基于BGP路由表的域间路径特性实验研究

Experimental study of BGP routing-table-based inter-domain path characteristics

边界网关协议(BGP)路由表中存放的相关信息可以反映互联网规模、运行状态及其体系结构的演化,是互联网基础性研究的重要组成部分,然而先前对BGP路由表的研究工作主要集中于路由表尺寸、网络覆盖范围和地址空间消耗等反映互联网规模的指标,对路径多样性等方面的研究比较缺乏。该文基于BGP IPv4路由表,引入域间路径特性分析模型,设计路径特性分析实验框架,开展了针对自治系统(AS)规模以及域间路径特性的统计分析工作,获得了隐藏的AS级路径属性及其参数分布。研究结果显示:现今互联网物理网络具有丰富的路径多样性;BGP选择的部分默认路径并非最短路径。该结果对于指导互联网域间路由的研究具有重要的意义。

The information stored in the routing table for the border gateway protocol （BGP） can reflect the scale of the Internet, the running state and the evolution of the architecture, which is important for basic research of the Internet. Previous studies of routing tables have mainly focused on the indicators that reflect the Internet scale, such as the routing table size, the Internet coverage, and the address consumption, but lack analyses of routing diversity. This paper introduces a characteristic analysis model for inter-domain paths and a path characteristic analysis framework based on the IPv4 routing table information in the BGP with statistical analyses of the AS scale and the inter-domain path characteristics. The results give information about the AS-level path attributes and their parameter distributions. The analyses show that the lnternet currently has a rich diversity of routing paths with some best paths selected by BGP not the shortest paths in the routing table. The results provide guidance for future inter-domain route planning.