For use with MikroTik You need to put E303 to modem mode.
Open your browser an go to
http://192.168.1.1/html/switchProjectMode.html
and
install drivers for modem
HUAWEI Mobile Connect - 3G Modem
in huavei terminal:
AT^U2DIAG=0 - switch to modem mode
AT^U2DIAG=375 - return to hilink mode
before use with PC need to reinsert device.
for use with PC install drivers for Ports
HUAWEI Mobile Connect - 3G Application Interface
and
HUAWEI Mobile Connect - 3G PC UI Interface
then use device like regular modem
p.s. My PC running on Win7x64