Since a few moth I have problems with my ADSL line:
1) it disconnects very often without reason

2) it disconnect when I receive a call

3) the connection speed was slower than expected

Finally, after lots of trouble I buy this splitter

and now the line is stable and fast as expected however it still drop when I receive a call. Actually, the splitter is used as a filter, just before the modem, I want to insert it at the beginning of the phone line as soon as possible and I hope that this solve definitively my problems.

This kind of splitter seems to be quite good compared the typical filter/splitter that you find in the shop, it also have a specs sheet, here is it

Click to access CLSP-008M2.pdf

mirror link:

CLSP-008M2