A Survey of Active and Router-Assisted Reliable Multicast Solutions

Abstract : Group communications, so-called multicast communications, have been introduced as early as 1986 as an efficient way to distribute on a large-scale basis data packets on the whole Internet. With the emergence of new applications driven by the increase of bandwidth in the networks (such as grid computing, large database replication, etc.), reliable multicast is foreseen to be one of the most challenging technologies of the next generation Internet. However, group communications are much more complex than point-to-point communications and solutions that have been implemented and deployed in the unicast world for ensuring reliability can not be so simply applied to the multicast area. Recently, a new.paradigm proposes to dynamically add additional functionalities into the routers, thus enabling a whole new range of distributed control mechanisms as opposed to the traditional end-to-end form of control. In this paper, we summarize the various active networking and router-assisted solutions for reliable multicast to avoid or limit the scalability problems of end-to-end approaches for loss recovery, congestion control and heterogeneity support. Then, with the hypothesis that active networking could be deployed on a large scale, we present how this technology could solve the remaining bottlenecks of multicast on wide-area networks.