Communications Research Centre Canada Ottawa, Ontario Canada
During the past few years, several multicast routing protocols have emerged, which are competing to provide efficient mechanisms to deliver Internet Protocol IP traffic to groups of users scattered throughout the Internet. The multiplicity of experimental protocols and the absence of any well-established standardised protocol for multicast routing indicates that multicast routing has many solutions and that no one implementation can provide the most satisfactory characteristics in every situation.This paper shows that much work is still needed to advance the state of the multicast routing technology. The main deficiencies of multicast routing protocols and their challenging design issues are illustrated by focusing on a few of the most popular multicast protocols being designed or experimented with today by the Internet Engineering TaskForce IETF. Most of the multicast routing technology trade-offs analysed in the report apply to the global Internet in general while some are more specific to the tactical communication networks.