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ASET
Lecture 1
I ntroduction to Data
Communication
Module 1
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ASET
ReceiverSender
Message
Protocol
Rules
.
.
.
Rules
..
.
Protocol
Transmission Medium
Data Communication
Data Communications are the exchange of data between twodevices via some form of transmission.
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ASET
1.Message: data.
2.Sender:The device that send the message.
3.Receiver: The device that receive the message.
4. Transmission Medium: The physical path betweensender and receiver, the message travel.
5.Protocol:Protocol is a set of rules that governs data
communication. It represents an agreement betweenthe communicating devices. Without a protocol, twodevices may be connected but not communicating.
Components of Data Communication
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ASET
Data Communication Characteristics
1. Delivery: The system must deliver data to the correctdestination.
2. Accuracy:
Data delivered accurately.
Altered data which left uncorrected are unusable.
3. Timelines:
The system must deliver data in timely manner without delay
(real-time).
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ASETData Flow in Communication
Simplex: one direction only.
Always one side sender and another sidereceiver.
Remote Control TV
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ASETData Flow in Communication
Half-Duplex:two-way alternate.
Walki-Talki
Each side maybe sender or receiver but not a same
time.
In different time
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ASETData Flow in Communication
cont.
Duplex: two-way concurrent.
Computer network
Mobile Network
Each side sender and receiver at same time.
At same time
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ASETNetwork
A Network is a set of node connect together by
communication link to sharing of resources and to transmit
information.
Node: Computer, Printer, Scanner, Software , PDA, etc.
Information: text, voice, picture, etc.
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ASETNetwork Components
Transmission media (wired, wireless ).
Network Operating System (NOS).
Network Interface Card (NIC).
Network Hardware:-
1. Hubs.
2. Switches.
3. Routers.
4. Gateways.
5. Access Point.
6. Repeaters.
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ASETNetwork Classification
Upon the transmission medium (type of connection):-
1. Point-to-point:
2. Multipoint:
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ASETPoint-to-Point
A pair of nodes connected together via dedicated link.
PC PCLink
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ASETMultipoint
Number of node connected and share a single link.
Server
PCPCPC
Link
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ASETNetwork Classification
Upon the scale (size):-
1. PAN (Personal Area Network).
2. LAN (Local Area Network).
3. CAN (Campus Area Network).4. MAN (Metropolitan Area Network).
5. WAN (Wide Area Network).
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ASETPAN (Personal Area Network)
PAN is a short-distance network design to individual user
(person).
PAN may be contain:- printer, mobile, computer, wirelessprinters , PDA, etc.
components of PAN connected together via Bluetooth , USB
cable ,IrDA (infrared), etc.
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ASETPAN cont.
Wireless PrinterIrDA
PDA
Scanner
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ASETLAN (Local Area Network)
A LAN is a group of node connected together in a small
specific area.
LAN may be contain workstations, computers, scanner,printers, servers, etc.
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ASETLAN cont.
..
...
Floor 1
Floor 2
Floor 3
Floor 4
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ASETCAN (Campus Area Network)
A CAN is a group of interconnection LAN within limited
geographical area.
A CAN using in school campus, military base, universitycampus ,etc.
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ASETCAN cont.
ABS
University library
ASET
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ASET
MAN (Metropolitan Area Network)
A MAN is a large computer network uses to connect between
LAN in different location (cities).
A MAN is a group of node connect together over city.
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ASETMAN cont.
LAN 1
CAN 4
LAN 3
LAN 2
Connect different branch
location in city
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ASETWAN (Wide Area Network)
A WAN is a computer network that covers large geographical
area.
WANs are used to connect types of networks together.
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ASETWAN cont.
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ASET
WAN
MAN
CAN
LAN
PAN
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ASETNetwork Criteria
A network must be able to meet a certain number of criteria.
The most important of these are Performance, Reliability,
and Security.
Data communication
network criteria
Performance Reliability Security
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ASET
Performance: The performance of network depends on a number of
factors:
Number of users
Type of transmission mediumHardware
Software.
The performance is evaluate by two networking metric :
Throughput and Delay.
Network Criteria
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ASET
Reliability:The network reliability is measured by the frequency of failure,
(the time it takes a link to recover from of failure).
In addition to accuracy of delivery, network reliability is
measured by
1. Frequency of failure
2. Recovery time of a network after a failure
Network Criteria
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ASETNetwork Criteria cont.
Security:
Network security include protecting data from unauthorized
access, protecting data from damage, and write policies and
implementing it for security issues.
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ASETNetwork Modes
Unicast Mode : Single source send to single node.
one-to-one
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ASETNetwork Modes cont.
Multicast Mode : Single source send to specific nodes(group) that are connected to same Network.
one-to-many
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ASETNetwork Modes cont.
Broadcast Mode : Single source send to all others node that
are connected to same Network
one-to-all
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ASETNetwork Software
Protocol Hierarchies Design Issues for the Layers
Connection-Oriented and Connectionless Services
Service Primitives
The Relationship of Services to Protocols
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ASETNetwork SoftwareProtocol Hierarchies
Layers, protocols, and interfaces.
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ASET
Design Issues for the Layers
Addressing
Error Control Flow Control
Multiplexing
Routing
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ASETReference Models
The OSI Reference Model
The TCP/IP Reference Model
A Comparison of OSI and TCP/IP
A Critique of the OSI Model and Protocols
A Critique of the TCP/IP Reference Model
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ASETOSI Reference Models
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ASETReference Models (2)
The TCP/IP reference model.
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ASETHybrid Model
The hybrid reference model .