Minimum fragmentation internetwork routing

The problem of minimizing the internetwork packet fragmentation cost by selecting an appropriate route from the origin to the destination network is investigated. It is shown that this problem is NP-complete, and optimal (minimum fragmentation cost) paths cannot be computed by fast algorithms when the intranetwork strategy is used. Then, the internetwork fragmentation strategy is considered, and a fast (i.e., polynomial time) routing algorithm, called Maxbottleneck, is presented. When a greedy fragmentation scheme is adopted, like the classical maximal one, the algorithm produces an optimal path when some conditions on the networks´ maximum packet sizes are met. A novel, non-greedy fragmentation scheme called bottleneck is also proposed. It is shown that the path produced by Maxbottleneck is always optimal when the bottleneck scheme is used