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