How to extract maximum information from event-driven topology updates

Link-state updating in communication networks undergoing topological changes is addressed. It is concluded that the best way of disseminating link-state information is through event-driven (ED) updating, and it is shown how to overcome the traditional drawbacks of ED updating. An efficient algorithm that extracts the maximum implicit information from ED topology updates by computing the latest time for which each processing node can be certain of the state of each network link is given. It is shown that the information obtained is equivalent to that obtained by continuous flooding of link-state information. A method that allows each node to refresh the above information continuously without running the algorithm more than once for each received update is presented, as is an approximate version of the algorithm that reduces communication overhead by limiting the radii of propagation.<>