Dynamic aggregation algorithms for forwarding information in distributed router architecture

As the Internet grows in size and bandwidth, packet-forwarding at the line card of routers became a technical challenge to overcome in the design of router architecture. One approach is to decrease the size of forwarding tables at line cards to reduce the time for table lookup and management. In this paper, we propose the novel algorithms that reduce the forwarding table size and the number of control packets for updating the forwarding table in a distributed router architecture. The algorithms build an aggregation tree, which aggregates the forwarding addresses dynamically. The dynamic insertion of a virtual node makes it possible to aggregate the forwarding address. The algorithms have been tested with more than 53000 BGP entries, which have been originated on a typical IPv4 BGP backbone router. We achieved 15 to 20 percent reduction in forwarding table size and number of control packets.