Does someone know what happened to the work of Sysmocom for VoLTE on the Volla Phones: blog post and technical investigation report.
I'm currently running a Librem 5 with PureOS, which in theory has VoLTE support in the modem. But can't get it working with Deutsche Telekom (works with Vodafone DE). So I think for VoLTE we need a different solution in the long term, then relying on IoT modems with VoLTE support.
I would like to make a "kick-off" donation for "2.1 Open Source IMS Implementation" to the UBports Foundation. It's tax-deductible, so say something like 1.000€ So someone capable from Sysmocom or so can start working on it.