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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. __ the 64 Kbps __ voice coding technique - This is used for the digital voice delivery in the __ or __
RTP timestamps - jitter
G.711 - PCM - PSTN or PBX(voip networks)
ends - begin - background noise - signal-to-noise threshold
40 - 20 - 8 - 12
2. 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.
person - computer
250 - 250 - 500
IP - RTP - UDP
Reliable User Data Protocol (RUDP) - UDP - TCP - RUDP
3. __ __ occurs when you have more than one compression/decompression cycle for each phone call and Voice degradation occurs
RTP is Realtime Transport Protocol - delay sensitive
compression - decompression
iLBC
tandom encoding
4. 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.
echo cancelers - software - DSP
tandom encoding
Latency
software - dynamic - RTP
5. Who scored highest in the MOS
2 - G.723.1
G.711 PCM
sizing
Jitter - interarrival - packet-based
6. The difference between when the packet is expected and when it is actually received is __. - exists only in __ ___ networks
busy house
Jitter - interarrival - packet-based
2 - G.723.1
echo cancelers - software - DSP
7. 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.
2 - G.723.1
PCM - speech - header - information
Handling delay - queuing delay
Jitter - interarrival - packet-based
8. __is characterized as the amount of time it takes for speech to exit the speaker's mouth and reach the listener's ear.
G.723.1 speech or audio - 6.3 - 5.3
Latency
sequence information - time-stamping
begins - front-end speech clipping.
9. __ is a __test given to listeners. The listeners give each sample of speech material a rating of __ (bad) to __ (excellent)
CRTP
queuing - unacceptable
continuous media - timing reconstruction
MOS - subjective -1 - 5
10. 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
VAD - bandwidth - 50
Echo
IP/RTP/UDP - delay - quality - constrained
11. __ __ replays the last packet received
begins - front-end speech clipping.
concealment strategy
jitter
IP/RTP/UDP - delay - quality - constrained
12. Using G.729 - just __ conversions from D/A cause the MOS score to decrease rapidly but __ is less resilient
Reliable User Data Protocol (RUDP) - UDP - TCP - RUDP
jitter buffer
2 - G.723.1
sequence information - time-stamping
13. RTP consists of a __ __ and a control part the called __
data part - RTP Control Protocol (RTCP).
MOS - subjective -1 - 5
groups payload - qos - combining
G.726 - ADPCM - 40 - 32 - 24 - 16
14. Voice samples are packed into the___ ___ of a UDP/RTP packet and thus the network header overhead would be __.
payload field - lower
250 - 250 - 500
tandem compression
person - computer
15. __ is not wasting __ when there is no sound to transmit. At least __ % is wasted
queuing - unacceptable
QoS
VAD - bandwidth - 50
Echo
16. 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).
person - computer
Handling delay - queuing delay
RTP timestamps - jitter
source codecs
17. How many times can a digital to analog conversion in my network and PSTN total network happen - __ speech is less robust conversion
source codecs
7 - compressed
continuous media - timing reconstruction
Echo
18. This adaptation of jitter buffer __ is effective in compensating for delays.
Handling delay - queuing delay
sizing
tandem compression
2 - G.723.1
19. __ protocol that carries audio and video packets - is the standard for transmitting__ __traffic across packet-based networks
7 - compressed
payload field - lower
RTP is Realtime Transport Protocol - delay sensitive
G.729 - voice - 8
20. __ builds in some reliability to the connectionless __ protocol - enables reliability with out using the overhead of __ - what protocol send multiples of the same packet __
ends - begin - background noise - signal-to-noise threshold
tandom encoding
Reliable User Data Protocol (RUDP) - UDP - TCP - RUDP
dial plan
21. You stop Echo in a PSTN by __ __ and is done in __ which is located on each __
Latency
echo tail - 25
software - dynamic - RTP
echo cancelers - software - DSP
22. 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
Handling delay - queuing delay
tandom encoding
forward error correction (FEC)
IP
23. __ __ conceals interarrival packet delay variation.
tandom encoding
IP - RTP - UDP
data part - RTP Control Protocol (RTCP).
jitter buffer
24. If a packet is lost What is replayed? packet loss is common in data networks but not in __
compression - decompression
echo tail - 25
VAD - bandwidth - 50
last packet - voice
25. __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
iLBC
continuous media - timing reconstruction
waveform codecs
26. PSQM was developed to 'hear' impairments caused by __ and __ and not packet loss or jitter
busy house
compression - decompression
G.711 PCM
person - computer
27. ___describes CELP compression that enables __ to be coded into _ Kbps streams;
Serialization delay
VAD - bandwidth - 50
waveform codecs
G.729 - voice - 8
28. A __ can trick the human ear into perceiving a higher-quality voice - but a __ cannot be tricked.
2 - G.723.1
person - computer
RTP timestamps - jitter
7 - compressed
29. RTP uses the __ __ to determine whether the packets are arriving in order - and it uses the __ __ information to determine the interarrival packet time (jitter).
waveform codecs
sequence information - time-stamping
jitter
source codecs
30. __ recommends no more than __ms delay one-way transmission
source codecs
G.728
RTP is Realtime Transport Protocol - delay sensitive
ITU-T - 150
31. Is the variation of packet interarrival time.
sizing
jitter
busy house
G.726 - ADPCM - 40 - 32 - 24 - 16
32. RTCP provides support for real-time conferencing of __ of any size within an Internet - does not send __ - offers __and supports __ media streams
ends - begin - background noise - signal-to-noise threshold
ITU-T - 150
Reliable User Data Protocol (RUDP) - UDP - TCP - RUDP
groups payload - qos - combining
33. __ 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
begins - front-end speech clipping.
person - computer
RTP is Realtime Transport Protocol - delay sensitive
34. Preferred codec for skype - PC to phone apps - A free speech codec suitable for robust voice communication over IP.
tandem compression
iLBC
echo tail - 25
software - dynamic - RTP
35. 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
G.711 PCM
echo cancelers - software - DSP
continuous media - timing reconstruction
36. ___ ___ are used within Cisco IOS Software to determine what level of ___ - if any - exists within the network.
G.723.1 speech or audio - 6.3 - 5.3
RTP timestamps - jitter
source codecs
purchase leased lines - purchase VPN and use access code - OR put voice on data network
37. 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.
IP
ends - begin - background noise - signal-to-noise threshold
tandom encoding
continuous media - timing reconstruction
38. 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
2 - G.723.1
dial plan
echo tail - 25
concealment strategy
39. You hear your own voice in the background ( 4wire)
IP - RTP - UDP
adaptive differential pulse code modulation (ADPCM) - G.726 - 32
CRTP
Echo
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.
adaptive differential pulse code modulation (ADPCM) - G.726 - 32
jitter buffer
tandom encoding
compression - decompression
41. VAD problems in determining when speech __ and __ - and in distinguishing speech from __ __. Its also known as __ __ __ __
ITU-T - 150
CRTP
ends - begin - background noise - signal-to-noise threshold
forward error correction (FEC)
42. Simplify the router - use H.323 gatekeeper or voice managers to avoid __ __
concealment strategy
jitter buffer
continuous media - timing reconstruction
tandem compression
43. Is the amount of time it takes to actually place a bit or byte onto an interface. Its influence on delay is relatively minimal.
Serialization delay
VAD - bandwidth - 50
groups payload - qos - combining
G.728
44. When companies merge make sure you configure the __ __
jitter
tandom encoding
7 - compressed
dial plan
45. Propagation delay in conjuction with handeling delay can cause noticeable
speech degradation
amplitude - hangover
sequence information - time-stamping
source codecs
46. Proxy server is not required in an __ based system
MOS - subjective -1 - 5
Handling delay - queuing delay
IP
waveform codecs
47. To make audio and video work with RTP what do you need. 2 things
queuing - unacceptable
sequence number and timestamp
QoS
<1%
48. What are 3 things you can do if they want to implement a corporate dial plan
sequence information - time-stamping
purchase leased lines - purchase VPN and use access code - OR put voice on data network
last packet - voice
PSQM - objective - computer
49. __ Kbps low-delay variation of CELP voice compression 16 kbps
IP - RTP - UDP
software - dynamic - RTP
tandom encoding
G.728
50. On a voip link What is the max packet loss
purchase leased lines - purchase VPN and use access code - OR put voice on data network
<1%
tandom encoding
ITU-T - 150