Confirming APN in use

[Peter Naulls]

On 10/20/22 05:06, Aleksander Morgado wrote:
> Hey Peter,
> 

> 
> In 4G there are 2 different sets of APNs required for a successful
> data connection: first, the initial EPS bearer settings (a.k.a. attach
> APN), which is used during modem registration phase; and second the
> data connection settings (a.k.a data APN), which is used during modem
> connection phase. These settings may be equal or different, it really
> depends on the operator. Some operators may require an attach APN that
> is by default not providing Internet access, and so a different data
> APN needs to be used if the user wants to get to the Internet. Some
> operators allow requesting no specific attach APN (i.e. using blank ""
> APN), so that the network decides which one is used.
> 

Thanks, that was very helpful. We have decided that for our use
cases, setting the initial bearer as well is going to be the best solution.

I can set this in my monitoring script, which should be OK - check
the APN when the modem becomes available, but I don't know if there's
a better place in the MM/netifd/OpenWrt scripts where this would be
better and more reliably done?  Changing the APN might well cause
the modem to reset, which is fine, but it's worth bearing in mind.