Cluster-based virtual router

At the data transfer center of large-medium-scale ISP or backbone networks in the Internet today, in order to satisfy the requirements of survivability and scalability, there are a group of routers on the same LAN to accomplish the task of packet forwarding, provide mutual backup and extend total capacity. The popular protocols, however, are not optimal for router clusters to provide the capabilities of fault recovery, load balance and resource utilization. In this paper, we present a solution of virtual router, which organizes and schedules these routers as an integrated interoperable domain. We develop a scalable architecture, proprietary protocols and a set of external link selection algorithms of the virtual router to improve the survivability and utilization of data transfer centers. The proprietary protocols confine the scope of the failure to virtual router and rebuild an alternative path around the failure to shorten fault recovery times to several seconds, which depend on interval of the periodic internal states update. The algorithm of external link selection distributes load over all available external links based on precise real time information to improve load balance and utilization of resources. As an independent system, the virtual router is transparent to other external nodes to simplify the Internet structure and path complexity logically. At the end, we evaluate the performance of virtual router by theoretic analysis and simulation experiments