4.9.4 TCP/IP

Question 1

What does TCP/IP stand for?

Answer 1

Transmission control protocol / internet protocol

Question 2

What is the TCP/IP protocol?

Answer 2

The protocol used in all parts of the internet to enable different devices tWo communicate.

Question 3

What are the four layers to TCP/IP?

Answer 3

• Application
• Transport
• Network
• Link

Question 4

What is the purpose of the layers?

Answer 4

Each layer is responsible for a separate part of communication over the internet.

Question 5

What makes up the protocol?

Answer 5

4 distinct layers, each being responsible for a separate part of communication over the internet.

Question 6

What is the role of the application layer?

Answer 6

Selects and uses the correct protocol to transmit data. The layer
interacts with the user with application software like a web browser

Question 7

How does the layer interact with the user?

Answer 7

Via application software.

Question 8

What is the role of the

Answer 8

• Establishes what’s called a virtual path: an end to end connection
between the sender and the receiver. The layer then splits the
transmission into packets.
• Each packet has a sequence number which identifies a packet’s
position in relation to other packets that form part of the same message.
Also contained in each packet is the port number to be used which
identifies the protocol in use.

Question 9

What is a virtual path?

Answer 9

An end to end connection between the sender and the receiver.

Question 10

What is the purpose of the sequence number?

Answer 10

Identifies a packet’s position in relation to other packets that form part of the same message.

Question 11

What is the purpose of the port number?

Answer 11

Identifies the protocol in use.

Question 12

What is the purpose of the network layer?

Answer 12

Provides the correct IP addresses for each packet’s source and destination.

Question 13

How are routers involved in the network layer?

Answer 13

Routers work within the network layer, using the IP addresses on a packet to send it to its destination.

Question 14

What is the purpose of the link layer?

Answer 14

• Controls physical connections between pieces of hardware in a network.
• Adds MAC addresses to packets which it receives from the network layer.
• MAC (which stands for media access control) addresses are
assigned to every device that can connect to a network by their
manufacturer and are unique to that device.

Question 15

What is the purpose of MAC addresses?

Answer 15

• MAC addresses identify the hardware to which a packet should be sent
• These MAC addresses change with every hop through a network

Question 16

What are MAC addresses?

Answer 16

• Addresses which are assigned to every device that can connect to a network by their manufacturer and are unique to that device.

Question 17

What occurs at the receiving end in TCP/IP protocol?

Answer 17

Once a packet has been received by its intended recipient, it is stripped of its extra information by reversing the TCP/IP stack.

Question 18

What happens with the link layer at the receiving end?

Answer 18

• The link layer removes MAC addresses from the packet.

Question 19

What happens with the network layer at the receiving end?

Answer 19

• Removes IP addresses before the transport layer uses the packet’s port number to determine the correct application to send the packet to.

Question 20

What happens with the transport layer at the receiving end?

Answer 20

Transport layer also uses the packet’s sequence number to ensure that it is in the correct position relative to other packets in the same transmission.

Question 21

What happens with the application layer at the receiving end?

Answer 21

Receives the packets and displays the information to the user accordingly.