Transport Layer

Question 1

what does the transport layer do?

Answer 1

Establish communication between processes

Question 2

whats the clien/server process?

Answer 2

Client process initiates communication
server process passively awaits communication

Question 3

How do we address processes ?

Answer 3

Processes must have a 32bit identifier wich includes the host ip and the process ports

Question 4

Whats Multiplexing?

Answer 4

agreggating the different messages from multiple sockets into one message with a header

Question 5

whats demultiplexing?

Answer 5

Parsing the received message into diferent segments and sending them to the corresponding sockets (via the specified ports)

Question 6

wich protocols does the internet use?

Answer 6

TCP and UDP

Question 7

what are the advantages of TCP?

Answer 7

connection oriented, reliable, secure, garantues in order delivery , flow and congestion control

Question 8

what are the basic operations for a TCP sender?

Answer 8

application data is broken into segments, tcp uses a timer to send segments and wait for ACK
unACK segemnts are retransmitted

Question 9

what are the basic operations for a TCP receiver?

Answer 9

detect errors during checksum,
ack data
assemble segments in correct order, duplicated segments are discarded

Question 10

how many segments are necessary exchange in a connection establishemnt (TCP)

Answer 10

3: SYN, SYN+ACK

Question 11

How many segments are necessary for closing a connection ? (TCP)

Answer 11

4 : FIN FIN ACK ACK