Bearer IPv4-Config / IPv6-Config

[Aleksander Morgado]

Hey Thomas,

> I'm new to the mailing-list and want to intro myself.
>
> I'm working for a IT service-provider company as a product-manager for managed services. I'm interested in Open Source and in OpenWRT as I'm traveling and working from a camper van. Modemmanager is a great peace of software, and the implementation on OpenWRT is a super-cool thing for the OpenWRT community.
>

Nice! Thanks for the kind words

> Environment:
> TP-Link TL-WR902AC v3 / OpenWrt 19.07.5 r11257-5090152ae3 / LuCI openwrt-19.07 branch git-21.222.69112-b41f377 / Telkom Speedstick V / Modemmanager  Luci-proto manually integrated
> Raspberry Pi B+ / OpenWrt 21.2.3 / Vodafone K6150
>
> Now my questions:
>
> After connecting the bearer token has statement IPv4-Config / IPv6-Config which includes the config-method (DHCP, static, ppp). I wonder who is setting this. Is this coming from the device (4G stick) or is this setting provided by the network-provider the device has registered into?

The IP method to use, either static/dhcp/ppp, is selected by
ModemManager in runtime, based on the device type and the ports it
exposes. The network operator has nothing to do in this regard.

> If you roam with the 4G stick you sometimes get IPv4 only, but in the home-net you will get IPv4/IPv6 dualstack. Is it fair to say the network (roaming access-provider) assigns the IP stack, regardless if your home apn does support dualstack or not?

I guess you can say that, yes. Different operators will have different
settings for roaming users.

> Is there in ModemManager a capability to pick a roaming network over the other, so I could pick always best one? Is the signalquality a good indication of good performing network?

With ModemManager you can request to lock to a specific operator given
its MCCMNC. E.g. you can run a 3GPP scan operation, get the list of
available networks, and then manually lock to a specific one. There's
no automatic way to do that by ModemManager itself; you could have a
watcher/monitor custom process to do that selection, but just looking
at signal quality may not be the best way. E.g. an LTE connection with
low-medium quality is likely much better than a 3G connection with
very high quality.


-- 
Aleksander
https://aleksander.es