Re: ttyUSB* device for ModemManager

[Dan Williams <dcbw redhat com>]

On Mon, 2011-11-21 at 15:13 +0530, Jaymin Patel wrote:
> Hello,
> 
> 
> I am using modem that is not detected as /dev/ttyUSB0 instead its
> detected as /dev/ttyUSB1. Want to know how ModemManager selects
> ttyUSB* device for Mobile Broadband connection.

MM selects the first port that passes probing as the main port (except
for Huawei modems where it always uses USB interface 0), unless it's
been "tagged" according to the udev rules.  Some modems only allow PPP
on specific USB interfaces, and for those we have to find the Windows
driver and look at the .INF files for which interface is supposed to be
the "modem" or PPP interface.  Note that USB interface numbers don't
directly correspond to the X in ttyUSBx (or ttyACMx).

What modem is it that you're having trouble with?  It may be as simple
as getting the Windows driver and figuring out what the port mapping is
supposed to be.

Dan