Evaluation of parallel processing control of virtual switch architecture on large-scale network

Power consumption of network (NW) equipment has been rapidly increasing; therefore it is necessary to build a resource-efficient NW. Router virtualization, which involves dynamically re-allocating virtual routers to physical resources as server virtualization, is becoming more common as a method of using NW equipment effectively and robustly. Edge routers which are gateways of core NWs should be virtualized because they have many functions and resources just as servers do. A metro NW is a 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 dynamic edge router re-allocation by changing the route of each Ethernet flow. Therefore, we previously proposed a virtual layer-2 switch architecture with scale-out control that can improve route control performance to trace dynamic virtual router re-allocation to use metro NW equipment effectively and robustly. The routes are controlled in parallel flow-by-flow on this architecture. When edge router failure occurs, the controller must change the routes of all flows passing through the failed edge router. On the other hand, load imbalance of this route change occurs among parallel processes. If we can distribute this load evenly, we can decrease resources for the controller deployed in advance. Therefore, in this paper we propose two re-allocation methods for allocating flows to parallel processes according to the virtual router re-allocation. We evaluated the methods through simulation and showed that they can evenly distribute load among parallel processes not only in large-scale metro NWs, but also in data center NWs, which have recently become an important type of large-scale layer-2 NW.