VoLTE support tinkering

I want to bring VoLTE support to SailfishOS and/or have a workaround to forward 3G connections. Let’s hack this feature into existence! If we can do it, Jolla will have to implement it, even if it just becomes an rpm install-able in the Jolla Store or OpenRepos.net

My Ideas include:

  • Enabling VoLTE in Android before flashing.

  • Tweaking file settings within the installer (related to the AOSP stuff or the Xperia Binaries).

  • Forwarding connections from 3G to SIP.

  • Forwarding connections from 3G to 4G.

  • Creating a “fake” VoLTE instance and forwarding 3G.

  • Sideloading VoLTE-related APKs into Alien Dalvik.

  • Getting VoLTE working in AlienDalvik and passing 3G to AlienDalvik.

Related topics:


When I get my Xperia 10 Plus, I will move to it, then use my XA2 as a test device.

Anyone who wants to join in helping test and do what they can to try to get VoLTE working, spread the word and test at your own pace.

Source: https://docs.rhino.metaswitch.com/ocdoc/books/sentinel-volte-documentation/2.6.0/sentinel-volte-administration-guide/features/scc-features/service-centralisation-features/reoriginationsharedinformation.html

I wonder if this will help or be of any use?

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I guess the best to mess around with this is to get a Gemini device since many of the relevants bins/libs are already there and probably only need to be configured/utilized.
First task would be to authenticate the simcard and obtain the credentials to authenticate the VoIP-stack (which is also already there but not fully implemented). Then, ofono should be patch to route calls through the voip-stack once that is authenticated and available.
Last but not least seamless handover should be implemented to allow switching networks between 2G/3G/VoLTE and WiFi.
Happy hacking :slight_smile:

PS: Maybe it would be worth to implemented VoIP and simcard authentication at first. No Handover possible then, but at least calls should be feasible whenever there is internet access available.


I’d messed up getting it enabled on my Xperia 10 Plus (I didn’t make sure that VoLTE was enabled and working in Android first). If I’d’ve gotten VoLTE enabled and then flashed, it may have made a difference, but I will try on my Xperia XA2 (after I finish migrating from it).

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I will be retrying my experiment to enable VoLTE on Android then flashing Android (as it wasn’t enabled on the Xperia 10 Plus before I flashed (my mistake)).

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I’ll reattempt on my Xperia XA2 after I fully migrate to my Xperia 10 Plus.

Does this mean that it’s possible to enable VoLTE on a X10 under Android? So that it’s necessary (or possible) to flash back to Android, enable VoLTE in the system settings, and then reflash SFOS, to make the phone hardware ‘fit for the future’ also under SFOS? (when VoLTE will be enabled in the future)
I did not enable some VoLTE related settings under Android before flashing SFOS. Should I better have done this before?

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I had the same thing, didn’t verify VoLTE was functional…

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The primary issue is that (from what I understand) is that Connman can’t pass the call info the the VoLTE stack properly.

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What have I to do to ‘reset’ the Xperia 10 back to Android 9, for enabling the phone’s Volte support ?
Or is there any possibility to do so under SFOS 4.0?

Jolla has instructions on how to do this.

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I was personally having issues with eMMA on my Xperia 10 Plus, so I will test on my Xpetia XA2…

Thank you, this is very helpful. So I will have to buy a cheap Windows laptop for re-flashing to Android with Emma…

Is there anything special I have to take care about, e.g. Windows version or so? Can it be the cheapest Laptop with an USB interface and preinstalled Win 10 Home edition?

No, just needs to be capable of running it. You might be able to do it all with Win2USB

there are virtual machines, so you don’t have to buy a laptop with other OS


Yeah, there is this, you cn use KVM to do it…

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However, it’s sometimes tricky to get KVM to redirect in different device states…

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