Abstract: Since Delay/Disruption holerant Networks(DTNs) have been proposed as the new evolution of MANET and WSN, the communication between nodes without end-to-end path is possible. DTNs have greate application prospects in the intelligent highway, biological monitoring, satellite communications, rural communication, personal information exchange, etc. Routing is a challenging and absorbing research field in DTNs. In this paper, we classified and analyzed the multi-copy routing, identified open research issues and intended to motivate new research and development in this area.

Key words: Delay tolerant network, Disruption tolerant network, Opportunistic network, Routing algorithm