Incoming calls in Germany - O2 -> no with vodafone -> YES


as stated above:

Incoming calls on my Librem5 (phosh) with an O2 sim are not received. No ring, no call, no notification about a missing call. Outgoing absolutely no problem Cals are established fast and properly.

With an Vodafone CallYa SIM (prepaid) all is running absolutely fine.

I have also downloaded the modem toll and enabled/disabled VoLTE.
Vodafone every setting works fine. O2 no incoming call regardless the VoLTE setting

Has someone had a similar problem? Any hints?



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Hallo Uwe,

I don’t have a O2 SIM card, I can only verify that calling with Vodafone CallYa works with or without VoLTE.

Currently I’m at Deutsche Telekom, where calling only works over 2G/GSM. VoLTE doesn’t work.

AFAIK @guido.gunther uses O2. Maybe he does know the trick.


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Hallo Jonathan,

As long Telekom will support telephony without VoLTE it would also be a good solution using their net.
What di really astonish me is that outgoing calls in O2 work fine and incoming all are missed.

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If you can find someone for whom O2 works fully, maybe compare modem firmware versions.

@joao.azevedo ?

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Have already written an email with the firmware status to Joao Azevedo :wink:


I use a prepaid SIM card from Aldi Talk. Calls work. Texting works.

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Could You please write here which modem-firmware works on Your Librem 5?

For my phone:

sudo bm818-fw-check 
[sudo] Passwort für purism: 
chat:  Jan 18 17:46:08 +BMSWVER: M100E_YCSN0_1.0.0_220926,YCSN0_M100E_1BAD_3117_V1.0.0.2_20220930,M100E_1.0.4_200715


apt search bm818

bm818-tools/byzantium,now 0.7-0pureos1 all  [installiert]
  Tools for the bm818 modem



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Same as yours.

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Some more about this:

A standard O2 SIM works perfect for sending and receiving calls.

My other O2 card is a multisim consisting of 3 SIMs with the same phone number and they all are ringing together on 3 devices for an incoming call.

And THIS multisim does not work correctly together with the modem.

I think this can only be fixed by Purism itself. Looks like a bug in the software




Bug or limitation? Would need investigation. Also it may not be the case that Purism can fix this since it may depend on blackbox modem functionality.

If it is important to you to have this looked at then you should raise an Issue.


Welcome in computer era :wink:
A perfect and stable running phone app on a new mobile phone may be a “feature” :wink:

Obviously nobody seems to have tested a multisim in the L5 ?
For this issue I am already in contact with the support. But I thought that perhaps anybody else here has had a similar problem with a multisim ?
On the PP it lasts more than 2 years and a lot of private work from “BiktorG” for an really stable and reliable running modem. Her released a lot of complete modem-firmware versions. Maybe here also is a quite similar process …

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The PinePhone has a completely different make of modem. So unfortunately whatever good work has been done on or with the specific modem for the PP won’t really benefit the Librem 5.

NB: limitation != feature. No way would I call it a feature unless perhaps there was a good reason not to use a multisim card (and I am aware of no such reason). If I said to you, for example, “the modem does not support LTE Band 11”, that is a limitation. It is not a bug. It is not a feature (presumably).


I hope VOLTE with German Telecom will be fixed. I’m afraid it will be needed soon.

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Yes, our providers are on her way to establish VoLTE as the only supported way to make and receive calls in the future.
I know that this will be an enormous effort for the programmers. But a phone without the ability to make phone calls is not a phone for me :wink:
Fortunately D2 aka Vodafone works ATM with VoLTE enabled or not

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I found in the internet that Biktorg also tried to make the modem of the L5 better. But it seems that he gave up because of limitations in RAM on the L5 modem