TCP and UDP Flashcards
What does UDP stand for?
Used datagram protocol
What is UDP?
It is a best effort protocol, data sent with no effort made to correct transmission errors.
What is the benefit of UDP
It has a much lower over head than TCP
What is a SYN packet?
It is a synchronise packet which contains his ISN (initial sequence number)
What is an ACK?
An acknowledgement
What is a SYN-ACK?
An acknowldgement of a received SYN packet. A SYN-ACK is sent back with a SYN and an ACK
What are the 3 stages of a 3 way handshake?
- SYN
- SYN-ACK
- ACK
What is the termination of a TCP connection called?
Teardown
What do both computers need to do to end a connection?
Send a FIN packet, both FIN packets need to be acknowledged
What do ports allow for?
Multiple endpoints and multiple connections at the same time to a single IP address
How many ports are there?
65, 535 TCP and 65, 535 UDP
What port number is used for DNS?
Port 53
What does a client need when it want to connect to a web server?
- Destination IP
- Destination port (80)
- Source IP (own IP)
- Source port (port is has assigned to the connection)
What is a socket?
One endpoint in a network communication. A socket is defined by the combination of an IP address and a port number
What does a socket pair do?
(two endpoints) uniquely identifies each TCP connection in a network
