Splendid isolation

Abstract

The correct operation of many networks depends on keeping certain kinds of traffic isolated from others, but achieving isolation in networks today is far from straightforward. To achieve isolation, programmers typically resort to low-level mechanisms such as Virtual LANs, or they interpose complicated hypervisors into the control plane. This paper presents a better alternative: an abstraction that supports programming isolated slices of the network. The semantics of slices ensures that the processing of packets on a slice is independent of all other slices. We define our slice abstraction precisely, develop algorithms for compiling slices, and illustrate their use on examples. In addition, we describe a prototype implementation and a tool for automatically verifying formal isolation properties.