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