5G connection problems with RUTX50

[siegler-mayn]

Hi everyone.

I have a problem with RUTX50 routers if they join a 5G NSA networks.
The router loses its mobile connection after some minutes, then remains offline for a few minutes (maybe 5 minutes), followed by an attempt to re-establish the connection (successfully).
The mobile connection (5G NSA) is then stable for a few minutes, then breaks off again.
The SIM card is locked and the RutOS-Web-UI says you have to unlock the SIM PIN manually even though the PIN entry is correct and stored in the config.

If only 4G connections are permitted, the mobile connection is permanent and stable.

Firmware used: RUTX_R_00.07.09.3
SIM slot used: SIM 2
Provider, operator: vodafone.de, Germany
Modem type according to RMS: Quectel RG501Q-EU
Modem firmware: RG501QEUAAR12A11M4G_04.200.04.200

5G band n28 (according to the community this has caused problems in the past) has already been excluded, the problem still exists.

In my example the RUTX50 uses multi-carrier aggregation.
LTE B1, B7, B20 and 5G N78 are aggregated at the moment. 5G N78 seems to be unreachable from time to time. So it comes and goes.
The Router is inside a building in the city of Berlin. The cellphone tower for 5G is around the corner.

Connection was broken at around 9:28 a.m. 3G/4G/5G leds were flashing, web UI shows “SIM 2 is locked, please provide PIN…”, “Data Connection Disconnected”, event log entry shows “Mobile Data disconnected (internal modem)”.
Automatic reconnection of the mobile connection (without the PIN being manually unlocked) 5 minutes later. Event log entry then shows “Mobile data connected” and subsequently “Joined 5G-NSA network (internal modem)” etc.

I have been able to download troubleshoot files and syslog. A screenshot of the RMS metrics site can give an impression on how instable the mobile connection is when using 5G network and how stable it is only using 4G network.
Inside the syslog it seems that the GSM process triggers the automatic reconnection.

I can’t find a file upload here. As I said, I can provide helpful files.

My problem looks similar to the issues described in this thread RUTX50 5G connection dropout (att. AndzejJ) - #107 by DelphiC
but I am creating a new topic for it has been requested.

I already wanted to contact helpdesk directly but it seems that I can’t log in nor reset my password over there.

Looking forward for your help.
Kind regards.

Jakob

[TeWe]

Are you on IPv4 only?
If not - try that.

[siegler-mayn]

Thanks for your reply.
I am already on IPv4 only and I am using Auto APN.
The screenshot seems familiar.

Kind regards
Jakob

[DelphiC]

Hello. I’m the original idiot from the old topic. Up front, I will tell you that I have never figured out what “actually” caused the 3 blinking lights, I tried flipping everything several times over and I think after 7.06 I have never seen it happen again. The original fix that greatly reduced the occurrence was resetting the router and updating from CLI. I’m no bleeding expert on routers or IT, but it seems like there is some kind of “residual” in the device that just keeps messing things up unless you zero everything out and go back up step-wise. Kick me if I’m wrong.

In as far as RUTX50 is working now, I have little to complain - it is fast and I rather like the interface. Recently I had some issues with 5GHz wifi dropping out, but I think it is the card, not the router. If you want I can post all my configs as they are now, but I’m not sure it’d be of huge help.

[siegler-mayn]

Some additional information to this topic:

• resetting the RUTX50 to factory defaults did not solve the problem even though I just finished the initial config assistant and added a PIN for SIM 2. Unfortunately the factory reset did lead to an RMS error: “the platform cannot validate this device’s authenticity…”
• downgrading the RUTX50 to FW RUTX_R_00.07.08.3 did not solve the problem. It seems that the process restarting the mobile connection after 5 minutes of failure does not exist within 7.08.3 so the device remains offline until I unlock SIM and restart locally
• upgrading the RUTX50 to FW RUTX_R_00.07.09.4 did not solve the problem. Same behaviour as with version 7.09.3.

Is there maybe a known issue with the Quectel RG501Q-EU and its firmware?
Is it possible to downgrade the modem firmware?