DPDK for UPF — packet detection rules at line rate

PFCP Rules in the UPF Fast Path

A production UPF's data plane is fundamentally a packet classifier. Each packet arrives, gets matched against a set of Packet Detection Rules (PDRs) configured by the SMF via PFCP Session Establishment, and routed through one of many Forwarding Action Rules (FARs). For uplink traffic from a UE: strip the GTP-U header to expose the inner IP packet, match the inner packet against uplink PDRs (typically by UE IP from session context and traffic flow template), apply the matched FAR (forward to data network, optionally with DSCP marking for QoS). For downlink traffic from the data network: match…