This paper presents a network service, which enables receive individual application demands and considers network condition information in order to achieve the best performance of network resources management and network information advisory service to the applications. The complications of the Internet, the increase of the users and the varieties of applications have made the condition of the network and the execution results unpredictable. All of these elements make the network service difficult to accomplish the real target. Here, we proposed the Demand Inquiring Service, a network service providing information and advisory services to the applications and at the same time managing the utility of network resources. The goals of Demand Inquiring Service are to function as automatic traffic engineering and to provide transparency about network condition to users and applications. Demand Inquiring Service provides services of storing, computing, forwarding the packets and giving higher user-friendly to users and applications.