Quiz 6 Flashcards
That the transport layer provides a reliable data transfer service means
The data sent by a sender is equal to the data received by the receiver and the order is preserved
The data sent by a sender equal the data received by the receiver
The receiver may only receive some of the data sent by the sender
The data sent by a sender is equal to the data received by the receiver and the order is preserved
Delivering the data contained in a transport-segment to the correct socket is called
encapsulation
demultiplexing
multiplexing
demultiplexing
It is possible for two processes running on different hosts to send UDP segments to the same port on another host?
True
False
True
What kind of packets are exchanges between protocol entities at the transport level?
Segments
Datagrams
Frames
Segments
Assume that a host receives a UDP segment and finds that the checksum is correct. What does the receiver know
The segment received is identifical to the segment sent with 100 % certainty
The segment received is equal to the segment sent with a very high probability
The segment received is equal to the segment sent with a very high probability
Suppose you are given the following three 8-bit bytes: 01010011, 01100110, 00110100. What is the 1complement of the sum?
00010010
10000100
00000000
00010010
Suppose we have a network that may duplicate datagrams, but where there are no transmissions errors, loss or overtaking. What protocol mechanism would you use to ensure reliable data transfer
Acknowledgements
Retransmission
Checksums
Sequence numbers
Sequence numbers
It is possible to deal with transmission errors on ACK/NAK segments in the RDT2.0 protocol by simply retransmitting the current data segment in case a corrupt ACK or NAK is received by the sender?
True
False
False
It is possible to avoid using NAK-segments in the RDT2.1 protocol by instead having sequence numbers in the acknowledgement - and still obtain a correct protocol.
True
False
True
If the sender transport protocol entity in the RDT2.0 receives a corrupt ACK/NAK segment – what does the sender know for sure?
Some segment was received by the receiver
A corrupt data segment was received by the receiver
No data segment was received by the receiver
Some segment was received by the receiver
How is a TCP socket / connection identified
By a tuple consisting of destination IP address and destination port number
By a tuple consisting of source port and destination port
By a tuple consisting of source port, source IP address, destination port, and destination IP address
By a tuple consisting of source port, source IP address, destination port, and destination IP address
For which of the following transport protocols are acknowledgements cumulative?
Go-back N
Stop-and-wait
Selective-repeat
Go-back N
What is the purpose of flow control
To reduce segment loss in the network
Ensure reliable transmission of transport segments
To avoid that the sender overflows the receiver with data
To avoid that the sender overflows the receiver with data
Loss of transport segments is always an indication of network congestion?
True
False
False
What is the required relationship between the sequence number range and the windows size in the selective repeat protocol
There is no required relationship
The sequence number range must be equals to the window size
The sequence number range must be at least twice the window size
The sequence number range must be at least twice the window size
