Concise Encoding of Flow Attributes in SDN Switches

Abstract

Network devices such as routers and switches forward traffic based on entries in their local forwarding tables. Although these forwarding tables conventionally make decisions based on a packet header field such as a destination address, tagging flows with sets or sequences of attributes and making forwarding decisions based on these attributes can enable richer network policies. For example, devices at the edge of a network could add a tag to each packet that encodes a set of egress locations, a set of host permissions, or a sequence of middleboxes to traverse; simpler devices in the core of the network could then forward packets based on this tag.