OSI Model

Order of OSI Layers

1. Physical

2. Data Link

3. Network

4. Transport

5. Session

6. Presentation

7. Application

What is the Physical Layer?

• Responsible for transmission and receipt of the bit stream to/from nodes

Physical Layer Protocols/Devices

Protocols

• Ethernet

• USB

• Bluetooth

Devices

• Hub

• Repeater

What is the Data Link Layer?

• Responsible for providing point-to-point validity of the data

Data Link Layer Protocols/Devices

Protocols

• Point to point

• Serial Line

• ATM

Devices

• Switch

• Bridge

• Wireless AP (WAP)

What is the Network Layer?

• Enables internetworking, provides globally unique addressing for every node in the network

• Determines routes between source and destination networks

Network Layer Protocols/Devices

Protocols

• IP

• Address Resolution (ARP)

• ICMP (ping)

Devices

• Router

• Layer 3 Switch

What is the Transport Layer?

• Responsible for host-to-hosts integrity of transmission

• Detects damaged or lost packets and generates retransmit requests

Transport Layer Protocols/Devices

Protocols and Devices

• TCP/UDP

What is the Session Layer?

• Establishes, maintains, and terminates host-to-host interactive sessions

• Used to uniquely identify a service application, or function on a host via ports

Session Layer Protocols/Devices

Protocols

• NFS

• RFC

• SQL

• NetBIOS

What is the Presentation Layer?

• Responsible for managing the way data is presented 

Presentation Layer Protocols/Devices

Protocols

• ASCII

• SSL

• JEPG

• GIF

• IMAP

What is the Application Layer?

• Provides the interface between users applications and network’s services

Application Layer Protocols/Devices

Protocols

• HTTP

• DNS

Device

• User Application

What Layers fall under Network Access?

• Physical

• Data link

What Layers fall under Internet?

• Network

What Layers fall under Transport?

• Transport

What Layers fall under Application?

• Session

• Presentation

• Application

Physical Layer Data Type

• Bits

Data Link Layer Data Type

• Frames

Network Layer Data Type

• Packets

Transport Layer Data Type

• Segments