Towards SLA Policy Refinement for QoS Management in Software-Defined Networking

Software-Defined Networking (SDN) is a dynamic, adaptable, controllable and flexible network architecture. It provides an extensible platform for delivery of network services, capable of responding quickly to service requirement changes. As a result, SDN has become a suitable scenario for the application of techniques and approaches for improved infrastructure management, such as Policy-Based Management (PBM). In PBM, using techniques such as refinement, a high-level policy-e.g., specified as a Service Level Agreement (SLA) - can be translated into a set of corresponding low-level rules, enforceable in various elements of a system. However, when using SLAs, their translation to low-level policies, e.g., for controller configuration, is not straightforward. If this translation is not done properly, the controller may not be able to meet the implicit requirements of the SLA, failing to satisfy the goals described in the high-level policy. This paper proposes a novel approach towards SLA policy refinement for Quality of Service (QoS) management (based on routing) in Software-Defined Networking. It consists of an initial manual process performed by an administrator, followed by an automatic policy refinement process executed by an OpenFlow controller. As a result, our approach is capable of identifying the requirements and resources that need to be configured in accordance with SLA refinement, and can successfully configure and execute reactive dynamic actions for supporting dynamic infrastructure reconfiguration.