I need to terminate my own DSL cable for FRITZ!Box. What is the correct pinout? I have a two-lead cable coming from my ADSL splitter. How can I connect it to FRITZ!Box?

To connect FRITZ!Box to the ADSL line from your splitter, you need a cable with an RJ45 plug at both ends. Only the two middle leads, pins 4 and 5, are used.
To connect a two-lead cable from your ADSL splitter to FRITZ!Box, proceed as follows:
  1. Install an RJ45 jack close to FRITZ!Box.
  2. Connect the two-lead cable from the splitter to pins 4 and 5 of the RJ45 jack.
  3. Connect FRITZ!Box to the RJ45 socket using the ADSL cable included in the package.