Route Preserving Stabilization

A distributed system is self-stabilizing if it returns to a legitimate state in a finite number of steps regardless of the initial state, and the system remains in a legitimate state until another fault occurs. A routing algorithm is loop-free if, a path being constructed between two processors p and q, any edges cost change induces a modification of the routing tables in such a way that at any time, there always exists a path from p to q. We present a self-stabilizing loop-free routing algorithm that is also route preserving. This last property means that, a tree being constructed, any message sent to the root is received in a bounded amount of time, even in the presence of continuous edge cost changes. Also, and unlike previous approaches, we do not require that a bound on the network diameter is known to the processors that perform the routing algorithm. We guarantee self-stabilization for many metrics (such as minimum distance, shortest path, best transmitter, depth first search metrics, etc.), by reusing previous results on r-operators.