PURPOSE: To constitute a network having high reliability by generating a parameter file with parameters describing a system to generate a control information table and referring to this table to check the error and contradiction of inputs.

CONSTITUTION: A system start command or the like and network information update parameters are inputted from a typewriter 100. Release media released for network nodes expanded throughout the country are generated on a floppy disk 120 to control a network. The print list of parameters of network information, generated information, or the like is presented by a line printer 140. Data of various generated network information are filed in a fixed magnetic disk device 150 to generate operatable network information. A computer system 160 uses input/output means to analyze parameters, check errors, link tables to one another, and generate network information of the final image.