Review the configuration of dial-up and modem software. Make sure the configuration is correct. Experiment with adjusting the data transfer rate downwards and turning software compression off in the modem software. Make sure that the modem has the latest flash-ROM update available. Modems carry software instructions on a ROM chip inside them.
Manufacturers release fixes and updates which can improve compatibility with other modems.
Check with the manufacturer, and follow the directions which are provided with the firmware upgrade. Telephone Line Testing Telephone lines used for voice can sometimes be unreliable when it comes to carrying data. Problems experienced with poor line quality can result in numerous, sometimes inconsistent results, such as inability to make connection, loss of connection and poor data transfer. Testing is carried out through a basic terminal program, such as ZTerm.