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