7. Mapping NQB to Standards of Other SDOs

For DOCSIS access networks, cable broadband services need a separate queue for DSCP 45 traffic and need that queue to share the rate-shaped service capacity with QB traffic. RFC 9957 provides further discussion of DOCSIS QProt.

For mobile networks, LTE can use a dedicated low-latency non-GBR EPS bearer, for example QCI 7, alongside the default EPS bearer. In 5G, a Data Radio Bearer with 5QI 7 can provide similar low-latency treatment, while unmarked traffic follows the default bearer.

For Wi-Fi, equipment SHOULD map DSCP 45 into a separate queue in the same Access Category as Default traffic, namely AC_BE. It is RECOMMENDED to provide a separate queue in UP 0 and map DSCP 45 there. If that is not possible, a Wi-Fi device MAY map DSCP 45 to UP 3.

Existing Wi-Fi networks often map DSCP 45 to UP 5 and AC_VI, giving separate queuing but also statistical priority over AC_BE. This is useful for interoperability, but it is not a fully compliant NQB PHB implementation. Wi-Fi systems MAY configure the EDCA parameters for AC_VI to match AC_BE, preserving the incentive principle when DSCP 45 reaches the Wi-Fi network from outside.

RFC 9956 updates RFC 8325 by changing the Standard service class to Standard and Non-Queue-Building, adding NQB treatment guidance, and adding a Non-Queue-Building row with NQB, RFC 9956, UP 0/3 or UP 5, and AC_BE or AC_VI. The update also adds that the NQB DSCP value 45 is an exception that encodes best-effort service.