FRITZ!Box 7330 Service - Knowledge Base
DSL connection drops frequently
The DSL connection between the FRITZ!Box and your DSL provider's exchange drops several times a day. When this occurs, the "Power" LED on the FRITZ!Box flashes and stays lit as soon as the Internet connection has been re-established.
If you have a DSL line with an additional analog landline, this issue may occur very often when you accept a call to your landline number or make a call from your landline.
The following error message is displayed in the event log of the FRITZ!Box:
- "DSL not responding (no DSL synchronization)
DSL synchronization starting (training)"
- The stability of the DSL connection primarily depends 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: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 Checking the event log of the FRITZ!Box
- Click "System" in the FRITZ!Box user interface.
- Click "Event Log" in the "System" menu.
- Check whether events also took place before the time when the error occurred, or whether only events are shown that took place after the error occurred.
- If events are also displayed that took place before the time the error occurred, proceed with the following section:
- If only events that took place after the error are displayed, follow the instructions given in our guide FRITZ!Box restarts occasionally.
2 Checking the cabling
It is often difficult to recognize mistakes in the cabling and they can remain unnoticed for a long time. Therefore, check the wiring in your home:
- Remove the DSL splitter if you are using the FRITZ!Box on an IP-based connection.
- Remove all cable extensions, unused cables, telephone jacks, and additional electrical components (for example surge protection, automatic extension outlets).
- Make sure that the FRITZ!Box is correctly connected to your DSL line. You will find detailed instructions on the installation poster included with the FRITZ!Box and in the manual.
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:
- Install the latest FRITZ!OS on your FRITZ!Box.
4 Increasing the interference resistance
Increase the interference resistance of your DSL connection; this reduces the number of interruptions of the DSL connection due to brief disturbances on the DSL line:
Note:Increasing the interference resistance of the DSL connection can slightly reduce the throughput of the DSL connection.
- Click "Internet" in the FRITZ!Box user interface.
- Click "DSL Information" in the "Internet" menu.
- Click on the "Line Settings" tab.
- Next to "Intended signal-to-noise ratio" under "Receive direction", move the setting one step farther to the left towards "Maximum stability".
Important:If you move the controls too far towards "Maximum stability", with some DSL lines you may no longer be able to establish a DSL connection. Therefore, do not select the setting "Maximum stability" right away. Instead, push the control gradually to the left in order to determine the best setting for your DSL line.
- Click "Apply" to save the settings.
- If the DSL connection continues to drop frequently, repeat steps 4 - 6 until the DSL connection is stable.
5 Checking the DSL line
There may be a problem with the DSL line. Since it may take a while for your DSL provider to check your line, you may be charged for the service, and our experience shows that there is often a problem with DSL lines even if they have been checked by your provider, proceed as follows:
- Disconnect the FRITZ!Box from the DSL line.
- Connect a different DSL modem to the DSL line.
- Test whether the DSL connection remains stable when you use this DSL modem.
- If the connection continues to drop, have your provider check your line. There is a problem with the DSL line.
ATTENTION!You may be charged for checking. Ask your provider about charges in advance!