Static Equivalence Checking for OpenFlow Networks

Software-defined networking (SDN) provides many advantages over traditional networking by separating the control and data planes. One of the advantages is to provide programmability, which allows administrators to control the behavior of the network. The network configuration may need to be changed for some reason. Whenever such changes are made, it can be required to verify that the forwarding behavior is preserved from the existing configuration, that is, whether the ruleset is properly reflected. In this paper, we propose the forwarding behavior based equivalence checking of OpenFlow networks. We present the formal definition of the network model and the forwarding behavior of the packet flow. Based on the definition, We present a method for checking the equivalence of OpenFlow network forwarding behaviors. Next, we present the implementation of the proposed method, using the constraint satisfaction method, which will be the basis for further extension.

Equivalence checking for weak bi-Kleene algebra

Pomset automata are an operational model of weak bi-Kleene algebra, which describes programs that can fork an execution into parallel threads, upon completion of which execution can join to resume as a single thread. We characterize a fragment of pomset automata that admits a decision procedure for language equivalence. Furthermore, we prove that this fragment corresponds precisely to series-rational expressions, i.e., rational expressions with an additional operator for bounded parallelism. As a consequence, we obtain a new proof that equivalence of series-rational expressions is decidable.