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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. ___ ___ are used within Cisco IOS Software to determine what level of ___ - if any - exists within the network.
speech degradation
250 - 250 - 500
RTP timestamps - jitter
IP/RTP/UDP - delay - quality - constrained
2. __ 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
CRTP
jitter
G.723.1 speech or audio - 6.3 - 5.3
PSQM - objective - computer
3. Simplify the router - use H.323 gatekeeper or voice managers to avoid __ __
tandem compression
Propagation delay
CRTP
sequence information - time-stamping
4. 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 tail - 25
2 - G.723.1
VAD - bandwidth - 50
tandem compression
5. __ the 64 Kbps __ voice coding technique - This is used for the digital voice delivery in the __ or __
G.711 - PCM - PSTN or PBX(voip networks)
dial plan
Propagation delay
VAD - bandwidth - 50
6. If a packet is lost What is replayed? packet loss is common in data networks but not in __
data part - RTP Control Protocol (RTCP).
speech degradation
PSQM - objective - computer
last packet - voice
7. Voice samples are packed into the___ ___ of a UDP/RTP packet and thus the network header overhead would be __.
payload field - lower
Latency
MOS - subjective -1 - 5
amplitude - hangover
8. __ recommends no more than __ms delay one-way transmission
jitter buffer
IP/RTP/UDP - delay - quality - constrained
ITU-T - 150
RTP is Realtime Transport Protocol - delay sensitive
9. What do you use to compress RTP header to 2 or 4 bytes
CRTP
Handling delay - queuing delay
echo cancelers - software - DSP
Latency
10. Caused by the length a signal must travel via light in fiber or electrical impulse in copper-based networks.
Propagation delay
software - dynamic - RTP
RTP is Realtime Transport Protocol - delay sensitive
40 - 20 - 8 - 12
11. __ __ occurs when you have more than one compression/decompression cycle for each phone call and Voice degradation occurs
PCM - speech - header - information
tandom encoding
IP
Handling delay - queuing delay
12. How do you fix queuing delay - you would add
Echo
40 - 20 - 8 - 12
person - computer
QoS
13. When companies merge make sure you configure the __ __
Reliable User Data Protocol (RUDP) - UDP - TCP - RUDP
sequence number and timestamp
G.711 PCM
dial plan
14. 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
busy house
payload field - lower
adaptive differential pulse code modulation (ADPCM) - G.726 - 32
15. Bob@nextdoorneighbor.com is a __ entry but coverts then to an __ address
sizing
data part - RTP Control Protocol (RTCP).
iLBC
DNS - IP
16. VAD problems in determining when speech __ and __ - and in distinguishing speech from __ __. Its also known as __ __ __ __
adaptive differential pulse code modulation (ADPCM) - G.726 - 32
ends - begin - background noise - signal-to-noise threshold
person - computer
Echo
17. Propagation delay in conjuction with handeling delay can cause noticeable
DNS - IP
tandom encoding
speech degradation
sequence information - time-stamping
18. Is the variation of packet interarrival time.
jitter
Jitter - interarrival - packet-based
G.729 - voice - 8
waveform codecs
19. __ __ conceals interarrival packet delay variation.
G.711 PCM
Echo
jitter buffer
40 - 20 - 8 - 12
20. How many times can a digital to analog conversion in my network and PSTN total network happen - __ speech is less robust conversion
continuous media - timing reconstruction
7 - compressed
waveform codecs
echo cancelers - software - DSP
21. 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
Propagation delay
G.726 - ADPCM - 40 - 32 - 24 - 16
person - computer
22. How does G.729 header go __/__/__
Echo
echo tail - 25
echo cancelers - software - DSP
IP - RTP - UDP
23. __is characterized as the amount of time it takes for speech to exit the speaker's mouth and reach the listener's ear.
Latency
jitter
VAD - bandwidth - 50
queuing - unacceptable
24. 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.
IP/RTP/UDP - delay - quality - constrained
G.726 - ADPCM - 40 - 32 - 24 - 16
software - dynamic - RTP
source codecs
25. It has a large header of __ bytes - Size of headers IP/RTP/UDP
40 - 20 - 8 - 12
queuing - unacceptable
iLBC
software - dynamic - RTP
26. 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
G.729 - voice - 8
RTP is Realtime Transport Protocol - delay sensitive
tandom encoding
forward error correction (FEC)
27. The difference between when the packet is expected and when it is actually received is __. - exists only in __ ___ networks
Echo
Jitter - interarrival - packet-based
Reliable User Data Protocol (RUDP) - UDP - TCP - RUDP
IP
28. __ protocol that carries audio and video packets - is the standard for transmitting__ __traffic across packet-based networks
sizing
RTP is Realtime Transport Protocol - delay sensitive
7 - compressed
groups payload - qos - combining
29. On a voip link What is the max packet loss
person - computer
<1%
IP/RTP/UDP - delay - quality - constrained
7 - compressed
30. 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)
iLBC
queuing - unacceptable
payload field - lower
ends - begin - background noise - signal-to-noise threshold
31. __ is not wasting __ when there is no sound to transmit. At least __ % is wasted
Reliable User Data Protocol (RUDP) - UDP - TCP - RUDP
PCM - speech - header - information
VAD - bandwidth - 50
software - dynamic - RTP
32. This adaptation of jitter buffer __ is effective in compensating for delays.
Serialization delay
IP
<1%
sizing
33. RTP consists of a __ __ and a control part the called __
person - computer
Reliable User Data Protocol (RUDP) - UDP - TCP - RUDP
forward error correction (FEC)
data part - RTP Control Protocol (RTCP).
34. 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).
source codecs
40 - 20 - 8 - 12
Echo
amplitude - hangover
35. __ is an _ measurement of voice quality and the __ measures the voice
2 - G.723.1
Serialization delay
PSQM - objective - computer
Reliable User Data Protocol (RUDP) - UDP - TCP - RUDP
36. PCM and ADPCM are examples of __ __
payload field - lower
waveform codecs
jitter
source codecs
37. 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
iLBC
IP/RTP/UDP - delay - quality - constrained
echo tail - 25
sequence number and timestamp
38. To make audio and video work with RTP what do you need. 2 things
software - dynamic - RTP
continuous media - timing reconstruction
Echo
sequence number and timestamp
39. __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
busy house
IP - RTP - UDP
RTP is Realtime Transport Protocol - delay sensitive
40. You stop Echo in a PSTN by __ __ and is done in __ which is located on each __
Latency
echo cancelers - software - DSP
CRTP
forward error correction (FEC)
41. ___describes CELP compression that enables __ to be coded into _ Kbps streams;
busy house
PCM - speech - header - information
MOS - subjective -1 - 5
G.729 - voice - 8
42. A __ can trick the human ear into perceiving a higher-quality voice - but a __ cannot be tricked.
RTP is Realtime Transport Protocol - delay sensitive
person - computer
waveform codecs
CRTP
43. __ is a __test given to listeners. The listeners give each sample of speech material a rating of __ (bad) to __ (excellent)
forward error correction (FEC)
G.723.1 speech or audio - 6.3 - 5.3
MOS - subjective -1 - 5
tandom encoding
44. 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.
echo tail - 25
ITU-T - 150
Handling delay - queuing delay
last packet - voice
45. Proxy server is not required in an __ based system
40 - 20 - 8 - 12
G.723.1 speech or audio - 6.3 - 5.3
IP
echo cancelers - software - DSP
46. Who scored highest in the MOS
waveform codecs
last packet - voice
echo cancelers - software - DSP
G.711 PCM
47. Time of day of highest calls on circuit focus those on the __
begins - front-end speech clipping.
dial plan
CRTP
busy house
48. VAD detects a drop-off of speech ___ - it waits a fixed amount of time before it stops putting speech frames in packets. This fixed amount of time is known as __ ( when the person stops talking)
forward error correction (FEC)
IP/RTP/UDP - delay - quality - constrained
groups payload - qos - combining
amplitude - hangover
49. 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
DNS - IP
250 - 250 - 500
IP/RTP/UDP - delay - quality - constrained
50. PSQM was developed to 'hear' impairments caused by __ and __ and not packet loss or jitter
G.729 - voice - 8
forward error correction (FEC)
compression - decompression
Reliable User Data Protocol (RUDP) - UDP - TCP - RUDP