RM5xxQ 24/7 uptime and reliability on Ubuntu host

We’re currently evaluating the use of Quectel 5G modems for a project that would require 27/4 reliability on an Ubuntu 20.04 host. After browsing the forums, it seems that the recommendation is to not use Modem Manager and Network Manager, but to use the Quectel provided quectel-CM.

Is quectel-CM suitable for an industrial use case that requires 24/7 reliability, i.e., does it automatically handle DHCP timeouts, network roaming, etc.? What are it’s limitations? Can it handle SIM card switches with different APNs?

Basically, I would like to know if I can get Modem Manager-like reliability out of quectel-CM, and if not, what are your suggestions?


Can I chip in with my experience using a variety of Quectel modems (including an RM500Q-AE) on Fedora?

Long ago I uninstalled ModemManager. Network Manager is running.

I run my Quectels in ECM mode with MBN active and automatic.

In general, MBN updates the APN when the modem is started with a different SIM. This depends on the set of installed MBN files.

ECM mode has seen one of my Quectels (EM06-E) run for 18 months plugged into a router without any connection monitoring or need for a modem reset.

I do not need to run any AT or shell commands on Fedora. I get Internet access seconds after plug-in.

I’m aware that not all modem + SIM combinations work in ECM mode however.

Thanks a lot for your reply. 18 months uptime - that’s impressive. I’m assuming you’re using the MBNs that ship with the modem firmware? Do you know if it is possible to create an MBN for a private 4G/5G network?

I am using the default list of MBN files. These are often upgraded with firmware upgrades.

MBN files can be deleted and added. As far as I know, they need to be provided by Quectel, uploaded to the modem and then added to the list. The last step is the easy one (it’s an AT command). I haven’t gone through this process myself.

I’ve just taken a Telstra SIM out of my RM500Q-AE, and installed a Vodafone Australia SIM.

This resulted in the “Germany-VoLTE-Vodafone” MBN file activating automatically.

The correct APN for this SIM is “live.vodafone.com”. But the MBN mechanism configured “web.vodafone.de” as the APN, and it works fine.

For a private network? We’ll need Quectel’s advice on that.

We are running quectel-CM on our industrial router with LTE mPCIe modules (EC25 mostly).
From my experience, it’s a very good utility, stable, maintained code, can handle SIM switching and disconnections but you need to run with it a few miles, maybe open a few defines in code to reach desired behavior. We had to do some tweaking, move to airplane mode in some configuration changes or expedite connection attempts.
Good thing is that code is readable, and the verbose logging dump of QMI traffic on the control channel allows you to have visibility on rejection reasons.



Thanks a lot for sharing your experience with the software, I’m going to start running some integration tests with quectel-CM and see how it behaves out of the box.


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