TRB140 Mobile Datat Connection Problems

Teltonika Networks
1

Hello all,

I have a problem with a TRB140.
The problem is that the mobile data connection disconnects and reconnects every few minutes.
The firmware is up to date (TRB1_R_00.07.04.5) and restarts of both the service and the whole modem have not helped. The SIM should also be ok.
Do you have any ideas for a solution?
Thank you in advance for any help.

3

Hello,

This type of behavior usually indicates an issue with the DNS server reachability. The servers advertised by ISP can sometimes be unreachable, and assuming Auto APN is used, the TRB140 will try pinging the DNS to verify the connectivity. To disable Auto APN, navigate to Network → Interfaces → General, edit the mob1s1a1 interface by pressing the pencil icon, and disabling the Auto APN feature. In the Custom APN field enter the APN provided by your carrier (can usually be found online or by contacting the carrier directly). Authentication might also be required. This information will be provided in the same page as the APN.
If the behavior stays the same, try running a continuous ping test on a LAN device to check if connectivity is available. For Windows, the command will look like so:

ping 1.1.1.1 -t

Let me know if my suggestion does not help.

Best regards,

4

Hello,

disabling the “Auto APN” Feature fixed the problem.

Thank you and best regards.

5

Hello again,
i’m afraid to tell you that the problem has unfortunately not been solved after all after disabling the “Auto APN”-Feature.
However, the connection is no longer interrupted continuously, but only when several SMS are sent at the same time. Unfortunately, I cannot attach a created troubleshooting file. I hope you can help me with the problem.

Best Regards.

6

Hello,

Are SMS being sent to the gateway, or from the gateway?
How often exactly are the messages being sent? Is VoLTE enabled?
What kind of messages are being sent? Are they commands, or are you using a forwarding service?

Best regards,

7

Hello,

we send normal SMS via the GUI, no commands. VoLTE is disabled.
The amount of SMS is irregular and if you send only one or a few they come through reliably. But it can be that we have to send many within a short time and then some are not sent. The page then loads and after a while you are back at the interface to send SMS and the previous one did not go out.

Best Regards.

8

Hello,

Could you try checking if the issue replicates when in 3G mode?
Just to clarify, have message sending been tried with VoLTE enabled?

Best regards,