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WorksheetsTransport Layer Quiz
Total questions: 72
Worksheet time: 44mins
One of the main duties of the transport layer is to provide ____________ communication.
node-to-node
host-to-host
process-to-process
None of the choices are correct
A client program normally uses ____________ port number. A server program normally uses __________ port number.
a well-known; an ephemeral
an ephemeral; a well-known
a private; a well-known
None of the choices are correct
A socket address is a combination of __________.
A MAC address and a logical address
A MAC address and a port number
a user-specific address and a logical address
None of the choices are correct
____________ means accepting items from more than one source. ______________ means delivering items to more than one source.
Demultiplexing; Multiplexing
Multiplexing; Demultiplexing
Encapsulation; Decapsulation
Pulling; Pushing
________ means the producer delivers the items when they are produced. _______ means the consumer takes the items when it is ready to do so.
Pushing; pulling
Pulling; pushing
Forwarding; accepting
None of the choices are correct
In the stop-and-wait protocol, the maximum send window size is ______ and the maximum receive window size is _______ where m is the number of bits in the sequence.
In the Go-Back-N protocol, the maximum send window size is ______ and the maximum receive window size is _______, where m is related to the number of bits in the sequence. number.
In the selective-repeat protocol, the maximum send window size is ______ and the maximum receive window size is _______, where m is the number of bits in the sequence.
UDP is a ________________ transport protocol.
connectionless, reliable
connection-oriented, unreliable
connectionless, unreliable
None of the choices are correct
UDP is an acronym for _______.
User Delivery Protocol
User Datagram Procedure
User Datagram Protocol
None of the choices are correct
At the transport layer, to define the processes, we need two identifiers called ____________.
logical addresses
physical addresses
port addresses
None of the choices are correct
The ports ranging from 0 to 1,023 are called the ___________ ports. The ports ranging from 1,024 to 49,151 are called ___________ ports. The ports ranging from 49,152 to 65,535 are called the ___________ ports.
well-known; registered; dynamic or private
registered; dynamic or private; well-known
private or dynamic; well-known; registered
private or dynamic; registered; well-known
UDP and TCP are two protocols at the ___________ layer.
data link
network
transport
application
Which of the following functions are performed by UDP?
process-to-process communication
host-to-host communication
node-to-node communication
None of the choices are correct
A port number is _______ bits long.
8
16
32
64
Which of the following does UDP provide?
flow control
connection-oriented delivery
error control
None of the choices are correct
The source port number on the UDP user datagram header defines _______.
the sending computer
the receiving computer
the process running on the sending computer
None of the choices are correct
To use the services of UDP, we need ________ socket addresses.
4
2
3
None
UDP packets are called __________ .
user datagrams
segments
frames
None of the choices are correct
UDP packets have a fixed-size header of _______ bytes.
16
8
40
32
TCP is a __________ protocol.
byte-oriented
message-oriented
block-oriented
None of the choices are correct
TCP groups a number of bytes together into a packet called a ___________.
user datagram
segment
datagram
None of the choices are correct
TCP is a(n) ___________ protocol.
connection-oriented
connectionless
both connection-oriented and connectionless
None of the choices are correct
TCP is a(n) _______ transport protocol.
unreliable
best-effort delivery
reliable
None of the choices are correct
TCP uses _________________ to check the safe and sound arrival of data.
an acknowledgment mechanism
out-of-band signaling
the services of another protocol
None of the choices are correct
The bytes of data being transferred in each connection are numbered by TCP. The numbering starts with a __________________.
0
1
randomly generated number
None of the choice
In TCP, the sequence number for each segment is the number of the _______ byte (virtual byte) carried in that segment.
first
last
middle
None of the choices are correct
Communication in TCP is ___________.
simplex
half-duplex
full-duplex
None of the choices are correct
In TCP, the value of the acknowledgment field in a sent segment defines the sequence number related to the ______ byte a party expects to receive next.
first
last
next
None of the choices are correct
The inclusion of the checksum in the TCP segment is ________.
optional
mandatory
depends on the type of data
None of the choices are correct
In TCP, a SYN segment consumes _____ sequence number(s).
no
one
two
None of the choices are correct
In TCP, a SYN + ACK segment consumes _____ sequence numbers.
no
three
two
one
In TCP, an ACK segment, if carrying no data, consumes ______ sequence number(s).
no
one
two
None of the choices are correct
The connection establishment procedure in TCP is susceptible to a serious security problem called the _________ attack.
ACK flooding
FIN flooding
SYN flooding
None of the choices are correct
The SYN flooding attack belongs to a group of security attacks known as a _____ attack.
denial of service
replay
man-in-the middle
None of the choices are correct
In TCP, a FIN segment consumes ____ sequence numbers if it does not carry data.
two
three
no
one
In TCP, a FIN + ACK segment consumes _____ sequence number(s) if it does not carry data.
two
three
one
no
In TCP, one end can stop sending data while still receiving data. This is called a ______ termination.
half-close
half-open
full-close
None of the choices are correct
TCP sliding windows are __________ oriented.
packet
segment
byte
None of the choices are correct
In TCP, the size of the send window is the ________ of rwnd and cwnd.
maximum
sum of
minimum
None of the choices are correct
In TCP, the window should not be _________.
opened
closed
shrunk
slide
In TCP, the receiver can temporarily shut down the window; the sender, however, can always send a segment of _____ byte(s) after the window is shut down.
ten
zero
one
None of the choices are correct
A serious problem can arise in the sliding window operation when either the sending application program creates data slowly or the receiving application program consumes data slowly, or both. This problem is called the ______.
silly window syndrome
unexpected syndrome
window bug
None of the choices are correct
Nagle's algorithm can solve the silly window syndrome created by the _________.
sender
receiver
both sender and receiver
None of the choices are correct
Clark's solution can solve the silly window syndrome created by the _________.
sender
receiver
both sender and receiver
None of the choices are correct
Delayed acknowledgment can solve the silly window syndrome created by the _________.
sender
receiver
both sender and receiver
None of the choices are correct
In TCP, an ACK segments that carry no data consumes _______ sequence number(s).
no
one
two
None of the choices are correct
In modern implementations of TCP, a retransmission occurs if the retransmission timer expires or ________ duplicate ACK segments have arrived.
one
two
three
None of the choices are correct
In TCP, ________ retransmission timer is set for an ACK segment.
one
a previous
no
None of the choices are correct
In TCP, there can be ______ RTT measurement(s) in progress at any time.
two
only one
several
None of the choices are correct
We need to multiply the header length field by _______ to find the total number of bytes in the TCP header.
2
4
6
None of the choices are correct
In TCP, urgent data requires the urgent pointer field as well as the URG bit (to be set) in the _______ field.
control
offset
sequence number
None of the choices are correct
In TCP, if the ACK value is 200, then byte _______ has been received successfully.
199
200
201
None of the choices are correct
In TCP, the _______ timer prevents a long idle connection between two TCPs.
retransmission
persistence
keepalive
None of the choices are correct
In TCP, the _______ timer is needed to handle the zero window-size advertisement.
retransmission
persistence
keepalive
None of the choices are correct
In TCP, Karn's algorithm is used in calculations by the _______ timer.
retransmission
persistence
keepalive
None of the choices are correct
In TCP, a special segment called a probe is sent by a sending TCP when the _______ timer goes off.
transmission
persistence
keepalive
None of the choices are correct
__________ control refers to the mechanisms and techniques to keep the load below the capacity.
flow
error
congestion
None of the choices are correct
In TCP's ________ algorithm the size of the congestion window increases exponentially until it reaches a threshold.
congestion avoidance
congestion detection
slow start
None of the choices are correct
In TCP's __________ algorithm the size of the congestion window increases additively until congestion is detected.
congestion avoidance
congestion detection
slow start
None of the choices are correct
________ treats the two signs of congestion detections, timeout and three duplicate ACKs, in the same way.
Taho TCP
Reno TCP
new Reno TCP
None of the choices are correct
In ______ TCP, when the connection is established, TCP starts the slow start algorithms and sets the ssthresh variable to a pre-agreed value (normally 64 or 128 kilobytes) and the cwnd variable to 1 MSS.
Taho TCP
Reno TCP
new Reno TCP
None of the choices are correct
The ___________ added a new state to the congestion control FSM, called the fast recovery state.
Taho TCP
Reno TCP
new Reno TCP
None of the choices are correct
The ___________ treated the two signals of congestion, timeout and arrival of three duplicate ACKs, differently.
Taho TCP
Reno TCP
new Reno TCP
None of the choices are correct
The __________ state in Reno TCP is a state somehow between the slow start and the congestion avoidance states.
congestion avoidance
congestion detection
slow recovery
None of the choices are correct
In the Reno TCP, when TCP enters the fast recovery, if duplicate ACKs continue to come, TCP ____________________________________.
stays in this state, but the cwnd grows additively
stays in this state, but the cwnd grows exponentially
moves to slow start state
moves to the congestion avoidance state but deflate the size of the cwnd to ssthresh value
In the Reno TCP, when TCP enters the fast recovery, if a timeout occurs, TCP ____________________________________.
stays in this state, but the cwnd grows additively
stays in this state, but the cwnd grows exponentially
moves to slow start state
moves to the congestion avoidance state but deflate the size of the cwnd to ssthresh value
In the Reno TCP, when TCP enters the fast recovery, if a new (non duplicate) ACK arrives TCP ____________________________________.
stays in this state, but the cwnd grows additively
stays in this state, but the cwnd grows exponentially
moves to slow start state
moves to the congestion avoidance state but deflate the size of the cwnd to ssthresh value
A later version of TCP, called ______ TCP, made an extra optimization on the _______ TCP.
New Reno; Reno
New Taho; Taho
New Reno; Taho
New Taho; Reno
In the slow start algorithm, the size of the congestion window grows ______________ until ___________________.
exponentially; it reaches a threshold
exponentially; congestion is detected
additively; it reaches a threshold
additively; congestion is detected
In the congestion avoidance algorithm, the size of the congestion window grows ______________ congestion is detected.
exponentially; it reaches a threshold
exponentially; congestion is detected
additively; it reaches a threshold
additively; congestion is detected
The congestion window size, after it passes the initial slow start state, follows a saw tooth pattern called _________________________________.
exponential increase, additive decrease
additive increase, exponential decrease
multiplicative increase, additive decrease
additive increase, multiplicative decrease
