Techniques for realizing efficient setting and utilization of configuration including storage volumes in a storage system having an initiator and a target, with a low cost configuration not requiring additional equipment such as a LAN and a server without limitations due to a low-transfer rate network are provided. The storage system has, e.g., an IS serving as an initiator, a TS serving as a target, and a frame relay device R for relaying the communication between the devices. The R has a DB for retaining the configuration information including the configuration of storage volumes in plural devices connected via plural ports, and an exclusive control unit for performing an exclusive control process of the configuration information in the DB upon setting for utilizing the storage volumes among the plural devices. According to update of the configuration of each device, the R updates the configuration information in the DB.