SLA-Aware Flow Provisioning in Next-Generation Software-Defined Networks

The next-generation software-defined networks (SDNs) are designed to be extremely flexible and cost-effective. However, complying with service-level agreements (SLAs) is often challenging with the softwarization of networks. To this end, we propose different methods and techniques in this paper to solve some crucial problems related to flow provisioning with SLA guarantees. The paper is divided into two parts: The first part focuses on the SLA-driven design of SDNs. First, we propose Bitstream, a programmable SDN protocol that can provide carrier-class features. We demonstrate Bitstream on the test-bed of custom-built FPGA-based Terabit white-boxes. We show the effectiveness of Bitstream in providing low latency and 50ms restoration in case of faults. Next, we propose techniques to make Bitstream more application-centric by including delay requirements of service requests. In the second part, we shift our focus to Network Function Virtualization (NFV). One of the biggest hurdles of adopting NFV is to provide a similar performance what a service provider is accustomed to with the traditional network hardware. First, we design an end-to-end service provider network with NFV data-centers. To provide highly-available services, we create an ILP framework intending to maximize the service provider's profit. We then propose a robust optimization extension for handling traffic uncertainty. Next, we propose a service function chain (SFC) realization theory that compares the requirements of an SFC request to the available resources in NFV infrastructure while providing availability and delay guarantees for the dynamic arrival of requests. Finally, we present an NFV use-case in the virtualized slicing of 5G networks. We propose a dynamic network slicing algorithm that creates/deletes/modifies slices while optimizing underlying virtualized resources. To handle uncertainty in the traffic requests, a stochastic optimization extension is also proposed.