PURPOSE: To prevent missing of a frame due to collision by making a node equipment on an indefinite communication network utilize an output of a MAC frame sent from a terminal equipment for the purpose of ring management so as to loop back to a transmission equipment with priority.

CONSTITUTION: When a node equipment 2 makes broadcast, an input frame from an output port 07 is inputted to an FIFO 16 and an input signal identification section 15. The input frame is given to the identification section 15, in which whether or not the frame is a frame from a TRN(token ring network) terminal equipment and a MAC frame is identified, In the case of the MAC frame, the end of the MAC frame is discriminated by detecting a final EDEL in the frame format. Then after the end of the reception of the MAC frame, the MAC frame fetched in the FIFO 16 is sent to a port i7. Thus, the MAC frame is again broadcast to all output ports and the transmission terminal equipment receives the MAC frame. As a result missing of the frame due to collision on the indefinite communication network is prevented.