As we know, the ADSL splitter box has 1 input and 2 outputs, one for phone signal line, and the other for internet signal line

Plug the telecommunication line into the input. Then in the output lines, I make the exchange. I plug the phone line to the internet output, and the internet line to the phone output

Then I dial the phone to call to a fax number

Surprisingly, I heard the busy tone, instead of fax tone.

Note: When I connect in normal way, plug the phone line to the phone output, and internet line to the internet output, this effect does not happen. That means I heard the fax tone as usual

Don't ever try something like this with the AC mains.

 

Don't ever try something like this with the AC mains.

 

Thank you, I never do that