A packet communication device, which provides a modular node capable of setting up the operation of the node at a time without updating a program in the node body when a new functional module is installed, sends a process setting content, requested by a configuration file specified by a manager, to functional modules as an offering message and determines whether or not the functional modules can process the content of the offering message. Based on the answers of offering, a configuration processing program of a node determines a functional module, to which processing it to be assigned, according to a predetermined method.