4.9.4.1 TCP/IP

What does TCP/IP stand for?

Transmission Control Protocol / Internet Protocol

How many layers are there in the TCP/IP stack?

4

What are the layers of TCP/IP?

• Application

• Transport

• Network

• Link

What happens in the application layer?

Selects and uses the correct protocol to transmit data

How does the application layer interact with the user?

With application software

→ e.g. web browser

What happens in the transport layer?

• Virtual path established

• Transmission split into packets

What is meant by a virtual path?

An end to end connection between the sender and the receiver

What happens in the network layer?

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

What component works in the network layer?

Routers use the IP addresses on a packet to send it to its destination

What happens in the link layer?

• Controls physical connections between pieces of network hardware

• Adds MAC addresses to packets in receives

How is the TCP/IP stack reversed?

• Link layer removes MAC address

• Network layer removes IP addresses

• Transport layer uses packet’s port number to determine the correct application to send the packet to

• Application layer receives the packets and displays the information accordingly

How are socket addresses formed?

Combining an IP address with a port number

What does a socket address do?

Identifies which of the applications on the recipient device a packet should be sent to