Rapid Routing with Guaranteed Delay Bounds

We consider networks in which each individual link is characterized by two delay parameters: a (usually very conservative) guaranteed upper bound on the worst-case delay, and an estimate of the delay that is typically encountered, across the link. Given a source and destination node on such a network and an upper bound on the end-to-end delay that can be tolerated, the objective is to determine routes they typically experience a small delay, while guaranteeing to respect the specified end-to-end upper bound under all circumstances. We formalize the problem of determining such routes as a shortest-paths problem on graphs, and derive algorithms for solving this problem optimally.