HyperOptics: A High Throughput and Low Latency Multicast Architecture for Datacenters

Multicast has long been a performance bottleneck for data centers. Traditional solutions relying on IP multicast suffer from poor congestion control and loss recovery on the data plane, as well as slow and complex group membership and multicast tree management on the control plane. Some recent proposals have employed alternate optical circuit switched paths to enable lossless multicast and a centralized control architecture to quickly configure multicast trees. However, the high circuit reconfiguration delay of optical switches has substantially limited multicast performance. In this paper, we propose to eliminate this reconfiguration delay by an unconventional optical multicast architecture called HyperOptics that directly interconnects top of rack switches by low cost optical splitters, thereby eliminating the need for optical switches. The ToRs are organized to form the connectivity of a regular graph. We analytically show that this architecture is scalable and efficient for multicasts. Preliminary simulations show that running multicasts on HyperOptics can on average be 2.1× faster than on an optical circuit switched network.