Hi Marko,

 >
> _And the fail log _(on reconnect):
>
> Jun 29 15:19:34 mx31tt01 daemon.debug ofonod[657]:
> gprs-context.c(240):at_gprs_activate_primary() cid 1
> Jun 29 15:19:34 mx31tt01 daemon.info ofonod[657]: Modem: >
> AT+CGDCONT=1,"IP","web.one.at"\r

Your modem is not responding to this AT command.  There's not much that 
can be done on the oFono side.  You need to figure out why the modem is 
acting this way.

> ...
>
> Jun 29 15:20:14 mx31tt01 daemon.err connmand[561]: Failed to change
> property: /he910_0/context15 org.ofono.ConnectionContext.Active:
> org.freedesktop.DBus.Error.NoReply Did not receive a reply. Possible

Regards,
-Denis