ModemManager auto reconnect

[Dan Williams]

On Tue, 2016-02-09 at 07:31 +1100, Brendan Simon (eTRIX) wrote:
> Hi,
> 
> I have a number or remotely deployed arm embedded linux systems that
> uses a 3G modem via USB to post http information once per second. 
>  The
> modem goes down from time to time.  One reason is we assert the power
> reset line on the modem once a day (as I've been told that the modems
> need to be reset periodically, otherwise functionality degrades or
> eventually lost).  The other reasons I am not sure of (service
> provider
> initiated?  bugs in the application code?
> 
> The modem can be off for many hours before eventually reconnecting
> (possibly by watchdog reboot) which is not acceptable for our real
> -time
> monitoring application.
> 
> Does MM automatically try to re-establish a connection if it sees the
> connection go down, or the modem is reset?
> 
> Are there recommended or suggested MM settings such that MM will
> continually try to reconnect if the modem goes down then back up?

This is left up to the connection manager that controls ModemManager
and tells it to connect.  So whatever you're using to tell ModemManager
to start the data connection, that's the thing that would monitor for
the modem being disconnected and periodically restart the data
connection.

Dan