Download ISM 3410 Telecomm and Networking in Business

Lecture 01
• We begin our lecture to ask ourselves a few
simple questions for this subject such as:
– Have you used telecommunications?
(to p2)
• Examples!
– How do define “telecommunications”?
(to p13)
– why do we need it for?
– can we survive without it?
(to p9)
(to p14)
• Different modes of telecomm applications!
(to p28)
• The concept of convergence
(to p15)
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Examples of
TelecommunicationApplications
1) telephone, mobile phone Figure 1-5
2) use of Internet, web browser Figure 1-6
3) airline reservation systems
(to p3)
(to p4)
- with combination of applications such as dial(to p5)
up line as shown in Figures 1-7 & 1.8
(to p7)
4) ATM, Octopus Figure 1-9
5) automated remote water meter reading
Figure 1-10
(to p8)
(to p1)
2
FIGURE 1-5
Simplified diagram of the components of a standard telephone call.
(a simple version)
(Note: we will learn more on how a telephone company works in the later lecture!) (to p2)
3
FIGURE 1-6
The telecommunications between a home computer and an Internet access provider.
A version of dial-up service via telephone co
Question: How does it differ, say, if you have subscripted a broadband service in HK?
(to p2)
4
FIGURE 1-7
The telecommunications connections between a traveler and an airline reservation computer through a local area network.
Note: This dial-up approach still applied to most travel agents in HK, however
its structure has changed substantially in this Internet age. How and why?
(to p6)
5
More example
.
FIGURE 1-8
The telecommunications connection between a traveler and an airline reservation computer through a leased line.
Another version of dial-up application but -This special line will provide a high speed and secure of
Information retrieval.
(to p2)
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FIGURE 1-9
An ATM connected to a computer by a telecommunications line.
Note: This is a simple
version of ATM
Question: What competitiveness has this application received ?
How does ATM work in HK?
(to p2)
7
.
FIGURE 1-10 Remote reading of a water meter using telecommunications.
Electricity
Question: What adv has this application brought to Businesses?
Can it applied to all cities over the world?
(to p2)
8
reserved.
Telecommunications and
Networking
• What is Telecommunications?
– Tele– Communications
– Telecommunications
(to p10)
(to p11)
(to p12)
(to p1)
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Definitions
• Tele– means by distance or distance apart
(to p9)
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Definitions
• communications
– information pass from one place to another
(to p9)
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Definitions
• Telecom refers as comm between parties
over a distance through electrical or
electromagnetic means (conventionally!)
• (note: we will spend more time to discuss more to
understand what does it meant for through e means)
(to p9)
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Why do we need
Telecommunications?
1) merging of IS and networking to transmit
information for business competitive power
2) obtaining information at the right place at a right
time, eg digital phone to acquire local temperature
3) allowing geographic dispersion of facilities and
people, such as telecommuting and e-commerce
4) allowing on-line marketing such as airline
ticketing systems so that selling products can
(to p1)
conduct directly, eg eBay, TaoBao (espeicall on Nov 11 in China)
13
-
Answer!
Yes:
If you like to live in a primitive form
of a life style
No:
If you live in an modern society or an
(to p57)
Informative world
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(to p1)
Way to classifying
telecommunication applications
• Consider Figure shown in the slide 16, we
can classify each of these applications by
their:
(to p17)
– geography
– Mode of connection
(to p23)
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(to p1)
(to p15)
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geography
•
•
•
•
•
(to p18)
Local area network (LAN)
Metropolitan area network (MAN)
(to p20)
Wide area network (WAN)
(to p61)
Backbone
(to p22)
Personal Area Network
(to p19)
(to p15)
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Local area network (LAN)
(device used to share resource between
PCs in a Lab)
(device used to connect LANs together)
It composes of nodes
And communication
links
Server
(to p17)
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Metropolitan area network (MAN)
(to p15)
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Wide area network (WAN)
– covers a large geographic area and uses circuits
provided by a common carrier
– many made up of a combination of switched or
leased, terrestrial and satellite, and private
microwave circuits
– typically span hundreds or thousands of miles
and provide data transmission rates from
64Kpbs to 2Gpbs
(to p21)
– Semantic view
20
(to p15)
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Personal Area Network
A network of a few meters, interconnecting wireless devices such as PDA,
Laptops, and other devices
(to p15)
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Modes of connection
• Fixed line connection
• Wireless connection
(to p24)
(to p25)
• Question: which mode should be acquired?
And why?
– Examples: home devices pic1, pic2, pic3
(to p61)
(to p62)
(to p63)
• Question: how to evaluate each of them
above?
(to p15)
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Fixed line connection
• Example:
(to p23)
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Wireless connection
• Wireless telephone connections
• Satellite and microwave connection
(to p26)
(to p27)
(to p23)
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Wireless telephone connections
(to p25)
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Satellite and microwave connection
(to p25)
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Convergence of technologies
• Convergence, which refers to coming together of
two areas or two companies, is happening at all
levels in telecomm:
– Products (local phone company Vs other phones in
market such as BO; USB devices )
– Companies (IBM and Apple for PC or notebooks)
– Technologies (fixed line vs Bluetooth or wireless)
(to p29)
• How to connect them together?
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Network Architecture
• A reference model that describes the layers of
hardware and software necessary to transmit data
between two points or for multiple devices /
applications to interoperate
• Reference models are necessary to increase
likelihood that different components from
different manufacturers will converse
• Two models to learn: OSI model and TCP/IP
(to p30)
protocol suite
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Standard models
• OSI
(to p31)
(to p48)
– Compatibility
•
•
•
•
(to p49)
TCP/IP
(to p51)
Others
(to p60)
Mobile network
Concept of logical and physical connections
(to p52)
in action
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OSI
– a worldwide organization known as ISO (International Standard Organization)
established rules and standards to oversee all these issues for vendors whose wish
to develop their products
– In 1978, ISO proposed a telecomm architecture called:
– Open System Interconnection (OSI)
– The ISO-OSI model
– the purpose of this model is to allow information/data interchange between
different brands of devices
– provides a basis for interconnecting dissimilar system/devices
– How it works
(to p32)
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ISO/OSI Model (cont.)
• OSI uses an architecture of layer approach
(a total of 7 layers) to represent the
components of the total process of
(to p32)
communication
• (See Figure 3.2, p91)
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(to p44)
Level 1: Physical connection
Levels 2-7: Logical connection
(exist in the software only)
(to p42)
(to p41)
(to p39)
(to p37)
(to p35)
(to p34)
(to p30)
Semantic view of their functions
(to p47)
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Layer 1: Physical link control
layer
• Layer 1: Physical link control layer
– connectivity on physical linkage
– allow bit streams from a device to flow onto the
network
– defines the electrical standards and signaling,
that is how connections could be established
and terminated
– the only layer in which data transmission
between devices takes place
34
(to p33)
Layer 2:
Data link control
layer
• Layer 2: Data link control layer
– defines standards for structured data into
frames and sending frames across the network
– it answers questions such as
•
•
•
•
1. Where a frame starts or ends
2. How errors are detected and corrected
3. How to handle polling and addressing
4. How machines are addressed
(to p36)
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Layer 2:
Data link control
layer
• Layer 2 (cont.)
– it requires to work closely to devices such as
modem/FEP
– it controls the situation when data is received
from the circuit faster than the receiver can
handle it (it will slow down the transmission
until further notice … this process is known as
pacing)
– note: IEEE fully subscribes to OIS architecture
for the 802 standards for LANs
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(to p33)
Layer 3: Network control layer
• Layer 3: Network control layer
– primary functions are network addressing and
routing
– generates acknowledgements that an entire
message has been received correctly
– responsible to break down messages end from
layer 4 that suit for data transmission
(to p38)
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Layer 3: Network control
layer(cont.)
• Layer 3 (cont.)
– it decides which communication circuit to
transmit data
– it assembles data from blocks of bits before
passing them up the level 4
(to p33)
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Layer 4: Transport control layer
• Layer 4: Transport control layer
– selects the route (if more than one is availble)
the transmission will take between two devices
– converts user addressing that is meaningful to
network software and hardware
– controls the flow of messages so that it will not
over/under run of the speed of other devices
– prevents the loss or duplication of entire
messages (Note: Layer 2 is for frames)
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(to p40)
Layer 4: Transport control layer
(cont.)
• Layer 4 (cont.)
– multiplexing several streams of messages from
higher levels onto one physical circuit and
adding appropriate headers to messages to be
transmitted to recipients
– eg. Operators sends computer down time to all
users in one command
(to p33)
40
Layer 5: Session control layer
• Layer 5: Session control layer
– temporary connection between
machines/programs for exchange of messages
– maintains and breaks a session between two
systems/users
– assign and control of priority to access and
passing message to the systems (such as icq
icon)
(to p33)
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Layer 6: Presentation layer
• Layer 6: Presentation layer
– deals with the way data is formatted and
presented to the users at the terminal
– performs constant format for data transmission
so that lower level would understand it
– software perform data transformation to meet
users’ need (such as different font size,
characters per line etc.)
(to p43)
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Layer 6: Presentation layer (cont.)
• Layer 6 (cont.)
– perform code conversion, data compaction, and
data encryption
– except data encryption, most aforementioned
tasks are done by software in the host computer
(to p33)
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Layer 7: Application or user layer
• Layer 7: Application or user layer
– is the ultimate end or data transmitted within
the network
– consists of application programs, and performs
the communicating commands such as data
editing, file editing etc
– performs the following 6 major functions
• 1. Common application service element (CASE),
that is define standard events such as logon,
password id.
(to p45)
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Layer 7: Application or user
layer(cont.)
• Layer 7 (cont.)
• 2. Job transfer and manipulation (JTM), defines
standard to transfer batch jobs between devices
• 3. File transfer, access and management (FTAM),
defines standard for transfer of files between
systems
• 4. Message oriented interchange system (MOTIS),
defines standard for interconnecting different system
in the word
• 5Office document architecture/office document
interchange facility (ODA/ODIF), provides
(to p46)
45
Layer 7: Application or user
layer(cont.)
• Layer 7 (cont.)
• 5. (cont.) a standard to allow the transfer, edit and
return of documents across system from multiple
vendors
• 6.Virtual terminal services (VTS), defines the virtual
terminal concept, including characters, graphics,
image, colors etc
(to p33)
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47
(to p33)
Telecomm Arch. & Standards (cont.)
The following two giants’ machines can also be
linked to the telecomm. standards of ISO/OSI:
1. IBM developed the SNA (Systems Network
Architecture)
2. DEC developed the DNA (Digital Network
Architecture)
(Note: many textbooks review these two architectures and we do not
cover in this subject!)
(Students who wish to gain a copy of these architectures can come to
see me later!)
(to p30)
48
Telecomm Arch. & Standards
TCP/IP
(cont.)
• TCP/IP (Transmission Control Protocol/Internet
Protocol),developed by USA Department of
Defense, is also a commonly practiced now
in industry
– it consists of 5 (or 4) layers (namely, physical,
network access, Internet, transport and
application)
(to p50)
(to p30)
49
TCP/IP
The OSI
Model
Application
Layer
Application or
Process Layer
Presentation
Layer
Session
Layer
Network
Access
• Provides communications services
for end user applications
• Supports the accomplishment
of telecommunications sessions
Host-to-Host Transport Layer
Transport
Layer
• Supports the organization and
transfer of data between nodes in
the network
Internet Protocol (IP)
Network
Layer
• Provides appropriate routing by
establishing connections among
network links
Network Interface
Data Link
Layer
• Supports error-free organization
and transmission of data in the
network
Physical Layer
Physical
Layer
• Provides physical transmission of
data on the telecommunications
(to p30
media in the network
50
Alternative view of 4 layers
(to p59)
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(to p30)
logical and physical connections
• A logical connection is one that exists only
in the software, while a physical connection
is one that exists in the hardware
• Note that in a network architecture, only the
lowest layer contains the physical
connection, while all higher layers contain
logical connections
• Applied in OSI model (to p53)
52
Logical and Physical Connections
(continued)
Physical connections in networks
(to p54)
53
Network Connections in Action
How does it apply to TCP/IP?
(to p55)
54
TCP/IP in action
Note:
(to p56)
55
The TCP/IP Protocol Suite in
Action
• Note the flow of data from user to Web
browser and back
• At each layer, information is either added or
removed, depending on whether the data is
leaving or arriving at a workstation
• The adding of information over pre-existing
information is termed encapsulation
56
Why?
1) shrinking world by telecomm.
2) direct and indirect use on the job remotely
- direct such as networking
- indirect such as Intranet, telecommute, m-commerce
3) widely use of IT at home such as home
entertainment – itv, icable, www, internet, AI
home appliances
4) new career in telecomm, e-com/business,
telecomm management, and other technical jobs as
reviewed in Figure 1-4
(to p58)
(to p14)
57
FIGURE 1-4
A partial list of telecommunications career opportunities.
Conventional
Product Designers
System Analysts
Business Analysts
E-/M- commerce Officers
Network Managers
CIO (Chief Information Officers)
21st Century
(to p57)
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59
(to p50)
Mobile network
(to p50)
Transaction Comptabilities Application Part (TCAP)
Telephone User Part (TUP
Signaling Connection Control Part (SCCP
60
(to p30)
Backbone network
61
(to p17)
62
(to p23)
63
(to p23)
64
(to p23)