A signaling protocol for a noisy communications channel.

The retransmission of signaling messages that data terminals (e.g., modems) might exchange prior to exchanging user data is controlled by arranging a data terminal that receives multiple copies of the same signaling message so that it saves only the first copy thereof, but transmits a response to the sending terminal following receipt of each such copy. The sending terminal terminates its transmission of the signaling message upon receipt of a response from the receiving terminal. The inventive procedure is especially advantageous for controlling the retransmission of signaling messages during a n-way handshake between two terminals.