1.1 Compare and contrast the Open Systems Interconnection (OSI) model layers and encapsulation concept

What are the 7 Layers of the OSI model in order?

- Layer 1 – Physical

- Layer 2 – Data link

- Layer 3 – Network

- Layer 4 – Transport

- Layer 5 – Session

- Layer 6 – Presentation

- Layer 7 – Application

What happens at the physical layer of the OSI model?

Defines the method of moving data between computers, so copper cable, fiber optic, radio wave

TAKES OFF PREAMLE AND FCS

What happens at the Data Link layer of the OSI model?

Any device that deals with MAC addresses

TAKES OFF MAC

What happens at the Network layer of the OSI model?

Create packets and attach an IP address to them

TAKES OFF IP

What happens at the Transport layer of the OSI model?

Segments and Reassembles Data

What happens at the Session layer of the OSI model?

Establishes connections, uses ports to get to the right application

TAKES OFF PORTS

What happens at the Presentation layer of the OSI model?

Data is formatted and converted

What happens at the physical layer of the OSI model?

API’s, can encrypt, authenticate and change the look of data

What is encapsulation?

The processes of preparing data to go onto a network, goes down the stack of the OSI model adding information onto the frame as it does.

What is decapsulation

Unpacks the Frame, goes up the OSI model unpacking each corresponding segment of the frame as it does.

What are the different segments of a Frame?

Preamble, MAC, IP, PORTS, DATA TYPE, DATA, FCS

What are TCP flags?

Give both sides detailed information about the state of the connection

What is the maximum amount of data a frame can hold?

1500 bytes

Largest size of a data unit in a communications protocol

Maximum Transmission Unit (MTU)