The survey tries to review the various problems and their solution in Delay Tolerant Network (DTN) while routing the packets. In this paper, going to discuss and see the overview of various methods used in the DTN. They are simbet and bubble rap which are the DTN routing algorithm and is used for identify the bridge nodes using betweenness centrality and similarity metrics in the network. Then watchdog and pathrater used for detecting the misbehaving nodes in the DTN. Practical incentive

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... l (Pi) is used for addressing the selfishness problem in DTN. Secure multilayer credit based incentive scheme (SMART) provide the incentives to the selfish node by using credits in the network.