Evaluation and Optimization of Connectivity-Based Stability- and "Quality of Service"-Metrics in Overlay Networks

覆盖网络中基于连接的稳定性和服务质量指标的评估和优化

• 批准号: 262650209
• 负责人: Professor Dr.-Ing. Günter Schäfer
• 金额: --
• 依托单位: Arbeitsgruppe Diskrete Mathematik und Algebra
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2014
• 资助国家: 德国
• 起止时间: 2013-12-31 至 2016-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/262650209?language=en
• 关键词: Evaluation; Optimization; Connectivity; Based; Stability

In network engineering, the creation of logical communication networks on top of underlying transport networks is a well-established concept. It is used in diverse application scenarios such as peer-to-peer networks, data center architectures, configuration of virtual private networks, the design of WDM-networks, the smart grid and in multiple visions of the future internet. In particular, all these applications feature a structural division into underlay (the transport network), overlay (the logical network) and an edge mapping, returning an underlay transport path for each logical connection in the overlay.Due to their indispensable role in present-day IT infrastructures, it is necessary to adopt overlay networks that are both failure- and attack-resistant. However, currently applied structural optimizations in overlay networks rather focus on improving communication efficiency or finding a local backup path for each overlay connection. Consequently, the removal or exhaustion of few underlay edges can effect a large number of overlay connections. Hence, the overlay's quality-of-service and availability parameters may decisively degrade.Determining such critical structures and studying realistic attack approaches are preconditions for the qualitative estimation of an overlay network's resiliency. Furthermore, they provide the basis for optimizations, since identified weaknesses may be resolved by an adaption of overlay structure or edge mapping.However, when compared with classical networks, the relevant graph measures exhibit substantially different properties. Due to dependencies between underlay and overlay connections, the MaxFlow-MinCut theorem is no longer valid. Measures of graph connectivity that are equivalent in classical networks may differ. This results in multiple available generalizations of graph connectivity, with different computational properties.Furthermore, the interactions between overlay and underlay affect load-dependent quality-of-service parameters, such as flow rates, jitter and delays. In the presence of a disadvantageous edge mapping, small deviations in the bandwidth of underlay connections can lead to considerable decrease in the overlay's quality-of-service.Based on these observation, the proposed project aims at the maximization of connectivity-based stability and quality-of-service measures in overlay networks. In particular, the following objectives shall be pursued:1. Investigation and refinement of attacker models in overlay scenarios2. Improvement of analysis methods of connectivity-based stability and quality-of-service measures in overlay networks with underlay changes3. Application of analysis methods on representative overlay networks4. Stability optimizations of overlay and edge mapping

在网络工程中，在底层传输网络之上创建逻辑通信网络是一个公认的概念。它被用于各种应用场景，例如对等网络，数据中心架构，虚拟专用网络的配置，WDM网络的设计，智能电网以及未来互联网的多种愿景。特别是，所有这些应用的特点是结构划分为传输网络（Transport Network）、覆盖网络（Overlay，逻辑网络）和边缘映射，为覆盖网络中的每个逻辑连接返回一条传输路径。由于它们在当今IT基础设施中不可或缺的作用，有必要采用同时具有抗故障和抗攻击能力的覆盖网络。然而，当前在覆盖网络中应用的结构优化更侧重于提高通信效率或为每个覆盖连接找到本地备份路径。因此，移除或耗尽少量的重叠边缘可以影响大量的覆盖连接。因此，覆盖网络的服务质量和可用性参数可能会决定性地降低。确定这些关键结构和研究现实的攻击方法是定性估计覆盖网络弹性的前提条件。此外，它们提供了优化的基础，因为识别出的弱点可以通过覆盖结构或边映射的自适应来解决。然而，与经典网络相比，相关的图度量表现出显著不同的性质。由于重叠连接和重叠连接之间的依赖性，MaxFlow-MinCut定理不再有效。在经典网络中等价的图连通性的度量可能不同。这导致了多种可用的图连通性的概括，具有不同的计算属性。此外，覆盖和覆盖之间的相互作用影响负载相关的服务质量参数，如流量，抖动和延迟。在一个不利的边缘映射的存在下，小偏差的带宽的重叠连接可以导致相当大的减少在覆盖的服务质量。基于这些观察，建议的项目旨在最大限度地提高基于连接的稳定性和服务质量的措施覆盖网络。具体而言，应追求以下目标：1.覆盖层网络中攻击者模型的研究和改进2.覆盖网络中基于连通性的稳定性和服务质量分析方法的改进分析方法在代表性覆盖网络上的应用4.叠置和边缘映射的稳定性优化