Exploiting as hierarchy for scalable route selection in multi-homed stub networks
Exploiting as hierarchy for scalable route selection in multi-homed stub networks
复制标题
在多宿主存根网络中利用层次结构进行可扩展的路由选择
DOI：
10.1145/1028788.1028829
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发表时间：
2004
期刊：
影响因子：
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通讯作者：
Srihari Nelakuditi
中科院分区：
文献类型：
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作者：
Sanghwan Lee;Zhi;Srihari Nelakuditi
多归巢是许多（尤其是大型）客户（或存根）网络中的一种常见做法。虽然多宿主的目的主要是为了增强可靠性，但它也越来越多地用于负载平衡和减少延迟。在本文中，我们解决了如何在多宿主<i>存根</i>网络中执行<i>可扩展</i>路由选择的问题，以优化通过往返时间（RTT）测量到各个目的地的网络延迟。一种直接的方法是通过每个提供程序对每个目的地执行RTT测量（例如，使用ping），并选择RTT最小的一个作为到目的地的“最佳”下一跳。还有别的吗？
Multi-homing is a common practice among many (especially large) customer (or stub) networks. Although the purpose of multi-homing is primarily for enhanced reliability, it has also increasingly been used for load balancing and latency reduction. In this paper, we address the problem of how to perform <i>scalable</i> route selection in a multi-homed <i>stub</i> network to optimize network latency to various destinations as measured by round-trip-time (RTT). A straight forward method is to simply perform RTT measurements (e.g., using ping) to each destination via each provider and select the one with the minimum RTT as the "best" next-hop to the destination. Is there a more.
To answer this question, we carry out a measurement-based study to analyze the differences of RTTs in using two different providers in a multi-homed stub network to reach a large number of randomly selected destinations. Our study reveals that because of the AS hierarchy, for a large fraction of the network prefixes, the two AS paths through two providers merge in the core of the Internet. Furthermore, the router at which the two router level paths merge is actually in the AS at which the AS level paths merge. This phenomenon causes the RTT difference between the two paths through the two providers to be determined by the <i>non shared</i> portion of the paths. Our study reveals that most of the two router level paths through the two upstream providers merge at the AS at which the two AS level paths merge. Based on this finding, we devise a scalable route (next-hop provider) selection algorithm using BGP information in a multi-homed stub network. We also present a preliminary evaluation.