Abstract: Delay Tolerant Network（DTN） is a class of networks that experience frequent and long-duration partitions due to sparse distribution of nodes.It has a broad prospect to new network applications for a better scalability，fault-tolerant and high performance.In DTNs path failure occurs frequently，sometimes even in a very short period routing is required to change，resulting in transmission delay and reception delay.And some well-known assumption of traditional networks are no longer true in DTNs.This paper presents path failure problems in DTNs.Traditional approaches are based on using precisely known network dynamics，which does not account for message losses.This paper describes the path failure process in DTNs when the path appears completely normal，completely failed and partially failed.Then a fault tolerant scheme to generate redundancy using erasure coding and full replication is adopted.This can greatly decrease the path failure probability.At last，a traffic DTN model is analyzed and evaluated.Results reveal the superiority of the scheme in comparison to other present schemes.

摘要： 延迟容忍网络的路由机制与传统的网络结构有很大不同。针对这类网络中的路径失效问题进行容错研究使得网络在出现路径失效时，能够不影响消息传送，并尽可能地提高消息的成功交付率，从而屏蔽路径失效问题。首先描述了延迟容忍网络中的一种路径失效问题，反映了在路径完全正常、存在部分失效以及完全失效情况下消息交付情况，并针对这一问题研究相应的容错方法。最后给出一个交通延迟容忍网络应用实例，并评价其容错方法的性能。