PURPOSE: To reduce Head of Line Blocking by sharing communication information in a unit switch into path buffers more than number of outgoing lines and resulting from dividing succeeding speech path stage outgoing lines and storing the information.

CONSTITUTION: Communication information inputted to a unit switch 1 is shared in the unit switch 1 into path buffers 112-1-112-K-2A more than number of outgoing lines K and resulting from dividing succeeding speech path stage outgoing lines and stored. Thus, Head of Line Blocking generated in an FIFO unit switch is reduced and the requirements having been a problem in a RAM type unit switch such as number of terminals of the unit switch and the control of terminal speed are relaxed because no complicated arbitration is required between specific means.