This book proposed a new structural overlay model. This model employs layered structure, and when constructing the network logical topology of peer nodes, it can detect rock-bottom physical network logical topology fast and efficiently and make it suitable to the rock-bottom network environment, and make the former be consistent to the latter as much as possible and then improve the whole performance of the systems. The goal is to construct a topology-aware overlay network, and improve the finding speed of information, and reduce unnecessary data transmission in networks.