Modeling and optimization of maximum flow survivable overlay multicast with predefined routing trees

Overlay networks employ underlying network technologies in order to provide end-system related communication and over the years overlays have been getting more and more attention in research community and in business world as well. Since overlays tackle many drawbacks present in pure “link-router-network” engineering, they have become an excellent solution for multimedia-oriented applications. A good example comprises multicast communications, where an overlay system, in contrast to IP Multicast, eliminates many issues related to scalability or management control. This paper focuses on modeling and optimization of overlay multicast networks aimed at realizing maximum throughput with survivability constraints, where survivability defines the ability of a multicast system to limit potential throughput losses in case of a failure of single virtual link. We present linear formulation derived from fractional tree packing problems based on predefined topologies which may route multicast traffic. Linear model might be used for obtaining optimal multicast structures, however its applicability is limited by increasing sizes of networks. Hence, we also design and evaluate heuristic searches dedicated to optimization of maximum flow survivable overlay multicast networks.