Question

For some unknown reason after one of the latest upgrades my Rutx09 doesn't know anymore how carrier aggregation works. But even worse, although my Wittenberg Lat 56 Duo is perfectly directed at a tower having B1, B3 and B20 bands antennas (Germany, o2), it mostly uses a B20 tower far away. Selecting B1 only sometimes works, sometimes the Rutx09 is not finding ANY B1 antenna, although there are more than one. Also auto selection doesn't make a difference. I downgraded and also upgraded already without using existing configurations, which didn't make a difference.

What's also interesting, my logs go back to 2020, which means I got almost 500 pages logs. Unfortunately I can't find a point in GUI to delete them.

Help really appreciated, it worked perfectly before (probably new modem firmware with the latest updates?).

Thanks in advance.

Tom

Answer 1

Hello,

  

The logs should not be causing any issues in this case.

If I understand correctly, your RUTX09 does not perform carrier aggregation and only rarely connects to other bands than B20.

I'd like you to update to the latest firmware (RUTX_R_00.07.04.1 at the moment), connect to the device using CLI (username is root), and run this command:

gsmctl -K

gsmctl -I

Then wait a few minutes, and run the gsmctl -I command again, repeating it once every few minutes for around 10 minutes. Paste the output into a .txt file and attach it to the original post.

I'd also like you to navigate to System → Administration → Troubleshoot and generate a troubleshoot file. This file can also be attached to the original post and will also be visible only to Teltonika moderators. This will provide me with some more signal parameters.

It could be the case, that the cell tower is simply overloaded, thus your RUTX09 simply uses a tower with less load. If this is the case, we will be able to force the router to connect to a selected tower.

  

Best regards,
DaumantasG

Comments

Thanks for the response and sorry for the late reply. Was busy this week. Will do that later and attach the files.

Tbh, I doubt that they are overloaded, I had always good and stable connection to the B1/B20 there, download was always between 8-10 MB/s, upload with around 6 MB/s peak. It seems more like it doesn't see the whole tower anymore for unknown reason. Telefonica / o2 already checked if there are any problems but denied that.

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root@Teltonika-RUTX09:~# gsmctl -K

Access tech: LTE | TDD mode: FDD | MCC: 262 | MNC: 3 | UE state: 3

root@Teltonika-RUTX09:~# gsmctl -I

"neighbourcell intra","LTE",6200,152,-13,-79,-49,0,-,-,-,-,-

"neighbourcell intra","LTE",6200,282,-17,-82,-56,0,-,-,-,-,-

root@Teltonika-RUTX09:~# gsmctl -I

"neighbourcell intra","LTE",6200,152,-13,-79,-47,0,-,-,-,-,-

"neighbourcell intra","LTE",6200,282,-17,-82,-55,0,-,-,-,-,-

"neighbourcell intra","LTE",6200,92,-20,-88,-55,0,-,-,-,-,-

root@Teltonika-RUTX09:~# gsmctl -I

"neighbourcell intra","LTE",6200,152,-13,-79,-48,0,-,-,-,-,-

"neighbourcell intra","LTE",6200,282,-16,-82,-59,0,-,-,-,-,-

root@Teltonika-RUTX09:~# gsmctl -I

"neighbourcell intra","LTE",6200,152,-13,-79,-48,0,-,-,-,-,-

"neighbourcell intra","LTE",6200,282,-17,-82,-55,0,-,-,-,-,-

"neighbourcell intra","LTE",6200,134,-20,-88,-55,0,-,-,-,-,-

root@Teltonika-RUTX09:~# gsmctl -I

"neighbourcell intra","LTE",6200,152,-13,-79,-47,0,-,-,-,-,-

"neighbourcell intra","LTE",6200,282,-14,-82,-52,0,-,-,-,-,-

"neighbourcell intra","LTE",6200,92,-20,-87,-53,0,-,-,-,-,-

"neighbourcell intra","LTE",6200,41,-20,-86,-53,0,-,-,-,-,-

root@Teltonika-RUTX09:~# gsmctl -I

"neighbourcell intra","LTE",6200,152,-14,-79,-47,0,-,-,-,-,-

"neighbourcell intra","LTE",6200,282,-18,-83,-54,0,-,-,-,-,-

"neighbourcell intra","LTE",6200,92,-20,-87,-54,0,-,-,-,-,-

root@Teltonika-RUTX09:~# gsmctl -I

"neighbourcell intra","LTE",6200,152,-13,-79,-47,0,-,-,-,-,-

"neighbourcell intra","LTE",6200,282,-16,-82,-53,0,-,-,-,-,-

"neighbourcell intra","LTE",6200,92,-20,-89,-54,0,-,-,-,-,-

"neighbourcell intra","LTE",6200,378,-20,-87,-55,0,-,-,-,-,-

root@Teltonika-RUTX09:~# gsmctl -I

"neighbourcell intra","LTE",6200,152,-13,-79,-48,0,-,-,-,-,-

"neighbourcell intra","LTE",6200,282,-17,-83,-54,0,-,-,-,-,-

"neighbourcell intra","LTE",6200,92,-20,-89,-55,0,-,-,-,-,-

root@Teltonika-RUTX09:~# gsmctl -I

"neighbourcell intra","LTE",6200,152,-13,-79,-48,0,-,-,-,-,-

"neighbourcell intra","LTE",6200,282,-15,-82,-54,0,-,-,-,-,-

"neighbourcell intra","LTE",6200,92,-20,-88,-55,0,-,-,-,-,-

"neighbourcell intra","LTE",6200,145,-20,-86,-55,0,-,-,-,-,-

"neighbourcell intra","LTE",6200,378,-20,-86,-55,0,-,-,-,-,-

root@Teltonika-RUTX09:~# gsmctl -I

"neighbourcell intra","LTE",6200,152,-13,-79,-49,0,-,-,-,-,-

"neighbourcell intra","LTE",6200,282,-16,-82,-55,0,-,-,-,-,-

"neighbourcell intra","LTE",6200,145,-20,-88,-56,0,-,-,-,-,-

"neighbourcell intra","LTE",6200,92,-20,-87,-56,0,-,-,-,-,-

root@Teltonika-RUTX09:~# gsmctl -I

"neighbourcell intra","LTE",6200,152,-13,-79,-48,0,-,-,-,-,-

"neighbourcell intra","LTE",6200,282,-16,-82,-55,0,-,-,-,-,-

"neighbourcell intra","LTE",6200,378,-20,-87,-56,0,-,-,-,-,-

"neighbourcell intra","LTE",6200,92,-20,-89,-56,0,-,-,-,-,-

"neighbourcell intra","LTE",6200,164,-20,-88,-56,0,-,-,-,-,-

root@Teltonika-RUTX09:~# gsmctl -I

"neighbourcell intra","LTE",6200,152,-13,-79,-49,0,-,-,-,-,-

"neighbourcell intra","LTE",6200,282,-16,-83,-55,0,-,-,-,-,-

"neighbourcell intra","LTE",6200,92,-20,-90,-57,0,-,-,-,-,-

These are the outputs of your comments. Added troubeshoot file to origin post

---

Hello,

  

It seems like the RUTX09 only sees the B20, which is why it is not connecting to the other bands. If you're sure you have not set any band lock in the WebUI, then this is most likely not a software issue, as the outputs of the aforementioned commands get the data directly from the modem.

Perhaps there is an issue with the antennas or their connectors? Are they fully screwed in?

Also, in the troubleshoot file and the command outputs, it seems like SINR is at zero, which should result in a very unstable connection or even disconnections. Maybe you have a lot of RF polluters in your area?

 

Best regards,
DaumantasG

---

I'm absolutely sure it is set to Auto for Band selection. Also, if I manually set it to B3, it connects to B3 (which is like 13 km away) . But setting it to B1, it won't connect to the B1 cell at the tower it always was linked to.

Since I didn't move anything, the antenna connectors shouldn't be a problem but I'll recheck that again later.

Cheers so far

---

Hello,

  

Could you try downgrading the device to the version you were using before this issue and check if it reappears? Just to make sure, that this is not software-related.

I'd also recommend to try and lock the device to a cell that provides B1. Instructions on how this could be done can be found here. This procedure should be performed when the device manages to connect to the B1, as otherwise, you will not know the PID of the cell.

If rolling back to the older firmware does help, I'd like you to take a troubleshoot file from the older version when everything is working well to compare with the new one.

There may be other factors why the signal reception has worsened so much:

• Cell tower load increase;
• Reduced transmission power on the operator side;
• Weather conditions;
• Antenna damage (corrosion, etc.);

Let me know if the downgrade helps.

  

Best regards,
DaumantasG 

---

Well, I even changed the antenna adaptors now, didn't change anything.

Couldn't find a working firmware, it's like the rutx09 got problems with B1 Band. Also, I manually switched to B3 only before, jumped to Status - Network, I got an error about the modem and got kicked out of GUI. Had to login again. There's defo something fishy.

I've attached another troubleshooting file now.

---

Hello,

  

Could you try replicating the issue, and generate a troubleshoot file then? It may lead us in the right direction, because as of now, this looks like a signal issue, and none of the logs contain anything about the modem disconnecting.

Also, I can see that the PDP is set to IPv6-only, could you try setting it to IPv4/IPv6 or IPv4-only?

  

Best regards,
DaumantasG

---

Last troubleshoot file was right after that behaviour.

And it is set to IPv4/IPv6 atm, don't know why it would say IPv6 only.

Ist there a way to completely wipe the Rutx09, through Bootloader firmware install for example?

---

Hello,

Yes, it can be performed by following this procedure.

Best regards,
DaumantasG

---

Cheers, I will give it a go, probably solving the issue.

---

Sure, let us know how it goes.

  

Best regards,
DaumantasG

---

Unfortunately, it didn't solve the problem. Forcing B3 work, if on Auto, it only connects to B20. B1 isn't found. Carrier aggregation doesn't work.

After setting B3 manually, I got kicked of the device and had to login again.

Got the message by screenshot, also a screenshot of unknown modem after login again. 

Also, two screens of the connection quality when set to auto (B20) and forced B3.

Can't see the point, why it's not taking the B3 by default.

​​​

Tomorrow I'll do a last test, taking the poor o2 homespot of my brother in law and plug it to the antennas.

---

Well, the o2 homespot didn't find a B1 neither, probably o2 changed something. But at least it found the tower the rutx09 isn't finding anymore.

So, last question. It's there a way to force a specific cell to be used? If so, what's the cli command for it please?

Thanks in advance

---

Hello,

  

Yes, there is, and that is what I wanted to recommend you try. I have written this article on our Wiki, which might be helpful in your case since the signal quality is not bad for band 3. Your device is running a Quectel modem and the cell locking should be supported.

Before performing the procedure, please remove any band locks or any other mobile network preferences (leave everything on Auto). Since the cell lock will get removed every time the device is rebooted, please copy the gsmctl -A 'AT+QNWLOCK...' command to System → Custom Scripts. This way the router will get locked to this cell every time it boots.

Please keep in mind, that there is a reason why this procedure is not added to the WebUI - the connection to a specific cell is usually at least partly managed by the carrier. Since you will be forcing the device to connect to a single cell, the connection times may take longer, or you might experience a different weird behavior. In this case, the cell lock should be removed.

Let me know if any further questions arise!

  

Best regards,
DaumantasG

---

Thanks, I'll have a look into it next weekend, prefer having more time in case anything goes wrong.

I'll report back ASAP.

---

Well, after locking the modem to the B20 cell of the tower it doesn't recognize anymore through putty, GUI told me internal modem is unreachable but came back a few seconds later with a different B20 cell. So, no, it doesn't work with cell locking. Trying the B3 cell of that tower makes the modem search forever for this cell. No clue what's going on.

Edit: I cant even lock the B3 cell I always connect to if I lock the Band to B3... Crashes the modem and afterwards it connects to B20 again

---

Hello,

Could you paste the exact command used for locking to a cell?

Best regards,
DaumantasG

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I used the command from the wiki.

gsmctl -A 'AT+QNWLOCK="common/lte",2,1234,567'

while I used the correct values (tried both, the one I was shown in console and directly from cellmapper).

Funny side note, when I was lying in the bed last night, I had wifi disabled and the phone connected to the B8 cell of the tower I wasn't able to manage to connect the Rutx09 to the B20 cell.

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I will message you via a private message.

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Update.

Upgraded modem firmware, which didn't work by doing it directly from usb, so I used WinSCP to copy files to /tmp on device which made me successfully do the upgrade. Unfortunately, this didn't solve my problem.

Today, I was playing around a bit and it seems like it's a problem with the antennas. If I have connected both antennas, it won't find the tower I want to reach. If I connect only one of the antennas together with one of the included antennas, it instantly works. No clue what the problem is if both LAT56 are connected, especially because it doesn't matter which one I use.

Was happy too early. Same happens again now, connecting to different tower again with poor speeds and no carrier aggregation...

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Another update here.

If I restart the modem, it's always connecting to the last cell.

But if I reboot the whole Router, after reboot it connects to the cells I want it to connect and carrier aggregation also works then. That's quite a strange behaviour.