[CaptainOfCoit]

> None of this is particularly difficult technically. Even simply slapping x509 certs on calls and having some basic filtering would achieve a lot.

Slapping x509 certs on probably some of the oldest telecommunications infrastructure in the world (both in terms of devices using it, and devices enabling it) wouldn't be "technically difficult"?

But I've never worked in telecommunications, maybe I'm overestimating how large piece of work this would be.

[zokier]

Relative to the effort that has been poured to volte etc and 3g/4g/5g in general.

[jstummbillig]

> maybe I'm overestimating

Probably not.