Research Of Traffic Engineering In Cross-domain Software Defined Networks

The increasing scale of software defined networks(SDN)raises the re-quirement of distributed control plane,for providing scalable,reliable and high performance network management capabilities.In particular,the flat design of distributed control plane enables the management of networks with multiple independent domains that is incapable of deploying a root controller.However,it is very difficult to avoid policy conflicts between multiple con-trollers in flat plane due to the lack of arbitration.In this paper,we ad-dress the problem of traffic engineering in a flat control plane,and design a distributed traffic engineering algorithm,called DisTE,which can provide max-min fair bandwidth allocation for flows and maximize the resource uti-lization,using a fully distributed arbitration mechanism.DisTE also preserves the local topology of each domain using the topology aggregation method,and supports consistency by multiple rounds of synchronizations.We ex-amine four strategies for determining the synchronization timings,and find that linearly decreasing interval method provides a better trade-off between network utilization and time costs.Experiments on a 717-switches 5-domain network topology demonstrate that DisTE could drive the link utilization ra-tio to more than 93%,and reduce up to 95%convergence time at cost of 3%relative error on fairness,compared to the centralized approach.