ZyXEL P-128 User Guide - Page 182

Prestige 128IMH ISDN Modem/ Router/Hub 15.2 Problems With the ISDN Line Problem Table 15-2 Troubleshooting the ISDN Line Corrective Action The ISDN initialization failed. This problem occurs when you attempt to save the parameters entered in menu 2, but receive the message, 'Save successful, but Failed to initialize ISDN; Press ESC to exit'. Check the error log (in menu 24.3.1), you should see a log entry for the ISDN initialization failure in the format, 'ISDN init failed. code...'. Note the code number, n. If the code is 1, the ISDN link is not up. This problem could be either the ISDN line is not properly connected to the Prestige or the ISDN line is not activated. Verify that the ISDN line is connected to the Prestige and to the wall telephone jack. If the code is 3, this indicates a general failure. Verify the provisioning information for your switch by contacting your telephone company. The ISDN loopback test failed. If the ISDN initialization is successful, then the loopback test should also work. Verify the telephone numbers that have been entered in menu 2. The loopback test dials the number entered in the 2nd Phone # field (except for switch types with only one phone number). If you need to dial a prefix (e.g., '9') to get an outside line, then you have to enter the telephone number as '95551212' or '914085551212'. If it is an internal line, you may only need to enter the last four or five digits (according to your internal dialing plan), e.g., 51212. 15-2 Troubleshooting