A packet switch includes a memory, and a processor coupled to the memory and configured to learn a pattern of a high-priority packet having a cyclicity, monitor a burst end point of the high-priority packet, based on a result of the learning, detect a shift of a time slot of the burst end point when a traffic flow rate of the high-priority packet changes, and determine the time slot to close transmission of a non-priority packet, based on the shift of the time slot.