The rapid development of network function virtualization (NFV) enables a communication network to provide in-network services using virtual network functions (VNFs) deployed on general IT hardware. While existing studies on NFV focused on how to provision VNFs from the provider’s perspective, little is done about how to validate the provisioned resources from the user’s perspective. In this work, we take a first step towards this problem by developing an inference framework designed to “look into” the NFV network. Our framework infers the structure and state of the overlay formed by VNF instances, ingress/egress points of measurement flows, and critical points on their paths (branching/joining points). Our solution only uses external observations such as the required service chains and the end-to-end performance measurements. Besides the novel application scenario, our work also fundamentally advances the state of the art on topology inference by considering (i) general topologies with general measurement paths, and (ii) information of service chains. Our evaluations show that the proposed solution significantly improves both the reconstruction accuracy and the inference accuracy over existing solutions, and service chain information is critical in revealing the structure of the underlying topology.

中文翻译：

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NFV的窥视镜：从外部观察推论NFV网络的结构和状态

网络功能虚拟化（NFV）的快速发展使通信网络可以使用部署在常规IT硬件上的虚拟网络功能（VNF）提供网络内服务。虽然有关NFV的现有研究集中于如何从提供者的角度配置VNF，但对于如何从用户的角度验证所配置的资源却做得很少。在这项工作中，我们通过开发旨在“研究” NFV网络的推理框架，迈出了解决这一问题的第一步。我们的框架可以推断出由VNF实例，测量流的入口/出口点及其路径上的临界点（分支/连接点）形成的叠加层的结构和状态。我们的解决方案仅使用外部观察，例如所需的服务链和端到端性能度量。除了新颖的应用场景外，我们的工作还通过考虑（i）具有常规测量路径的常规拓扑，以及（ii）服务链信息，从根本上改进了拓扑推断的最新技术。我们的评估表明，与现有解决方案相比，所提出的解决方案显着提高了重构精度和推断精度，并且服务链信息对于揭示基础拓扑的结构至关重要。