[Germany] SMS not sending with VoLTE enabled

REPRODUCIBILITY: 100% (always)
HARDWARE: Sony Xperia 10 II - Dual SIM - xqau52 - xqau52 - - aarch64
UI LANGUAGE: Deutsch (user: de_DE, os: de_DE.utf8)
REGRESSION: not specified


When VoLTE is registered in network settings, SMS messages cannot be delivered. They repeatedly fail.
(German provider)


4G/LTE capable network


  1. Enable VoLTE
  2. Compose SMS message
  3. Try to send


SMS gets delivered


SMS delivery fails with a message


  • Patchmanager: yes
  • OpenRepos: yes
  • Chum: yes
  • Other: none specified


Disabling VoLTE makes messages get delivered again
Tested with two different numbers from different German provider networks - O2 and Telekom (apparently, could be a ported number) I can ask what network they are using if needed

the initial version of this bug report was created using Bugger 0.9.9+git4

It sounds very similar to SMS sending not working on xperia 10 III – with VoLTE on
Can you confirm?

Ah, didnt see that one. Thanks!
basically, yes. Sounds like the same issue.
I could reproduce it reliably though

Cannot confirm with Vodafone, Germany, VoLTE,, Xperia 10 III

I had once a sm which stayed in a state of “sending in progress”.
I resent three times but the message was received on the other side three times.
All other messages webt well.

Can confirm with o2 LOOP on Xperia 10 III

Can confirm the issue too - Yettel BG.

Maybe there could be setting, when VoLTE is enabled.
SMS over IP:
-Auto / Default
-Force / Enabled

As there is two ways to send SMS on 4G network with VoLTE, via radiosignaling with cell tower or via IMS IP connection. Mobile network won’t always support both.

This sounds a bit strange… do you have a source?

But what really seems out of whack is that you’d want/need a setting, as opposed to just detecting the capabilities of the IMS server. Does any other platform do this?

Other platforms probably detect the method automatically.
O2 Germany doesn’t support SMS via IMS, for instance it is not possible to send SMS through a VoWifi-only connection (e.g. with an Android device).
I don’t expect much to change (as well as I don’t expect VoWifi to be implemented in the foreseeable future) due to low ressources @jolla. The workaround (temporarily disabling VoLTE to send messages) works fine, so at least for me it’s not much of a problem since I barely use SMS anyways.
It also seems necessary to disable VoLTE on O2 Germany to call the Congstar virtual mobile network, because otherwise the connection would be terminated instantly as soon as the called party answers the call. Some minor issues, well, it’s beta status, after all.

More likely is that SMS over IP is just disabled by manufacturer.
And enabled only networks that has known to have working SMS over IP support.

It seems to be vice versa in sailfishos - the volte settings enables sms via ims solely even though not all providers support it. Therefore it’s not possible to send sms when volte is enabled. The other platforms obviously use the network protocol as fallback, which sailfishos diesn’t use. As I wrote above, O2 Germany is known to not support SMS via IMS, therefore it is not possible to send SMS while in VoWifi mode only with an Android device, but it DOES work through LTE even when VoLTE is enabled since Android seems to fall back.

Sms will not be sent in The Netherlands through Vodafone either.

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