All-optical packet/circuit switching-based data center network for enhanced scalability, latency, and throughput

Abstract

ata centers (DCs) are currently the largest closedloop systems in the information technology (IT) and networking worlds, continuously growing toward multi-million-node clouds [1]. DC operators manage and control converged IT and network infrastructures in order to offer a broad range of services and applications to their customers. Typical services and applications provided by current DCs range from traditional IT resource outsourcing (storage, remote desktop, disaster recovery, etc.) to a plethora of web applications (e.g., browsers, social networks, online gaming). Innovative applications and services are also gaining momentum to the point that they will become main representatives of future DC workloads. Among them, we can find high-performance computing (HPC) and big data applications [2]. HPC encompasses a broad set of computationally intensive scientific applications, aiming to solve highly complex problems in the areas of quantum mechanics, molecular modeling, oil and gas exploration, and so on. Big data applications target the analysis of massive amounts of data collected from people on the Internet to analyze and predict their behavior.All these applications and services require huge data exchanges between servers inside the DC, supported over the DC network (DCN): the intra-DC communication network. The DCN must provide ultra-large capacity to ensure high throughput between servers. Moreover, very low latencies are mandatory, particularly in HPC where parallel computing tasks running concurrently on multiple servers are tightly interrelated. Unfortunately, current multi-tier hierarchical tree-based DCN architectures relying on Ethernet or Infiniband electronic switches suffer from bandwidth bottlenecks, high latencies, manual operation, and poor scalability to meet the expected DC growth forecasts [3].These limitations have mandated a renewed investigation D Abstract Applications running inside data centers are enabled through the cooperation of thousands of servers arranged in racks and interconnected together through the data center network. Current DCN architectures based on electronic devices are neither scalable to face the massive growth of DCs, nor flexible enough to efficiently and cost-effectively support highly dynamic application traffic profiles. The FP7 European Project LIGHTNESS foresees extending the capabilities of today's electrical DCNs through the introduction of optical packet switching and optical circuit switching paradigms, realizing together an advanced and highly scalable DCN architecture for ultra-high-bandwidth and low-latency server-to-server interconnection. This article reviews the current DC and high-performance computing (HPC) outlooks, followed by an analysis of the main requirements for future DCs and HPC platforms. As the key contribution of the article, the LIGHTNESS DCN solution is presented, deeply elaborating on the envisioned DCN data plane technologies, as well as on the unified SDN-enabled control plane architectural solution that will empower OPS and OCS transm...

Wireless Communication in Data Centers: A Survey

“…It might be noted, however, that intra-rack communication is realized using electrical switching. This is because, traditional electrical cables (e.g., 10 GigE) are viable for distances below 10 meters (i.e., intra-rack communication) [120]. Moreover, the prices of the enabling technologies of optical communications are relatively high as compared to that of commodity electrical networking elements.…”

Optical Networking Paradigm: Past, Recent Trends and Future Directions

“…If OPS and OCS architectures are integrated, both best-effort and QoS guaranteed services can be provided on the same infrastructure. Recently, some research projects have also investigated integrated packet/circuit switching in [65], [74]- [76].…”

Optimal Virtual Slice Composition Toward Multi-Tenancy Over Hybrid OCS/OPS Data Center Networks

“…In order to properly map the virtual link, half of the total bandwidth should be mapped in one direction and the remaining half in the other. Constraints (8) and (9) account for this, forcing that the bandwidth assigned to a virtual link in a particular path p should be equal to the bandwidth assigned to the symmetrical pathp. In this way, the total assigned bandwidth is halved among the two directions of the communication.…”

“…In this context, the FP7 European project LIGHTNESS [9] presents a revolutionary architecture solution for the DCN. It is based on a hybrid OCS/OPS DCN, harnessing the superior flexibility, scalability and bandwidth of the optical transport medium, as well as a unified Software Defined Network (SDN)-based control plane for a fast control and configuration of the DCN infrastructure.…”