BA-BGP:一种基于备份AS通告的域间路由协议

摘要

BGP协议通过触发全局、反应式收敛应对网络拓扑和策略变化,然而由于其收敛时间过长、收敛过程中大量AS经历不可达、环路,造成大量转发中断,难以支持VoIP、远程医疗等关键业务的应用.本文提出了一种基于备份AS通告的新型域间路由协议BA-BGP,在不影响BGP协议动态性的基础上,通过在更新报文中增加备份AS属性,使AS节点可以获取到达目标的备份AS地址,当节点面临瞬时失效时可将报文封装转发到与备份AS关联的路径,从而降低了转发中断.大量模拟实验证明,通过采用具有互联网特征的拓扑以及广泛采用的BGP策略,BA-BGP有效降低了链路失效引起的瞬时失效率与转发中断时间,增强了网络可靠性.%The BGP routing protocol triggers global and reactive convergence to dynamically adapt to network topology and policy changes, Nevertheless, the long convergence time, transient disconnectivity and forwarding loop during the routing convergence process lead to forwarding disruption, which makes BGP hard to support the critical business applications such as VolP, interactive tele-surgery.In this paper, We present BA-BGP, a novel inter-domain routing protocol based on backup AS advertisement.BA-BGP does not affect the BGP dynamic behavior, AS node learns the backup AS address associated to destination by adding the Backup AS attribute in the update packets.BA-BGP provides a feasible encapsulation forwarding path associated backup AS when the AS node experience failure, which reduces the forwarding disruption time.Through a detailed evaluation on the Internet characteristic topology and the widely-used BGP policy, we show that BA-BGP improves network survivability effectively,and reduces the transient failure and forwarding disruption time in case of link failure.