Install, create account and configure Linphone.
- Open https://www.linphone.org/free-sip-service.html&action=recover on your browser.
- Username is: "YourName" without @something.org and email you used to create the account.
Linphone for Android
- Select "Use Linphone Account"
- Check box "Use your username and password instead of your phone number"
- Username is: "YourName" without @something.org and password of your account. Domain is; "sip.linphone.org", check box "TLS".
- Go to app menu and select settings.
Linphone for GNU/Linux
Install Linphone on GNU/Linux...