Hierarchical policies are useful in many contexts in which resources are shared among multiple entities. Such policies can easily express the delegation of authority and the resolution of conflicts, which arise naturally when decision-making is decentralized. Conceptually, a hierarchical policy could be used to manage network resources, but commodity switches, which match packets using flow tables, do not realize hierarchies directly.This paper presents Hierarchical Flow Tables (HFT), a framework for specifying and realizing hierarchical policies in software defined networks. HFT policies are organized as trees, where each component of the tree can independently determine the action to take on each packet. When independent parts of the tree arrive at conflicting decisions, HFT resolves conflicts with user-defined conflict-resolution operators, which exist at each node of the tree. We present a compiler that realizes HFT policies on a distributed network of OpenFlow switches, and prove its correctness using the Coq proof assistant. We then evaluate the use of HFT to improve performance of networked applications.

So ware De ned Networks, which provide a programmable, logically centralized abstraction of network control, o er an escape from the current state of enterprise and datacenter network con guration, plagued by brittle, static solutions involving manual setting of myriad devices. But if SDNs provide an operating system for the network, we are missing the analog to system callsan API for end-users and their applications to take part in network con guration. In response, we propose participatory networking, a new paradigm for network con guration in which users submit requests or hints for current and future network properties such as quality of service, access control, and path selection. We describe the initial design and implementation of a participatory networking system, PANE, and its solutions to the challenges of resource arbitration and privilege delegation.

So ware De ned Networks, which provide a programmable, logically centralized abstraction of network control, o er an escape from the current state of enterprise and datacenter network con guration, plagued by brittle, static solutions involving manual setting of myriad devices. But if SDNs provide an operating system for the network, we are missing the analog to system callsan API for end-users and their applications to take part in network con guration. In response, we propose participatory networking, a new paradigm for network con guration in which users submit requests or hints for current and future network properties such as quality of service, access control, and path selection. We describe the initial design and implementation of a participatory networking system, PANE, and its solutions to the challenges of resource arbitration and privilege delegation.