osi model
Post on 23-Jun-2015
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OSI MODEL (7 layers)
Mohamed Shokr
@shokronline
/mohamed shokr
Before start
Protocol is the law in networking world
Network devicesoNIC (network interface card)oRouter oSwitchoBridgeo ...........etc
Network companies (microsoft_ junipr _redhat _cisco)
Network Devices
HubNIC
Switch
RouterBridge
Networking Companies
(OSI)MODELOpen Systems Interconnect
Who made:
What means ?!
• A Model of How Protocols and Networking components could be made.
• “Open” means ;can be used by anyone.
• (OSI) Model is 7 layers.
• OSI layers is logic.
Why Layers…?
Breaks down the complex. Study complex system.Developing system.Helps in troubleshooting.Each layer has aspecific funcition
OSI layers :
• Application .All
• Presention .People
• Session .Seem
• Transport .To
• Network .Need
• Data link .Data
• Physical .Processing
Real Example:_
7 Layers
Microsoft & Redhat
Cisco & Juniper
Application Layers
• Application Layer .• Presentation Layer .• Session Layer .
Application Layer
• Interface Application
• Exampleso HTTP: browsing protocol.o FTP: file transfer protocol.o SMTP: simple mail transfer protocol.
Presentation Layer
• Format of data .
• Compression and Decompression of data .
• Encryption and Decryption of data.
Session Layer
• Set sessions between applications . example : msn messenger
• Specifies communication mode . (simplex – half duplex – full duplex)
• Data stream :010010101010101010101010011110001010100
Transport Layers
• Transport Layer .• Network Layer .• Datalink Layer .• Physical Layer .
Transport Layer• Tasks : - Flow control - Error recovery
• Protocols : -TCP -UDP
• Segmentssegment1 TCP segment2 TCP
Network Layer
• Tasks : -Best way to move data - Routing - IP addressing
• Packets
segment1 TCPIP
Datalink LayerData Link
Logical Link Control Media Access Control
oLLC: Frame network layer.oLLC: Network layer protocol.
oMAC: Address the frame.oMac: Make H & T .
oSwitch.
oFrames segment1 TCPIPHeader Tailer
Addresses ErrorDetection
Mac Address
Physical Layer
• Send & Receive Bits
• Hub
segment1 TCPIPHeader Tailer
001010101010101010101010101010101010101010101010101000
DATA UNITS
Any Qutions?
• Ask
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