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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. Who scored highest in the MOS
waveform codecs
compression - decompression
G.711 PCM
Handling delay - queuing delay
2. Defines many different causes of delay (actual packetization - compression - and packet switching) and is caused by devices that forward the frame through the network. Includes __ ___ for congested networks.
RTP is Realtime Transport Protocol - delay sensitive
last packet - voice
Handling delay - queuing delay
ends - begin - background noise - signal-to-noise threshold
3. __ is a __test given to listeners. The listeners give each sample of speech material a rating of __ (bad) to __ (excellent)
MOS - subjective -1 - 5
dial plan
VAD - bandwidth - 50
speech degradation
4. It has a large header of __ bytes - Size of headers IP/RTP/UDP
Serialization delay
40 - 20 - 8 - 12
Reliable User Data Protocol (RUDP) - UDP - TCP - RUDP
tandem compression
5. ___ ___ are used within Cisco IOS Software to determine what level of ___ - if any - exists within the network.
begins - front-end speech clipping.
groups payload - qos - combining
Jitter - interarrival - packet-based
RTP timestamps - jitter
6. Preferred codec for skype - PC to phone apps - A free speech codec suitable for robust voice communication over IP.
busy house
iLBC
sizing
G.711 PCM
7. 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.
groups payload - qos - combining
continuous media - timing reconstruction
RTP timestamps - jitter
amplitude - hangover
8. How many times can a digital to analog conversion in my network and PSTN total network happen - __ speech is less robust conversion
7 - compressed
tandem compression
Reliable User Data Protocol (RUDP) - UDP - TCP - RUDP
jitter buffer
9. __ 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
Handling delay - queuing delay
MOS - subjective -1 - 5
RTP timestamps - jitter
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
PCM - speech - header - information
source codecs
echo cancelers - software - DSP
11. 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
software - dynamic - RTP
Serialization delay
payload field - lower
echo tail - 25
12. To make audio and video work with RTP what do you need. 2 things
tandem compression
software - dynamic - RTP
G.711 - PCM - PSTN or PBX(voip networks)
sequence number and timestamp
13. __ __ replays the last packet received
person - computer
ends - begin - background noise - signal-to-noise threshold
concealment strategy
data part - RTP Control Protocol (RTCP).
14. RTP consists of a __ __ and a control part the called __
G.711 PCM
data part - RTP Control Protocol (RTCP).
CRTP
250 - 250 - 500
15. The difference between when the packet is expected and when it is actually received is __. - exists only in __ ___ networks
QoS
Jitter - interarrival - packet-based
queuing - unacceptable
busy house
16. __ __ conceals interarrival packet delay variation.
ITU-T - 150
2 - G.723.1
sequence information - time-stamping
jitter buffer
17. 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).
Latency
source codecs
tandem compression
G.729 - voice - 8
18. __ the 64 Kbps __ voice coding technique - This is used for the digital voice delivery in the __ or __
Propagation delay
G.711 - PCM - PSTN or PBX(voip networks)
DNS - IP
Latency
19. A __ can trick the human ear into perceiving a higher-quality voice - but a __ cannot be tricked.
Serialization delay
person - computer
sequence number and timestamp
iLBC
20. PSQM was developed to 'hear' impairments caused by __ and __ and not packet loss or jitter
G.711 - PCM - PSTN or PBX(voip networks)
tandom encoding
compression - decompression
G.711 PCM
21. __ __ occurs when you have more than one compression/decompression cycle for each phone call and Voice degradation occurs
continuous media - timing reconstruction
data part - RTP Control Protocol (RTCP).
waveform codecs
tandom encoding
22. This adaptation of jitter buffer __ is effective in compensating for delays.
sizing
G.728
tandom encoding
person - computer
23. RTCP provides support for real-time conferencing of __ of any size within an Internet - does not send __ - offers __and supports __ media streams
payload field - lower
groups payload - qos - combining
last packet - voice
QoS
24. Is the variation of packet interarrival time.
adaptive differential pulse code modulation (ADPCM) - G.726 - 32
person - computer
jitter
sizing
25. ___describes CELP compression that enables __ to be coded into _ Kbps streams;
G.711 PCM
40 - 20 - 8 - 12
G.729 - voice - 8
last packet - voice
26. Caused by the length a signal must travel via light in fiber or electrical impulse in copper-based networks.
queuing - unacceptable
G.723.1 speech or audio - 6.3 - 5.3
jitter buffer
Propagation delay
27. Time of day of highest calls on circuit focus those on the __
busy house
data part - RTP Control Protocol (RTCP).
software - dynamic - RTP
ITU-T - 150
28. Propagation delay in conjuction with handeling delay can cause noticeable
compression - decompression
sizing
ends - begin - background noise - signal-to-noise threshold
speech degradation
29. __ is not wasting __ when there is no sound to transmit. At least __ % is wasted
VAD - bandwidth - 50
Echo
G.723.1 speech or audio - 6.3 - 5.3
sizing
30. Customers that have almost unlimited bandwidth - however - consider __ a worthwhile mechanism to enhance reliability and voice quality - mechanism makes it more probable that one of the packets will make the journey from sender to receiver
CRTP
last packet - voice
jitter buffer
forward error correction (FEC)
31. What are 3 things you can do if they want to implement a corporate dial plan
compression - decompression
7 - compressed
concealment strategy
purchase leased lines - purchase VPN and use access code - OR put voice on data network
32. Simplify the router - use H.323 gatekeeper or voice managers to avoid __ __
tandem compression
speech degradation
G.726 - ADPCM - 40 - 32 - 24 - 16
echo tail - 25
33. 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
DNS - IP
PSQM - objective - computer
IP
IP/RTP/UDP - delay - quality - constrained
34. __ builds in some reliability to the connectionless __ protocol - enables reliability with out using the overhead of __ - what protocol send multiples of the same packet __
RTP is Realtime Transport Protocol - delay sensitive
Latency
Propagation delay
Reliable User Data Protocol (RUDP) - UDP - TCP - RUDP
35. 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.
begins - front-end speech clipping.
echo cancelers - software - DSP
VAD - bandwidth - 50
PSQM - objective - computer
36. Bob@nextdoorneighbor.com is a __ entry but coverts then to an __ address
person - computer
Latency
DNS - IP
G.729 - voice - 8
37. Is the amount of time it takes to actually place a bit or byte onto an interface. Its influence on delay is relatively minimal.
adaptive differential pulse code modulation (ADPCM) - G.726 - 32
tandom encoding
Serialization delay
QoS
38. __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
PCM - speech - header - information
G.728
forward error correction (FEC)
IP/RTP/UDP - delay - quality - constrained
39. How do you fix queuing delay - you would add
250 - 250 - 500
purchase leased lines - purchase VPN and use access code - OR put voice on data network
jitter buffer
QoS
40. 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.
last packet - voice
G.726 - ADPCM - 40 - 32 - 24 - 16
tandom encoding
250 - 250 - 500
41. __ Kbps low-delay variation of CELP voice compression 16 kbps
speech degradation
250 - 250 - 500
software - dynamic - RTP
G.728
42. Using G.729 - just __ conversions from D/A cause the MOS score to decrease rapidly but __ is less resilient
2 - G.723.1
tandom encoding
G.723.1 speech or audio - 6.3 - 5.3
tandem compression
43. How does G.729 header go __/__/__
IP - RTP - UDP
G.726 - ADPCM - 40 - 32 - 24 - 16
tandem compression
RTP timestamps - jitter
44. __ describes __ coding at __ - __ - __ and __ Kbps; you also can interchange ADPCM voice between packet voice and public phone or PBX networks
IP - RTP - UDP
tandem compression
PSQM - objective - computer
G.726 - ADPCM - 40 - 32 - 24 - 16
45. 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)
ends - begin - background noise - signal-to-noise threshold
echo tail - 25
queuing - unacceptable
amplitude - hangover
46. __is characterized as the amount of time it takes for speech to exit the speaker's mouth and reach the listener's ear.
2 - G.723.1
software - dynamic - RTP
source codecs
Latency
47. You hear your own voice in the background ( 4wire)
busy house
jitter buffer
speech degradation
Echo
48. RTP uses the __ __ to determine whether the packets are arriving in order - and it uses the __ __ information to determine the interarrival packet time (jitter).
sequence information - time-stamping
source codecs
PCM - speech - header - information
compression - decompression
49. PCM and ADPCM are examples of __ __
speech degradation
2 - G.723.1
G.723.1 speech or audio - 6.3 - 5.3
waveform codecs
50. When companies merge make sure you configure the __ __
PSQM - objective - computer
G.728
dial plan
250 - 250 - 500