Making Linkstar Unlock Cables

I need help to unlock a linkstar modem. I have located the serial port, but it is left to me to make the cable.

My questions are -

1. In making the cable is it the two ends that will be connectors? What does each end look like

The folowing information is not explanatory enough

"Only the middle 4 pins are used (use a 4 pin connector phone plug) Looking at the phone plug with the clip facing away from you.
pin 1 goes to pin 5 on the serial connector
pin 2 goes to pin 2 on the serial connector
pin 3 goes to pin 3 on the serial connector
pin 4 not used "

WHAT IS THE LOOPBACK ABOUT?

"some loopbacks on the serial connector
7 and 8 are looped
1 and 4 are looped
6 and 4 are looped"


I will be very grateful if you can explain how to make the cable from 2 phone connectors and a 8wire network cable. I will be very happy if a quick response is given.

The serial port is at the back of your PC. It is a 9-pin port where you usually put a  mouse (if you are using a serial mouse).

If you are using the old Linkstar version, it does not show the serial/RJ11 port on the outside. Its inside the modem, but you 'll be voiding your warranty.