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