In compute/memory dynamic packet/circuit switch placement for optically disaggregated data centers

Network function services on conventional hybrid data center (DC) architectures such as HELIOS are hard-wired and dedicated to specific network resources. This limits flexibility and performance to handle diverse traffic patterns. Furthermore, disaggregation of server resources has shown promising potential to improve resource utilization, which has been a limitation of conventional server-centric DCs. This paper presents a reconfigurable hybrid disaggregated DC (dRedBox) architecture that combines the concept of server resource disaggregation with cutting-edge software and electronic and optical technologies. The dRedBox architecture provides a remarkable amount of flexibility and connectivity through hardware-based multilayer network function service programmability. This allows for multilayer network services to be dynamically deployed at runtime to network resources and, in turn, handle diverse traffic patterns. Furthermore, this study proposes algorithms and strategies for selecting and deploying electronic packet switching and optical circuit switching function services to implement virtual machine network requests across dRedBox and conventional hybrid disaggregated architectures under different traffic patterns. Finally, the performance of the various strategies on the dRedBox and conventional hybrid disaggregated DC architectures is evaluated in terms of blocking probability, energy efficiency, network utilization, and cost. Extensive results show that, at 10% blocking probability, dRedBox architecture achieves 100% gain on VM placement and 92% energy savings compared with conventional hybrid disaggregated architectures

Key performance indicators for elastic optical transponders and ROADMs:the role of flexibility

Flexible optical networks will provide the required service diversity to manage unpredictable traffic patterns and growth. However, a key challenge is to quantify flexibility in order to indicate the associated performance of individual components and subsystems required to support networks and correlate it with other figures of merit. Measurable key performance indicators will aid the process towards the design and deployment of cost effective and efficient optical networks. Moreover, the design and placement of network elements within a network influences the resultant network-wide flexibility and performance. In this paper, we highlight critical design parameters for key optical components, optical transmission and switching subsystems using flexibility as an additional figure of merit. We derive models to measure the flexibility of key optical components, optical transmission and switching subsystems based on entropy maximization. Using these models, we evaluate flexibility and design trade-offs of the presented enabling technologies with other key performance indicators such as spectral efficiency, lightpath reach, total capacity, normalized cost, connectivity and others. This study provides an advanced and more informed set of design rules that quantify and visualize the different degrees of flexibility of enabling technologies and associated performance based on required specification and/or functionality

Archon: a function programmable optical interconnect architecture for transparent intra and inter data center SDM/TDM/WDM networking

This paper reports all-optical, function programmable, transparent, intra-inter data center networking (DCN) using space and time division multiplexing (SDM/TDM) within data centers and wavelength division multiplexing (WDM) between data centers. A multi-element fiber (MEF) is used for SDM transmission to provide a large quantity of optical links between the top-of-racks (ToRs) and the function programmable cluster switch. Beam-steering large-port-count fiber switches (LPFS), used as central cluster switches and inter-cluster switch, provide a single hop optical circuit switching (OCS) solution, and also enable network function programmability for DCN to support variable traffic patterns and different network functions. A TDM switch as a plug-in function provides intra-cluster communication with variable capacity and low latency. The flat-structured intra data center architecture, with a circuit-switched SDM and TDM hybrid network enables scalable, large-capacity and low-latency DCN communication. In addition, all-optical ToR-to-ToR inter-DCN is realized through metro/core networks. A highly-nonlinear fiber (HNLF) based all-optical SDM-to-WDM converter transfers three SDM signals to 3-carrier spectral superchannel signals, which are transmitted to the destination DCN, through the metro/core networks. The all-optical ToR-ToR cross-DCN connections enable the geographically distributed DCNs to appear as one big data center