Bloomflow: Openflow extensions for memory efficient, scalable multicast with multi-stage bloom filters

摘要

In-packet bloom filter based multicast is a family of techniques that have been recently proposed to address scalability issues in IP multicast. The main problem motivating these techniques is that network forwarding elements supporting traditional IP multicast store group specific forwarding state for every multicast tree traversing the element, resulting in poor memory scalability in networks with many active groups. Techniques in this family address this problem by encoding multicast routing information into in-packet bloom filters, which are memory efficient, probabilistic data structures for representing set membership. However, in existing approaches the probabilistic nature of bloom filters results in false positive packet delivery, thereby introducing forwarding anomalies, unnecessary bandwidth utilization, and violations of security policies.