Path Switching: Reduced-State Micro-Flow Handling in SDN Using Path Information

The advent of virtualization, containerization and the Internet of Things (IoT) is leading to an explosive growth in the number of endpoints. Ideally with Software Defined Networking (SDN), one would like to customize packet handling for each of these endpoints or applications. However this typically leads to a large growth in network state. It is worthwhile to ask whether the benefits of micro-flow control can be retained without a large growth in network state and without using aggregation.In this paper, we describe an incrementally deployable SDN friendly packet forwarding mechanism, called Path Switching, that achieves this by compactly encoding a packet's path existing address fields. Path Switching accomplishes a reduction in network forwarding state similar to that achieved by source routing while retaining the benefits of fixed size packet headers. We have extended Open vSwitch (OVS) to transparently support Path Switching as well as an inline service component for folding midbox services into OVS. The extensions require no protocol changes as Path Switching does not change header formats. Our implementation supports a full suite of advanced network services including network virtualization, traffic engineering, service chaining and endpoint mobility as well as a web based graphical management system.