Check out https://molly.im/. It's a hardened Signal fork with one version stripping the google dependencies out of it. Push notifications work flawlessly even with battery optimization enabled. Source: over 1 year ago

The one benefit is that we now have no reason NOT to use Molly (the hardened version of Signal). Previously I didn't just because of sms. https://molly.im/. Source: over 1 year ago

Hi, you can add the repository in fdroid of a fork of signal, Molly Molly , you have a FOSS version. Source: over 1 year ago

Signal uses Curve25519, AES-256, and HMAC-SHA256 for its e2e encryption. So unless you believe those algorithms are insecure, there's no reason to think that their server setup is a compromise on your messages' security. Fear of "future decryption" applies equally to all forms of encrypted communication, regardless of which servers the messages go through. And since AES-256 is known to resist quantum computing... - Source: Hacker News / over 1 year ago

I don't know if they are technically allowed but https://molly.im exists. - Source: Hacker News / over 1 year ago

Well I can tell you that any SIP program can do this, one that comes to mind is Linphone. But you do need a provider. Almost all providers deal with UDP. You might be able to find one that transmits over tcp but that’ll be a very small list. TCP isn’t reliable for VoIP, for media anyway. At best you’ll find one that encrypts the signaling over TLS, which is TCP. But audio, even if encrypted too, is done over UDP.... Source: over 1 year ago

Does Linphone (https://linphone.org/) not meet that need of cross platform (website claims versions for all major OS'es) and open source (https://gitlab.linphone.org/BC/public/linphone-desktop)? - Source: Hacker News / over 1 year ago

Similarly, you can use any SIP (VoIP) provider (e.g. VOIPo Cloud), and configure the SIP account details in your native phone app. This way you will also be able to use a SIP softphone on your computer (e.g. LinPhone on Linux or Telephone on Mac), or even a real SIP phone in your home. Depending on your SIP plan you may or may not be able to make international calls this way. Source: over 2 years ago

I heard on RFD Fonus is using linphone.org to code their service. Source: almost 3 years ago