First sorry for the late answer, i'm a little bussy, yet posting in bt4 prefinal thread.
and because i'm moving this thread to bt4 prefinal.

Quote Originally Posted by bitvijays View Post
lsusb output is
Bus 002 Device 009: ID 12d1:1001 Huawei Technologies Co., Ltd. E620 USB
this device called Huawei Technologies Co., Ltd. E620 USB Modem. so basically it's hwawei e620 modem.

Maybe you want try to look at this,

for usb_modeswitch, you can add manual configuration, you can look for id storage device and id for modem, then you can edit the configuration, basically (again) the format still the same,
DefaultVendor=  0x???? ;this is vendor for storage
DefaultProduct= 0x???? ;this is product id for storage

TargetVendor=   0x???? ;and this line and below belong to modem id.
TargetProduct=  0x????
from your output, it's look like your modem vendor 12d1 and id 1001. find the default or storage product id.

if you done nothing before than lsusb, then that vendor and id belong to your storage default. then you must looking for modem id. because the vendor would be the same.