Saudi Electronic University IT 210 CHAPTER 22 1)UDP and TCP are two protocols at the___________layer

Saudi Electronic University

IT 210

CHAPTER 22

1)UDP and TCP are two protocols at the___________layer. A) data-link

B) network C) transport

D) application

 

2 A port number is           bits long. A) 8

B) 16 C) 32 D) 64

 

3 Which of the following does UDP provide? A) Flow control

B) Connection-oriented delivery C) Error control

D) None of the choices are correct

 

4 The source port number on the UDP user datagram header defines     . A) the sending computer

B)            the receiving computer

C)            the process running on the sending computer D) None of the choices are correct

 

5 To use the services of UDP, we need  socket addresses. A) four

B) two C) three

D) None of the choices are correct

 

6 UDP packets are called               . A) user datagrams

B) segments C) frames

D) None of the choices are correct

 

                 

 

7 UDP packets have a fixed-size header of           bytes. A) 16

B) 8 C) 40 D) 32

 

8 TCP is a              protocol. A) byte-oriented

B) message-oriented C) block-oriented

D) None of the choices are correct

 

9 TCP groups a number of bytes together into a packet called a  . A) user datagram

B) segment C) datagram

D) None of the choices are correct

 

10 TCP is a(n)     protocol. A) connection-oriented

B)            connectionless

C)            both connection-oriented and connectionless D) None of the choices are correct

 

11 TCP is a(n)     transport protocol. A) unreliable

B) best-effort delivery C) reliable

D) None of the choices are correct

 

12 TCP uses        to check the safe and sound arrival of data. A) an acknowledgment mechanism

B)            out-of-band signaling

C)            the services of another protocol D) None of the choices are correct

 

 

13 The bytes of data being transferred in each connection are numbered by TCP. The numbering starts with a   .

A) 0 B) 1

C) randomly generated number D) None of the choices are correct

 

14 In TCP, the sequence number for each segment is the number of the               byte (virtual byte) carried in that segment.

A) first B) last

C)            middle

D)           None of the choices are correct

 

15 Communication in TCP is         . A) simplex

B) half-duplex C) full-duplex

D) None of the choices are correct

 

16 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.

A) first B) last C) next

D) None of the choices are correct

 

17 The inclusion of the checksum in the TCP segment is . A) optional

B)            mandatory

C)            depends on the type of data

D)           None of the choices are correct

 

                 

 

18 In TCP, a SYN segment consumes       sequence number(s). A) no

B) one C) two

D) None of the choices are correct

 

19 In TCP, a SYN + ACK segment consumes          sequence numbers. A) no

B) three C) two D) one

 

20 In TCP, an ACK segment, if carrying no data, consumes             sequence number(s). A) no

B) one C) two

D) None of the choices are correct

 

21 The connection establishment procedure in TCP is susceptible to a serious security problem called the                attack.

A) ACK flooding B) FIN flooding C) SYN flooding

D) None of the choices are correct

 

22 The SYN flooding attack belongs to a group of security attacks known as a        attack.

A) denial of service B) replay

C)            man-in-the middle

D)           None of the choices are correct

 

                 

 

23 In TCP, a FIN segment consumes        sequence numbers if it does not carry data. A) two

B) three C)  no D) one

 

24 In TCP, a FIN + ACK segment consumes           sequence number(s) if it does not carry data.

A) two B) three C) one D) no

25 In TCP, one end can stop sending data while still receiving data. This is called a               termination.

A) half-close B) half-open C) full-close

D) None of the choices are correct

 

26 TCP sliding windows are          oriented. A) packet

B) segment C) byte

D) None of the choices are correct

 

27 In TCP, the size of the send window is the      of rwnd and cwnd. A) maximum

B)  sum  of C) minimum

D) None of the choices are correct

 

28 In TCP, the window should not be      . A) opened

B) closed C) shrunk D) slide

 

 

29 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. A) ten B) zero C) one

D) None of the choices are correct

 

30 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           . A) silly window syndrome

B) unexpected syndrome C) window bug

D) None of the choices are correct

 

31 Nagle's algorithm can solve the silly window syndrome created by the              .

 

A) sender B) receiver

C)            both sender and receiver

D)           None of the choices are correct

 

32 Clark's solution can solve the silly window syndrome created by the  . A) sender

B)            receiver

C)            both sender and receiver

D)           None of the choices are correct

 

33 Delayed acknowledgment can solve the silly window syndrome created by the

                . A) sender B) receiver

C)            both sender and receiver

D)           None of the choices are correct

 

 

34 In TCP, an ACK segments that carry no data consumes              sequence number(s). A) no

B) one C) two

D) None of the choices are correct

 

35 In modern implementations of TCP, a retransmission occurs if the retransmission timer expires or      duplicate ACK segments have arrived.

A) one B) two C) three

D) None of the choices are correct

 

36 In TCP,            retransmission timer is set for an ACK segment. A) one

B) a previous C) no

D) None of the choices are correct

 

37 In TCP, there can be  RTT measurement(s) in progress at any time. A) two

B)            only one

 

C)            several

D)           None of the choices are correct

 

38 We need to multiply the header length field by           to find the total number of bytes in the TCP header.

A) 2 B) 4 C) 6

D) None of the choices are correct

 

                 

 

39 In TCP, urgent data requires the urgent pointer field as well as the URG bit (to be set) in the field.

A) control B) offset

C)            sequence number

D)           None of the choices are correct

 

40 In TCP, if the ACK value is 200, then byte         has been received successfully. A) 199

B) 200 C) 201

D) None of the choices are correct

 

41           control refers to the mechanisms and techniques to keep the load below the capacity.

A) Flow B) Error

C)            Congestion

D)           None of the choices are correct

 

42 In TCP's           algorithm the size of the congestion window increases exponentially until it reaches a threshold.

A) congestion avoidance B) congestion detection C) slow start

D) None of the choices are correct

 

43 In TCP's           algorithm the size of the congestion window increases additively until congestion is detected.

A) congestion avoidance B) congestion detection C) slow start

D) None of the choices are correct

 

                 

 

44           treats the two signs of congestion detections, timeout and three duplicate ACKs, in the same way.

A) Taho TCP B) Reno TCP

C)            New Reno TCP

D)           None of the choices are correct

 

45 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. A) Taho

B)            Reno

C)            new Reno

D)           None of the choices are correct

 

46 The   added a new state to the congestion control FSM, called the fast recovery state.

A) Taho TCP B) Reno TCP

C)            new Reno TCP

D)           None of the choices are correct

 

47 The   treated the two signals of congestion, timeout and arrival of three duplicate ACKs, differently.

A) Taho TCP B) Reno TCP

C)            new Reno TCP

D)           None of the choices are correct

 

48 The   state in Reno TCP is a state somehow between the slow start and the congestion avoidance states.

A) congestion avoidance B) congestion detection C) slow recovery

D) None of the choices are correct

 

 

49 In the Reno TCP, when TCP enters the fast recovery, if duplicate ACKs continue to come, TCP               .

A)           stays in this state, but the cwnd grows additively

B)            stays in this state, but the cwnd grows exponentially C) moves to slow start state

D) moves to the congestion avoidance state but deflate the size of the cwnd to ssthresh value

 

50 In the Reno TCP, when TCP enters the fast recovery, if a timeout occurs, TCP

                .

 

A)           stays in this state, but the cwnd grows additively

B)            stays in this state, but the cwnd grows exponentially C) moves to slow start state

D) moves to the congestion avoidance state but deflate the size of the cwnd to ssthresh value

 

51 In the Reno TCP, when TCP enters the fast recovery, if a new (non duplicate) ACK arrives, TCP             .

A)           stays in this state, but the cwnd grows additively

B)            stays in this state, but the cwnd grows exponentially C) moves to slow start state

D) moves to the congestion avoidance state but deflates the size of the cwnd to ssthresh value

 

52 A later version of TCP, called TCP, made an extra optimization on the                 TCP.

A) new Reno; Reno B) new Taho; Taho C) new Reno; Taho D) new Taho; Reno

 

                 

 

53 In the slow start algorithm, the size of the congestion window grows                                       until                .

A) exponentially; it reaches a threshold B) exponentially; congestion is detected C) additively; it reaches a threshold

D) additively; congestion is detected

 

54 In the congestion avoidance algorithm, the size of the congestion window grows

                .

A) exponentially; it reaches a threshold B) exponentially; congestion is detected C) additively; it reaches a threshold

D) additively; congestion is detected

 

55 The congestion window size, after it passes the initial slow start state, follows a saw tooth pattern called        .

A)           exponential increase, additive decrease B) additive increase, exponential decrease C) multiplicative increase, additive decrease D) additive increase, multiplicative decrease

 

56 Stream Control Transmission Protocol (SCTP) is a new               protocol. A) reliable, character-oriented

B)            reliable, message-oriented

 

C)            unreliable, message-oriented D) None of the choices are correct

 

57 SCTP allows   service in each association. A) only single-stream

B)            multistream

C)            only double-stream

D)           None of the choices are correct

 

                 

 

58 In SCTP, a data chunk is numbered using         . A) a TSN

B)  an  SI C) an SSN

D) None of the choices are correct

 

59 To distinguish between different streams, SCTP uses                . A) a TSN

B)  an  SI C) an SSN

D) None of the choices are correct

 

60 The control information in SCTP is carried in the           . A) header control field

B) control chunks C) data chunks

D) None of the choices are correct