Patent ID: 8385357

Claim:
A network device that transfers frames, comprising: a transmission port that conducts a transfer process by repeating a constant cycle, the constant cycle including a reserved transfer time interval in which a plurality of reserved frames are transferred at corresponding reserved time slots, and a free transfer time interval in which non-reserved frames are transferred without time slot reservation; a cycle timer; a mode switching control unit that monitors a transfer state of the transmission port and selects a store-and-forward system as a transfer method when the transmission port is in the transfer process and selects a cut-through system as a transfer method when the transmission port is not in the transfer process; and a transfer prohibition control unit that, when the transmission port is not in the transfer process, selects the cut-through system as a transfer system when a non-reserved frame is transmitted, and switches a transfer method of the non-reserved frame to the store-and-forward system with reference to the cycle timer when the reserved transfer time interval is established.