About the talk
Presenter: Robert Bauer, Institute of Telematics, KIT, Karlsruhe (Lehrstuhl Zitterbart)
Title: „Flow Delegation: Flow Table Capacity Bottleneck Mitigation for Software-defined Networks“
The talk with subsequent Q&A session will present an overview of Mr. Bauers planned dissertation. A short abstract of the dissertation can be found below.
The dissertation introduces flow delegation, a new way to deal with flow table capacity bottlenecks in Software-defined Networks (SDN). Such bottlenecks occur when SDN switches provide insufficient flow table capacity which can lead to performance degradation and/or network failures. Flow delegation addresses this well-known problem by automatically relocating flow rules from a bottlenecked switch to neighboring switches with spare capacity. Different from existing work, this new approach can be used on-demand in a transparent fashion, i.e., without changes to the network applications or other parts of the infrastructure. The thesis makes three main contributions:
1) It introduces a novel concept for transparent flow rule delegation (the underlying core mechanism) and discusses the associated practical challenges such as monitoring, rule aggregation or control message interception, complemented with two independent proof-of-concept implementations.
2) It presents several novel algorithms for flow delegation based on combinatorial optimization and heuristics. These algorithms work with multiple conflicting objectives and operate in the millisecond range on commodity hardware, i.e., they are fast enough to be used in practice
3) The feasibility and performance of the new approach is evaluated based on a wide range of different scenarios. As a main result, it is shown that flow delegation can reduce the need for over-provisioning by at least 25% in the vast majority of the cases (even those without bottlenecks) which can lead to substantial savings with respect to capital and operational expenditure.