The "IP" in "VoIP" means, specifically, "IP" as in "Internet Protocol" - it does not refer to packet-based systems in general.

That's why I asked if you were specifically dealing with "IP" (ie, "Internet Protocol") back then.

Yes, there are telecom-specific packet systems.

But thetrouble with IP specifically is that it was not designed for voice traffic - and that is precisely what causes the specific problems that the OP is seeing!

Of course, some VoIP systems cope better with the limitations than others - and, as you say, that is likely to be reflected in the price...