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