TCP/IP

Question 1

What does TCP do?

Answer 1

Ensures datagrams are reliably sent and different types of data can be accessed simultaneously. It allows the receiving computer to tell which port (and which application) to send the datagram to. It also waits for confirmation of the arrival of datagrams, and can resend damaged ones. Because of this, it is relatively slow.

Question 2

What do ports 20 and 21 do in TCP?

Answer 2

FTP (File Transfer Protocol). Port 20 for sending and receiving files, port 21 for control

Question 3

What does port 22 do?

Answer 3

SSH (Secure Shell), allows secure login to computers.

Question 4

What does Port 25 do?

Answer 4

SMTP (see terms)

Question 5

What does port 80 do?

Answer 5

HTTP (see terms)

Question 6

How does IP work?

Answer 6

Datagrams from TCP are wrapped in another datagram containing sender and receiver IP addresses. The datagram is then passed through the internet to the correct receiver, where it is unwrapped and passed to TCP.