Preserving Routes during Fast Convergence

We present a protocol for maintaining a routing tree that is maximal with respect to any given (bounded and monotonic) routing metric. This protocol has three adaptive properties. First, the protocol is stabilizing: starting from any state, the protocol stabilizes to a state where a maximal tree is present. Second, the protocol assumes no upper bound on the length L of the longest network path, nonetheless, its stabilization time is O (L deg), where deg is the node degree in the network. Third, the spanning tree remains connected while adapting to a change in the edge weights in the network. This last property makes the protocol suitable for a routing policy that ensures each message is delivered to its destination, even while the routing tree is adapting to the new edge weights.