I was trying to install my modem yesterday and today, since my home Internet connection had been activated. I did everything according to the instructions, and every step went smoothly.  However, there is still no internet connection cause the modem is not connected to the network. I plugged DSL cable to the 4-pin socket located in my room. Everything fits perfectly, so I don’t see the issue here. I also repeated the procedure many time and reset the apparatus. 
What might be wrong?

Thank you in advance!