A storage control apparatus of the present invention controls the number
of multiple commands issued from a host machine without shutting down the
host machine. A communication port of the storage control apparatus
carries out communications with the hosts in accordance with the iSCSI
protocol. Command processing resources are managed for each communication
port. A resource allocation control part calculates the number of
commands capable of being received on the basis of the remaining amount
of command processing resources inside shared port resources, a change in
the number of commands received from a host, communication delay time,
and the state of execution of a command issued from a host or the like. A
MaxCmdSN is calculated by adding the results of command processing by a
command execution part and the receivable number calculated by the
resource allocation control part to the value of the latest CmdSN
received from a host. The storage control apparatus adds the MaxCmdSN to
a transmission frame and transmits it to the host.