ACA Quality of Service & Media Handling

Question 1

Which DSCP value is recommended by Cisco and widely used for marking VoIP RTP media traffic to ensure priority queuing?

Accepted Answer

EF (Expedited Forwarding, DSCP 46)

Answer

EF (Expedited Forwarding, DSCP 46) is the standard DSCP marking for real-time voice RTP traffic, ensuring it receives lowest latency and jitter in network queues.

Question 2

In AudioCodes Mediant, which parameter configures the DSCP value applied to outgoing RTP packets?

Accepted Answer

Premium Service Class Media (PremiumServiceClassMedia)

Answer

The PremiumServiceClassMedia parameter sets the DSCP/ToS value stamped on outgoing RTP media packets, enabling QoS prioritization in the network.

Question 3

What is the primary purpose of a jitter buffer in VoIP media processing?

Accepted Answer

To absorb network delay variation and deliver audio packets to the codec at a steady rate

Answer

A jitter buffer temporarily stores arriving RTP packets to smooth out variable network delays, providing a steady stream of audio samples to the decoder.

Question 4

AudioCodes Mediant supports which type of jitter buffer that automatically adjusts its depth based on network conditions?

Accepted Answer

Adaptive jitter buffer

Answer

The adaptive jitter buffer dynamically increases or decreases its depth in real time based on measured network jitter, balancing latency against packet loss concealment.

Question 5

What is Packet Loss Concealment (PLC) in AudioCodes media processing?

Accepted Answer

An algorithm that synthesizes substitute audio when RTP packets are lost, reducing perceived quality degradation

Answer

PLC generates plausible substitute audio frames when packets are missing, minimizing the audible impact of network packet loss on voice quality.

ACA - Audiocodes Certified Associate Practice Test

ACA - Audiocodes Certified Associate Practice Test

ACA Quality of Service & Media Handling