A correct, zero-overhead protocol for network updates

Abstract

In this paper, we describe a new protocol for the safe update of OpenFlow networks. This protocol meets the packet consistency and weak flow consistency conditions, requires neither on-switch resources nor the diversion of packets to refuges during updates, and alls into the family of Trace-based update protocols. The feature of this protocol is a sequence of per-switch rule updates. We derive a logic circuit for the update sequence, such that there exists a consistency-preserving update for the switch network if and only if the circuit is satisfiable subject to unsatisfiability of invariant violations; further, each satisfying minterm of the circuit yields a consistency-preserving update sequence. © 2013 ACM.