Enabling emergency flow prioritization in SDN networks

Emergency services must be able to transfer data with high priority over different networks. With 5G, slicing concepts at mobile network connections are introduced, allowing operators to divide portions of their network for specific use cases. In addition, Software-Defined Networking (SDN) principles allow to assign different Quality-of-Service (QoS) levels to different network slices.This paper proposes an SDN-based solution, executable both offline and online, that guarantees the required bandwidth for the emergency flows and maximizes the best-effort flows over the remaining bandwidth based on their priority. The offline model allows to optimize the problem for a batch of flow requests, but is computationally expensive, especially the variant where flows can be split up over parallel paths. For practical, dynamic situations, an online approach is proposed that periodically recalculates the optimal solution for all requested flows, while using shortest path routing and a greedy heuristic for bandwidth allocation for the intermediate flows.Afterwards, the offline approaches are evaluated through simulations while the online approach is validated through physical experiments with SDN switches, both in a scenario with 500 best-effort and 50 emergency flows. The results show that the offline algorithm is able to guarantee the resource allocation for the emergency flows while optimizing the best-effort flows with a sub-second execution time. As a proof-of-concept, a physical setup with Zodiac switches effectively validates the feasibility of the online approach in a realistic setup

Providing Bandwidth Guarantees with OpenFlow

Quality of Service (QoS) control is an important concept in computer networking, as it is related to end-user experience. While providing QoS guarantees over the Internet has long been deemed too complicated, the emergence of Software- Defined Networking (SDN), and OpenFlow as its most popular standard, may facilitate QoS control.In this paper, we consider how to enable bandwidth guarantees with OpenFlow. Our design allows QoS flows to send more than their guaranteed rates, as long as they do not hinder other guaranteed and/or best-effort flows.Furthermore, our design uses OpenFlow’s meter table to aggregate traffic. Our traffic aggregation functionality only adds overhead to the first switch, but no other complexity is incurred at the subsequent switches.Network Architectures and Service