Dynamics of a loop-free path-finding algorithm

The dynamics of a loop-free path-finding algorithm (LPA) based on predecessor information and a single-hop internodal synchronization mechanism is investigated. LPA is compared with a loopfree algorithm based on diffusing computations, DUAL, and an ideal link-state (ILS) algorithm based on topology broadcast. Comparisons include the dynamic response of the algorithms to a single and multiple link-cost changes as well as single link and router failures and recoveries. The results show that LPA requires a significantly smaller number of messages than ILS and DUAL to update routing tables when multiple changes in link costs occur. LPA´s performance is always significantly better than DUALs and significantly better than ILSs after node failures and resource additions (in some instances, ILS requires almost four times as many messages). After a link failure, LPA requires approximately the same time to converge as ILS and at most twice as many messages