Performance study of dynamic QoS management for OpenFlow-enabled SDN switches

Software-defined Networking (SDN) is a promising and powerful concept to introduce new dimensions of flexibility and adaptability in today´s communication networks. In particular, the realization of Quality of Service (QoS) concepts becomes possible in a flexible and dynamic manner with SDN. Although concepts of QoS are well researched, they were not realized in communication networks due to high implementation complexity and realization costs. Using SDN to realize QoS mechanisms enables emerging concepts, such as application-aware resource management solutions. These emerging concepts demand latency or data rate guarantees for end-user applications, e.g., video streaming or gaming. However, the impact of dynamic QoS management on network traffic has not been studied in detail yet. This paper provides a first study of the impact on dynamic QoS mechanisms and their realizations for OpenFlow-enabled SDN switches. Although SDN and, in particular, OpenFlow as one dominant realization claim to provide a standardized interface to control network traffic, our measurement results show a noticeable diversity for different OpenFlow switches. In detail, our investigations reveal a severe impact on the performance of TCP-based network traffic among different switches. These observations of switch diversity may provide SDN application developers insights when realizing QoS concepts in an SDN-based network.