1. Chapter 3 Understanding the OSI Model

2. Chapter 3 Overview Understanding the OSI Model
Understanding the TCP/IP Model
Mapping devices on the OSI and TCP Models
Mapping Protocols on the OSI and TCP/IP Models 2

3. Understanding the OSI Model
The seven layers of the OSI Model 3

4. Understanding the OSI Model
Layers interact only with adjoining layers
Encouraged creation of industry standards
Network communication processes are segmented 4

5. Understanding the OSI Model
Mnemonics to remember the layers 5

6. Application Layer DNS HTTP FTP TFTP DHCP LDAP POP3 SMTP IMAP SNMP SMB6

7. Presentation Layer
Determines how to format and present the data 7

8. Session Layer Maintains and Terminates Sessions Simplex Half-duplex
Full-duplex 8

9. Transport Layer Handles flow control, reliability, and error checking
TCP
Connection-oriented
Three-way handshake
UDP
Connectionless
Best effort 9

10. Introducing Ports Logical ports Physical ports 65,536 TCP ports
65,536 UDP ports
Used by services
Physical ports
On computers, routers, switches
Cables plug into these ports 10

11. Network Layer Determines best route to destination IPv4 IPv6 ARP IGMP
ICMP
ICMP
IPSec
RIP
OSPF 11

12. Data Link Layer Logical Link Control Media Access Control
(LLC) IEEE 802.2
Media Access Control
(MAC) IEEE 802.3
PPTP
L2TP
Token Ring
ATM
Frame Relay 12

13. MAC Addresses 13

14. Putting it Together
Data travels up and down the OSI Model 14

15. Packets and Frames
Names of data at different layers 15

16. Understanding the TCP/IP Model
Four Layers
Application Layer
Transport Layer
Internet Layer
Link Layer 16

17. Mapping Devices
Physical layer 17

18. Mapping Devices
Data Link layer 18

19. Mapping Devices
Network layer 19

20. Mapping Devices
Application layer 20

21. Mapping Protocols on the OSI and TCP/IP Models21

22. Chapter 3 Summary Understanding the OSI Model
Understanding the TCP/IP Model
Mapping devices on the OSI and TCP Models
Mapping Protocols on the OSI and TCP/IP Models 22