Yes, thank you both.
But I understood correctly by reading the Free website, that WiFi was activatable according to his desire and that the V5 had 4 RJ45.
So it was getting all good.
My only concern was to still want to connect 4 VOIP phones in parallel.
And there it still does not seem very possible in wire.
I have read the site quite completely
http://goctruc.free.fr/Telephonie/InstSimp.html
And I saw that the Voip plug had less fishing than the standard FT network.
So 2 or 3 phones at most, using modern ones. At free you had to make a mod (capacitor) so that it works with more than 2.
All this by wire.
Because with a WiFi base, there is no problem of feasibility (but I don't want one
).
I found it strange that there is a base with amplification, serving by wire, a network of telephones in parallel.
For me, it is in the field of the possible without WiFi, and of better quality, if one is not embarrassed to keep fixed stations.
As it is simpler, in technology, than a WiFi phone, I asked the question, in case this system exists somewhere, or, possibly, if it would be possible to tinker with one, a bit like the old switchboards, but all at the same time.
Yep, minimal amplification should be enough ...