NWC203c 4

In the scenario above, what should be the value of frame number y at receiver B?

• A, 3

• B, 8

• C, 7

• D, None of the above

If the probability of error is very low in a communication link, which of the following statements is true about performance of ARQ protocol?

• A, Stop-and-wait and Go-back-N ARQ protocols have similar performance

• B, Stop-and-wait and Selective Repeat ARQ protocols have similar performance

• C, Go-back-N ARQ and Selective Repeat ARQ protocols have similar performance

• D, None of the above

In peer-to-peer protocol, the purpose of Automatic Repeat Request is

Two answer

• A, to ensure a sequence of information packet is delivered with an ACK request

• B, to ensure a sequence of information packet is delivered in order

• C, to ensure a sequence of information packet is delivered without errors or duplication despite transmission errors and losses

• D, to ensure a sequence of information packet is delivered out-of-order

Which of the basic elements of ARQ is associated with negative acknowledgement

• A, Timeout mechanism

• B, ACKs

• C, NAKs

• D, Error detecting code

In Go-Back-N ARQ, a procedure where transmission of a new frame is begun before the completion of time of the previous frame transmission is called

• A, Transitioning

• B, Pipelining

• C, Channeling

• D, None of the above

In Stop-and-Wait protocol, sequence number are not required

• A, True

• B, False

The disadvantage of Stop-and-Wait protocol

• A, Error free communication channel does not exist

• B, Acknowledgement may get lost

• C, Deadlock situation may occur

• D, All of the above

Which of the following statements are true for the best-effort service of IP?

• A, Packets can arrive with errors or be lost

• B, Packets can arrive out-of-order

• C, Packets can arrive after very long delay

• D, All of the above

Which of following services belong to the data link layer?

• A, Insert framing information into the transmitted stream to indicate the boundaries that define frames

• B, Provide error control to ensure reliable transmission

• C, Provide flow control to prevent the transmitter from overrunning the receiver buffer

• D, All of the above

Which ARQ flow control protocol is used by TCP?

• A, Stop-and-Wait

• B, Selective Repeat

• C, Go-back-N

• D, None of the above