1. Mr. Kunjan D Shinde
Assistant Professor
Department of Electronics and Communication Engineering
PESITM Shivamogga.
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Mr. Kunjan D. Shinde, Asst. Professor, Dept. of
E&CE, PESITM Shivamogga.
UNIT 1
Network Models
Layered Task
OSI Model
Working of
Physical layer, Data link layer, Network layer
Transport layer, Session layer, Presentation layer
Application layer
TCP/IP Protocol Suite
Working of each layers
Addressing
Physical, Logical, Port, and Specific addressing. Acall Last_Class
Telephone and Cable Networks for Data Communication
Telephone Networks
Dial up modem
DSL
Cable TV for data Transmission
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Mr. Kunjan D. Shinde, Asst. Professor, Dept. of
E&CE, PESITM Shivamogga.
Layered Task
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Mr. Kunjan D. Shinde, Asst. Professor, Dept. of
E&CE, PESITM Shivamogga.
Seven Layers of OSI model
ISO- International Standards Organization.
- International Organization for Standardization.
- Established in 1947
- Multifunctional body dedicated to worldwide
agreement on international standards.
- ISO standard that covers all aspect of Network
Communication is OSI model
OSI – Open System Interconnect Model
- 1st introduced in late 1970’s
- has 7 ordered layers
- Open System is set of protocols that allows two
different system to communicate regardless of their underlying
hardware or software
- OSI is not a protocol
- purpose is to facilitate communication b/w different
systems without changing its logic of underlying h/w and s/w.
ISO is Organization. OSI is the Model
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Mr. Kunjan D. Shinde, Asst. Professor, Dept. of
E&CE, PESITM Shivamogga.
The Interaction Between layers in the OSI Model
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Mr. Kunjan D. Shinde, Asst. Professor, Dept. of
E&CE, PESITM Shivamogga.
An exchange of data using the OSI model
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Mr. Kunjan D. Shinde, Asst. Professor, Dept. of
E&CE, PESITM Shivamogga.
Physical Layer
Functions of Physical layer
Physical Layer is responsible for movements of individual bits from one hop(node) to the
next.
- Physical Characteristics
- Data Rate
- Synchronization of Bits
- Line Configuration
- Physical Topology
- Transmission Mode
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Mr. Kunjan D. Shinde, Asst. Professor, Dept. of
E&CE, PESITM Shivamogga.
Data Link Layer
Functions of Data Link layer
Data Link Layer is responsible for moving frames from one hop(node) to the next.
- Framing
- Physical Addressing
- Flow control
- Error Control
- Access Control
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Mr. Kunjan D. Shinde, Asst. Professor, Dept. of
E&CE, PESITM Shivamogga.
Hop to Hop Delivery
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Mr. Kunjan D. Shinde, Asst. Professor, Dept. of
E&CE, PESITM Shivamogga.
Network Layer
Functions of Network layer
Network Layer is responsible for the delivery of individual packets from source to
destination.
- Logical Addressing
- Routing
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Mr. Kunjan D. Shinde, Asst. Professor, Dept. of
E&CE, PESITM Shivamogga.
Source to destination Delivery
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Mr. Kunjan D. Shinde, Asst. Professor, Dept. of
E&CE, PESITM Shivamogga.
Transport Layer
Functions of Transport layer
Transport Layer is responsible for the delivery of the message from one process to another.
- Service point addressing
- Segmentation and Reassembly
- Connection control
- Flow control
- Error control
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Mr. Kunjan D. Shinde, Asst. Professor, Dept. of
E&CE, PESITM Shivamogga.
Reliable Process to process delivery
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Mr. Kunjan D. Shinde, Asst. Professor, Dept. of
E&CE, PESITM Shivamogga.
Session Layer
Functions of Session layer
Session Layer is responsible for dialog control and synchronization.
- Dialog control
- Synchronization
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Mr. Kunjan D. Shinde, Asst. Professor, Dept. of
E&CE, PESITM Shivamogga.
Presentation Layer
Functions of Presentation layer
Presentation Layer is responsible for Translation, compression and encryption.
- Translation
- Encryption
- Compression
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Mr. Kunjan D. Shinde, Asst. Professor, Dept. of
E&CE, PESITM Shivamogga.
Application Layer
Functions of Application layer
Application Layer is responsible for providing services to the user.
- Network Virtual terminal
- File transfer, access, and management
- Mail services
- Directory Services
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Mr. Kunjan D. Shinde, Asst. Professor, Dept. of
E&CE, PESITM Shivamogga.
Summary of Layers in OSI model
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Mr. Kunjan D. Shinde, Asst. Professor, Dept. of
E&CE, PESITM Shivamogga.
TCP/IP Protocol Suite
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Mr. Kunjan D. Shinde, Asst. Professor, Dept. of
E&CE, PESITM Shivamogga.
Addressing
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Mr. Kunjan D. Shinde, Asst. Professor, Dept. of
E&CE, PESITM Shivamogga.
Physical Addressing
07:01:02:01:2C:4B
A 6-byte (12 hexadecimal digits) physical address.
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Mr. Kunjan D. Shinde, Asst. Professor, Dept. of
E&CE, PESITM Shivamogga.
Logical Addressing
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Mr. Kunjan D. Shinde, Asst. Professor, Dept. of
E&CE, PESITM Shivamogga.
Port Addressing
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Mr. Kunjan D. Shinde, Asst. Professor, Dept. of
E&CE, PESITM Shivamogga.
Port Addressing
753
A 16-bit port address represented
as one single number.
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Mr. Kunjan D. Shinde, Asst. Professor, Dept. of
E&CE, PESITM Shivamogga.
Specific Addressing
Specific address is used in some applications which need user friendly addresses.
Example
email: kunjanshinde@pestrust.edu.in
- used to define the address of the receiver.
URL- Universal Resource Locator
URL- www.pestrust.edu.in/pesitm/
-used to find a document on World Wide Web
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Mr. Kunjan D. Shinde, Asst. Professor, Dept. of
E&CE, PESITM Shivamogga.
The telephone network had its beginnings in the late 1800s and was originally created
to provide voice communication.
Need to communicate digital data results in the invention of the dial-up modem
High speed downloading – DSL- Digital Subscriber Line
The entire network, which is referred to as the plain old telephone system (POTS), was
originally an analog system using analog signals to transmit voice.
PSTN : Public Switched Telephone Networks
Telephone networks use circuit switching.
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Mr. Kunjan D. Shinde, Asst. Professor, Dept. of
E&CE, PESITM Shivamogga.
It has 3 major components
1. Local Loops – Twisted pair cable, END/local central office, BW- 4kHz for voice
08362222954
2. Trunks – is a transmission media handles Communication b/w offices
3. Switching Offices - to avoid physical link b/w two subscriber, Telephone company
has switches.
- A switch connects several local loops or trunks and allows a
connection b/w different subscribers.
Major Components of Telephone Networks
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Mr. Kunjan D. Shinde, Asst. Professor, Dept. of
E&CE, PESITM Shivamogga.
Telephone companies developed a new technology when the traditional modems
reached their peak data rate, this new technology was DSL- Digital Subscriber
Line.
DSL is used to provide higher-speed access to the Internet.
Digital subscriber line (DSL) technology is one of the most promising for
supporting high-speed digital communication over the existing local loops.
Variants of DSL are
ADSL -Asymmetric
HDSL -High bit rate
SDSL -Symmetric
VDSL -Very high bit rate
xDSL - generally referred as xDSL where x = A, H, S, or V.
Digital Subscriber Line
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Mr. Kunjan D. Shinde, Asst. Professor, Dept. of
E&CE, PESITM Shivamogga.
Some points on ADSL
ADSL- Asymmetric –b’coz it uses a different speed in upstream and downstream.
- downstream has higher data rate than upstream
ADSL is an asymmetric communication technology designed for residential users; it is
not suitable for businesses.
The existing local loops can handle bandwidths up to 1.1 MHz (data and voice
Communication).
ADSL is an adaptive technology.
The system uses a data rate based on the condition of the local loop line.
1. Using Existing Local Loops
-uses a existing local loops.
-new BW was achieved by ADSL, b’coz of change in the filter used by TC.
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Mr. Kunjan D. Shinde, Asst. Professor, Dept. of
E&CE, PESITM Shivamogga.
Some points on ADSL Cont’d..
2. Adaptive Technology
-1.1 MHz is a theoretical bandwidth of Local Loops.
- some factors that influence the change in BW property are Distance, Size of the
cable, Signaling used and so .on..
- Hence these factors need to be taken care, so the Adaptive Technology.
Adaptive technology is used to test the conditions of the channel and to find the
available BW of the line
- Data rate of the ADSL is not fixed, it changes based on the condition and type of
local loop cable.
3. Discrete multitone Technique (DMT)
-Modulation Technique used by ADSL is DMT.
-No predefine way to set the BW and divide among the users (each s/m can decide
on its BW division).
- typical BW -1.104MHz is divided in to 256 channels.
-each channel uses the BW of 4.312kHz
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Mr. Kunjan D. Shinde, Asst. Professor, Dept. of
E&CE, PESITM Shivamogga.
Discrete Multitone technique
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Mr. Kunjan D. Shinde, Asst. Professor, Dept. of
E&CE, PESITM Shivamogga.
Bandwidth Division in ADSL
-Voice - Channel 0
- Idle - Channel 1 to 5
- Upstream data and Control -Channel 6 to 30 (24 channels), QAM modulation is
used and BW is 24*4000*15=1.44Mbps {normal 500kbps b’coz of noise}
- Downstream Data and Control - Channel 31 to 255 (24 channels), QAM modulation
is used and BW is 224*4000*15=13.4Mbps{normal 8Mbps b’coz of noise}
34. 13/08/2015 39
Mr. Kunjan D. Shinde, Asst. Professor, Dept. of
E&CE, PESITM Shivamogga.
High-bit-rate digital subscriber line (HDSL): It’s an alternative to T-1 line(1.544
Mbps)
Limitation of T-1 line is it uses alternative mark inversion(AMI) encoding, which is
very susceptible to attenuation at high frequencies. Thus the length of T-1 line is
limited to 3200ft (1km). Thus there is need of repeater for longer distances.
HDSL uses 2B1Q encoding which is less susceptible to attenuation. Up to a
distance of 12000ft(3.86km) a data rate of 1.544Mbps can be achieved without
repeaters.
HDSL uses 2 twisted pairs (One pair for each direction) to achieve full-duplex
transmission.
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Mr. Kunjan D. Shinde, Asst. Professor, Dept. of
E&CE, PESITM Shivamogga.
The cable TV network started as a video
service provider, but it has moved to the
business of Internet access. In this section, we
discuss cable TV networks per se; in Section
9.5 we discuss how this network can be used to
provide high-speed access to the Internet.
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Mr. Kunjan D. Shinde, Asst. Professor, Dept. of
E&CE, PESITM Shivamogga.
Communication in the traditional cable TV
network is unidirectional.
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Mr. Kunjan D. Shinde, Asst. Professor, Dept. of
E&CE, PESITM Shivamogga.
Communication in an HFC cable TV network
can be bidirectional.
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Mr. Kunjan D. Shinde, Asst. Professor, Dept. of
E&CE, PESITM Shivamogga.
Cable companies are now competing with
telephone companies for the residential
customer who wants high-speed data transfer.
In this section, we briefly discuss this
technology.
Bandwidth
Sharing
CM and CMTS
Data Transmission Schemes: DOCSIS
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Mr. Kunjan D. Shinde, Asst. Professor, Dept. of
E&CE, PESITM Shivamogga.
Downstream data are modulated using the 64-
QAM modulation technique.
The theoretical downstream data rate
is 30 Mbps. The theoretical upstream data rate
is 12 Mbps.
Upstream data are modulated using the QPSK
modulation technique.
