During its 3-year workplan the project achieved all of its objectives:
• Objective 1: Develop scalable hybrid interconnect architecture for a dynamically reconfigurable datacentre.
A hybrid interconnect architecture was developed and studied thoroughly in terms of scalability, cost and power consumption. NEPHELE’s network architecture scales linearly with the number of datacenter hosts and consolidates compute and storage networks over a single, Ethernet optical TDMA network. Low latency, hardware-level dynamic re-configurability and quasi-deterministic Quality-of-Service (QoS) are supported in view of disaggregated datacenter deployment scenarios.The studies underpin the feasibility to scale the NEPHELE architecture at a medium-sized datacentre achieving strong reduction in power consumption, yet without a cost premium.
• Objective 2: Extend SDN control plane for slotted network operation for the dynamic allocation of optical DC network resources.
NEPHELE developed the OCEANIA and Opendaylight SDN controllers, managing and configuring the ToR and POD switches of its architecture. The north- and south-bound interfaces of the network controller were also developed along with the SDN agents, allowing the realization of slotted operation of the DCN dataplane. NEPHELE’s SDN framework is available as open-source software.
• Objective 3: Integrate application centric allocation of network resources with SDN datacenter orchestrator.
Several scheduling / bandwidth allocation algorithms were developed and evaluated during the project reducing execution time even for large DCNs. Integration of the scheduling algorithms in OCEANIA allows the dynamic reconfiguration of the data plane components according to application requirements.
• Objective 4: Enable end-to-end SLA provisioning with dynamic inter-datacenter resource management.
NEPHELE studied and evaluated the performance of resource allocation algorithms for inter-datacenter use cases. The NEPHELE inter-domain orchestrator, NIDO, interfaces i) with the OCEANIA controller for NEPHELE datacenter domains, and ii) with NEPHELE Julius SDN controller for the elastic optical transport network domain that connects NEPHELE datacenters. NIDO orchestrates through the domain controllers the provisioning of end-to-end inter-datacenter connections, providing the required service levels.
• Objective 5: Develop fully functional components enabling network convergence over a transparent Ethernet optical DC network.
NEPHELE developed and characterized the main elements of its network architecture, namely the ToR and pod switch comprising fully functional optical subsystems controlled by an Ethernet switch with FPGA port extenders. A broad range of optical components were experimentally investigated during the ToR and pod development stage. Alongside with the hybrid ToR implementation, a forward-looking all-optical design was implemented. In addition, a converged switch, storage and compute platform was developed, comprising optically enabled and interchangeable switch subsystems. This activity also led to the invention of an electro-optical connector for object-oriented end nodes.
• Objective 6: Demonstrate dynamic inter- and intra-datacenter connectivity with prototype subsystems.
The software and hardware components of NEPHELE were integrated successfully into a demo platform comprising a vertically integrated datacentre testbed assembly. Dynamic intra-datacenter operation was achieved in various routing scenarios during real time demos. The NEPHELE testbed was incorporated into the developed inter-datacenter demonstration platform verifying NEPHELE’s inter-DC connectivity and operation.
