TCP

Question 1

What are the three steps involved in TCP?

Answer 1

1. Connection Establishment
2. Data transfer
3. Connection Termination

Question 2

What is another term for the connection establishment in TCP?

Answer 2

Three-way handshake.

Question 3

What is passive open?

Answer 3

Server binding to and listening at a port to open up for connections.

Question 4

What must server have done before client can connect with server?

Answer 4

passive open.

Question 5

When can client perform an active open with a server?

Answer 5

After server has performed a passive open.

Question 6

What is the first step of the three way handshake when establishing client server connection?

Answer 6

Client sets the segment sequence number to a random value A and sends a SYN to the server.

Question 7

What is the second step of the three way handshake when establishing client server connection?

Answer 7

Server sets the acknowledgement number to one more than the received sequence number (A + 1). Sequence number for packet is set to a random number (B), and SYN-ACK acknowledgement is sent to client.

Question 8

What is the third step of the three way handshake when establishing client server connection?

Answer 8

Client sets the sequence number to the received acknowledgement value (A + 1), acknowledgement number is set to one more than the received sequence number (B + 1) and ACK is sent back to server.

Question 9

What do the 1 and 2 steps of the connection handshake establish?

Answer 9

Connection parameter (sequence number) for one direction and acknowledge it.

Question 10

What do the 2 and 3 steps of the connection handshake establish?

Answer 10

Connection parameter (sequence number) for other direction and acknowledge it.

Question 11

What type of handshake is involved four client server connection termination?

Answer 11

Four-way handshake with each side of the connection terminating independently.

Question 12

What is the first step in the four-way connection termination handshake?

Answer 12

One endpoint sends a FIN packet to the other endpoint.

Question 13

What is the second step in the four-way connection termination handshake?

Answer 13

The endpoint receiving the initial FIN packet responds with an ACK.

Question 14

What is the third step in the four-way connection termination handshake?

Answer 14

The endpoint receiving the initial FIN packet sends a FIN packet.

Question 15

What is the fourth step in the four-way connection termination handshake?

Answer 15

Endpoint that sent the initial FIN packet responds with an ACK then waits for timeout before closing connection.

Question 16

What are five key features of data transfer in TCP?

Answer 16

1. Data transfer is ordered.
2. Retransmission of packets.
3. Error free data transfer.
4. Flow control.
5. Congestion control.

Question 17

What does ordered data transfer mean?

Answer 17

Destination host rearranges data according to sequence number.

Question 18

What does retransmission of packets mean?

Answer 18

Any cumulative stream not acknowledged is retransmitted.

Question 19

What does error free data transfer mean?

Answer 19

Duplicate packets are discarded, and packets are retransmitted when needed. Means that data is transferred error free.

Question 20

What does flow control mean for data transfer?

Answer 20

The limit placed on the rate a sender transfers data to guarantee reliable delivery.

Question 21

What does congestion control mean for data transfer?

Answer 21

Controlling the rate of packets entering the network to avoid congestion collapse. Prevents senders from overwhelming the network.