Sufficient conditions for optimal multicast communication

In this paper, we give a general technique for computing optimal multicast calling schedules in any multiprocessor system that utilizes a direct network interconnection structure as long as a few simple conditions are satisfied. Since almost any real system will satisfy these conditions, this result essentially means that multicast can always be performed in [log(d+1)] phases where d is the number of multicast destinations. In particular, previous results on optimal multicast algorithms in specific direct network topologies are simply corollaries of our result.