RUT956 firmware version vs mobile data issues

I have received a new batch of RUT956 routers, they are different from discontinued RUT955:

  • the box is not the original one from Teltonika with a logo
  • these routers have a sticker on the bottom with a QR, user and password, among other data
  • the stock firmware is 7.2.4, date 2022.07.20, the “Modem firmware version” is shown as a string of characters

If you update the firmware to the last version, currently 7.4.5, mobile data disconnections are shown on the status page and the mobile interface doesn’t work properly, perhaps the “SIM switch” feature is triggered, but it’s not configured. The “Modem firmware version” is shown as “OK”.

Mobile data works up to version 7.2.9, from version 7.3 the problems are the same than the version 7.4.5. The “Modem firmware version” is shown as “K”.

I wonder:

  • How can these routers use a firmware version from 2022.07.20 when they were released recently ?
  • Is there any incompatibility of these routers with recent firmware versions ?

I’m reading a lot of posts with problems related to SIM errors or mobile data issues, have you changed the modem hardware or something similar ?

Thanks in advance.


RUT956 was released over a year and a half ago, and it’s initial firmware release was RUT9M_R_00.07.01.5, which was released at 2022.03.29, thus it is entirely possible that firmware 07.02.4 was installed on the device.
As for the troubleshooting steps, I will ask you to:

  • Update the device to RUT9M_R_00.07.04.5 without the option Keep settings enabled (or if the device is already on this version, simply perform a factory reset);

  • Navigate to Network → Interfaces → General, edit the mob1s1a1 (SIM1) or mob1s2a1 (SIM2) interface, disable Auto APN feature, and enter the APN provided by your carrier;

  • Finally, in the Firmware update page, check if the modem does not have any updated available (internet connection required).

If none of these steps help, I will ask you to replicate the issue, then navigate to System → Administration → Troubleshoot, open the System logs, and paste the logs from the past few minutes. This may help me determine the root cause of the issue. Make sure to remove any sensitive information!

Best regards,

Thanks for your answer.

We have followed your instructions and our conclusion is that mobile communications fail depending on the SIM card, that is, an Internet SIM works with firmware 7.4.5 but not a M2M SIM, but this M2M SIM works with firmware 7.2.4-7.2.9

This is a weird issue, we attach a log according to your request.

Thanks in advance. (13.0 KB)


It seems like the modem connects to the carrier, but gets kicked off the network after two minutes. This behavior seems to come from the mobile network itself, thus I’d suggest verifying that no APN authentication is needed. If its not, when the issue replicates, please log into the CLI of the device, and run the following command:

gsmctl -A 'AT+CEER'

This will hopefully provide us with the reason for rejection from the mobile network.
It would also be helpful if you could attach the logs from the working firmware after the device connects to the network.

Best regards,

We don’t use any user/password, and it works for 1-2 minutes, after that time the mobile networks disconnects every time. But it works with firmware 7.2.4-7.2.9 !

RUT956 login: root

BusyBox v1.34.1 (2023-07-24 11:59:22 UTC) built-in shell (ash)

| _ \ _ | | / _ / |
| |
) | | | | | | | _
| _ <| |
| | |
| || |) |
| _\

Teltonika RUT9M series 2023

root@RUT956:~# gsmctl -A ‘AT+CEER’
+CEER: Regular deactivation

and once in a while:
root@RUT956:~# gsmctl -A ‘AT+CEER’
+CEER: Network failure


Thank you for providing the information.
There were a lot of changes to the mobile connectivity in v7.3, so the issue may occur from something being changed there. When possible, please attach the connection logs from the latest firmware that connects successfully, and I’ll compare them. Thank you.

Best regards,

System log for RUT956 using firmware version 7.2.9. (10.9 KB)


In order to resolve the issue that you are currently experiencing, additional provision of further confidential details is required. Hence, it is recommended that you reach out to your designated sales manager or the reseller from whom you acquired the device in question. They will be able to assist you in addressing this matter more effectively. Make sure to mention this query!

Best regards,


Disable VoLTE on mob1s1a1, reboot and the problem is solved, don’t ask me why, just a lot of trial and error, and some intuition.

Indeed, there were a lot of changes to the mobile connectivity in v7.3.

Best regards.

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