RM520NGLAA module working on Windows 11, but not on Ubuntu 22.04

Technical Subjects Driver
1

Hi there,
I’m trying to get a RM520NGLAA module running on Ubuntu 22.04, but it is not able to connect to the internet. It only shows up as mobile broadband connection very briefly, but disappears after a few seconds. I think I set up my drivers according to this comment, but please provide me with the latest driver version and possibly some instructions on how to ensure the right driver and firmware versions.

I suspect the ubuntu ModemManager to be part of the problem, as I read about this online, so I would be happy to try setting up the connection with the Quectel Connect Manager. So please provide me with its newest version and some instructions on how to get the modem running as well.

I installed the necessary drivers on a Windows 11 Laptop and could confirm that the modem works as expected on Windows 11. So I would think that it is not firmware related, but I would still be happy to update to the newest firmware version as well if you provide me with the file, tools and instructions.

Thanks already a lot in advance!
Best
Noel

2

The RM520N is not full supported by the ModemManager. You can try the Quectel ConnectManager.

3

It is almost the same with EC20 How to set up with EC20 on Ubuntu - Technical Subjects / Driver - Quectel Forums.

q_drivers/Quectel_QConnectManager_Linux_V1.6.7 at master · QuectelWB/q_drivers (github.com)

4

Thanks a lot for the quick reply with the drivers and instructions.
By disablilng the modem manager and running the connection manager I indeed get the internet connection to work, but apart from within the connection manager and the ip address of the wwan0 interface, the connection is not showing up anywhere in the system.
Now, when I try to activate a vpn connection, that I want to access from the mobile network, I get an error that no source connection can be found. Is there a way to fix this? I really need to get this vpn connection running.

5

I do not understand, could you provide any logs?

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In the meantime, I found a solution for the vpn, but I found that there is still a massive difference between the speed when using the modem in Linux vs in windows:

Ubuntu 22.04:

image (3)
image (3)1920×1200 269 KB

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Windows 11:

image (4)
image (4)1918×1079 122 KB

Do you have any idea what could cause this and also how I can fix this? Because at a speed of 1.5 Mbps the modem is not really usable for me, especially as it is a lot slower than a previously used LTE Module with perfect plug&play abilities in Ubuntu that we’re trying to upgrade from.

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The Connection via the Connection Manager also still seems to be quite unstable as the internet connection is not always working. For this example something seems to be wrong with the “udhcpc”:

image (5)
image (5)1920×1200 384 KB

I’ll gladly provide you with some logs, if you tell me which ones exactly and where to find them :slightly_smiling_face:

Thanks a lot in advance!

9

Performance is hard to figure out. You have to figure out where the problem is. Is it a poor signal or a driver problem?