There have been many proposals to support multicast in the Internet. These proposals can be roughly categorized as being either infrastructure-based, with the multicast functionality provided by designated network nodes, or host-based, with the multicast functionality provided by the members of the multicast group itself. These two classes have very different performance characteristics; typically infrastructure-based solutions are far more scalable, while the host-based solutions are far more deployable and flexible.

This paper proposes a multicast architecture, that is a hybrid of the two approaches, based on the Internet Indirection Infrastructure (i3). i3 provides a general-purpose rendezvous primitive that end hosts can use to implement multicast in a scalable, flexible, and deployable manner. To demonstrate the feasibility of this approach, we have designed and implemented a scalable solution for multicast, and then extended it to provide reliable data delivery. To evaluate our design we perform extensive simulations, and experiments on two test-beds: a PC cluster, and a small size Internet-wide test-bed consisting of 13 end-hosts. From simulations, we found that the 90th percentile latency stretch for 65,536 receivers is less than 5. Also, for 4,096 receivers, no more than 1.5 duplicates were generated for each lost packet.