Overlay multicasting at a path-level granularity for multihomed service nodes

While multiple access links enhance the availability and utilization of multicast service nodes, the resource allocation balancing needs to be performed on a link basis, which is usually not considered in most overlay multicast routing algorithms. To accurately represent the bandwidth consumption of each overlay node, we need not only a multihomed proxy model to describe the overlay multicast routing problem at a path-level granularity but also a systematic approach to solve this problem under this model. In this paper, we first identify all possible physical paths as candidates for overlay links and then combine the path selection process with the overlay multicast routing process to calculate the final overlay tree. By this way, the underlying network resources on multiple access links can be used more efficiently.