A management agent ME1 of a target T1 receives a request of log-in from an initiator of interest and determines whether or not a number of initiators that currently log in the target T1 reaches a predetermined allowable number of simultaneous log-in (steps S210 and S212). In the case of an affirmative answer, the management agent ME1 reads an ordinal number of precedence 'n' allocated to a GUID of the initiator of interest from a queue (step S213) and reads a time constant mapped to the input ordinal number of precedence 'n' from a time constant table (step S214). The management agent ME1 subsequently sends a status packet, which includes a log-in error status and the time constant, to the initiator of interest (step S216). The initiator of interest receives the status packet, reads the time constant included in the input status packet, and outputs another request of log-in to the target T1 at a timing specified by the time constant. This arrangement of the present invention practically ensures that the initiator that outputs the first request of log-in first to the target T1 gains the log-in first.