Raspberry Pi 4, Dual USB Sierra LTE Modules, lets talk

For Developers
1

Hello all,
The ultimate goal is to run dual LTE service with 2 modules via USB to a Raspberry Pi 4.

To further utilize the Pi4 hardware, I want to see if there is a way to run OpenWRT on a separate partition or in a virtual environment so that it is possible to use the Pi as a multi application device using an OS, such as a Linux distro. Would be cool to have it serve as a smart home AI. and this could be a pipe dream but worth asking about.

Would love to open the floor for instructions, discussions, criticisms, alternatives.
Just getting OpenWRT to load balance the 2 modules would be an awesome start.

Cheers everyone!!

2

You are asking about some experiment that, yes, it could work, but probably will not work well or as you wish/expect.
You should give a try QEMU, there are people that tryed macos and windows https://www.raspberrypi.org/forums/viewtopic.php?f=62&t=6014 , so you could try and x86 32bit image and boot, you will have virtualized ethernet, and may be direct usb access too.
Some people use: https://github.com/Botspot/Pi-Power-Tools

If your network configuration involves dual band, and 4gb usb dongles, you could try to setup that on debian/arch/fedora by yourself, I recommend a minimal debian image.
there is possible to do everything in your imagination:


https://www.tecmint.com/setup-linux-as-router/
https://www.google.com/search?q=debian+dual+wan+load+balancing

https://zeroshell.org -> https://zeroshell.org/zeroshell-3-9-0-for-raspberry-pi/
https://www.vyos.io/ -> https://www.google.com/search?vyos+raspberry+pi

but...

For stable networking I recommend that you get a cheap OpenWRT Router with USB support, it could be a TL-wr1043nd (1 USB) or a TL-WDR3600 or WDR4300 (both have dual band and dual USB)... there is also the TL-WR842ND... If you want something small with 5Volt/USB power there is the TL-MR3020.

With devices with 1 USB you could use a external powered capable USB-HUB, but you should check compatibility. Some people even power a TL-MR3020 with one of the ports, and power the usb-hub with a 5V (2A or more) powerbrick. There is also a 5Volt capable network Switch very small: Tl-sf1005d if you need to plug more devices.

You could also search for better/newer devices like the gl inet ones, or similar.

Use a small and cheap Sandisk CruzerFit 16gb (usb 2.0) or a newer Sandisk UltraFit 16gb Black (the silver one has temperature problems) and put ext-root there so you will have plenty of space for software packages. You could put a Openwrt 15.05 on the device configure extroot and boot to a 19.07 on the USB flash drive.

Raspberry Pi works better via cable. so you could use one of those ports. Raspberry Pi works better with raspbian (debian based) but there you could try Arch, Fedora, etc. try to get used with minimal debian images, so you will be able to learn to install packages and grow in features on your systems by yourself using ssh console and not so much the GUI/desktop, that is the best way to learn Linux for Systems/Servers.
If you are learning you will probably have to have at least two raspberrys,no problem with 2 rpi4 but rpi4 is very new, I dont know if you will have some limitations, rpi3 it may be cheaper and is still very common too.

3

You never fail to amaze Braian.
I will look further into your suggestions, got plenty to read up on and test.
I will research the distros to see what best fits the purpose and best for firewall/ light server.

5

So I totally bailed on the Debian distro project and am going with openWRT. I am in the process of figuring out the 2 USB ports and trying to assign them as WAN ports and proper rules.
I started to read over your MWAN3 instructions but am a little confused.
In the first half are you saying simply change some firewall rules and hold off on installing MWAN3?
I could be drained as i have been at this for a few days.
i did find out that on RPi 4 it appears to assign usb0 as the first device that is plugged up and then usb1 as the next. kind of a first come first serve thing. Lucky for me this doesn't matter as i will balance them equally.
I just reset everything as i broke something (oops_)
any suggestions i will take in and try tomorrow. thanks

6

Hi, I recommend that you start from bottom first, try to get internet with 1 of the 4g and try to ping using command line or use wget to see if you get internet from the 4g properly, then you could set on the 1st 4g iface a higher metric to be able to test the 2nd 4g connection, if both works then you will be able to create an interface and assign that physical iface into that, and use it later for mwan3.
hope I was clear enough.