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Test your basic knowledge |
CCNA Voice - 3
Start Test
Study First
Subjects
:
cisco
,
it-skills
,
ccna
Instructions:
Answer 50 questions in 15 minutes.
If you are not ready to take this test, you can
study here
.
Match each statement with the correct term.
Don't refresh. All questions and answers are randomly picked and ordered every time you load a test.
This is a study tool. The 3 wrong answers for each question are randomly chosen from answers to other questions. So, you might find at times the answers obvious, but you will see it re-enforces your understanding as you take the test each time.
1. How many times can a digital to analog conversion in my network and PSTN total network happen - __ speech is less robust conversion
7 - compressed
echo tail - 25
busy house
<1%
2. __ builds in some reliability to the connectionless __ protocol - enables reliability with out using the overhead of __ - what protocol send multiples of the same packet __
40 - 20 - 8 - 12
Reliable User Data Protocol (RUDP) - UDP - TCP - RUDP
dial plan
sizing
3. PCM and ADPCM are examples of __ __
waveform codecs
source codecs
250 - 250 - 500
compression - decompression
4. RTCP provides support for real-time conferencing of __ of any size within an Internet - does not send __ - offers __and supports __ media streams
dial plan
person - computer
ITU-T - 150
groups payload - qos - combining
5. __ Kbps low-delay variation of CELP voice compression 16 kbps
busy house
tandem compression
G.728
Propagation delay
6. __ __ occurs when you have more than one compression/decompression cycle for each phone call and Voice degradation occurs
tandom encoding
QoS
MOS - subjective -1 - 5
data part - RTP Control Protocol (RTCP).
7. You hear your own voice in the background ( 4wire)
Echo
forward error correction (FEC)
MOS - subjective -1 - 5
person - computer
8. These techniques can be grouped together generally as __ __ and include variations such as linear predictive coding (LPC) - code excited linear prediction compression (CELP) - and multipulse - multilevel quantization (MP-MLQ).
Reliable User Data Protocol (RUDP) - UDP - TCP - RUDP
jitter
sequence number and timestamp
source codecs
9. This adaptation of jitter buffer __ is effective in compensating for delays.
sizing
begins - front-end speech clipping.
echo cancelers - software - DSP
iLBC
10. VAD problems in determining when speech __ and __ - and in distinguishing speech from __ __. Its also known as __ __ __ __
ends - begin - background noise - signal-to-noise threshold
sequence number and timestamp
sequence information - time-stamping
CRTP
11. Preferred codec for skype - PC to phone apps - A free speech codec suitable for robust voice communication over IP.
7 - compressed
RTP timestamps - jitter
speech degradation
iLBC
12. How do you fix queuing delay - you would add
IP/RTP/UDP - delay - quality - constrained
2 - G.723.1
QoS
MOS - subjective -1 - 5
13. The difference between when the packet is expected and when it is actually received is __. - exists only in __ ___ networks
sequence number and timestamp
Jitter - interarrival - packet-based
ends - begin - background noise - signal-to-noise threshold
IP
14. Is the amount of time it takes to actually place a bit or byte onto an interface. Its influence on delay is relatively minimal.
payload field - lower
iLBC
VAD - bandwidth - 50
Serialization delay
15. When companies merge make sure you configure the __ __
Serialization delay
dial plan
person - computer
queuing - unacceptable
16. __by default - sends two 10-ms G.729 speech frames in every packet - If you send more __ frames you put in a packet the fewer ___ you require but if you loose a packet the more __ you lose
VAD - bandwidth - 50
<1%
PCM - speech - header - information
source codecs
17. In an unmanaged - congested network - ___delay can add up to two seconds of delay (or result in the packet being dropped). This lengthy period of delay is___ in almost any voice network. delay)
G.728
person - computer
Echo
queuing - unacceptable
18. The data part of RTP is a thin protocol that provides support for applications with real-time properties - such as __ __ (for example - audio and video) - including __ __ - loss detection - and content identification.
continuous media - timing reconstruction
source codecs
PCM - speech - header - information
amplitude - hangover
19. The problem with VAD is detecting when speech __. This is known as__ Usually - the person listening to the speech does not notice this cut off because it did not record and transmit any codec.
40 - 20 - 8 - 12
adaptive differential pulse code modulation (ADPCM) - G.726 - 32
Handling delay - queuing delay
begins - front-end speech clipping.
20. __ Describes a compression technique that you can use to compress ___or other __ signal components of multimedia service at a low bit rate - MP-MLQ provides greater quality at __ Kbps - CELP provides flexibility at __Kbps
G.723.1 speech or audio - 6.3 - 5.3
250 - 250 - 500
source codecs
last packet - voice
21. Time of day of highest calls on circuit focus those on the __
VAD - bandwidth - 50
data part - RTP Control Protocol (RTCP).
busy house
sizing
22. To reduce the overall ___ overhead introduced by the 54-byte header - multiple voice samples can be packed into a single Ethernet frame to transmit. Although this can increase the voice ___ - increasing this count can improve the overall voice___ - e
sizing
Serialization delay
IP/RTP/UDP - delay - quality - constrained
Handling delay - queuing delay
23. __ the 64 Kbps __ voice coding technique - This is used for the digital voice delivery in the __ or __
Serialization delay
continuous media - timing reconstruction
ends - begin - background noise - signal-to-noise threshold
G.711 - PCM - PSTN or PBX(voip networks)
24. Proxy server is not required in an __ based system
RTP timestamps - jitter
IP
forward error correction (FEC)
Handling delay - queuing delay
25. Is the variation of packet interarrival time.
software - dynamic - RTP
2 - G.723.1
jitter
PCM - speech - header - information
26. RTP consists of a __ __ and a control part the called __
groups payload - qos - combining
G.729 - voice - 8
G.711 PCM
data part - RTP Control Protocol (RTCP).
27. If a packet is lost What is replayed? packet loss is common in data networks but not in __
purchase leased lines - purchase VPN and use access code - OR put voice on data network
last packet - voice
adaptive differential pulse code modulation (ADPCM) - G.726 - 32
forward error correction (FEC)
28. __ recommends no more than __ms delay one-way transmission
last packet - voice
ITU-T - 150
QoS
concealment strategy
29. Bob@nextdoorneighbor.com is a __ entry but coverts then to an __ address
DNS - IP
dial plan
continuous media - timing reconstruction
IP/RTP/UDP - delay - quality - constrained
30. The jitter buffer found within Cisco IOS ___ is considered a __ queue. This queue can grow or shrink exponentially depending on the interarrival time of the __ packets.
RTP is Realtime Transport Protocol - delay sensitive
jitter buffer
software - dynamic - RTP
tandem compression
31. __ is an _ measurement of voice quality and the __ measures the voice
concealment strategy
groups payload - qos - combining
IP - RTP - UDP
PSQM - objective - computer
32. Echo cancellers are limited by the total amount of time they wait for the reflected speech to be received __ __. A good time to configure is __ms
echo cancelers - software - DSP
QoS
echo tail - 25
IP
33. Who scored highest in the MOS
G.723.1 speech or audio - 6.3 - 5.3
G.711 - PCM - PSTN or PBX(voip networks)
G.711 PCM
software - dynamic - RTP
34. Voice samples are packed into the___ ___ of a UDP/RTP packet and thus the network header overhead would be __.
Serialization delay
amplitude - hangover
VAD - bandwidth - 50
payload field - lower
35. Propagation delay in conjuction with handeling delay can cause noticeable
G.711 PCM
tandem compression
groups payload - qos - combining
speech degradation
36. __ __ replays the last packet received
concealment strategy
ITU-T - 150
waveform codecs
QoS
37. It has a large header of __ bytes - Size of headers IP/RTP/UDP
groups payload - qos - combining
40 - 20 - 8 - 12
2 - G.723.1
VAD - bandwidth - 50
38. Using G.729 - just __ conversions from D/A cause the MOS score to decrease rapidly but __ is less resilient
payload field - lower
source codecs
data part - RTP Control Protocol (RTCP).
2 - G.723.1
39. __ protocol that carries audio and video packets - is the standard for transmitting__ __traffic across packet-based networks
RTP is Realtime Transport Protocol - delay sensitive
queuing - unacceptable
forward error correction (FEC)
continuous media - timing reconstruction
40. RTP uses the __ __ to determine whether the packets are arriving in order - and it uses the __ __ information to determine the interarrival packet time (jitter).
purchase leased lines - purchase VPN and use access code - OR put voice on data network
adaptive differential pulse code modulation (ADPCM) - G.726 - 32
concealment strategy
sequence information - time-stamping
41. __ __ conceals interarrival packet delay variation.
PCM - speech - header - information
jitter buffer
G.711 PCM
G.728
42. Caused by the length a signal must travel via light in fiber or electrical impulse in copper-based networks.
waveform codecs
source codecs
Propagation delay
RTP is Realtime Transport Protocol - delay sensitive
43. __ is not wasting __ when there is no sound to transmit. At least __ % is wasted
payload field - lower
G.729 - voice - 8
iLBC
VAD - bandwidth - 50
44. Satellite transmission takes approximately __ ms for a transmission to reach the satellite and another __ ms for it to come back down to Earth. This results in a total delay of __ ms.
sequence information - time-stamping
250 - 250 - 500
jitter buffer
G.729 - voice - 8
45. To make audio and video work with RTP what do you need. 2 things
iLBC
Echo
250 - 250 - 500
sequence number and timestamp
46. Another compression method used often is ____ . A commonly used instance of this is ITU-T __ - which encodes using 4-bit samples - giving a transmission rate of __ Kbps.
VAD - bandwidth - 50
amplitude - hangover
adaptive differential pulse code modulation (ADPCM) - G.726 - 32
last packet - voice
47. You stop Echo in a PSTN by __ __ and is done in __ which is located on each __
2 - G.723.1
last packet - voice
echo cancelers - software - DSP
queuing - unacceptable
48. ___ ___ are used within Cisco IOS Software to determine what level of ___ - if any - exists within the network.
RTP timestamps - jitter
RTP is Realtime Transport Protocol - delay sensitive
<1%
tandem compression
49. On a voip link What is the max packet loss
Serialization delay
<1%
sizing
G.723.1 speech or audio - 6.3 - 5.3
50. __ is a __test given to listeners. The listeners give each sample of speech material a rating of __ (bad) to __ (excellent)
source codecs
PCM - speech - header - information
MOS - subjective -1 - 5
jitter buffer