  We develop Bellman equation based approach for infinite time horizon optimal
impulsive control problems. Both discounted and time average criteria are
considered. We establish very general and at the same time natural conditions
under which a canonical control triplet produces an optimal feedback policy.
Then, we apply our general results for Internet congestion control providing a
convenient setting for the design of active queue management algorithms. In
particular, our general theoretical results suggest a simple threshold-based
active queue management scheme which takes into account the main parameters of
the transmission control protocol.
