An ISDN (Integrated Services Digital Network) line is a type of digital telecommunications technology that allows for the simultaneous transmission of voice, data, and video over a single line. ISDN lines are commonly used for business applications, as they offer a higher level of reliability and bandwidth than traditional analog phone lines. If an ISDN line is not working properly, a simple test can be performed to check the line’s status.
To check an ISDN line, one will need a standard analog phone. Connect the phone to the ISDN line under test, then dial the following codes:
