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Cordless telephone rings only once, intermittently, or not at all. However, incoming calls can be answered

A cordless telephone from another manufacturer is registered with the DECT base station of the FRITZ!Box. When you receive a call, the telephone only rings once, at irregular intervals, or not at all. Calls can still be answered with the telephone.

1 Cordless telephone does not comply with the DECT standard

The cordless telephone is not fully DECT-GAP-compatible and does not transmit a correct Equipment Manufacturer Code (EM code) to the FRITZ!Box when it is registered, which is why the following happens:

Note:DECT-GAP is a widely used standard for cordless telephones and wireless data transmission. All FRITZ!Fon models support this standard.

  • Due to the incorrect or missing EM code, the FRITZ!Box assumes that the telephone is responsible for the ring tone control. However, the telephone is not able to, so neither of the devices take over the ring tone control.
    • or
  • The FRITZ!Box takes over the ring tone control because, due to the incorrect or missing EM code, it assumes that the cordless telephone is not able to. However, the telephone also takes over ring tone control, which leads to errors.

Changing the ring tone settings

The following setting forces the cordless telephone to take control of the ring tones. However, if the error persists, the telephone being used is not able to.

  1. Click "Telephony" in the FRITZ!Box user interface.
  2. Click "Telephony Devices" in the "Telephony" menu.
  3. Click the (Edit) button for the respective telephone.
  4. Click on the "Ring Tones" tab.
  5. In the "Ring Tone Settings" section, select the option "Handset external ring" from all of the drop-down lists.
  6. Click "OK" to save the settings.
  7. If the error persists, consult the manufacturer of the telephone for a solution.

    Note:The DECT setting "Enable troubleshooting for cordless telephones not compatible with GAP" on the FRITZ!Box user interface has no effect on this error.