Solving multicast problem in cloud networks using overlay routing

Currently, multicast in cloud networks without the support of underlay IP multicast relies on one-to-all replications, which wastes networking resources and may induce bottlenecks. In this paper, we point out this issue should be solved as an overlay routing problem and the special architecture of cloud networks should be fully exploited. Then we propose a solution which includes a SDN framework and an algorithm to construct a degree-constrained overlay multicast routing tree. Our simulations show that its performance is better than current solution. Moreover, it can deal with various multicast groups and it scales well with both group size and cloud size.