What is hardware handshaking, and why is it important?
With built-in data compression, such as v.42bis, files can be compressed by the modem before being sent, which allows much higher rates of data to be sent. However, this brings up another problem – there has to be a way for the computer to tell the modem to stop sending data until the computer can finish processing the data that has already been received, then tell the modem to continue sending data. One way to do this is for the computer to insert two control characters, called XON and XOFF, into the d at a stream to tell the modem when to stop and resume sending data. This is called software handshaking, and is somewhat slow when using an external high-speed modem. There is also the danger that if the file you are transmitting also cont ains XON or XOFF characters, the modem might be fooled into aborting the transmission. A better way is to use hardware handshaking. This involves sending electrical current down two of the pins of a serial the serial cable to tell the m od em when to
