Filter Installation


How Do I Filter my DSL Connection?

Whether you have just signed up for new internet service with InterBel or have had service for a while, the age old question has been, "What do I do with these filters ?" and "Why do I need them ?" Well let us help clear up the waters on these little devices that are needed to keep your DSL and Phones working properly.

A DSL filter is an analog low-pass filter installed between analog devices (such as telephones or analog modems) and a plain old telephone service (POTS) line, in order to prevent interference between such devices and a digital subscriber line (DSL) service operating on the same line. Without DSL filters, signals or echoes from analog devices at the top of their frequency range can result in reduced performance and connection problems with DSL service, while those from the DSL service at the bottom of its range can result in line noise and other issues for analog devices.1

So how do I install these?

Line filters are simple to install.  They are designed to always be connected to your telephone jack and you need one on every device that connects to your home telephone network excluding your DSL modem.  Connecting a line filter to your dsl modem directly may cause interrupted internet service.

Let's look at a Single Inline Filter installation.  Does your filter look like this?


Single Inline Filter

If your filter looks like this one, it was designed to only be plugged into a phone.  This filter should NEVER be plugged into a DSL modem and should be connected only at the phone jack.  Please view the image below to see how this filter should be connected.

As stated before, anything that plugs into a phone jack, (Satellite Receiver, Caller ID, Fax, Answering Machine) must have a single inline filter on it.

But what do we do if I have limited phone jacks in my house and I need to share my jack for not only the phone, but my DSL modem?  

Your solution lies below:


Inline Adapter/Filter

An inline adapter takes and separates your DSL connection from your phone.  Typically you will only need one of these in your home connected to 1 phone device and your DSL modem.  Please view the diagram below for installation instructions.

Congratulations, you have successfully learned how to use your DSL filters.  Just as any electronic device, filters can go bad after time.  If you ever start experiencing line noise or your internet seems to be slow, checking or replacing filters is a great first step in troubleshooting your connection issue.

Hopefully this walk-through has been helpful in bringing to light what filters are for and why they are needed.  For optimal performance, please insure all filters are installed before attempting to go online.  If you need additional filters, please contact our office at 889-3311.  If you are still unsure of how to use your filters or are having issues with your internet connection, please don't hesitate to contact our 24x7 technical support staff at 889-1500.  Happy Surfing!

Images taken from and 

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Sunday the 24th.