VoIP support

Roadmap

It looks like Linphone 3.5.1 or newer has everything Tails need, so it would be good to test it (probably with OnionCat).

The new OnionCat unidirectional mode (default since r555) should be tested for VoIP.

Blueprint: https://tails.boum.org/blueprint/VoIP_support/

Subtasks

• #6222 (closed)
• #6223
• #6236 (closed)
• #10071
• #11241 (closed)

Related issues

• Related to #11551
• Related to #14567
• Related to #5435 (closed)
• Blocks #9232

Original created by @tails on 5709 (Redmine)