Programmable Network Data Planes (Dagstuhl Seminar 19141)

Software-Defined Networking (SDN) started the "softwarization" of networking. By relocating the control plane onto a logically centralized machine, SDN gave programmers the ability to specify the behavior of the network directly in software, unleashing a major transformation both in the networking research community and in industry. However, a key limitation of the original SDN vision was the limited functionality exposed in protocols such as OpenFlow. Recent efforts to develop reconfigurable data planes and high-level network programming languages has made it possible to truly program the data plane -- i.e., to change the way packets are processed on network devices. The ability to fully program the network-both control and data plane-is expected have a profound impact on the field of networking in the coming years. In this seminar we discussed the key questions and problems to be addressed in the next 10 years on the area of programmable dataplanes, and how they will potentially shape the future of networking. As an outcome we are now working on a research agenda to serve as the start of a discussion with networking researchers, practitioners, and the industry as a whole. This report is a first step towards that goal.