Forwarding of multicast packets with hybrid methods based on Bloom filters and shared trees in MPLS networks

Abstract

Multicast forwarding in the context of IP-MPLS networks for services like VPLS has important scalability issues. Alternatives to per-VPLS tree construction based on aggregation of multipoint requests onto shared trees have been studied. Other works have focused on stateless forwarding based on Bloom filters. Both suffer from some type of forwarding anomalies. This paper proposes the combination of both forwarding modes: shared multicast trees and an efficient variant of stateless switching based on Bloom filters. Simulations prove that constraining the forwarding to the shared tree is an effective mechanism to prevent most side effects of Bloom filter-based forwarding, making the combined technique a good trade-off in terms of forwarding state consumption, yielding best performance in terms of overhead with respect to each technique in isolation.