This work is licensed under a Creative Commons Attribution-NonCommercial- NoDerivatives 4.0 International License. This is a postprint version of the following published document: Vidal, I., Garcia-Reinoso, J., Soto, I. & Valera, F. (2011). Evaluating extensions to IMS session setup for multicast- based many-to-many services. Computer Networks, 55(3), pp. 600–621. DOI: 10.1016/j.comnet.2010.09.011 © 2010 Elsevier B.V.