Distributed and scalable control plane for next generation routers: A case study of OSPF

The growing traffic on the core Internet entails new requirements related to scalability and resiliency of the routers. One of the promising trends of router evolution is to build next generation routers with enhanced memory capacity and computing resources, distributed across a very high speed switching fabric. The main limitation of the current routing and signaling software modules, traditionally designed in a centralized manner, is that they do not scale in order to fully exploit such an advanced distributed hardware architecture. This paper discusses an implementation for an OSPF architecture for next generation routers, aiming at increasing the scalability and resiliency. The proposed architecture distributes the OSPF processing functions on router cards, i.e., on both control and line cards. Therefore, it reduces the bottlenecks and improves both the overall performance and the resiliency in the presence of faults. Scalability is estimated with respect to the CPU utilization and memory requirements.