Asterisk on a mirabox with chandougle

my other problem is that i bought a mirabox to use for my asterisk pbx
install asterisk 11.4 everything works perfect. my problem is that
i have failed to mount my modem on Mirabox to use chandougle as my gsm gateway
Mirabox does not have usbtty . it loads it as a usb. i have used Sakis3G script still no success

any one who has managed to mount usbmodem on Mirabox please help