基于双向转发检测协议的光突发交换链路快速故障检测方案

Fast failure detection scheme for OBS links based on BFD

由于光突发交换(OBS)网络通常采用单向资源预留机制,一般的链路故障检测方法难以在OBS网络中使用,因此本文基于双向转发检测(BFD)协议设计了符合OBS数据传输机制的链路故障检测方案,并根据实际网络需要设定了BFD报文的发送周期与检测时间,从而满足了OBS网络快速故障检测的要求。以NSFNET为仿真网络,实现了业务流量发生器与节点故障发生器,对BFD在单链路场景与网络场景下的链路故障检测性能进行了仿真。仿真结果显示,在单链路场景下,OBS网络平均丢包率<0.001;在网络场景中,由于存在资源冲突、固定偏置时间等OBS网络自身的因素,OBS网络平均丢包率接近0.1。

Optical Burst Switching （OBS） network is a solution to realize all-optical internets. However, common link failure detection mechanisms are hardly used for OBS networks due to its special oneway resource reservation mechanism in the OBS. To meet the need of OBS data transmission,this paper designs a new fast failure detection scheme based on the Bidirectional Forwarding Detection （BFD） protocol. It sets both the transmitting period and detection time according to the practical requirements of OBS networks to achieve the fast failure detection. In the simulation part, the NSFNET is chosen as the simulation network to impletment both the OBS traffic generator and node failure generator. Moreover, the performance of link failure detection for BFD is simulated in the single path scenario and network scenario. Simulation results show that the average packet drop rate is lower than 0. 001 in the single path scenario, While it is nearly 0.1 in the network scenario for the restrictions of OBS net works such as resource contention and fixed offset time.