FRITZ!Box 4020 Service - Knowledge Base

FRITZ!Box 4020 Service

Cannot access the internet with a mobile broadband dongle

The FRITZ!Box cannot connect to the internet by means of a mobile broadband dongle connected to it that complies with the mobile standard LTE (4G) or UMTS/HSPA (3G).

Simply proceed as described below. After each measure, check whether the problem is solved.

Note:All instructions on configuration and settings given in this guide refer to the latest FRITZ!OS for the FRITZ!Box.

1 FRITZ!Box does not detect a mobile broadband dongle

  1. Click "Home Network" in the FRITZ!Box user interface.
  2. Click "USB Devices" in the "Home Network" menu.
  3. Check whether the mobile broadband dongle is displayed under "Overview of Devices".
  4. If the mobile broadband dongle is not displayed, follow the instructions in our guide FRITZ!Box does not detect a mobile broadband dongle.

2 Entering your account information in the FRITZ!Box

The FRITZ!Box does not connect to the internet if no account information has been entered. Therefore, enter account information in the FRITZ!Box even if it is not required to use your mobile network operators's internet connection.

  1. Click "Internet" in the FRITZ!Box user interface.
  2. Click "Mobile Communications" in the "Internet" menu.
  3. Enter a character string of your choice in the "User name" and "Password" fields.
  4. Click "Apply" to save the settings.

3 Error caused by Huawei E1550

The FRITZ!Box does not obtain a DNS server from your mobile broadband dongle if you are using the mobile broadband dongle Huawei E1550. This means that it cannot resolve the names of internet addresses (for example and access internet servers. This is caused by an error in the mobile broadband dongle's firmware.

  1. Consult your internet service provider or Huawei for a solution.

    Note:According to our experience, the error does not occur when using the Huawei mobile broadband dongle E1550 with version 11.608.10.00.47 of the firmware.

4 Vodafone K5006-Z is not supported.

The mobile broadband dongle MF821 from ZTE marketed under the name K5006-Z by Vodafone cannot be used with the FRITZ!Box's USB port. This mobile broadband dongle only supports the proprietary QMI protocol (Qualcomm MSM Interface) and not the PPP protocol required by the FRITZ!Box.

5 Samsung GT-B3740 is not supported

Samsung's mobile broadband dongle GT-B3740 cannot be used with the FRITZ!Box's USB port because Samsung designed this LTE dongle for use with manufacturer-specific interfaces. This is not an error on the part of the FRITZ!Box, this is due to technical reasons on the part of the Samsung dongle.

Note:Some mobile network operators offer the LTE dongle GT-B3740 under their own name. The FRITZ!Box detects the LTE dongle GT-B3740 as a USB storage device.

6 D-Link mobile broadband dongles are not supported

Mobile broadband dongles from D-Link (for example DWM-222, DWM-221, DWM-157) cannot be used with the FRITZ!Box's USB port. If possible, we shall add support for mobile broadband dongles from D-Link in a future FRITZ!OS update.

Note:You can have the push service notify you by email when new updates are available. In addition, you can configure the FRITZ!Box so that new updates are installed automatically. You can enable these options under "System > Push Service" or "System > Update > Auto Update" in the user interface.