4. NQB Sender Requirements

A microflow is eligible for NQB marking when it sends smooth, non-bursty traffic at a low data rate relative to typical path capacity. The RFC frames this as no more than about 1% of typical network path capacity, and as a pacing condition where IP bytes sent in any interval T are less than or equal to (R * T) + MTU.

Applications are RECOMMENDED to use DSCP value 45 (decimal) to mark NQB microflows. The choice supports separate queuing in existing Wi-Fi deployments and keeps implementation practical for equipment that classifies DSCP ranges.

If a microflow exceeds the rate equation in the first paragraph of Section 4, the application MUST NOT mark that traffic with the NQB DSCP. NQB marking also does not exempt an application from congestion-response guidance such as RFC 8085; applications remain responsible for detecting insufficient capacity and reacting appropriately.