There is disclosed in one example a radio access network (RAN) user plane processing entity (UPPE) for a mobile data network, including: a hardware platform; a virtual switch to operate on the hardware platform; a network interface to communicatively couple to a local server; and a software defined networking controller, including a radio access network (RAN) control plane (CP) sniffer, and configured to: receive a control plane traffic offloading rule via a northbound interface, the traffic offloading rule configured to offload a class of traffic to the local server; operate the RAN CP sniffer to build a user-plane flow control message according to the offloading rule; and send the flow control message to the virtual switch.