Constrained shortest path routing method
A real-time method for routing subject to an acceptable delay constraint between nodes in high-speed data networks, such as PNNI protocol networks, uses an illustrative two-phase algorithm employing Dijkstra's algorithm at each phase. In an illustrative first phase, the Dijkstra SPF algorithm is used in seeking the shortest cumulative delay from the destination to the source, thereby generating cumulative delay labels from a node j to the destination node k. The delay results are then employed in the second phase, where the Dijkstra SPF algorithm is illustratively employed for determining administrative weight (AW) as the link metric subject to modification in accordance with results obtained in the first phase.