VoLTE support progress

I executed the commands with screen as @Kyle_Rankin wrote flipped the hardware switch (waited 10 seconds to re-enable) and it seems that both incoming and outgoing call stay in 4G (same with mobile data on or off). I tried 8 calls. 1 switched to 2G. The rest 7 remained in 4G. The preferred method is “2G,3G,4G”. So do I leave the modem as is (in VoLTE state) or there may be other issues? I guess if it works, it should be left on. Yes? The carrier is in Greece (cosmote). I write this for maybe a user in the same country (or for tourists :slight_smile: )

Unless the UI had crashed and only shown 4G :upside_down_face: But I will try again after reboots.


It stays at 4G after a reboot.


That may depend on your tolerance for risk. I think Purism is intentionally not enabling VoLTE by default. It probably hasn’t had a lot of testing with a lot of carriers around the world. Comment @joao.azevedo ?

My recommendation would be: if you choose to leave it enabled then keep a copy of the instructions to enable and disable with you at all times, either printed out or saved on your phone or both.

1 Like

The following behavior is observed systematically:

  1. Boot from L5 being powered off.
  2. After boot and after it connects to the mobile carrier with 4G we dial out.
  3. The connection drops to 2G
  4. The HKS is flipped. If enabled in a couple of seconds it can not dialout or in.
  5. If HKS is re-enabled after 10 seconds. Calls work.
  6. Dialout now stays with 4G and does not drop to 2G.

I have repeated this sequence from yesterday 4 times. It is always the same results.


Yes! that is exactly what I have done!. I have copied the commands in a file on the L5.


VoLTE on the Librem 5 is not yet enabled by default for a reason. It is still under tests, and it has risks at the moment. I would not recommend enabling VoLTE to anyone that is not willing to accept the risks. And accept that if it does not work they will have to troubleshoot the modem.


OK, then, I will disable it… :cry:

Unfortunately has no effect on AT&T network US with Awesim. 4G still does not pass calls, and people calling are directed to voicemail.

Please work with our support team if you aren’t receiving incoming calls with AweSIM so we can figure out what’s going on. We will be able to get it to work.

1 Like

Can some of the folks who are using VoLTE already on Librem 5 share their experience?

I consider to switch on VoLTE because at work the GSM (2G) signal is pretty poor while LTE (4G) is very good. So when I get called and the modem goes down to GSM (there is no 3G in Germany anymore). The call quality and stability is then pretty poor. If the GSM signal is good, I don’t have major issues with calling :slight_smile:

1 Like

As a U.S. customer, I bought my L5 pre set up with 4G and Awesim sim card. (so my experience may or may not mimic yours), But so far, I’ve found the call quality/signal strength to be equal to my iPhone with AT&T.

I have a L5 with a SIMple service plan, and VoLTE calls/cellular service have been fine for me in my location.

I am using VoLTE in Germany can you DM me your carrier name?

1 Like

Its Deutsche Telekom.


Great work Purism!


where is that setting?


fiacco: It need install: https://source.puri.sm/Librem5/bm818-tools/-/jobs/390480/artifacts/download
after install execute: sudo usermod -a -G dialout purism then reboot, then will see an app on Home, in order to work it need the modem enabled with sim card.


Seems you stumbled onto a tool that one of our devs recently made like 3 days ago :wink:

Since this is still quite recent there are still some things to sort out and some merge requests have been done to address it.

This is something that will be addressed in a next version so that people do not have to do this step manually.
Another is to improve the LTE call test.

So while the basics are already there it is still a work in progress.


Yes i stumbled with the newer Purism-tools for the modem, i shared the version 0.1 but now already exist the version v0.5 with more fruits. With this tools i finally tested the VoLTE on my Librem 5 and it work really good on my case, the only bad things it that the modem crash very often, i hope that Purism programmers fix this bug.

Would this likely be any use with my issue regarding not being able to connect to T-mobile?