open system interconnection
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Transcript of open system interconnection
SUBJECT:COMPUTER
NETWORKSTOPIC:
OSI MODEL
CREATED BY:RUCHI MAURYATWINKAL PARMARSHIVALI SALUNKHE
OPEN SYSTEM INTERCONNECTION
OSI –open system interconnection model.
Conceptual model.Developed by ISO in 1984. ISO : Dedicated to defining global
communication and standards. logical framework
Introduction
7 Layers Of OSI Model
Application
Presentation
Session
Transport
Network
Data link
Physical
Top layer serve as window Interface between programme and
protocol stack.Enable to access network.
7. Application Layer
7. Application Layer
To Presentation Layer
From Presentation Layer
Network virtual terminalFile transfer , access and
managementMail services
7. Application LayerFunctions:
Also called Translation layer. concerned with syntax and semantics
of the information It can be viewed as the translator for
the network. translate data from a format into a
common format then translate the common format to
a format .Manages data-format information.
6. Presentation Layer
110011000111
H611001100011
1H6
From Application Layer To Application Layer
To Session Layer From Session Layer
6. Presentation Layer
6. Presentation LayerFunctions:
Character code TranslationData ConversionData CompressionData Encryption
hold ongoing communications (called a session) across a network.
orderly communication defines the format of the data establish and manages the
session reconnect the session if it
disconnects.
5. Session Layer
H5
syn syn syn
From Presentation Layer
To Transport Layer
Session Layer
From Transport Layer
To Presentation Layer
H5
syn syn syn
Session Layer
5. Session Layer
Session establishment, maintenance and termination.
Dialog Control security and access controlSynchronization
5. Session LayerFunctions:
End to end message deliveryError checking No duplication or errors are occurringMessage arrive in orderAcknowledgementRetransmits the data if error is found
4. Transport Layer
4. Transport Layer
Message acknowledgmentMessage traffic controlSession multiplexingFlow control
4. Transport LayerFunctions:
source to destination delivery.across multiple networks (links). converting logical addresses into
physical addresses.determines that how data transmits
between the network devices.Handles addressing messages for
delivery.
3. Network Layer
deciding how to route transmissions between computers
3. Network Layer
110011000111
H311001100011
1H3
From Transport Layer To Transport Layer
To Data Link Layer From Data Link Layer
Packet Packet
Logical-Physical Address Mapping Internetworking Logical AddressingRoutingPacketizingFragmentation
3. Network LayerFunctions:
provides a reliable linknode-to-node deliveryHandles special data frames
(packets)error-free transfer defines the format of data
2. Data Link Layer
Data Link layer consists of two sub-layers:1. Logical Link Control (LLC) sublayer2. Medium Access Control (MAC) sublayer
2. Data Link Layer
110011000111
H2 T211001100011
1H2 T2
From Network Layer To Network Layer
To Physical Layer From Physical Layer
Frame Frame
FramingPhysical AddressingFlow ControlError ControlAccess Control
2. Data Link LayerFunctions:
Lowest LayerTransmitting individual bitsMechanical electrical specification
1. Physical Layer
Transmission Media
110011000111
110011000111
H1 H1
Bit representationTransmission rateSynchronizingTransmission modePhysical Topology
1. Physical LayerFunctions:
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