Xin Jin will present his FPO "Dynamical Control of Software-Defined Networks" on Wednesday, 6/29/2016 at 2pm in CS 401.   The members of his committee are Jennifer Rexford (adviser), Readers: David Walker and Ratul Mahajan (Microsoft Research); Nonreaders: Jennifer Rexford, David Walker, Aarti Gupta, Ratul Mahajan (Microsoft Research), and Nick Feamster. A copy of his thesis is available in Room 310. Everyone is invited to attend his talk. The abstract follow below. Network management is critical to provide fast, reliable and secure network services. Software-defined networking (SDN) is a new network architecture to simplify network management by integrating network control to a centralized control platform. Network operators run various applications on the control platform to perform different management tasks, like routing, monitoring, load balancing and firewall. These applications have complex interactions with each other, making it difficult to deploy and reason about their behaviors. The frequent network events, such as traffic shifts, cyber attacks, and device failures, further exacerbates the problem. Each application needs to reconfigure the network, in order to react to the events. It is challenging to correctly and efficiently combine configuration changes from multiple applications, distribute these changes to a distributed collection of network devices, and coordinate changes across network devices in different layers. In this thesis, we present a new control architecture that can efficiently handle network events for multiple applications and across the network and optical layers. We identify and study the following three key components of the architecture. (i) CoVisor: A network hypervisor that can compose multiple applications and can effi- ciently merge configuration changes from these applications in the face of network events. To protect the network from malicious and buggy applications, CoVisor also provides topology virtualization and fine-grained access control to constrain what each application can see and do. (ii) Dionysus: A network update scheduler that can quickly and consistently distribute configuration changes to multiple switches. Dionysus uses a dependency graph to capture the dependencies between update operations, and dynamically schedules the operations based on runtime conditions. The approach both eliminates undesirable transient behaviors like loops, blackholes and congestion, and reduces the update time. (iii) Owan: A traffic management system that can jointly control the optical and network layers. Owan optimizes optical circuit setup, routing and rate allocation together, and dynamically adapts them to workload changes. The joint management significantly improves data transfers over the wide area network. We have built software controllers and hardware testbeds, and evaluated them with prototype experiments and large-scale simulations using network topologies and traffic traces from production networks.