 |
| 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 |
|
|
.