What is the purpose of mapping DSCP values to QoS queues in a network?

• A. DSCP values encrypt data in the IP header
• B. DSCP values indicate priority and map to higher-priority queues to ensure time-sensitive traffic receives preferred treatment
• C. DSCP values allocate IP addresses to packets
• D. DSCP values determine the physical link speed

Answer: (B)

The purpose is to turn the priority tag in a packet into real, organized handling across the network. DSCP tagging marks each IP packet with a service level, and network devices read that tag to place the packet into a corresponding QoS queue. By mapping these DSCP values to higher-priority queues, time‑sensitive traffic—such as voice or real-time video—gets preferential treatment, experiencing lower latency and less jitter even when the network is busy. This helps ensure that critical applications perform reliably while less urgent traffic is queued in lower-priority paths.

DSCP does not encrypt data, assign IP addresses, or set the physical link speed, so those aspects aren’t related to why we map DSCP values to QoS queues.