Routing and Buffering Strategies in Delay-Tolerant Networks: Survey and Evaluation

Delay Tolerant Networks (DTNs) have attracted considerable attention in recent years. This kind of network works in communication environments subject to delays and disruptions. Traditional end-to-end routing fails in DTNs due to intermittent connections. A variety of routing strategies for DTNs have been proposed in the past. In this paper, we present a survey of these strategies and provide a classification. Moreover, we evaluate their use in social contact networks. Buffer management strategies are also needed to support routing operations. The technical issue is to design sorting policies that determine the transmission and drop order of messages in the buffer. We identify several sorting indexes and evaluate their performance.