PURPOSE: To attain the reception of a new call even during the resumed processing and to avoid dis connection of a received call after the end of re sumed processing by not sending a signal representing the established synchroni zation till the restart processing is finished when the resumed processing takes place but sending the signal after the resumed processing is finished.

CONSTITUTION: When the resumed processing takes place in a packet handler main body 53, the content of a main memory in the packet handler main body 53 is initialized. When packet terminal equipments 3-2, 3-3, for example, are in the calling state, the frame synchronizing state between the packet terminal equipments 3-2, 3-3 and a packet exchange station 31 and between the packet exchange station 31 and a packet link controller 52 is taken. However, the signal representing the establishment of the synchronization is not sent from the packet link controller 52 till the resumed processing is generated and then finished. When the resumed processing is finished, the signal representing the establishment of the synchronization is sent from the packet link controller 52.