@kristatos
I just did a few tests, here in France there is not much variety in primary networks, we have 4 providers: Orange (the most important, historical provider), SFR, Bouygues and Free (my provider).
As far as I can tell (I don't have thousands of numbers to call to do a proper statistic) calls toward Orange and SFR ring, calls toward Bouygues and Free don't. The fact that a number is fixed or mobile don't matter.