ESAT Forouzan - Chapter 23: Congestion Control and Quality of Service

Question 1

The maximum length of time that traffic is generated at the peak rate is called the ___________.
a. Average data rate
b. Maximum burst size
c. Effective bandwidth
d. Constant bit rate

Answer 1

b. Maximum burst size

Question 2

The ____ is the maximum data rate of the traffic
a. Average data rate
b. Peak data rate
c. Maximum burst size
d. Effective bandwidth

Answer 2

b. Peak data rate

Question 3

The effective bandwidth is based on _________.
a. Average data rate
b. Peak data rate
c. Maximum burst size
d. All of the above

Answer 3

d. All of the above

Question 4

_____traffic features sudden data rate changes in very short periods of time.
a. Constant-bit-rate
b. Variable-bit-rate
c. Bursty
d. Peak-bit-rate

Answer 4

c. Bursty

Question 5

When the load is greater than the capacity, the delay _______
a. Decreases
b. Increases linearly
c. Goes to infinity
d. Goes to zero

Answer 5

c. Goes to infinity

Question 6

______ is a closed loop mechanism to alleviate congestions
a. A choke point
b. Implicit signaling
c. Explicit signaling
d. All of the above

Answer 6

d. All of the above

Question 7

For a system using TCP, the sender window size is determined by the _____ window size
a. Receiver
b. Sender
c. Congestion
d. (a) and (c)

Answer 7

d. (a) and (c)

Question 8

Slow start is used in conjunction with ______as a TCP congestion control strategy
a. Additive increase
b. Additive decrease
c. Multiplicative increase
d. Multiplicative decrease

Answer 8

a. Additive increase

Question 9

The FECN informs the _____ of congestion while the BECN informs the _____ of congestion
a. Destination; interface
b. Destination; sender
c. Sender; destination
d. Interface; sender

Answer 9

b. Destination; sender

Question 10

_____ is a flow characteristic in which the delay varies for packets belonging to the same flow
a. Choke point
b. Throughput
c. Additive increase
d. Jitter

Answer 10

c. Additive increase

Question 11

In _____ queuing the first packet into the queue is the first packet out of the queue
a. FIFO
b. LIFO
c. Priority
d. Weighted fair

Answer 11

a. FIFO

Question 12

The ____ traffic shaping method gives a host credit for its idle time
a. Leaky bucket
b. Token bucket
c. Traffic bucket
d. Bursty bucket

Answer 12

b. Token bucket

Question 13

A flow-based QoS model designated for IP is called________
a. Integrated services
b. Differentiated services
c. RSVP
d. Multicast trees

Answer 13

a. Integrated services

Question 14

A signaling protocol that helps IP create a flow is called _____
a. Integrated services
b. Differentiated services
c. RSVP
d. Multicast trees

Answer 14

c. RSVP

Question 15

RSVP uses _____ messages
a. Path
b. Resv
c. Resource
d. (a) and (b)

Answer 15

d. (a) and (b)

Question 16

In a RSVP reservation style called ______ filter, the router creates a single reservation that can be shared by a set of flows.
a. Wild card
b. Fixed
c. Shared explicit
d. All of the above

Answer 16

c. Shared explicit

Question 17

Differentiated services was designed to handle the ______ problem associated with Integrated Services
a. Scalability
b. Stability
c. Reservation
d. All of the above

Answer 17

a. Scalability

Question 18

A ____ is a Differentiated Services traffic conditioner
a. Meter
b. Marker
c. Shaper
d. All of the above

Answer 18

c. Shaper

Question 19

When added to Be, Bc should be less than the ________
a. CIR
b. Access rate
c. Committed burst size
d. (a) and (b)

Answer 19

b. Access rate

Question 20

What is the relationship between the access rate and the CIR?
a. CIR is always equal to the access rate
b. CIR is greater than the access rate
c. CIR is less than the access rate
d. CIR plus Bc is equal to the access rate

Answer 20

c. CIR is less than the access rate

Question 21

A Frame Relay network is committed to transfer ______ bps without discarding any frames
a. Bc
b. Be
c. CIR
d. (a) and (b)

Answer 21

a. Bc

Question 22

In Frame Relay the transmission rate can never exceed _____.
a. Bc
b. Be
c. CIR
d. The access rate

Answer 22

d. The access rate

Question 23

The cell _______ is the difference between the CTD maximum and minimum
a. Loss ratio
b. Transfer delay
c. Delay variation
d. Error ratio

Answer 23

c. Delay variation

Question 24

The cell ____ is the ratio of lost cells to cells sent
a. Loss ratio
b. Transfer delay
c. Delay variation
d. Error ratio

Answer 24

a. Loss ratio

Question 25

The _____ service class is particularly suitable for applications with bursty data
a. CBR
b. VBR
c. ABR
d. UBR

Answer 25

c. ABR

Question 26

The _____ service class is suitable for customers who need real-time video transmission without compression
a. CBR
b. VBR
c. ABR
d. UBR

Answer 26

a. CBR

Question 27

The ______ is greater than the SCR.
a. PCR
b. MCR
c. CVDT
d. All of the above

Answer 27

a. PCR

Question 28

________ measures the variation in cell transmission time
a. SCR
b. PCR
c. MCR
d. CVDT

Answer 28

d. CVDT

Question 29

If the SCR is 60 000, the PCR is 70 000 and the MCR is 55 000, what is the minimum number of cells that can be sent per second?
a. 55 000
b. 60 000
c. 70 000
d. 5000

Answer 29

a. 55 000

Question 30

The ____ is the fraction of the cells delivered in error
a. CLR
b. CTD
c. CDV
d. CER

Answer 30

d. CER

Question 31

If the maximum CTD is 10 μs and the minimum CTD is 1μs, the _______ is 9μs
a. CLR
b. CTD
c. CDV
d. CER

Answer 31

c. CDV