overload)
Internet (Internet trading, taxation, employment, nature of business, tradebarriers, censorship, child protection, internet banking, security, changing natureof work, branch closures and job losses, radio and video)
Telecommuting (work from home), blurring between work and home, morestress, advantagesand disadvantages)
-
7/27/2019 DATA COMM CHAPTER 4.pptx
45/156
Graham Betts
netiquette is etiquette/ manners on netMany people rely on messaging systems more
than spoken or face to face communication.written word only recipient miss out on (e.g. bodylanguage and voice inflection)privacy (employers have right to read e-mail at
work)Spam is overloading mailboxesWork/ information overload from ever growingnumber of emails
Issues relating to messaging systems
Issues relating to internet trading
-
7/27/2019 DATA COMM CHAPTER 4.pptx
46/156
Graham Betts
Issues relating to internet trading
employment ramifications
Effect on trade barriers and taxationlaws
Phishing and security
-
7/27/2019 DATA COMM CHAPTER 4.pptx
47/156
Graham Betts
branch closures and job lossesdecreasing number of bank branchesjob losseschanging nature of worksecurity of banking details
Issues relating to internet banking
-
7/27/2019 DATA COMM CHAPTER 4.pptx
48/156
Graham Betts
Physical boundaries
telecommuting is working from home
virtual organisations
national trade barriers
-
7/27/2019 DATA COMM CHAPTER 4.pptx
49/156
Graham Betts
Acknowledgements
Slides 11-15 were originally created by Bob
Baker and have been modified by Graham
Betts
A number of slides have been adapted from a
slide show by Loretta Kocovska around 2001
especially the illustrations on slides 18,39,40,
41, 42 and 43
Serial Data Transmission
-
7/27/2019 DATA COMM CHAPTER 4.pptx
50/156
Serial Data Transmission
Figure 4.2 shows the concept of serial
transmission.
Due to the sequential nature of the serial data
transmission, usually it takes longer time to
send this way.
Serialtransmission is used for long-distance
communications..
Figure 4 2: Serial data transmission
-
7/27/2019 DATA COMM CHAPTER 4.pptx
51/156
Figure 4.2: Serial data transmission
A B
0 1 1 0
Clock4 T
T T T T
Figure 4.1: Serial data transmission
Parallel Data Transmission
-
7/27/2019 DATA COMM CHAPTER 4.pptx
52/156
Parallel Data Transmission
All the bits of a code word are transferred
simultaneously and as a result, it is extremely
fast.
One wire for each bit of information to be
transmitted. This means a multi wire cable
must be used.
Used for short-distance communications and
within a computer
Figure 4 3: Parallel data transmission
-
7/27/2019 DATA COMM CHAPTER 4.pptx
53/156
Figure 4.3: Parallel data transmission
MSB
A3
A
A2
A1
A0
LSB
A3
A2 B
A1
A0
0
Clock
T
0
1
1
The Differences between Serial and Parallel
-
7/27/2019 DATA COMM CHAPTER 4.pptx
54/156
Transmission
Table 2 : The Differences between Serial and
Parallel Transmission.
Modes of Data Transmission
http://localhost/var/www/apps/conversion/tmp/scratch_6/Table%204.2.dochttp://localhost/var/www/apps/conversion/tmp/scratch_6/Table%204.2.dochttp://localhost/var/www/apps/conversion/tmp/scratch_6/Table%204.2.dochttp://localhost/var/www/apps/conversion/tmp/scratch_6/Table%204.2.doc -
7/27/2019 DATA COMM CHAPTER 4.pptx
55/156
Modes of Data Transmission
Modes of Data Transmission is the flow of
data between two points.
i. Simplex
ii. HalfDuplex
iii. Full Duplex
iv. Full Full Duplex
SIMPLEX
-
7/27/2019 DATA COMM CHAPTER 4.pptx
56/156
SIMPLEX
Data flows in only one direction on the data
communication line (medium).
Examples are radio and television broadcasts.
They go from the TV station to your home
television
Simplex Transmission
-
7/27/2019 DATA COMM CHAPTER 4.pptx
57/156
Simplex Transmission
Half-Duplex
-
7/27/2019 DATA COMM CHAPTER 4.pptx
58/156
Half Duplex
Data flows in both directions but only one
direction at a time on the data communication
line.
For example, a conversation on walkie-talkies
is a half-duplex data flow. Each person takes
turns talking. If both talk at once - nothing
occurs!
-
7/27/2019 DATA COMM CHAPTER 4.pptx
59/156
Half-Duplex Transmission (Walkie-Talkie)
Full-Duplex
-
7/27/2019 DATA COMM CHAPTER 4.pptx
60/156
Full Duplex
Data flows in both directions simultaneously.
Modems are configured to flow data in both
directions.
Full duplex (FDX) operation requires 2
separate communication channels, so that
simultaneous 2 way communication can occur.
Full-Duplex transmission
-
7/27/2019 DATA COMM CHAPTER 4.pptx
61/156
Full Duplex transmission
Full-Full Duplex
-
7/27/2019 DATA COMM CHAPTER 4.pptx
62/156
Full Full Duplex
Data flows in both directions simultaneously
and in the same time received data.
Network Topology
-
7/27/2019 DATA COMM CHAPTER 4.pptx
63/156
Network Topology
Main Types of Physical Topologies:
i. Star
ii. Bus
iii. Ring
iv. Mesh
v. Hybrid
Star Topology
-
7/27/2019 DATA COMM CHAPTER 4.pptx
64/156
Designed with each node (file server,workstations, and peripherals) connecteddirectly to a central network hub, switch, or
concentrator . All computers are connected to a centralized
mainframe computer.
Consists of central host and all nodes areconnect to a host. The host will control theflow of communication in the network.
Star Topology
-
7/27/2019 DATA COMM CHAPTER 4.pptx
65/156
Star Topology
Bus Topology
-
7/27/2019 DATA COMM CHAPTER 4.pptx
66/156
All nodes (file server, workstations, and
peripherals) are connected to the linearcable.
That is consists of single central cable
(Backbone).
All nodes are sharing the backbone to
communicate with each other on the
network.
Bus Topology
-
7/27/2019 DATA COMM CHAPTER 4.pptx
67/156
p gy
Ring Topology
-
7/27/2019 DATA COMM CHAPTER 4.pptx
68/156
Each node connects to exactly two other
nodes, forming a single continuous pathway
for signals through each node - a ring.
Data travels from node to node, with eachnode along the way handling every packet.
A node failure or cable break might isolate
every node attached to the ring.
Ring Topology
-
7/27/2019 DATA COMM CHAPTER 4.pptx
69/156
g p gy
Mesh topology
-
7/27/2019 DATA COMM CHAPTER 4.pptx
70/156
p gy
Each node must not only capture and
disseminate its own data, but also serve as a
relayfor other nodes, that is, it must
collaborate to propagate the data in thenetwork.
The message propagates along a path, by
hopping from node to node until thedestination is reached.
Mesh Topology
-
7/27/2019 DATA COMM CHAPTER 4.pptx
71/156
p gy
Hybrid Topology
-
7/27/2019 DATA COMM CHAPTER 4.pptx
72/156
y p gy
A combination of topologies that do not exhibit thecharacteristics of any standard topology.
Connects network components by combining the features oftwo or more other topologies (such as star, bus, and ring).
The resulting hybrid topology exhibits features (and
limitations) of its comprising network components. Examplesof hybrid topologies include the star-wired ring and star-wiredbus.
Network Classification
-
7/27/2019 DATA COMM CHAPTER 4.pptx
73/156
A network consists of two or more computers
that are linked in order to share resources
(such as printers and CDs), exchange files, or
allow electronic communications. The computers on a network may be linked
through cables, telephone lines, radio waves,
satellites, or infrared light beams.
LAN (Local Area Network)
-
7/27/2019 DATA COMM CHAPTER 4.pptx
74/156
A group of computers connected within a building, single
floor, small company or a campus.
Useful for sharing resources like files, printers, games orother applications.
Most local area networks are built with relatively
inexpensive hardware such as Ethernet cables, network
adapters, and hubs. A LAN connects network devices over a relatively short
distance.
LAN Network
http://compnetworking.about.com/library/glossary/bldef-ethernet.htmhttp://compnetworking.about.com/cs/lanvlanwan/g/bldef_lan.htmhttp://compnetworking.about.com/cs/lanvlanwan/g/bldef_lan.htmhttp://compnetworking.about.com/library/glossary/bldef-ethernet.htm -
7/27/2019 DATA COMM CHAPTER 4.pptx
75/156
MAN (Metropolitan Area Network)
-
7/27/2019 DATA COMM CHAPTER 4.pptx
76/156
A large computer network that usually spans a
city or a large campus.
Usually interconnects a number oflocal area
networks (LANs) using a high-capacitybackbone technology, such as fiber-optical
links, and provides up-link services to wide
area networks (or WAN) and the Internet.
Metropolitan Area Network
http://en.wikipedia.org/wiki/Local_area_networkhttp://en.wikipedia.org/wiki/Local_area_networkhttp://en.wikipedia.org/wiki/Wide_area_networkhttp://en.wikipedia.org/wiki/Wide_area_networkhttp://en.wikipedia.org/wiki/Internethttp://en.wikipedia.org/wiki/Internethttp://en.wikipedia.org/wiki/Wide_area_networkhttp://en.wikipedia.org/wiki/Wide_area_networkhttp://en.wikipedia.org/wiki/Local_area_networkhttp://en.wikipedia.org/wiki/Local_area_network -
7/27/2019 DATA COMM CHAPTER 4.pptx
77/156
WAN (Wide Area Network)
-
7/27/2019 DATA COMM CHAPTER 4.pptx
78/156
Very large networks that interconnect smaller LAN networks,for a large geographic area like a country (i.e., any networkwhose communications links cross metropolitan, regional, ornational boundaries.). WANs are usually for privatecompanies; however, some built by internet service providers
connect LANs to the internet. WAN can use a combination of satellites, microwave, and link
and variety of computers from mainframes to terminals. A'node' on a WAN is a LAN
Wide Area Network
-
7/27/2019 DATA COMM CHAPTER 4.pptx
79/156
GAN (Global area Network)
-
7/27/2019 DATA COMM CHAPTER 4.pptx
80/156
GAN refers to any network that is composed
of different interconnected computer
networks (WANs) and also covers an unlimited
geographical area.
THE END
http://www.webopedia.com/TERM/N/network.htmlhttp://www.webopedia.com/TERM/W/wide_area_network_WAN.htmlhttp://www.webopedia.com/TERM/W/wide_area_network_WAN.htmlhttp://www.webopedia.com/TERM/N/network.html -
7/27/2019 DATA COMM CHAPTER 4.pptx
81/156
TOPICS MENU
-
7/27/2019 DATA COMM CHAPTER 4.pptx
82/156
Graham Betts
TOPICS MENU
Characteristics of Communication Systems
Examples of Communication Systems
Transmitting and Receiving
Other Information Processes
Issues Related To Communication Systems
Click on the topic of your choice
C i i T
-
7/27/2019 DATA COMM CHAPTER 4.pptx
83/156
Graham Betts
Communications Glossary
Communications Networking Glossary
Glossary of Networking terms at Clock.org
Communications Terms
http://bettscomputers.com/moodle/mod/glossary/view.php?id=76http://www.lantronix.com/learning/glossary.htmlhttp://www.clock.org/~jss/glossary/http://www.clock.org/~jss/glossary/http://www.lantronix.com/learning/glossary.htmlhttp://bettscomputers.com/moodle/mod/glossary/view.php?id=76 -
7/27/2019 DATA COMM CHAPTER 4.pptx
84/156
Graham Betts
Characteristics of
Communication Systems
Protocols
Handshaking
Speed of TransmissionError Checking
Communication Settings
Characteristics of Communication
-
7/27/2019 DATA COMM CHAPTER 4.pptx
85/156
Graham Betts
More Information
must be a Sender and ReceiverA protocol is a set of rules which governs the transfer of data between
computers. Protocols allow communication between computers and networks.Handshaking is used to establish which protocols to use. Handshaking
controls the flow of data between computers
protocols will determine the speed of transmission, error checking method,size of bytes, and whether synchronous or asynchronous
Examples of protocols are: token ring, CSMA/CD, X.25, TCP/IP
Systems
http://www.bettscomputers.com/communications.htmhttp://www.bettscomputers.com/communications.htmhttp://www.bettscomputers.com/communications.htm -
7/27/2019 DATA COMM CHAPTER 4.pptx
86/156
Graham Betts
5 Basic Components
Every communication system has 5 basic requirements
Data Source(where the data originates)
Transmitter (device used to transmit data)
Transmission Medium(cables or non cable)
Receiver (device used to receive data)
Destination(where the data will be placed)
-
7/27/2019 DATA COMM CHAPTER 4.pptx
87/156
Graham Betts
5 Basic Components
Transmission Media Speed
-
7/27/2019 DATA COMM CHAPTER 4.pptx
88/156
Graham Betts
Bandwidth:The amount of data which can be transmitted on amedium over a fixed amount of time (second). It is measured on Bits perSecond or Baud
Bits per Second (bps): A measure of transmissionspeed. The number of bits (0 0r 1) which can be transmitted in a second(more)
Baud Rate: Is a measure of how fast a change of state occurs(i.e. a change from 0 to 1) (more)
Transmission Media Speed
http://bettscomputers.com/moodle/course/view.php?id=14http://bettscomputers.com/moodle/course/view.php?id=14http://bettscomputers.com/moodle/course/view.php?id=14http://bettscomputers.com/moodle/course/view.php?id=14 -
7/27/2019 DATA COMM CHAPTER 4.pptx
89/156
Graham Betts
This file has now been broken into four packets
PACKET
Packets
Transmissions are broken up into smaller
units or data transmissions called packets
PACKET PACKET PACKET
Example
A data file is divided into packets.
It does not matter what the transmission is. It could be Word
document, a PowerPoint or an MP3. Imagine this Green box
is a file for transfer
-
7/27/2019 DATA COMM CHAPTER 4.pptx
90/156
Graham Betts
Packets and OSI
After the file is divided into packets extrainformation is required to make sure it all goes
back together correctly. The OSI model helps
to look after this. The OSI model also provides much more
information which is included with each
package.
OSI 7 Layer Model
-
7/27/2019 DATA COMM CHAPTER 4.pptx
91/156
Graham Betts
More Information on OSI
OSI Open System InterconnectionOSI is not a protocol but a list of protocols
divided between 7 layers with each layer
having a different set of functions.Each packet is layered/packaged with
protocols from each of the layers as it is
processed.
The process of layering the protocols around
each package is called encapsulation. The final
encapsulated data packet is called a frame.
Originally Created by Bob Baker
Modified 2006
Graham Betts
Open Systems InterconnectionOriginally Created by Bob BakerModified 2006
Graham Betts
http://www.bettscomputers.com/osilayersmodel.htmhttp://www.bettscomputers.com/osilayersmodel.htm -
7/27/2019 DATA COMM CHAPTER 4.pptx
92/156
Graham Betts
File
OSI Reference model
Layer 7 application
Layer 6 presentation
Layer 5 session
Layer 4 transport
Layer 3 network
Layer 2 data link
Layer 1 physical
Transmission Medium
File
Sender Receiver
File
Each file
is divided
into
packets The received
frame is then
unpacked
in theopposite order
Graham Betts
Each Packet
will
then be
Encapsulated
with
PROTOCOLS
The protocolsWill be added
systematically
Layer
By layer
The encapsulated
Packet is called
a frame
Originally Created by Bob Baker
Modified 2006
Graham BettsServices Performed at Each Layer
-
7/27/2019 DATA COMM CHAPTER 4.pptx
93/156
Graham Betts
Layer 7 application
Layer 6 presentation
Layer 5 session Layer 4 transport
Layer 3 network
Layer 2 data link
Layer 1 physical
Identification, authentication
Format conversion
Set-up coordinate conversation
Ensures error-free transfer
Routing of data through network
Error control and synchronisation
Placing signals on the carrier
Graham Betts
Originally Created by Bob Baker
Modified 2006
Graham Betts
-
7/27/2019 DATA COMM CHAPTER 4.pptx
94/156
Graham Betts
Examples of protocols
Layer 7 application
Layer 6 presentation
Layer 5 session
Layer 4 transport
Layer 3 network
Layer 2 data link
Layer 1 physical
E-mail, Web browser, Directory
POP, SMTP, FTP, HTTP, DNS
Sockets
TCP
IP
PPP, Ethernet, Token ring
100baseT
More on Protocols
Graham Betts
Originally Created by Bob Baker
Modified 2006
Graham Betts
http://bettscomputers.com/moodle/mod/resource/view.php?id=653http://bettscomputers.com/moodle/mod/resource/view.php?id=653 -
7/27/2019 DATA COMM CHAPTER 4.pptx
95/156
Graham Betts
EncapsulationApplicationPresentation
Session
Transport
Network
Data Link
Physical
data
Device 1 Device 2
dataH6 T6
dataH5 T5
dataH4 T4
(packet)H3 data T3
H2 data T2
H1 data T1
carrier FRAME
Application
Presentation
Session
Transport
Network
Data Link
Physical
A typical frame DestinationAddress
Source
AddressData Padding CRCPreamble
FRAME FRAME FRAME
(Packet)
Graham Betts
Error Checking Methods
-
7/27/2019 DATA COMM CHAPTER 4.pptx
96/156
Graham Betts
Parity bit check Check sum
* data transmitted in blocks, each block addedto give a total checksum
* used in X Modem protocol
Cycle redundancy check
Error Checking Methods
More on internet
http://bettscomputers.com/moodle/course/view.php?id=60http://bettscomputers.com/moodle/course/view.php?id=60 -
7/27/2019 DATA COMM CHAPTER 4.pptx
97/156
Graham Betts
HSC Topic 3.3
Examples of Communication
Systems
-
7/27/2019 DATA COMM CHAPTER 4.pptx
98/156
Graham Betts
Examples of Communication Systems
- E-mail- Voice Mail - Fax- Smart Phone - Instant Messaging- Telecommuting - Video-conferencing- Groupware - Telephony
- E-Commerce - The Internet- Bulletin board system - The Web- Global positioning system
-
7/27/2019 DATA COMM CHAPTER 4.pptx
99/156
Graham Betts
HSC Topic 3.4
Transmitting and Receivingin Communication Systems
Communication concepts
(transmission of data, protocols and handshaking, networks, LANs andWANs,Topologies, Network Access Methods)
Network Hardware (NICs, Servers, Routers and Switches, Bridges and gateways, Hubs, Transmission
media
Network Software
NOSs, Network Operating System Tasks, Logon and Logoff Procedures, Intranets andExtranets
-
7/27/2019 DATA COMM CHAPTER 4.pptx
100/156
Graham Betts
Any transmission May be:
analog or digital
Serial or parallel
Communication Concepts
l
-
7/27/2019 DATA COMM CHAPTER 4.pptx
101/156
Graham Betts
Sender transmitted
Data is transmitted, on a single channel, one bit at a timeone after another
- Much faster than parallel because of way bits processed(e.g. USB and SATA drives)
Receiver received
Serial Transmission
101 0 0 1 1 0
Parallel Transmission
-
7/27/2019 DATA COMM CHAPTER 4.pptx
102/156
Graham Betts
Receiverreceiv
ed
-each bit has its own piece of wire along which it travels- often used to send data to a printer
Send
ertransmitted
All bits are sent simultaneously
1
0
01
1
0
0
1
Why Not use Parallel Instead of serial?
-
7/27/2019 DATA COMM CHAPTER 4.pptx
103/156
Graham Betts
Due to inconsistencies on channels data arrives atdifferent times
Because of the way it is transmitted packet switching
cannot be used
The above two points makes parallel slower than
serial and requires higher bandwidth.
Parallel transmissions are rarely used anymore
Synchronous Vs
A h T i i
-
7/27/2019 DATA COMM CHAPTER 4.pptx
104/156
Graham Betts
Synchronous Transmissionall data sent at once and no packet switching
Asynchronous TransmissionUses stop/ start bits
most common type of serial data transfer
Allows packet switching
Allows sharing of bandwidth (i.e. talk on phone
while another person is using internet)
AsynchronousTransmissions
Transmission Direction
-
7/27/2019 DATA COMM CHAPTER 4.pptx
105/156
Graham Betts
- simplex: One direction only
Transmission Direction
Half Duplex Transmission
-
7/27/2019 DATA COMM CHAPTER 4.pptx
106/156
Graham Betts
half duplex: Both
directions but
only one
direction at a
time
Full Duplex Transmission
-
7/27/2019 DATA COMM CHAPTER 4.pptx
107/156
Graham Betts
full duplex:
send and
receive bothdirections at
once
3 Common Protocols
-
7/27/2019 DATA COMM CHAPTER 4.pptx
108/156
Graham Betts
Ethernet (Ethernet Network)
-Carrier Sense Multiple Access/Collision Detection (CSMA/CD)
-TCP/IP
3 Common Protocols
-
7/27/2019 DATA COMM CHAPTER 4.pptx
109/156
Graham Betts
Ethernet
Developed at Xerox in 1976.
First protocol approved as an industrystandard protocol 1983
LAN protocol used on bus and star
Most popular LAN protocol
Inexpensive
Carrier Sense Multiple Access/Collision
-
7/27/2019 DATA COMM CHAPTER 4.pptx
110/156
Graham Betts
Carrier Sense Multiple Access/Collision
Detection (CSMA/CD)
- Used on bus networks to avoid data
collisions.
TCP/IP
-
7/27/2019 DATA COMM CHAPTER 4.pptx
111/156
Graham Betts
Developed in 1973 for use on theARPANET which was a defense forceresearch network.
-Adopted in 1983 as the Internet standard.all hosts on the Internet are required touse TCP/IP.
- Allows transfer of data using packetswitching
TCP/IP
-
7/27/2019 DATA COMM CHAPTER 4.pptx
112/156
Graham Betts
LANs Vs WANs
LANis local Area network which is anetwork confined to a small geographic area
which is a building or a group of buildings.
WANis wide area network which is anetwork spread over a large geographic area.
The largest WAN is the internet.
-
7/27/2019 DATA COMM CHAPTER 4.pptx
113/156
Graham Betts
Examples of LANS
3 different types of LANS are:
Ring
BusStar
Uses an empty data packet
called a token and a specialRing
-
7/27/2019 DATA COMM CHAPTER 4.pptx
114/156
Graham Betts
protocol called token ring.
Packets travel around the ring
in a clockwise direction.
Clients require an emptytoken to transmit data.
Advantages
- no collisions because all
data travels in same direction.
Disadvantages
- fails if an individual node in
the network fails
Ring
BUS TOPOLOGY
http://bettscomputers.com/moodle/course/view.php?id=10 -
7/27/2019 DATA COMM CHAPTER 4.pptx
115/156
Graham Betts
A bus is a form of Ethernet. Nodes linked by a cable known as the bus. Bus transmits in
both directions and uses CSMA/CD protocol
Advantages
- Easy to set up and maintainfailure of one node does not affect
network
Disadvantages
-Higher rate of data collision thanwith a bus network
-fails if there is any damage to the
bus
Star
-
7/27/2019 DATA COMM CHAPTER 4.pptx
116/156
Graham Betts
All data is sent from one client
to another through the server.
Advantages
- If one client fails no other
clients are affected.
Disadvantages
- If central file server fails thenetwork fails.
-
7/27/2019 DATA COMM CHAPTER 4.pptx
117/156
Graham Betts
Network Hardware
What is a Network?
-
7/27/2019 DATA COMM CHAPTER 4.pptx
118/156
Graham Betts
A network is a number of computers andperipheral devices connected together so
as to be able to communicate (i.e. transfer
data)Each device in a network is called a
node.
Terminals are data entry points whichcan also display.
NETWORKS: categorized by size
-
7/27/2019 DATA COMM CHAPTER 4.pptx
119/156
Graham Betts
LAN a network that connects computers in a limitedgeographical area.
MAN a backbone that connects LANs in a metropolitanarea such as a city and handles the bulk of communicationsactivity across that region.
WAN covers a large geographical area such as a city orcountry. Communication channels include telephone lines,Microwave, satellites, etc.
NETWORKS: categorized by size
NETWORK TOPOLOGIES(categorizing by shape)
-
7/27/2019 DATA COMM CHAPTER 4.pptx
120/156
Graham Betts
(categorizing by shape)
Bridge
-
7/27/2019 DATA COMM CHAPTER 4.pptx
121/156
Graham Betts
Large networks can be separated into two or more smaller networks using a bridge.
This is done to increase speed and efficiency. This type of network is called a segmentedLAN and has largely been superseded by the use of switches which can transfer data
straight to a computer and thus avoid bottleneck jams which bridges were designed to
fix.
Bridge
Bridge
Gateway
-
7/27/2019 DATA COMM CHAPTER 4.pptx
122/156
Graham Betts
Often used to connect a LAN with a WAN. Gateways join two or
More different networks together.
Gateway
Internet
Internet, Intranet, Extranet
-
7/27/2019 DATA COMM CHAPTER 4.pptx
123/156
Graham Betts
Internetpublic/international network which is used to access information, e-shopping, e-
banking, email
Intranetprivate network (LAN or WAN) used to share resources in secure environment
uses web pages (HTML to view) and TCP/IP protocols (to make connection)
Extranetintranet that has been extended to include access to or from selected external organizations
such as customers, but not general public.
Note: Connections via leased lines, or network interconnections.
Transmission Media
http://www.bettscomputers.com/transmissionmedia.htm -
7/27/2019 DATA COMM CHAPTER 4.pptx
124/156
Graham Betts
twisted pair telephone cable coaxial cableThick black cable used for higher
bandwidth communications than twisted pair
(i.e. Optus cable) fibre optic data transferred through pulses of
light. Extremely fast.
Non cable methods such as satelite,microwave, wireless and bluetooth
More on internet
Network HardwareMore on Internet
http://www.bettscomputers.com/transmissionmedia.htmhttp://www.bettscomputers.com/transmissionmedia.htmhttp://bettscomputers.com/moodle/course/view.php?id=61http://bettscomputers.com/moodle/course/view.php?id=61 -
7/27/2019 DATA COMM CHAPTER 4.pptx
125/156
Graham Betts
SERVERS: Help to manage the network and the resources of that network.On larger networks servers commonly have specialised tasks such as: File Servers:stores and manages files, Print Servers: manages printers and print jobs, MailServer: Manages email, Web Server: manages web access.
Routers: connects multiple networks and are protocol independent. can beused in place of a switch or bridge.
Switches: smart hubs which transmit packets to the destination port onlyHubs: like double adapters /power boards in the home except instead ofplugging in extension cords we are plugging in computers to allow them tocommunicate.
More on Internet
Some Network Administration
T k
http://bettscomputers.com/moodle/course/view.php?id=61http://bettscomputers.com/moodle/course/view.php?id=61 -
7/27/2019 DATA COMM CHAPTER 4.pptx
126/156
Graham Betts
- adding/removing users
- assigning users to printers
- giving users file access rights
- installation of software and sharing with users
- client installation and protocol assignment- logon and logoff procedures
- network based applications
Tasks
-
7/27/2019 DATA COMM CHAPTER 4.pptx
127/156
Graham Betts
Other Information Processesin Communication Systems
Collecting: phone as collection device with voice mail,EFTPOS terminal as a collection device for electronicbanking
processing: sending of attachments with e-mail, encodingand decoding methods, including: analog data to analog
signal, digital data to analog signal, digital data to digitalsignal, analog data to digital signal, client-serverarchitecture: the client controls the user interface and theapplication logic server controls access to the database
Collecting
-
7/27/2019 DATA COMM CHAPTER 4.pptx
128/156
Graham Betts
Collecting: The following are collection devices:ATMs for internetbanking, EFTPOS for stores, microphone and video camera for videoconferencing. Data can be analog or digital
g
P i
-
7/27/2019 DATA COMM CHAPTER 4.pptx
129/156
Graham Betts
Processing
Processing: Is the manipulation or changingthe data into a more useable format. The
processing may include changing the
appearance of the data, the file type orstorage options.
Di l i
-
7/27/2019 DATA COMM CHAPTER 4.pptx
130/156
Graham Betts
Displaying
Displaying: How the information is
made available for the user to see
-
7/27/2019 DATA COMM CHAPTER 4.pptx
131/156
Graham Betts
Issues related to
Communication Systems
Messaging Systems (social context, Danger of Misinterpretation, PowerRelationships, Privacy and confidentiality, power relationships, electronic junkmail, information overload)
Internet (Internet trading, taxation, employment, nature of business, tradebarriers, censorship, child protection, internet banking, security, changing nature
of work, branch closures and job losses, radio and video)
Telecommuting (work from home), blurring between work and home, morestress, advantagesand disadvantages)
Issues relating to messaging
t
-
7/27/2019 DATA COMM CHAPTER 4.pptx
132/156
Graham Betts
netiquette is etiquette/ manners on netMany people rely on messaging systems morethan spoken or face to face communication.
written word only recipient miss out on (e.g. bodylanguage and voice inflection)privacy (employers have right to read e-mail atwork)Spam is overloading mailboxesWork/ information overload from ever growingnumber of emails
systems
Issues relating to internet trading
-
7/27/2019 DATA COMM CHAPTER 4.pptx
133/156
Graham Betts
employment ramifications
Effect on trade barriers and taxationlaws
Phishing and security
Issues relating to internet
banking
-
7/27/2019 DATA COMM CHAPTER 4.pptx
134/156
Graham Betts
branch closures and job lossesdecreasing number of bank branches
job losseschanging nature of worksecurity of banking details
banking
Physical boundaries
-
7/27/2019 DATA COMM CHAPTER 4.pptx
135/156
Graham Betts
Physical boundaries
telecommuting is working from home virtual organisations
national trade barriers
Acknowledgements
-
7/27/2019 DATA COMM CHAPTER 4.pptx
136/156
Graham Betts
Acknowledgements
Slides 11-15 were originally created by BobBaker and have been modified by Graham
Betts
A number of slides have been adapted from aslide show by Loretta Kocovska around 2001
especially the illustrations on slides 18,39,40,
41, 42 and 43
-
7/27/2019 DATA COMM CHAPTER 4.pptx
137/156
a tour of new features
introducing
POWERPOINT 2010
EnhancingYour Presentation
-
7/27/2019 DATA COMM CHAPTER 4.pptx
138/156
We have features for every step of the way
Author YourPresentation
Enrich YourPresentation
Deliver YourPresentation
-
7/27/2019 DATA COMM CHAPTER 4.pptx
139/156
Author Your Presentation
Design, organize, and collaborate
Getting Startedwith Templates
-
7/27/2019 DATA COMM CHAPTER 4.pptx
140/156
Use sample templatesto kick-off
your presentation and focus on the
content (youre viewing one right
now!)
You dont have to start from scratch.
If you need help with a status report
or ideas for a photo album, look no
further.
Too much information?
-
7/27/2019 DATA COMM CHAPTER 4.pptx
141/156
Org
anizewith
Sections
Divide and conquer a large presentation by organizing your
presentation with sections.
You can name, print, and
apply effects to an entire
section easily.
-
7/27/2019 DATA COMM CHAPTER 4.pptx
142/156
Simultaneous edits on one single document.
No more waiting your turn or managing
multiple versions.
Its about team work, and co-authoringwill
get you there.
Collaboration
-
7/27/2019 DATA COMM CHAPTER 4.pptx
143/156
Enrich Your Presentation
Stylize, edit, and animate your media
-
7/27/2019 DATA COMM CHAPTER 4.pptx
144/156
Its not just about the visuals, but strengthening
YOUR MESSAGE.
New Picture Effects
-
7/27/2019 DATA COMM CHAPTER 4.pptx
145/156
Picture Color, Corrections, Artistic Effects,
and Background Removal allow you to customize images for your story
Animate This
-
7/27/2019 DATA COMM CHAPTER 4.pptx
146/156
Check out this animation:
With the Animation Painteryou can re-create the same animation with one click
Video Perfect
-
7/27/2019 DATA COMM CHAPTER 4.pptx
147/156
You can do a lot more with videos in
PowerPoint 2010.
Videos can be embedded in your
presentation. Thats right, no more
lost videos!
Also, you can recolor the entire video
or apply a video style easily. Your
videos will look great!
Want to jump to a
-
7/27/2019 DATA COMM CHAPTER 4.pptx
148/156
Fountain Geyser
bookmark in your video?
Hover over the video andyoull be pleasantly surprised.
Did we mention you can add
bookmarks, includefades, and
trimyour videos now?
Exciting new transitions
-
7/27/2019 DATA COMM CHAPTER 4.pptx
149/156
What about the beautiful transitionsyouve been seeing?
They are new too.
-
7/27/2019 DATA COMM CHAPTER 4.pptx
150/156
Deliver Your Presentation
Broadcast and compress for seamless delivery
BROADCAST IT
-
7/27/2019 DATA COMM CHAPTER 4.pptx
151/156
Show and tell your presentation with
Broadcast Slide Show
Share your presentation in real-time with
anyone with a browser, directly from
PowerPoint.
Youll never have to say, Next slide, please
again!
BROADCAST IT
-
7/27/2019 DATA COMM CHAPTER 4.pptx
152/156
Record your presentation with
Create a Videoand capture narrations,
animations, media, and much more.
Upload, embed, and share away!
Spread the Message!
-
7/27/2019 DATA COMM CHAPTER 4.pptx
153/156
For a media-rich presentation, you
can Optimize for Compatibility
orCompress Media to share your
presentation reliably without
exploding your inbox
Package your presentation
for easy sharing
-
7/27/2019 DATA COMM CHAPTER 4.pptx
154/156
?
But wait
Theres More!
View your slides from anywhere!
AccessAnywhere
-
7/27/2019 DATA COMM CHAPTER 4.pptx
155/156
Check out the
PowerPoint Web App
Access slides wherever you are
-
7/27/2019 DATA COMM CHAPTER 4.pptx
156/156
Whats Your Message?POWERPOINT 2010