NeTS: Small: Eiffel: Efficient and Flexible Software Packet Scheduling

现代通信网络以高速运行，这需要对数据传输的时间进行复杂的控制，以实现网络资源的有效共享。定时控制是通过部署在核心网络组件和用户系统中的数据包调度功能来实现的。本课题研究了网络组件软件中分组调度的设计与部署。这样的部署允许1)短的开发周期，允许跟踪技术状态，2)增强操作的灵活性，以及3)功能可移植性，允许以最小的额外工作在多个位置部署调度功能。该项目将通过开发和评估计算结构和算法来解决调度功能软件部署的挑战，这些结构和算法能够实现有效的软件包调度，以及允许用户根据自己的需要定制调度功能的机制。先进的调度功能是现代高速网络成功的核心，是当前和未来先进网络应用基础设施和数据中心网络的核心组成部分。分组调度是优化网络性能和利用率的许多最新创新的核心组成部分。现代网络以两种特定的方式依赖于数据包调度器：1)终端主机的流量整形和分层带宽共享，以及2)硬件交换机的调度。对于未来的网络，随着CPU（中央处理单元）容量和网络接口卡支持的速率的增长，流量数量和支持速率方面的规模预计将进一步增加。此外，网络运营商更喜欢开发周期更短的可编程网络组件。本课题的重点是在软件中设计和部署高效灵活的分组调度。虽然网络功能的硬件实现总是比相应的软件实现更快，但软件调度器有几个优点，包括更短的开发周期和在多个网络位置的多个平台上部署它们的能力。软件包调度具有挑战性，因为调度策略实现固有的计算复杂性，难以平衡效率和灵活性，并且需要仔细管理内存使用。考虑到软件包调度的重要性和这些挑战，该项目旨在开发和评估高效灵活的软件包调度程序的方法。更具体地说，该项目力求：1)通过为调度器配备高效的数据结构来提高效率，开发使调度器能够权衡准确性以提高效率的数据结构，并开发控制内存使用的背压机制，以及2)在不牺牲效率的情况下，通过启用调度策略的映射来提高灵活性，这些调度策略需要按流排序，而不是数据包排序，以及在脱队列操作时重新排序数据包或流。以及任意塑造政策。该项目还将为计算机网络课程开发可访问的教育内容，特别强调现代网络的分组调度。最终，该项目的目标是推进软件调度器的技术水平，使它们在未来网络的不同位置实际使用时可行。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Modern communication networks operate at high speeds that require sophisticated control of the timing of data transmissions to enable efficient sharing of network resources. The control of timing is performed by data packet scheduling functions deployed in core network components as well as user systems. This project considers the design and deployment of packet scheduling in network component software. Such deployment allows for 1) short development cycles, enabling the tracking of the state of the art, 2) enhanced flexibility of operation, and 3) function portability enabling the scheduling function to be deployed at multiple locations with minimal additional effort. The project will address the challenges of the software deployment of scheduling functions by developing and evaluating computation structures and algorithms that enable efficient software packet scheduling as well as mechanisms that allow users to tailor the scheduling functions to their needs. Advanced scheduling functions are central to successful modern high-speed networks, the core component of current and future advanced network applications infrastructure and data center networks.Packet scheduling is the core component of many recent innovations in optimizing network performance and utilization. The modern networks rely on packet schedulers in two specific ways: 1) traffic shaping and hierarchical bandwidth sharing at end-hosts, and 2) scheduling in hardware switches. For future networks, the scale in terms of number of flows and supported rates is expected to increase further with the growth of CPU (central processing unit) capacity and rates supported by network interface cards. Furthermore, network operators prefer programmable network components which have shorter development cycles. The focus of this project is on the design and deployment of efficient and flexible packet scheduling in software. While hardware implementation of network functionality will always be faster than its corresponding software implementation, software schedulers have several advantages including a shorter development cycle and the ability to deploy them on multiple platforms in multiple network locations. Software packet scheduling is challenging because of the inherent computational complexity of scheduling policy implementations, the difficulty of balancing efficiency with flexibility, and the need to carefully manage memory usage. Motivated by the importance of software packet scheduling and with these challenges in mind, the project aims to develop and evaluate approaches for efficient and flexible software packet schedulers. More specifically, the project seeks to: 1) Improve efficiency by equipping schedulers with efficient data structures, developing data structures that enable the scheduler to trade off accuracy for increased efficiency, and developing backpressure mechanisms that control memory usage, and 2) Improve flexibility without sacrificing efficiency by enabling the mapping of scheduling policies that require per-flow ranking in addition to or instead of packet ranking, and a re-ordering of packets or flows upon dequeue operation, and arbitrary shaping policies. The project will also develop accessible educational content for computer networking classes with specific emphasis on packet scheduling on modern networks. Ultimately, the project's goal is to advance the state of the art in software schedulers, making them feasible for practical use in diverse locations in future networks.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.