ModemManager and ppp

[Aleksander Morgado]

On Mon, Mar 13, 2017 at 11:05 AM, Martin MOKREJŠ <mmokrejs at gmail.com> wrote:
>>> Is this a matter of configuration, lack of support, or simply outside
>>> the scope of ModemManager? Is there a way to use ModemManager to
>>> initiate the ppp connection?
>>
>> Initiating a ppp session is currently out of scope of MM. MM will put
>> the TTY in connected mode; then you need to (externally, another app)
>> launch pppd on the TTY that MM reported as "connected".
>>
>> The whole MM sequence is the same for TTY-only and QMI/MBIM+wwan
>> devices; just launch --simple-connect, if successful it creates a
>> bearer object that is in connected state. The bearer object will
>> report which is the data interface to use (which could be a wwan, or a
>> TTY) and also which method to use (ppp over the tty, or DHCP or Static
>> IP config over the wwan). An application that wants to use MM as modem
>> management and handle multiple modem types needs to handle all 3
>> methods and use explicitly the one reported by MM (e.g. some modems
>> won't be able to use DHCP over a wwan and in that case static IP
>> setting needs to be performed).
>
> This should go into ModemManager manual page plus the follow-ups translating
> CLOCAL into CRT/RTS wording and AT commands people may try to include in
> their ppp config files.

I agree that this should be part of the documentation; I should try to
spend some time to write this up. Regarding AT commands people may try
to include in their ppp config files: none should be needed, the
control protocol is all work of MM.

-- 
Aleksander
https://aleksander.es