RUTX50 drops connectivity on 5G NSA while uploading large files to internet

My mobile internet provider upgraded my internet subscription from 4G LTE only to 5G NSA, which substantially improved internet download speeds on my RUTX50 modem. However, I spotted a serious issue in my RUX50 right after the 5G NSA mode was enabled on my subscription. Namely, whenever I upload large files to the internet using RUX50 in 5G NSA mode, the connectivity drops after tens of minutes of heavy bandwidth usage. The connectivity drops for a few minutes, and then it is automatically restored. Still, the connection keeps dropping off again after some time, and the cycle continues. If I enable 4G LTE only mode, the connectivity remains stable.

There seem to be similar topics on this forum regarding connectivity issues of RUTX50 in 5G modes, but the issue I am facing is different:

  • It occurs on the latest Teltonika firmware RUTX_R_00.07.23.3 and modem firmware RG501QEUAAR12A11M4G
  • It concerns the older modem RG501Q-EU (which should be more reliable than the newer one)
  • I can very easily reproduce the issue by simply uploading large files for longer periods of time
  • I have tried enforcing 5G in NSA only mode (disabling SA), which did not help
  • System log has only entries like “IPv4 connectivity started to fail”, kernel log has nothing at the time of the connection drops
  • It only happens in 5G NSA mode, not in 4G mode.

At least for now, the issue seems to be with the internet connectivity. According to the status page of RUTX50, the modem keeps its connection to an LTE cell and a 5G NSA cell during the issue. Thus, it is nearly impossible for me to debug why this happens. I would need Teltonika’s help with the resolution. Could this be a serious malfunction at the hardware level?

Who is your Network Provider?

How big is a large file to you? 1Gb? or 5Gb for example?

I have a RUTX50 and when my provider was EE UK i suffered IPv4 failing and offline issues and downloading 5Gb+ files was almost impossible. The largest file i’ve uploaded will be a little over 1Gb when i was with EE UK and at the time it uploaded in one go 1st time, but this will have been a couple of years ago now.

I switched provider a month ago to Three UK for this very reason, and it doesn’t happen any more, i no longer suffer Ipv4 failing and or offline issues.

Hi,

My provider is Telia Finland. At the moment, I cannot upload even a 1GB file without the drop. It is trivial to reproduce the issue with heavy uploads, but so far, I have not seen the same with heavy downloads. Did you encounter the issue also in 5G NSA mode only?

I just stumbled upon this thread describing very similar issues: Telekom Deutschland 5G NSA Issue

Teltonika’s reposnse is needed!

I tried tweaking things as you are doing and i failed to resolve the issue. I was nearing the end of my 2 1/2yr EE UK preloaded sim and bought a 3 month preloaded Three UK sim to try.

The Three UK sim is so much better, so i switched network Provider and bought a 2 1/2yr preloaded Three UK sim and so far into my second month with them, i won’t be going back to EE UK.

5G SA isn’t available in my area yet, so i can only use 5G NSA at the mo.

Teltonika should consider this issue as a priority. ZTE, Huawei, and other Chinese shady 5G NSA routers work in all mobile network providers without issues.

Hello, have nearly the same with my OTD500. In my case the Modem temperature grow up under load over 90 °C and the Modem drops the connection to the 5G Network.

Look here : OTD500 shows Modem Temperature at 90 °C - #3 by Ahrensfd

Check the temperature of your Modem

I thought about the temperature also, but it remains under 60 °C always.

Greetings @Web,

Thank you for reaching out.

Could you please clarify the following:

  • Is it possible to test the device using a SIM card from a different provider?
  • Have you tried updating the modem firmware? You can do so by navigating to System → Firmware → Update Firmware → Modem Update.

This information will help us investigate the issue further.

Kind regards,
V.

Hello,

I can test the NSA connection with a prepaid subscription from a different mobile operator, if it helps to pinpoint the cause of the issue. The modem firmware is already in its latest version.

Hello,

Thank you for confirming that the modem firmware is already up to date.

Please let me know the outcome of the tests using a SIM card from a different provider, as this information will help us continue the investigation.

Best regards,
V.

Hi,

I have been testing for a few days the NSA connenction with two SIM cards. It seems that the modem of RUTX50 does not interplay well with Telia. I see often the connectivity drops that I described earlier with Telia. With Saunalahti SIM card, I have not seen a single connection drop so far.

I want to emphasize that I have not heard any compatibility complaints from others in the Telia NSA network. Chinese NSA routers work well in both networks, so there is most likely an issue in the modem or its firmware.