MCF-SMF Hybrid Low-Latency Circuit-Switched Optical Network for Disaggregated Data Centers
This paper proposes and experimentally evaluates a fully developed novel architecture with purpose built low latency communication protocols for next generation disaggregated data centers (DDCs). In order to accommodate for capacity and latency needs of disaggregated IT elements (i.e., CPU, memory), this architecture makes use of a low latency and high-capacity circuit-switched optical network for interconnecting various end points that are equipped with multi-channel silicon photonic based integrated transceivers. In a move to further decrease the perceived latency between various disaggregated IT elements, this paper proposes a novel network topology that cuts down the latency over the optical network by 34% while enhancing system scalability and channel bonding over multi-core fiber (MCF) switched links to reduce head to tail latency and in turn increase sustained memory bandwidth for disaggregated remote memory. Furthermore, to reduce power consumption and enhance space efficiency, the integration of novel MCF-based transceivers, fibers, and optical switches are proposed and experimentally validated at the physical layer for this topology. It is shown that the integration of MCF-based subsystems in this topology can bring about an improvement in energy efficiency of the optical switching layer, which is above 60%. Finally, the performance of this proposed architecture and topology is evaluated experimentally at the application layer where the perceived memory throughput for accessing remote and local resources is measured and compared using electrical circuit and packet switching. The results also highlight a multi-fold increase in application perceived memory throughput over the proposed DDC topology by utilization and bonding of multiple optical channels to interconnect disaggregated IT elements that can be carried over MCF links.