Best Practices for Marking Video and Voice Media

D.

In a Cisco Unified Communications network, marking video and voice media is an essential practice for ensuring Quality of Service (QoS). QoS is the ability of the network to provide different priority levels to different types of traffic, thereby ensuring that critical traffic, such as voice and video, is delivered with minimal delay and jitter.

The recommended best practice for marking video and voice media in a Cisco Unified Communications network is option A: Voice Cos 5 (IP Precedence 6, PHB AF41, or DSCP 16) Video Cos 4 (IP Precedence 5, PHB EF, or DSCP 32).

In this recommended configuration, Voice Cos 5 is used for marking voice media. Voice Cos 5 corresponds to IP Precedence 6, PHB AF41, or DSCP 16. IP Precedence 6 is a high-priority value that indicates that the traffic should be treated as voice traffic. PHB AF41 is a Class Selector value that indicates high-priority traffic with moderate drop probability. DSCP 16 is a value that indicates Expedited Forwarding (EF), which is a service that provides low delay, low loss, and low jitter.

For marking video media, Video Cos 4 is used. Video Cos 4 corresponds to IP Precedence 5, PHB EF, or DSCP 32. IP Precedence 5 is a value that indicates that the traffic should be treated as critical traffic. PHB EF is a value that indicates Expedited Forwarding, which is a service that provides low delay, low loss, and low jitter. DSCP 32 is a value that indicates the EF service.

This recommended configuration ensures that voice traffic is given higher priority than video traffic. Voice traffic is marked with a higher priority value (IP Precedence 6 or DSCP 16) than video traffic (IP Precedence 5 or DSCP 32), which ensures that voice traffic is always given priority over video traffic when there is congestion on the network.

Overall, this configuration helps to ensure that voice and video traffic are delivered with minimal delay and jitter, thereby ensuring a high-quality user experience.