一种基于序列比对的路由对称性定量分析方法

路由对称性是互联网的基本属性之一。基于序列比对计算，提出一种路由对称性定量分析方法，可客观地评价不同网络主机的路由对称程度。使用该方法，对互联网的AS级路由对称性特征进行了定量分析，主要发现有：（1）互联网的AS级路由对称程度较高，分析中仅3．74％的主机对存在严重AS级路由不对称。（2）路由对称性与路由长度有关，较长路由长度的主机对AS级路由对称程度较低。（3）不同网络主机的路由对称程度不是均匀分布。

Sequence Alignment Based Approach for Quantified Analyzing Route Symmetry

Route symmetry is a fundamental property of the Internet, while previous works mainly studied it qualitatively. Based on sequence alignment, a quantificational method for analyzing route symmetry was proposed. It quantified the route symmetry with alignment scores, and it could evaluate the route symmetries of different hosts objectively. Then the AS level route symmetry characteristic of Internet was analyzed quantitatively by using this method, the main findings are: (1) The AS level route symmetry of Internet is high, only 3.74% hosts analyzed show serious AS level route asymmetry. (2) The route symmetry is related to route length, host pairs with longer route have lower route symmetry degree. (3) The route symmetry of different hosts is not uniformly distributed.