Virtual wide-area networks (WANs) are WAN-as-a-service cloud offerings that aim to bring the performance benefits of dedicated wide-area interconnects to enterprise customers. In this work, we show that the topology of a virtual WAN can render it both performance and cost inefficient. We develop Cornifer, a tool that designs virtual WAN topologies by deciding the number of virtual WAN nodes and their location in the cloud to minimize connection latency at low cost to enterprises. By leveraging millions of latency measurements from vantage points across the world to cloud points of presence, Cornifer designs virtual WAN topologies that improve weighted client latency by 26% and lower cost by 28% compared to the state-of-the-art. Cornifer identifies virtual WAN topologies at the Pareto frontier of the deployment cost vs. connection latency trade-off and proposes a heuristic for automatic selection of Pareto-optimal virtual WAN topologies for enterprises.

翻译：虚拟广域网（WAN）是网络即服务的云产品，旨在为企业客户提供专用广域互联的性能优势。本研究表明，虚拟广域网的拓扑结构可能导致其性能和成本效率低下。我们开发了CORNIFER工具，通过确定虚拟广域网节点的数量及其在云中的部署位置，设计低延迟且成本低廉的企业级虚拟广域网拓扑。基于全球监测点向云接入点发送的数百万次延迟测量数据，CORNIFER设计的虚拟广域网拓扑相比现有最优方案，将加权客户端延迟降低26%，成本降低28%。该工具能够在部署成本与连接延迟的帕累托前沿识别最优虚拟广域网拓扑，并提出了一种启发式算法，可为企业自动选择帕累托最优的虚拟广域网拓扑方案。