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