Signals transmitted back and forth over a communications network in order to establish a valid connection between two stations. A "hardware handshake" uses dedicated wires such as the request-to-send (RTS) and clear-to-send (CTS) lines in an RS-232 serial transmission. A "software handshake" sends codes such as "synchronize" (SYN) and "acknowledge" (ACK) in a TCP/IP transmission. See
RTS,
CTS and
RS-232.