[QUFB]

SHAKEN/STIR is rolling out very, very, very slowly. Interoperability is poorly defined and carriers seem to be sharing on an ad-hoc basis.

Anyone with a prepaid credit card can spoof numbers, make calls for < $0.005/minute, just by running apt-get install asterisk with a minimal configuration.

[eitland]

And for anyone who wonders, here's the Wikipedia entry: https://en.m.wikipedia.org/wiki/STIR/SHAKEN