.. SPDX-FileCopyrightText: 2021 Open Networking Foundation .. SPDX-License-Identifier: Apache-2.0 Glossary ======== - DBUF: Software service responsible of implementing the UPF Downlink buffering feature - DDN: Downlink Data Notification - PCP: Programmable Control Plane team, now merged with PDP into SD-Fabric - PDP: Programmable Data Plane team, now merged with PCP into SD-Fabric - QFI: QoS Flow Identifier - TOST: Trellis, ONOS, Stratum and Tofino, the predecessor of SD-Fabric (now obsolete) - TNA: Tofino Native Architecture - UPF: 5G User Plane Function - UP4: P4 implementation of UPF of control-stack based on ONOS