发表机构
CNIT - University of Rome “Tor Vergata”（意大利罗马托尔维加塔大学国家信息技术研究中心）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
针对光数据中心网络的不平衡流量需求，提出一种由借用度B控制的叶脊型全光架构，利用成熟组件实现波长借用，性能接近最优且成本更低。
AI 中文摘要
东西向流量的增长，加上电子交换的成本和功耗，推动在数据中心网络中集成低功耗、高速率的全光层。本文提出一种叶脊型全光架构，其中默认波长配置为每个源-目的叶节点对应一个波长，可重新配置以适应不平衡的流量需求：一个叶节点未使用或负载较轻的波长可被另一个需求更高的叶节点借用。这种拓扑工程能力与基于两跳迂回的流量工程方案相结合，可控制波长负载同时限制迂回流量的数量。该架构的关键特征是，其波长可重配置程度由单个可调参数——借用度B决定，范围从无到全；性能评估显示，远低于最大B时即可实现接近最优的性能，节省了全可重配置解决方案的复杂度和成本。此外，该光结构依赖成熟的数据中心级组件，即阵列波导光栅（AWGs）、阵列波导光栅路由器（AWGRs）、无色光交叉连接器（OXCs）和合路器，其重配置速度使该架构可部署在流量需求持续数秒或更长时间的网络层级，例如机架组（pods）之间。该架构还具备时分多址（TDMA）透明性，未来工作可利用这一特性在不改变光结构的情况下将借用单元细化到单个波长以下。
英文摘要
The growth of east-west traffic, along with the cost and power consumption of electronic switching, is motivating the integration of a low-power, high-rate, all-optical layer within the data center network. This paper presents a spine-leaf all-optical architecture in which the default wavelength configuration, one wavelength per source--destination leaf pair, can be reconfigured to accommodate unbalanced traffic demand: wavelengths that are unused or lightly loaded at one leaf are borrowed by another leaf with higher demand. This topology-engineering capability is combined with a traffic-engineering scheme, based on two-hop detouring, enabling the control of wavelength load while limiting the amount of detoured traffic. A key feature of the architecture is that its degree of wavelength reconfigurability is set by a single tunable parameter, the borrowing degree $B$, ranging from none to full; performance evaluation shows that near-optimal performance is achieved well below the maximum $B$, saving the complexity and cost of fully reconfigurable solutions. Furthermore, the optical fabric relies on mature, data-center-grade components, namely AWGs, AWGRs, colorless OXCs, and combiners, whose reconfiguration speed makes the architecture deployable at network tiers where traffic demand persists over seconds or longer, e.g., among groups of racks (pods). The architecture is also TDMA-transparent, a property that future work could exploit to refine the borrowing unit below a whole wavelength without changing the optical fabric.
