MPSS: Multiprotocol Stateless Switching

The Multiprotocol Label Switching (MPLS) architecture has become a true success story in the world of telecommunications. However, MPLS becomes cumbersome if multicast communication is needed, as aggregating of labels is not easy. Because of that, when providing Multicast VPNs, operators need to trade-off bandwidth usage with the amount of multicast state, sacrificing efficiency. Forwarding with Bloom filters in the packet headers offers the opportunity to have quasi-stateless network elements; the amount of forwarding plane state does not depend on the number of paths/trees the node participates in. In this paper, we propose Multiprotocol Stateless Switching (MPSS), the marriage of MPLS and Bloom filter based forwarding. The forwarding architecture inherits the flexibility of MPLS and gives operators the opportunity to offer Multicast VPN services while avoiding the difficult process of fine-tuning the trade-off between bandwidth usage and state.