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