LODGE: LOcal Decisions on Global statEs in programmable data planes

In stateful Software Defined Network (SDN) data planes, network switches hold some local flow-related states thanks to which they are able to perform decisions by locally executing simple algorithms. While stateful data planes provide better reactiveness in respect to vanilla SDN, states are still bounded to single switches which represents a significant restraint for network-wide applications. To deal with the current limitations of stateful data planes we introduce and provide design guidelines for LODGE, a model according to which distributed network applications are able to make local decisions at each switche based on some global variables shared across other switches. We describe the implementation of LODGE with a basic application providing support for the detection of Distributed Denial of Service (DDoS) attack in a scenario of stateful data planes involving P4 and Open Packet Processor (OPP) enabled switches. We validate the two implementations in a small emulated testbed and we show the beneficial effects on the reduction of the total network traffic.