Relaxed min-augmented range trees for the representation of dynamic IP router tables

When an Internet router receives a packet p from an input link interface, it uses p’s destination field to look up a routing database. The result of the lookup provides an output link interface, to which packet p is forwarded. In dynamic router tables, where IP lookup is intermixed with table updates, lookups may be delayed while a preceding update completes. To minimize this delay, it is important that updates are performed as fast as possible. In relaxed balanced data structures, rebalancing is uncoupled from updates such that the rebalancing tasks can be performed gradually in less busy times. We investigate how the min-augmented range tree, a structure which can be utilized for IP lookup, can be relaxed. Our experiments with real IPv4 routing data indicate that the relaxed balanced min-augmented range tree has a significant advantage over the strictly balanced version.