osi model by amjad, rimsha safi ullah and iqra
TRANSCRIPT
ISO International Standard OrganizationEstablished In 1947Open System Interconnection Model Understanding And Designing A
Network Architecture
INTRODUCTION
Allow Different Types Of Network To Communicate
Avoidable Duplication Of Equipment Resources
Breaks Network Communication Into Smaller Parts
To Facilitates Standardization Of Network Components
NEED OF OSI
7. Application
6. Presentation
5. Session
4. Transport
3. Network
2. Data Link
1. Physical
LAYERS OF OSI
Upper Layers
Lower Layers
Middle Layer
7. Application
6. Presentation
5. Session
4. Transport
3. Network
2. Data Link
1. Physical
DIVISION OF LAYERS
Representation Of Bits.Physical Topology.Data Rate.Synchronization Of Bits.Transmission Mode.Hub
PHYSICAL LAYER
Purpose• Manages The Flow Of Data Over The Physical Media
Responsible For Error-Free Transmission
DATA LINK LAYER
Optimal Path. Data Is In The Form Of Packets Logical (IP) Addressing Routing Main Protocols At This Layer
Are IP ,ICMP ,ARP Logical addressing.
NETWORK LAYER
Purpose• Addressing And Routing The Packets
Example Application At The Router• If The Packet Size Is Large, Splits Into Small Packets
NETWORK LAYER
Service-Point Addressing.Segmentation And Reassembly.Connection Control.Flow Control.Error Control.
TRANSPORT LAYER
Purpose• Repackage Proper And Efficient Delivery of packagesError freeIn sequenceWithout Duplication
TRANSPORT LAYER
Dialog control.Synchronization.Purpose• Oversee A Communication Session• Establish• Maintain• Terminate
SESSION LAYER
Translation.Encryption.Compression.Compatibility With OS.Proper Encapsulation Of Data For Network Transmission.
Data Formatting ( ASCII, Binary)
PRESENTATION LAYER
Purpose• Formats Data For Exchange Between Points Of CommunicationEx: Between Nodes In A Network
Example:• Redirector Software• Formats For Transmission To The Server
PRESENTATION LAYER
User Use DataFile Transfer, Access, And Management.
Mail Services.Directory Services.
APPLICATION LAYER
Purpose• The application layer is responsible for providing services to the user.
Examples• File Request From Server• E-mail Services
APPLICATION LAYER
The International Standards Organization Open Systems Interconnection Allows Diverse Systems To Communicate. Provides Guidelines. The Physical Layer:Transmit A Bit. The Data Link Layer:Deliveres Data Units.The Network Layer:Source-To-Destination
Delivery Of Packet.
SUMMARY
The Transport Layer : Process-To-Process Delivery Message.
The Session Layer: Synchronizes.The Presentation Layer : The
presentation layer is responsible for translation, compression, and encryption.
The Application Layer:Provides User Interface And Support For Services.
SUMMARY
SummaryThe International Standards Organization created a model called the Open
Systems Interconnection, which allows diverse systems to communicate. The seven-layer OSI model provides guidelines for the development of
universally compatible networking protocols. The physical layer coordinates the functions required to transmit a bit
stream over a physical medium. The data link layer is responsible for delivering data units from one station
to the next without errors. The network layer is responsible for the source-to-destination delivery of a
packet across multiple network links. The transport layer is responsible for the process-to-process delivery of the
entire message. The session layer establishes, maintains, and synchronizes the interactions
between communicating devices. The presentation layer ensures interoperability between communicating
devices through transformation of data into a mutually agreed upon format. The Application Layer Enable user, (human or software) to access the
network and Provides user interface and support for services (email, Remote file access, shared database management system).