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DSL data rate is too low

The DSL data rate displayed in the FRITZ!Box user interface is significantly lower than the DSL speed guaranteed by the DSL provider.


  • The data rate of the DSL connection depends primarily on the length and quality of the access line. Faults in the cabling or problems with the internet service provider's exchange (DSLAM) can also affect it.

    Important:With many DSL lines, it is not possible to fully achieve the guaranteed throughput. That is why DSL providers say they offer DSL speeds "up to" a certain value.

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 Checking the maximum throughput

The DSL provider sets a maximum achievable throughput for every DSL connection. The actual speed that can be achieved on your DSL connection cannot be higher than the maximum throughput:

  1. Click "Internet" in the FRITZ!Box user interface.
  2. Click "DSL Information" in the "Internet" menu.
  3. Click on the "DSL" tab.
  4. Check the "Max. DSLAM throughput" line to see which maximum data rate was set for your line.
  5. If your DSL provider guaranteed you a higher throughput, contact your DSL provider.

2 Checking the cabling

Faults in the cabling often go unnoticed, but it can significantly reduce the DSL data rate. Therefore, check the wiring in your home:

  1. Remove the DSL splitter if you are using the FRITZ!Box on an IP-based connection.
  2. Remove all cable extensions, unused cables, telephone jacks, and additional electrical components (for example surge protection, automatic extension outlets).
  3. Insert the DSL cable (Y cable) into the "VDSL" socket on the FRITZ!Box.
  4. Insert one of the shorter ends of the cable into the DSL socket and leave the other end of the cable hanging (see left fig.). If you are using the FRITZ!Box on a VDSL bonding line, also insert the second end of the cable into the VDSL bonding socket (see right fig.).

    Fig.: Connecting FRITZ!Box with an IP-based DSL line (left) or a VDSL bonding line (right)

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

Installing the latest FRITZ!OS makes your FRITZ!Box compatible with the latest DSL technology used by DSL providers in their DSL exchanges:

  1. Install the latest FRITZ!OS on the FRITZ!Box.

4 Checking the data rate with a different DSL modem

With many DSL lines, it is not possible to fully achieve the maximum throughput guaranteed by the DSL provider. To find out whether the data rate achieved by the FRITZ!Box is limited by your line or whether there is a technical problem, check the data rate with a different DSL modem:

  1. Disconnect the FRITZ!Box from the DSL line.
  2. Connect a different DSL modem to the DSL line.
  3. Test which data rate you achieve with the other DSL modem. Test the other modem as soon afterwards as possible to ensure that you test it under the same conditions.
  4. If the data rate you achieve with the other modem is also significantly lower than the data rate agreed on with your DSL provider, have your provider check your line.

    ATTENTION!You may be charged for checking. Ask your provider about charges in advance!