Proposal of scale-out control architecture of virtual wide area layer-2 switch on metro network

Abstract

Power consumption of network equipment has been rapidly increasing, so it is therefore necessary to build a resource efficient network (NW). Router virtualization, which involves dynamically reallocating virtual routers to physical resources as a server virtualization, is becoming more common as a way to use network equipment effectively and robustly. Especially, edge router which is gateway of core network should be virtualized, because edge routers have many functions and resources just as servers do. A metro NW is wide area layer-2 aggregation NW that connects each user's residential gateway to edge routers. To achieve edge router virtualization, the metro NW must trace the dynamic edge router reallocation by changing a route of each Ethernet flow. Furthermore, access/metro NWs occupy a large proportion of the total NW power consumption, so logically centralized control architecture suits to the metro NW to change routes flexibly because it can use resources effectively by avoiding resource deployment in many locations. However, it is not scalable. When many Ethernet flows need to be accommodated in a metro NW, it can not change routes of the flows quickly enough. Therefore, we propose a virtual wide area layer-2 switch architecture with scale-out control that can improve the route control performance even in a worst case edge router node failure by processing in parallel flow-by-flow, by considering route information, and by rebalancing the load between parallel processes dynamically. We evaluated the proposed architecture through theoretical analysis and experiments with prototype. The results showed that the proposed architecture can increase the number of flows accommodated in a metro NW.