Computer Networking Lesson 2 Review

The job of delivering the data included in the transport-layer segment to the appropriate socket, as defined in the segment fields, is called ______. 

The sending host will need to gather data from different sockets and encapsulate each data chunk with header information to create segments, and then forward the segments to the network layer. We refer to this job as ​ (a)   . 

• multiplexing
• demultiplexing

Which application-layer protocol(s) typically depend(s) on TCP as an underlying transport-layer protocol? Select all that apply.

• SMTP

• DNS

• FTP

• Telnet

• HTTP

Which application-layer protocol(s) typically depend(s) on UDP as an underlying transport-layer protocol? Select all that apply.

• SMTP

• DNS

• FTP

• RIP

• SNMP

One method for Reliable Transmission is for the receiver to send an ACK for the most recently received in-order packet. The sender would then send all packets from the most recently received in-order packet, even if some of them had been sent before. The receiver can simply discard any out-of-order received packets. This is called ​ (a)   .

• Go-back-N
• Fast retransmit
• Selective ACK-ing

What are some methods of ensuring reliable transmissions? Select all that apply.

• Selective ACKing

• Fast retransmit

• Fast ACKing

• Go-back-N

• Slow retransmit

The method of using acknowledgments from the receiving host and timeouts (when no acknowledgement is received in a set amount of time) to ensure reliable transmission over TCP is known as:

.

• Automatic Repeat Request (ARQ)

• Go-back-N

• Fast retransmit

• Selective ACKing

The simplest implementation of the Automatic Repeat Request (ARQ) method is known as ....

• Wait for ACK ARQ

• Halt and Wait ARQ

• Stop and Wait ARQ

• Wait TTL ARQ

Using the Go-back-N method, a single packet error can cause a lot of unnecessary retransmissions. What does TCP implement to solve for this problem?

• Selective ACKing

• Fast retransmit

• Duplicate ACKing

• Automatic Repeat Request

What happens during Selective ACKing? (Select all that apply)

• The receiver selects which packets to acknowledge

• The receiver acknowledges a correctly received packet even if it is not in order

• Any out-of-order packets the receiver acknowledges remain in the buffer until missing packets are received

• The sender retransmits packets it suspects were received in error