Delay-Tolerant Networks (DTNs) are wireless networks that often experience temporary,even long-duration partitioning.Current DTN researches mainly focus on pure delay-tolerant networks that are extreme environments within a limited application scope.It motivates the identification of a more reasonable and valuable DTN architecture,which can be applied in a wider range of environments to achieve interoperability between some networks suffering from frequent network partitioning,and other networks provided with stable and high speed Intet access.Such hybrid delay-tolerant networks have a lot of applications in real world.A novel and practical Cache-Assign-Forward (CAF) architecture is proposed as an appropriate approach to tie together such hybrid networks to achieve an efficient and flexible data communication.Based on CAF,we enhance the existing DTN routing protocols and apply them to complex hybrid delay-tolerant networks.Simulations show that CAF can improve DTN routing performance significantly in hybrid DTN environments.