End System Multicast

While the traditional IP network supports unicast datagram service, Deering, in his seminal SIGCOMM'88 paper, advocated extending the IP service model and router functionalities to support multicast. In the decade that followed, hundreds of technical papers and tens of Ph.D dissertations were written on various aspects of IP multicast. In addition, IP Multicast was incorporated into both IPv4 and IPv6 by the IETF, the standard organization for the Internet. However, despite significant amount of efforts by research, standard, application, router vendor, and service provider communities in the last decade, IP multicast service is still not offered on the Internet today.

In this talk, I will present the End System Multicast (ESM) project, which was among the first to take the position that IP Multicast is the wrong approach for supporting multipoint applications in the Internet. In the ESM architecture, end systems or hosts, instead of routers, implement all multicast related functionality including membership management and packet replication. To validate the approach, we have developed and deployed an Internet video broadcasting system based on ESM. I will report our experiences and reflect on the lessons we learned.