Title: Design and Evaluation of a User-Aware Network Abstraction Layer for Partially Deployed Software-Defined Networks Abstract: Innovations in networking are hampered by complex, monolithic devices, domain knowledge that is hidden in human-centered manuals, and the huge amount of diverse device capabilities and incompatible configuration interfaces. Software-Defined Networking (SDN) promises to reduce the complexity by introducing standardized configuration interfaces and by splitting the data forwarding from the routing decisions through a logically centralized controller. In this talk we first discuss the challenge of how to operate legacy networking devices and SDN devices in the same network. Afterwards we introduce the design of a Network Services Abstraction Layer (NSAL) for hybrid networks to ease the operation of such hybrid networks. Subsequently we discuss theoretical and practical performance limits in terms of the reconfigurations possible through the NSAL and present the design and evaluation of a machine-learning based pipeline which allows accurate predictions of the performance limits of an NSAL instance. The last part of the talk is dedicated to the question how the user of a network is affected by network reconfigurations and how the introduced NSAL can be extended to enable user-level fairness for overutilized network segments.