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