Increasing multicast transmission rate with localized multipath in software-defined networks

Network layer multicast is a highly efficient one-to-many transmission mode. Data rates supported by different group members may differ if these members are located in different network environments. Currently there are roughly two types of methods solving the problem, one is limiting the data rate so that every group member can sustain transmissions, and the other is building multiple trees to increase the provision of network bandwidth. The former is inefficient in bandwidth usage, and the latter adds too many states in the network, which is a serious problem in Software-Defined Networks. In this paper, we propose to build localized extra path(s) for each bottleneck link in the tree. By providing extra bandwidth to reinforce the bottleneck links, the overall data rate is increased. As extra paths are only built in small areas around the bottleneck links, the number of states added in the network is restrained to be as small as possible. Experiments on Mininet verify the effectiveness of our solution.