Chapter 3 - Exit questions

Which is true about a transport layer function?

• extend host-to-host delivery to process-to-process data delivery and error checking

• segment a message from the application layer into smaller chunks with the size limited by the MSS

• provide either reliable or best-effort transport service to application layer protocols

• All are correct.

_____ provides no guarantees of segment delivery, orderly delivery of segments, or integrity of the data in the segments.

• UDP

• TCP

• IP

• PING

Which of the following shows the required values for a UDP socket?

• Destination IP address

• destination port number

• Source IP address

• source port number

Which of the following shows the required values for a TCP socket?

• Destination IP address

• destination port number

• Source IP address

• source port number

Which of the following application layer protocols typically uses UDP?

• PING

• SMTP

• DNS

• HTTP/1

What is the purpose of the UDP checksum?

• It is used to reassemble received UDP segments into a message before passing the message to the application layer protocol on a receiving host.

• It is used to determine whether bits within the UDP segment have been altered as it moved from a source to a destination.

• It is used to assure that UDP on a receiving side has received all UDP segments transmitted from UDP in a sending side.

• No correct answer

Which of the following mechanisms ensures that a receiver has received messages transmitted from a sender?

• Flow control

• Congestion control

• Three-way handshake

• Acknowledgement

______ uses a three-way handshake before it starts to transfer data.

• PING

• Traceroute

• TCP

• UDP

What are the sequence number of (C); and the acknowledgement number of (E)?

• (C) Seq=116

• (C) Seq=124

• (E) ACK=118

• (E) ACK=108

When a TCP sender received three duplicate ACKs from a TCP receiver, the TCP sender performs ______, retransmitting the missing segment before that segment’s timer expires.

• a fast retransmit

• a slow retransmission

• connection establishment

• Go-Back-N retransmission