A network system suitable for remote monitoring or remote control of equipments is provided. When an execution of a server-side object is requested from a client terminal device to a server, the server requests an execution of an equipment-side object to the equipment(s). The execution request of the server-side object from the client terminal device is performed by use of a first identifier assigned to the server-side object, and the execution request of the equipment-side object is performed by use of a second identifier assigned to the equipment-side object. Since the server has an identifier setting function of setting a correspondence relation between the first identifier and the second identifier, it is possible to reduce burden on the client terminal device, and flexibly cope with cases of exchanging and increasing the equipment(s) in the network system without considering specific identification information of the equipments such as IP address.
