What are two reasons that AF41 is marked for the audio and video channels of a video call? (Choose two.)
A. to prioritize video over other high -priority traffic classes
B. to give video calls a higher priority than AP41 in the QoS policy
C. to allow high-definition quality calls over low-speed links
D. to preserve lip synchronization between the audio and video channels
E. to provide separate classes for audio calls and video calls
DE
QoS Marking Differences Between Video Calls and Voice-Only Calls; A voice-only telephone call would have its media classified as CoS 5 (IP Precedence 5 or PHB EF), while the voice channel of a video conference would have its media classified as CoS 4 (IP Precedence 4 or PHB AF41). The audio and video channels of a video call both be marked as CoS 4 to (1) preserve lip-sync between audio and video channels and (2) provide separate classes for audio-only calls and video calls