Quiz(Week 4)

Q1 . A transport layer protocol implements a timer to address the loss problem. The timer cannot expire if there is no loss. True or False?

Q2 . A reliable transport protocol must implement both ACK and NAK if it wants to address bit errors as well as packet loss problems. True or False?

Q3 . Stop-and-Wait:

A. receiver buffers packets

B. has only 1 bit for the sequence number

C. requires a large sequence number space

D. requires more than 1 bit for the sequence number

Q4 . Stop-and-Wait cannot provide reliability. True or False?

Q5 . For short distances, Stop-and-Wait is always efficient, but it fails to support high throughput only when the distance between the client and server is large. True or False?

Q6 . Pipelining increases throughput (compared to stop-and-wait) linearly with the window size (number packets the sender can have in the pipeline without having to stop and wait for the ACK). True or False?

Q7 . In Go-Back-N, the sender window cannot be equal to the sequence number space. True or False?

Q8 . For a 4-bit sequence number field in the packet header, the maximum possible window size for Selective Repeat is

A.15

B.16

C. 8

D. 7

Q9 . To speed up file transfers, a Selective Repeat implementation is using a window size of 8. The sequence number field in the packet header must be at least

A. 8-bit long

B. 4-bit long

C. 3-bit long

D. 16-bit long