1. OSI Reference Model
Kashif Ishaq

2. OSI Reference Model Application 7 Presentation 6 Session 5 Transport 4
Network 3
Data link 2
Physical 1

3. OSI Reference Model Application 7 Presentation 6 Session 5 Transport 4
Network 3
Data link 2
Physical 1
Media Layers
Host Layers

4. OSI Reference Model Application 7 Presentation 6 Protocol Data Unit
Session 5
Transport 4
Network 3
Data link 2
Physical 1
Hardware Layers
Devices resides
Software Layers
PDU
Protocol Data Unit

5. OSI Reference Model All applications runs on this layer
Web applications
Chat applications
DNS
FTP
TFTP
HTTP
File and Print Services
Massagers
Web Browsers
Presentation
Session
Transport
Network
Data-Link
Physical

6. OSI Reference Model Presents Data / Data Representation
Application
Presents Data / Data Representation
Encryption / Decryption
Compression / Decompression
Coding / Decoding
MPEG, JPEG, RTF, MP3
Presentation
Session
Transport
Network
Data-Link
Physical

7. OSI Reference Model Logical Sessions between Application Create Stay
Terminate
Keeps different applications data separate
form one another
ASP, NetBIOS, Half/Full Duplex, RTP, SIP
Presentation
Session
Transport
Network
Data-Link
Physical

8. OSI Reference Model Setup Communication mode
Application
Setup Communication mode
Reliable and non-reliable communication
Segments the data
Flow Control
Windowing
Acknowledgements
TCP / UDP
PORT Numbers
Presentation
Session
Transport
Network
Data-Link
Physical
A port number is part of the addressing information used to identify the senders and receivers of messages.
Port numbers are most commonly used with TCP/IP connections

9. OSI Reference Model Logical Addressing Best path selection
Application
Presentation
Logical Addressing
Best path selection
IP Addressing
Data Packets / Route Update Packets
Router uses this Layer
Session
Transport
Network
Data-Link
Physical

10. Sub Layers of Data-link layer
OSI Reference Model
Physical Transmission of Data
Error Notification
Network Topology
LLC
MAC
Application
Presentation
Session
Transport
LLC 802.2
Identify Layer 3 Protocol
Flow control
Sequencing of control bits
Network
Data-Link
Physical
Sub Layers of Data-link layer
MAC 802.3
Physical addressing
How packets placed on media
Error notification only
Ordered delivery of frames

11. OSI Reference Model Physical Media Related Bits Hubs Repeaters
Application
Application
Presentation
Presentation
Physical Media Related
Bits
Hubs
Repeaters
DCE - DTE
Session
Session
Transport
Transport
Network
Network
Data-Link
Data-Link
Physical
Physical

12. Encapsulation OSI Reference Model Application Data Presentation
Session
Segment
Segment
Data
Transport
Packets
Packets
Segment
Data
Network
Data-Link
Frames
Frames
Packets
Segment
Data
Physical
Bits

13. Three Layer Model of Cisco
Core Layer
Distribution Layer
Access layer

14. Three Layer Model of Cisco
Core Layer
Core of the Network
Responsible for transporting large amount of traffic
All users can affect by failure of this layer
Low Latency Technologies…
FDDI
ATM
FAST ETHERNET
GIGABIT ETHERNET
Redundant Links Available on this layer
Distribution Layer
Access layer

15. Three Layer Model of Cisco
Core Layer
Known as Workgroup Layer
Communication point between Access and Core Layer
Features includes…
Packet Filtering
ACL
Policies on the Network
Security Policies
Address Translation
Firewalls
Redistributing between Routing Protocols
Intern VLAN Routing
Broadcast and Multicast Domains
Distribution Layer
Access layer

16. Three Layer Model of Cisco
Core Layer
Control users and workgroups access to internetwork
resources
Knows as Desktop layer
Ethernet Switching
Static Routing
Workgroup connectivity into distribution layer
Separate the Collision Domains
Distribution Layer
Access layer

17. Reliable / non-reliable
Data Transmission
Application
Application
Application data
Data representation
Session management
Reliable / non-reliable
Port numbers
Logical addresses
Route
Physical address
Media conversion
Presentation
Presentation
Session
Session
Transport
Transport
Network
Network
Data-Link
Data-Link
Physical
Physical

18. Transport Layer TCP Sync Sync-Ack Ack
End-to-End data transport services on different manners
TCP
Three Way Handshaking
Acknowledgment
Windowing
Sequencing
Sync Sync-Ack Ack

19. Transport Layer
End-to-End data transport services on different manners
TCP
Three Way Handshaking
Acknowledgment
Windowing
Sequencing

20. Transport Layer
End-to-End data transport services on different manners
TCP
Three Way Handshaking
Acknowledgment
Windowing
Sequencing

21. Transport Layer TCP Sequence numbers Packet identification for layer
End-to-End data transport services on different manners
TCP
Three Way Handshaking
Sequence numbers
Packet identification for layer
Retransmit and Acknowledgement
Acknowledgment
Windowing
Sequencing

22. OSI REFERENCE MODEL WITH THE REFERENCE OF PROTOCOLS
Application:
NNTP, SIP, DNS, FTP, HTTP, NFS, NTP, SMTP, SNMP, Telnet, DHCP, RTP
Presentation:
TLS, SSL
Session:
Named PIPE, NetBIOS, SAP, L2TP, PPTP, SOCKS, ASP, SQL
Transport:
TCP, UDP, SPX
Network:
IP (v4, v6), ICMP, IPSec, IGMP, IPX, AppleTalk
Data link:
ATM, SDLC, HDLC, ARP, SLIP, 802.3, Frame Relay, PPP, X.25, Switching Protocols
Physical:
DSL, 802.3, 802.5, , , IEEE 1394, SONET, POTS, OTN, USB, Bluetooth, Hubs