How to implement 3g/4g gsm bonding of two modems for higher connection stability?

Question

linux

It is necessary to implement the operation of the Internet from two 3g / 4g modems so that if one loses the signal, then we continue to work from the second, due to a different coverage area from the operator. You don't need a channel extension, you just need connection stability. I would be grateful for any links and advice.

Answer 1

Router with two USB ports.

Answer 2

This is not bonding. Bonding is from another story.
What you want is LOAD BALANCING & FAILOVER.
It is better to buy a ready-made device for such things, since you
1) will need to write a script that will monitor the operation of the channel
2) if the channel has fallen, then switch to a backup one.
It is stupid to switch routing or, even better, to do packet marking from the network.
Since a simple switch to the second channel does not switch already open connections and they will wait for the timeout to fail.
https://serverfault.com/questions/93678/load-balan ...
www.opennet.ru/docs/RUS/LARTC/x348.html
https://habrahabr.ru/post/279777/help.ubuntu.ru
/wiki/ip_balancing

Answer 3

1) We take a router with OpenWRT and USB. For example - TP-Link 1043 or 1045 (same hardware). It is important that the router has at least 8 meters of memory.
2) We take a usb hub for 3 ports with a separate power supply. We connect the hub to the router, and the modems to the hub.
3) We assemble the OpenWRT firmware with support for the necessary modems, mwan3 and other goodies. The main thing is support for usb, modems and mwan3.
4) We upload the firmware to the router, configure each of the modems separately, check that they work.
5) Set up mwan3 according to the instructions from the openwrt website.
6) Testing.
Z.Y. It is better to collect from the latest stable branch.