中文摘要：

随着Internet的快速发展，域间路由变得越来越重要．域间出口选择优化问题成为域间路由协议研究的一个重要问题．当前的域间出口选择机制通常缺乏灵活性和有效性，例如，这些机制往往忽略路由的稳定性、网络的动态性、选择的实时性、流量工程等诸多因素．基于以上因素，作者提出了一种基于链路状态变化的高效的BGP出口选择框架．该框架能够根据AS的多目标提供一种灵活的路由优化方法．基于控制规则和当前的链路状态，每个BGP路由器能够在线选择合适的出口．该框架具有灵活性、可扩展性以及健壮性．在此基础上，讨论了其中的一个基于链路故障的关键算法．模拟实验表明，该文所提出的机制对网络管理者是灵活而有效的．

英文摘要：

With the rapid development of Internet, Interdomain egress selection optimization is one of interdomain routing becomes more important. the important problems in the research of interdomain routing protocol. Current mechanisms of interdomain egress selection are often inflexible or ineffective with ignoring many factors such as routing stability, network dynamics, the demand of real time, traffic engineering and so on. This paper proposes and evaluates a framework to facilitate efficient selection of Border Gateway Protocol （BGP） egress for Autonomous System （AS） when Interior Gateway Protocol （IGP） link state changes. It can provide a flexible means for AS to optimize routing according to their multiple goals. Based on control rules and current link state, every BGP router can select appreciate egress points online. The framework is extensible, flexible, and robust. A critical algorithm based on link failures is applied to illustrate the main idea of the framework. Simulation results demonstrate that this solution is feasible and expressive for the network administrators.