PURPOSE: To easily judge relative relation between respective trace events constituting both trace data to be sampled at a communication control equipment and a host device.

CONSTITUTION: Just before issuing a trace activating request and when receiving a time information reporting request, a time information reporting means 11 reports time information to a communication control equipment 2. A trace data writing means 21 writes a time information event based on the reported time information and a trace event in a trace area 26. A free-run timer processing means 22 initializes a free-run timer in the case of reporting the time information. An interval timer processing means 23 starts an interval timer in the case of reporting the time information and stops the interval timer in the case of receiving a trace stopping request. At the timeout of the interval timer, a time information report requesting means 24 issues a time information reporting request to a host device 1.