AitF: FULL: Collaborative Research: Compact Data Structures for Traffic Measurement in Software-Defined Networks

软件定义网络(SDN)通过将“控制平面”(决定如何处理流量)与“数据平面”(实际转发每个分组)分开，正在改变网络设计和管理的方式。许多大公司-如谷歌、微软和Facebook-已经部署了SDN技术，许多设备供应商支持用于对其交换机进行编程的开放接口。虽然SDN的大部分工作都集中在如何控制网络上，但测量网络中的流量也同样重要。流量测量有助于识别拥塞链路、拒绝服务攻击、性能问题和配置错误，还可以决定网络未来应如何转发流量。然而，今天的商用交换机对流量测量的支持相当原始。在该建议中，PI将对所谓的“紧凑数据结构”的算法研究引入SDN中的可编程流量测量问题。紧凑的数据结构可以在交换机内存和处理资源方面以有限的开销给出测量问题的近似答案。该项目是跨学科的，汇集了计算机网络和理论计算机科学的研究人员，将实际问题与新的解决方案相匹配。提出的研究从设计新的查询抽象来收集现有SDN交换机上的流量统计数据开始，然后逐步识别新的紧凑数据结构，以便未来的交换机能够以合理的开销支持更丰富的流量测量。研究人员与网络管理员和交换机供应商保持密切联系，使他们能够在对运营要求和硬件限制的深入了解中使项目落地，并影响未来的SDN技术。该项目旨在确定用于收集各种流量统计数据的交换机数据平面架构，以及用于各种分析的可编程草图和样本集，以权衡精确度和资源。该体系结构将包括控制器和交换机之间的测量控制API，这需要通信高效的接口，以及用于指定流量查询的高级语言，以及控制器上的运行时系统，该系统将这些查询编译为发送到具有合适CDS的交换机的命令。这些挑战将使用在SDN和新的重新设计中广泛流行的OpenFlow API来解决。这是网络和算法社区之间的对话，相互告知什么是可能的，什么是必需的，最终什么是有效和有用的。

Software-Defined Networking (SDN) is changing the way networks are designed and managed, by separating the "control plane" (which decides how to handle the traffic) from the "data plane" (which actually forwards each packet). Many large companies---like Google, Microsoft, and Facebook---have already deployed SDN technology, and many equipment vendors support open interfaces for programming their switches. While most work on SDN focuses on how to control the network, measuring the traffic in the network is equally important. Traffic measurement is useful to identify congested links, denial-of-service attacks, performance problems, and configuration mistakes, and also drives decisions of how the network should forward traffic in the future. However, the support for traffic measurement in today's commodity switches is quite primitive. In this proposal, the PIs bring algorithmic research on so-called "compact data structures" to bear on the problem of programmable traffic measurement in SDNs. Compact data structures can give approximate answers to measurement questions with limited overhead in terms of switch memory and processing resources. The project is interdisciplinary, bringing together researchers in computer networking and theoretical computer science to match practical problems with novel solutions. The proposed research starts with designing new query abstractions for collecting traffic statistics on existing SDN switches, and then progresses to identifying new compact data structures so that future switches can support much richer traffic measurement at reasonable overhead. The researchers have close ties with network administrators and switch vendors, allowing them to ground the project in a strong understanding of both operational requirements and hardware constraints, and also influence future SDN technology.This project aims to identify a switch data-plane architecture for collecting diverse traffic statistics, as well as a small set of programmable sketches and samples for variety of analyses to trade-off accuracy and resources. The architecture will include a measurement control API between the controller and the switch, and this needs a communication-efficient interface, along with a high-level language for specifying traffic queries, and with that, a run-time system on the controller that compiles these queries into commands to the switches with suitable CDSs. These challenges will be addressed using OpenFlow API that is widely popular for SDNs and in new redesigns. This is a conversation between the networking and algorithmic communities, mutually informing each other on what is possible, what is required, and ultimately what is effective and useful.