Network virtualization is a promising technology for overcoming Internet ossification by enabling multiple Virtual Networks (VNs) to coexist on a shared substrate network. One critical aspect in NV environments is the capability of operators to allocate resources in the substrate network to support VNs in an optimal manner. This is known as Virtual Network Embedding (VNE). In the same context, online VN migration is the process meant to re-allocate components of a VN in real-time and seamlessly to the end-users. Although progress has been made to address VN migration, there has been little investigation on integral migration approaches assessed under different VN environment conditions. The main contribution of this paper is a VN migration framework that addresses the online VN migration problem holistically, namely considering different aspects that affect the efficiency of resource (re)allocations and the VNE acceptance ratios, such as migration policies, trigger conditions, and the CPU capacity requirements for Intermediate Substrate Nodes. An evaluation methodology is developed for analyzing the performance of the proposed framework on substrate infrastructures of different sizes and densities. Extensive software simulations on substrate networks of varying size (50 to 250 nodes) and link density (0.06 to 0.6) discover the migration-oriented parameters that contribute to enhance VNE up to 18.7%. We also compare the framework performance against two state-of-the-art mechanisms that improve online VNE while looking for VNE solutions and observed acceptance ratio enhancements up to 3× higher when using our framework on a physical network with 100 nodes and a density of 0.06.

中文翻译：

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虚拟网络迁移的整体框架，以提高网络虚拟化环境中的嵌入率

网络虚拟化是一种通过使多个虚拟网络 (VN) 在共享的基础网络上共存来克服互联网僵化的有前途的技术。NV 环境中的一个关键方面是运营商能够在底层网络中分配资源以最佳方式支持 VN。这称为虚拟网络嵌入 (VNE)。在相同的上下文中，在线 VN 迁移是一个过程，旨在实时无缝地将 VN 的组件重新分配给最终用户。尽管在解决 VN 迁移方面取得了进展，但对在不同 VN 环境条件下评估的整体迁移方法的研究很少。本文的主要贡献是一个 VN 迁移框架，它从整体上解决了在线 VN 迁移问题，即考虑影响资源（重新）分配效率和 VNE 接受率的不同方面，例如迁移策略、触发条件和中间基板节点的 CPU 容量要求。开发了一种评估方法，用于分析所提出的框架在不同尺寸和密度的基板基础设施上的性能。对不同大小（50 到 250 个节点）和链路密度（0.06 到 0.6）的基板网络进行了广泛的软件模拟，发现了有助于将 VNE 增强高达 18.7% 的面向迁移的参数。