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