Which three QoS mechanisms can be configured to improve VoIP quality on a converged network?

Which three QoS mechanisms can be configured to improve VoIP quality on a converged
network? Select three.

A.
The use of a queuing method that will give VoIP traffic strict priority over other traffic

B.
The use of RTP header compression for the VoIP traffic.

C.
The proper classification and marking of the traffic as close to the source as possible

D.
The use of 802.1QinQ trunking for VoIP traffic

E.
The use of WRED for the VoIP traffic

Explanation:

In order to optimize the quality of VOIP calls, QoS should be implemented to ensure that
VOIP traffic is prioritized over other traffic types.
By providing a strict queue for VOIP traffic, you will ensure that voice calls take
precedence over the other traffic types.
In order to properly provide for QoS across the network, the voice traffic should be
marked to give priority as close to the source as possible. This will ensure that the traffic
is prioritized end to end.
Finally, WRED (Weighted Random Early Detection) could be configured to prevent
congestion. WRED can be used to selectively drop less important traffic types, instead of
dropping the voice packets when links become busy.
Incorrect Answers:
B: Compression can be used to lower the bandwidth required to transmit VOIP calls, but
it will not help with improving the voice quality. In general, compression of any kind
lowers the quality of VOIP.
D)
The trunking method used will have no bearing on the VOIP quality.