Patent ID: 6031848
Filing Date: 2000-02-29
Classification: H04L,H04Q

Abstract:
A method for preventing baud rate blockage from occurring between first and second communicating devices, said first and second devices communicating with each other via a serial connection extending therebetween, the first and second devices being data circuit terminating equipment (DCE) and data terminal equipment (DTE), respectively, the DCE being capable of establishing communication through a communication link, separate from the serial connection, with a DCE peer device, wherein the DCE provides either said fixed baud rate operation or autobaud operation and the DTE provides fixed baud rate operation, the method comprising the steps of, in the DCE:detecting whether the DCE is set to said fixed baud rate operation;if the DCE is set to said fixed baud rate operation, providing an indication signifying said fixed baud rate operation so as to obtain, via the serial connection, entries from the DTE of at least one pre-defined data value occurring over a pre-defined interval of time;obtaining said entries, in response to the indication, from the DTE and communicated over the serial connection;detecting, in response to said entries communicated by the DTE to the DCE, communication errors arising from a baud rate mismatch between the DCE and the DTE; andin the event a totalized number of said communication errors occurring during said interval exceeds a predefined threshold, changing operation of the DCE from the fixed baud rate operation to the autobaud operation whereby the DCE can detect a fixed baud rate then being used by the DTE for communication over the serial connection and set its own baud rate for communication over said connection to match that of the DTE so as to prevent said baud rate blockage from occurring between the DTE and DCE for communication over the serial connection therebetween.