I have CDMA/LTE on Samsung J3 Luna Pro, Sm-s327vl . CDMA is going obsolete. CDMA is gone from Canada, Verizon, Tracfone by end of 2020, and will probably be gone from Sprint soon.
Therefore to keep regular calling/texting, I need to convert my phone from CDMA/LTE to LTE + VoLTE. Tracfone told me, it is up to the phone maker Samsung to provide a software update to give me VoLTE. Tracfone is right because the T-Mobile compatibility checker says my phone won't work because it lacks VoLTE.
It's a low-end phone that is now unsupported. It still supports calls over 3G though. The phone will probably not last until 3G is decommissioned though.
That's why I think the only way to have calling/texting on my CDMA/LTE phone is to use a Voip service like Skype that can call non-voip users, such as landlines.
I'm right. The solution for an otherwise obsolete CDMA phone is to use a VOIP service such as Fongo or TextNow. Fongo is free on wifi, but charges $$ for data & for text messaging & is only for Canada. Textnow is for USA & Canada. https://www.cbc.ca/news/business/cellphone-free-mobile-app-1.3545053
