Interesting experiment with ADSL splitter

[Jeniffer Chris]

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

Second experiment

I have been considering what happens if I make the feedback from out put to input of a ADSL splitter, as well as change input to output and vice versa
Below are my steps:
- Take the first splitter, plug the phone line to the Net output (NOT the input) of it
- Plug the input of the first splitter to the input of the second splitter
- Plug the Phone output of the second splitter to the phone output of the first one
- Plug the Net output of the second splitter to Modem, and connect to laptop

See diagram in my attached screenshot

Here I made some abnormal things:
- Telephone signal transmits into the output, not the input of the splitter
The output of second splitter is connected back to the first one

Surprisingly, my laptop can access internet normally. Nothing wrong happens
Why my extraordinary actions do not affect the operation of the splitters?