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