2.7 Next Generation Network Priority Service

New Generation Network Priority-Service (NGN-PS) is a US Presidentially-directed program to define and deploy priority communications in commercial service provider next generation packet-switched networks. First Responders, National Security, and Emergency Preparedness need priority access and priority services to better serve the public interest when the network is facing severe overload conditions.

Despite the original directive of NGN-PS as mentioned above, this feature can be used by any operator to prioritize VoLTE traffic based on subscription information stored in the HSS or SPR.

The DSR assigns all NGN-PS messages higher priority over non NGN-PS messages (request and answers). The DSR then allows control for the NGN-PS feature on a per Diameter interface basis and for any combination of the following LTE and IMS diameter interfaces: Gx, Rx, Cx/Dx and Dh/Sh. The DSR supports optional NGN-PS/Advance-Priority HSS and NGN-PS/Advance-Priority SPR modes for Gx interface as specified in LTE_GIR and IMS_GIR specifications. Additionally, DSR also allows to tag the ingress messages as NGN-PS messages using DRMP AVP value “0” for any diameter interface. This allows operators to support NGN-PS for diameter interfaces which do not have 3GPP defined AVP’s to identify the message as NGN-PS message.

If required the DSR throttles normal traffic to an engineered capacity such that internal resources (related to message queuing, resource pools, and message control functions) are always available for a small amount of additional NGN-PS traffic. Specific alarms and measurements allow evaluation of NGN-PS transactions.

Figure 2-37 NGN-PS Support