Hierarchical routing using link vectors

An area-based link-vector algorithm (ALVA) is introduced for the distributed maintenance of routing information in very large internetworks. According to ALVA, destinations in an internetwork are aggregated in areas in multiple levels of hierarchy. Routers maintain a database that contains a subset of the topology at each level of the hierarchy. This subset corresponds to those links used in preferred paths to reach destinations (nodes inside the same immediate area or remote areas). The ALVA is the first hierarchical routing algorithm based on link-state information that does not require complete topology information at each level in the hierarchy. The correctness of the ALVA is verified. Simulation results are presented showing that the ALVA outperforms the OSPF in terms of communication and storage overhead