2 - Data encapsulation

Question 1

Application - what type of service are in this layer

Answer 1

HTTP, JPEG, Mail Server.

PDU - Data

Question 2

Presentation - What does this do to the data

Answer 2

Formats the data to the appropriate data -
So it can be read by the device on the other side.
If its a picture (JPEG) then it will format into JPEG so other device receive the same.

PDU - Data

Question 3

Session - what is the difference with session and transport

Answer 3

session is in charge of how the amount of connections. It organizes each session and makes sure each are separate from the others. e.g session 25 not 26

transport is in charge of end to end communication

Question 4

Transport - what does end to end communication mean in transport layer

Answer 4

make sure data was sent and received, proof of this is in the receipt.

1 of 2, 2 of 2.

making sure the full data was sent across.
If the other side does not receive a particular segment it request for it, and it will be sent.

It also looks into Port numbers.

Question 5

Network - what does this layer focus on

Answer 5

It is interested mainly in the address and destination it needs to go to.

Street name and Number.
Ip address - logical address.

How will it get to the location.
Which path will it select.

This is mainly dealing with ip address, routing table and Routers

Question 6

Data link - what does this layer do

Answer 6

It Frames everything.
Places everything in correct order e.g source address, destination address, session etc.

Handles errors in the physical layer, flow control and frame synchronization.

This mainly deals with - Mac-Addresses, and switches.

Question 7

Physical layers -

Answer 7

Send via electrical signals in bits.

Cables and wires

Question 8

which direction does Encapsulation happen ?

Answer 8

From a application layer down to physical.

7 to 1

Question 9

which direction does De-encapsulation happen ?

Answer 9

Frpm physical layer to presentation layer.

1 to 7