1. Predetermined hardware or software activity designed to establish or maintain two machines or programs in synchronisation.
Handshaking often concerns the exchange of messages or packet
s of data between two systems with limited buffer
A simple handshaking protocol
might only involve the receiver sending a message meaning "I received your last message and I am ready for you to send me another one."
A more complex handshaking protocol
might allow the sender to ask the receiver if he is ready to receive or for the receiver to reply with a negative acknowledgement meaning "I did not receive your last message correctly, please resend it" (e.g. if the data was corrupted en route).
uses voltage levels or pulses on wires to carry the handshaking signals whereas software handshaking
uses data units (e.g. ASCII
characters) carried by some underlying communication medium.
in bit-serial data transmission such as EIA-232
may use either hardware or software handshaking.
2. The method used by two modem
s to establish contact with each other and to agreee on baud rate
, error correction and compression protocol
3. The exchange of predetermined signals between agents connected by a communications channel to assure each that it is connected to the other (and not to an imposter).
This may also include the use of passwords and codes by an operator.