FRITZ!Box 7340 Service - Knowledge Base

FRITZ!Box 7340 Service
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Integrated fax reception fails occasionally or always fails

Although you configured the internal fax according to our guide, fax reception either fails occasionally, or it always fails. You either cannot receive faxes at all, or they are incomplete. One of the following error messages may be displayed in the event log of the FRITZ!Box:

  • "Not Acceptable Here (488)"
  • "Not Acceptable Here (606)"
  • "Unsupported Media Type (415)"
  • "E-mail delivery failed. [Message]"
  • "Error while saving the message on USB storage."
  • "An error occurred during fax reception. The document was not received or is incomplete."

Important:Some of the settings described here are only displayed if the advanced view is enabled in the user interface. The configuration procedure and notes on functions given in this guide refer to the latest FRITZ!OS

Simply proceed as described below. After each measure, check whether the issue persists.

1 Installing the latest FRITZ!OS for the FRITZ!Box

2 Enabling fax transmission with T.38

If you would like to use an Internet telephone number for faxing, then you must enable T.38 (fax over IP) for fax transmission in the FRITZ!Box. With T.38, a special network protocol is used for fax transmission instead of fax tones. As a result, transmission is significantly less susceptible to interference:

  1. Click "Telephony" in the FRITZ!Box user interface.
  2. Click "Telephone Numbers" in the "Telephony" menu.
  3. Click on the "Line Settings" tab.
  4. Enable the option "Fax transmission using T.38" in the "Voice Packets" section.
  5. Click "Apply" to save your settings.

3 Checking the event log of the FRITZ!Box

Since some error messages are only displayed once in the event log, restart the FRITZ!Box:

Restarting the FRITZ!Box

  1. Click "System" in the FRITZ!Box user interface.
  2. Click "Backup" in the "System" menu.
  3. Click on the "Restart" tab.
  4. Click the "Restart" button.

Checking the event log

Check the event log for error messages as soon as fax reception fails for the first time after the restart:

  1. Click "System" in the FRITZ!Box user interface.
  2. Click "Event Log" in the "System" menu.
  3. Click on the "Telephony" tab.
  4. Check whether one of the following error messages is displayed in the event log after fax transmission fails, and note the corresponding information:
    • "An error occurred during fax reception. The document was not received or is incomplete."
      • In some cases, this message is displayed even though you received the complete fax. This occurs if data packets were occasionally lost during transmission. In these cases you can ignore the error message.
      • If this message returned at the same time as the message "E-mail delivery failed." or "Error while saving the message on USB storage.", please follow the instructions given for the corresponding message.
    • "E-mail delivery failed. [Message]"
      • The fax document cannot be forwarded to the specified e-mail address because the e-mail address or the account information for your e-mail account was not correctly entered for the push service.
    • "Error while saving the message on USB storage."
      • The fax document cannot be copied to the USB storage device because it is full or data cannot be written to it.
    • "Unsupported Media Type (415)"
      • Your Internet telephony provider does not support a requested codec or does not allow fax transmission as a rule.
    • "Not Acceptable Here (488)" or "Gewünschter Rufaufbau wird nicht unterstützt (606)"
      • Your Internet telephony provider does not support the T.38 standard. Without T.38 (Fax over IP), fax transmission over the Internet is not reliable.
        • Disable T.38 in the FRITZ!Box user interface. You may be able to send and receive faxes without using T.38.

          Note:If you cannot send and receive faxes without using T.38, then you can use an Internet number of an Internet telephony provider that does support T.38 to receive faxes. If your FRITZ!Box is connected with a landline (analog or ISDN), you can also use a landline number instead of the Internet number to send faxes.

4 Checking whether T.38 was used for fax transmission

The following steps are only necessary if you would like to receive faxes using an Internet telephone number:

  1. Click "Telephony" in the FRITZ!Box user interface.
  2. Click "Telephone Numbers" in the "Telephony" menu.
  3. Click on the "Voice Transmission" tab.
  4. Look for aborted faxes under "Display table on completed telephone calls" and check whether "T.38" is displayed in the "Coding" column for these faxes:
    • If "T.38" is displayed:
      • The standard T.38 was used for this fax transmission.
    • If "T.38" is not displayed:
        The standard T.38 was not used for this fax transmission. Your Internet telephony provider must support the T.38 standard. Without T.38 (Fax over IP), fax transmission over the Internet is not reliable.

      Note:If your Internet telephony provider does not support T.38, then you can use an Internet number of an Internet telephony provider that does support T.38 to receive faxes. If your FRITZ!Box is connected with a landline (analog or ISDN), you can also use a landline number instead of the Internet number to send faxes.

If you are still not able to receive faxes, there are no further settings in your FRITZ!Box that influence faxing.