ttyACM0, ttyUSB0, usb0 ???

[José Queiroz <zekkerj gmail com>]

Hi,

I used to use a 3g usb dongle (Sony MD300). The first time I plugged
it, it created a device called "ttyACM0", in a way that I could use
wvdial and use pppd to conect it.

But after some updates on NetworkManager, it started to show up as
"usb0", and the pppd process was hidden in some way that wvdial could
no more work.

Now I have another dongle (Onda MSA405HS), from another ISP, and when
I plug it, it shows up as "ttyUSB2". I can easily connect using
wvdial, but NetworkManager doesn't works.

My questions:

1) Why did the MD300 changed from "ttyACM0" to "usb0"? Will this be a
rule, in all 3g connections?

2) Why didn't "ttyUSB2" turned into "usb0", also?

3) The MSA405HS have 2 other devices, "ttyUSB0" and "ttyUSB1". Why do
NM chooses to work with "ttyUSB2"?

4) How can I configure NM to give me more information, said, activate
debug messages right from boot?

5) I created a connection called "Claro3G" to use with the MD300, and
another one called "TimWeb" to use with the MSA405HS. How can I assure
that "Claro3G" will use the "usb0" device, and "TimWeb" will use
"ttyUSB2"?