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Dokument informacyjny #198

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 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 into the "DSL" socket on the FRITZ!Box and into the socket labeled "F" on the telephone jack or into the DSL line.
    Connecting FRITZ!Box with a DSL line in Germany (left) and in other countries (right)

2 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 afterward 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!