Demand for network services such as video conferencing has grown by leaps and bounds over the last several years. Muticasting is a vital part of the communication architecture. It takes into account users dropping in and out of the network in a dynamic fashion (for example, in a live social interaction setting such as internet chat rooms). Hence there is a need to quickly compute effective routing. This book presents efficient routing algorithms that are easy to implement. In addition, intractability results are presented; these describe the best possible solution that we can hope to obtain within a reasonable amount of time. This book will be useful to industry professionals in the data communication industry, who can start with the heuristics described here and develop a better approach; and to graduate students in Data Networking, Combinatorial Optimization, Approximation Algorithms and Computational Complexity. It should serve as a handy reference to academics in these fields.