Forwarding Anomalies in Bloom Filter Based Multicast
Several recently proposed multicast protocols use in-packet Bloom filters to encode multicast trees. These mechanisms are in principle highly scalable because no per-flow state is required in the routers and because routing decisions can be made efficiently by simply checking for the presence of outbound links in the filter. Yet, the viability of previous approaches is limited by the possibility of forwarding anomalies caused by false positives inherent in Bloom filters. This paper explores such anomalies, namely packets storms, forwarding loops and flow duplication. The authors propose stateless solutions that increase the robustness and scalability of Bloom filter based multicast protocols.