thank you
now i'm trying using old E1750 modem (i never used before, so i don'è know if the script under usb_modeswitch is correct)...
next month i'll use the 3g key i use in the car, so will be more correct
@now wvdial says me:
--> WvDial: Internet dialer version 1.61
--> Initializing modem.
--> Sending: ATX
ATX
OK
--> Sending: ATQ0 V1 E1 S0=0 &C1 &D2 +FCLASS=0
ATQ0 V1 E1 S0=0 &C1 &D2 +FCLASS=0
OK
--> Sending: AT+CGDCONT=1,"IP","TM",,0,0
AT+CGDCONT=1,"IP","TM",,0,0
OK
--> Modem initialized.
Segmentation fault