Balanced and resilient application layer multicast

In the context of Application Layer Multicast(ALM), quality of high-bandwidth real-time communication over best effort networks is mainly constrained by node capacity and link loss characteristics observed along multicast delivery path. Our ALM solution is based upon Cluster-Oriented, Regular and Multi-trees(CORM) structure and can overcome these constraints by adequately supporting loss recovery, load-balance and moreover, loss-balance (the loss caused by nodes failures is roughly balanced and within a small range). Clusters in a hierarchy uniformly distribute forwarding load among all participating peers. Regular (constant node degree) constraint makes cluster maintenance and optimization as a whole. Furthermore, for improving robustness, we design and implement linear network coding scheme, proactive parent recovery mechanism and cluster splicing algorithm in terms of CORM. Experimental results obtained via network simulation show that CORM has lower average link stress (by about 22%), and more even node stress than NICE protocol. More importantly, failure recovery properties such as recovery time and loss-balance, are much better by using orders of magnitude lower control traffic. Moreover, we analyze performance effect caused by combining various regular degree and cluster size.