A Preemptive Hybrid Approach to Minimum Spanning Tree Restoration in Large Mesh SDN Networks
Wayne Collymore · 2019
Achieving high levels of network resiliency has long been a major objective for data centre and service providers. Recently, Software Defined Networking (SDN) has arrived with the ability to extend centralised programmability, control and management to all aspects of networking. For traditional TCP/IP networks, due to the close coupling of the control and data plane on network devices, protocols that provide recovery and restoration operate effectively in a distributed manner. In practice a programmed SDN controller is at the heart of any SDN deployment. SDN controllers offers opportunities for algorithms to operate at a logically global or centralised level. Shifting distributed protocols away from localised switches or routers to a centralised controller effectively creates a level playing field for algorithms. A global view of the entire network is now available not only to the network programmer or manager, but also to all the algorithms programmed at the controller. Although a central view may be an advantage, little is known about the behaviour of different restoration algorithms and their recovery in a centralised controller when operating under a worst case environment such a scaled wired mesh SDN topology. This paper presents the SDN implementation and analysis of a range of Minimum Spanning Tree (MST) algorithms, their key performance metrics are evaluated and based on these results a preemptive approach to path restoration is proposed. Initial results of the approach show considerable time savings in the initial stages of building an MST.