Technology for reducing user plane congestion is disclosed. An inquiry request message can be received at a mobility management entity (MME) from a congestion information collection function (CICF). The inquiry request message can request an international mobile subscriber identity (IMSI) and a packet data network (PDN) connection identifier (ID) associated with user equipments (UEs) that are impacted by radio access network (RAN) user plane congestion. The IMSI and the PDN connection ID that are associated with the UEs can be identified based in part on the inquiry request message. An inquiry response message that includes the IMSI and the PDN connection ID can be sent to the CICF to enable the CICF to discover an assigned policy and charging rules function (PCRF) for the UEs that are impacted by the RAN user plane congestion, wherein the PCRF is configured to implement network policies to reduce the RAN user plane congestion.