Resetting Bearer on OpenWRT

[James Hilliard]

I'm running modemmanager on OpenWRT and am getting this error fairly
regularly such as when I use AT commands to manually change LTE
bands(is there a better way to change/lock bands than using AT
commands?): "Bearer not allowed to connect, not registered in 3GPP
network"

Doing "ifup broadband" resolves the issue(at least until it loses the
bearer again) since resetting the interface triggers
proto_modemmanager_setup() to flush and reset the bearer but I don't
see a way to automatically get modemmanager state change notifications
to OpenWRT so that I can trigger the bearer reload directly from the
modemmanger state change event. I assume that's because modemmanager
uses dbus and OpenWRT uses ubus right? I've used a cron job as a
workaround to monitor the bearer and issue an "ifup broadband" when
it's lost.

I'm using a Sierra Wireless MC7455 with a WG3526-P router, I have some
posts here with more info on how I have things configured
https://ltehacks.com/viewtopic.php?p=797&sid=f25d40df6ce86dc8933781a5309dbba2#p797.