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