Self-Assessment Quizzes Chapter 3 MC,T&F
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1.
Consider the latency model for dynamic congestion windows. Which of the following components contribute to latency
round trip time, RTT
all of the above
the transmission time of the object, O/R
the sum of all the stalled times
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2.
When a TCP segment arrives to a host, the socket to which the segment is directed depends on
the destination port number
the source IP address of the datagram that encapsulated the segment
the source port number
all of the above
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3.
UDP has which of the following characteristics:
regulated send rate
three-way hand shake for connection establishment
connection state at the server
none of the above
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4.
When a UDP segment arrives to a host, in order to direct the segment to the appropriate socket, the OS uses
the source port number
the destination port number
the source IP address
all of the above
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5.
The stop-and-wait protocol is highly inefficient when
when there is a short distance between source and destination and the transmission rate is large
when there is a large distance between source and destination and the transmission rate is high
when there is a large distance between source and destination and the transmission rate is low
when there is a short distance between source and destination and the transmission rate is low
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6.
Pipelining requires which of the following
unique sequence numbers for each in-transit packet
transmitting many packets before receiving acknowledgements
sender-side buffering of unacknowledged packets
all of the above
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7.
TCP applies fast retransmit to a segment when
none of the above
the segment's timer expires
it estimates unusually large RTTs
when it receives three ACKs for an earlier segment
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8.
Nmap is often used to:
Measure round-trip times between hosts.
Decipher encrypted traffic
Measure throughput between hosts
Do port scans over a range of ports at a target host.
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9.
With SYN ******s, when a server receives a SYN segment, it returns a SYNACK with:
with an initial sequence number that is a hash of the IP addresses and port numbers in the SYN segment (as well as of other things).
with a randomly chosen initial sequence number;
initial sequence number 1;
none of the above.
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10.
Over a TCP connection, suppose host A sends two segments to host B, host B sends an acknowledgement for each segment, the first acknowledgement is lost, but the second acknowledgement arrives before the timer for the first segment expires.
Host A will retransmit the second segment
Host A will retransmit the first segment
Host A will retransmit both segments
Host A will retransmit neither segments
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11.
Consider an HTTP Web server using persistent connections. Suppose the server spawns a separate process for each client that connects to the server. Then each of these spawned processes will have different server port numbers.
True
False
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12.
Host A is sending host B a large file over a TCP connection. Assume host B has no data to send A. Host B will not send acknowledgements to host A because host B cannot piggyback the acknowledgements on data.
True
False
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13.
The size of the TCP RcvWindow never changes throughout the duration of the connection.
True
False
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14.
Suppose host A is sending a large file to host B over a TCP connection. If the sequence number for a segment of this connection is m, then the sequence number for the subsequent segment will necessarily be m+1.
True
False
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15.
The TCP segment has a field in its header for RcvWindow.
True
False
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16.
Suppose that the last SampleRTT in a TCP connection is equal to 1 sec. Then Timeout for the connection will necessarily be set to a value >= 1 sec.
True
False
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17.
Suppose host A sends host B one segment with sequence number 38 and 4 bytes of data. Then in this same segment the acknowledgement number is necessarily 42.
True
False
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18.
Suppose that host A wants to send data over TCP to host B, and host B wants to send data to host A over TCP. Two separate TCP connections - one for each direction - are needed.
True
False
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19.
The MSS is the maximum size of a TCP segment including headers.
True
False
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20.
In TCP, the acknowledgement number that a host puts in a segment is the sequence number of the next byte the host is expecting from the sender.
True
False
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