Network Controller Extension for Unsplittable Data Flows in the SDN Environment

Despite the network bandwidth capacity grows significantly during recent years, effective network resources management and congestion avoidance remains a non-trivial task. In the past years, real-time services are still more popular, and live video streams, IP based calls or high definition videoconferences are a normal part of our lives. When it comes to load balancing, these multimedia sessions are slightly different from the others, because they may not be handled per-packet, but we need to handle them perflow, where the flow of the packets belonging to one multimedia session must be considered unsplittable. This is because these services are jitter-sensitive, and with increasing jitter, the QoS degrades. We designed a network controller for Software-Dermed Networks environment based on the open-source OpenFlow protocol controller Ryu, that is aware of all data flows that are being transmitted over the network, as well as their bandwidth consumption, so that based on these data it is able to distribute these data flows between the networks disjoint paths in order to avoid or minimize the congestion, when the network gets utilized close to its theoretical maximum capacity. The controller is designed to be able to be extended by any load balancing decision method, so the network operator can choose the most appropriate approach for his network.