Scalable multicast control-plane for optical packet forwarding engines: A multiway SVRF approach

In control-plane of optical packet forwarding engines (OPFEs), the group-membership query algorithm determines the egress through which a packet should be forwarded. To implement a high-performance multicast-enabled switch/router, a super-fast group-membership query algorithm is the key element within the PFEs which require the following essential properties: high link-bandwidth, high port-density, high forwarding speed, high scalability, and affordable cost. Current group-membership query approaches such as Bloom filter (BF) and Scalar-Pair Vectors Routing and Forwarding (SVRF) still suffer from serious weaknesses in terms of the space/time inefficiency, false-positive error, and low maintainability, etc. To accommodate these weaknesses, we propose an improved forwarding scheme–M-way Scaler-matrix and Vectors Routing and Forwarding (M-way SVRF) by re-examining the idea of the original SVRF. The M-way SVRF divides a ρ-bit port identifier into M-sub-blocks in the memory unit, thus element's keys belonging to distinct sub-blocks are able to reuse relatively smaller identical prime keys. Compared to previous works, simulation results show that the membership queries can be partitioned to leverage task parallelism, and better performance in the aspects of memory consumption and computational complexity, especially when the port-density of optical PFE is sufficiently high.