To efficiently adjust jitter information by adjusting the size of a frame and a service quantity through a pre-session frame, so as to synchronize a frame counter within a specific delay difference.

In a data communication network, constituted by connecting plural nodes, each node system 30, when cells are inputted to jitter controllers 32 to 34 having a frame counter, holds them until a corresponding virtual arriving time and then sends them to a scheduler 16, together with dead line information. The scheduler 16 compares them with the dead lines of all the cells and transmits a nearest cell to a next node. Then deadline information is expressed by the counted value of frame counters 32-1 to 34-1 which are pre- synchronization at the setting step of connection. In addition, the boundary of a frame is aligned by presynchronization, and the frame counter is synchronized, based on the mismatching delay and the delay restriction value of a slot boundary between adjacent nodes and the size of the frame.