Askey USB modem detected but there is no internet connection

[Hermanh]

I am not really supprised by that. Your USB is used as an ethernet interface. I hoped it was another interface name. That would solve the problem of someone else.

[Hermanh]

For Guest:
I did make a mistake in the post regarding to the command

route add default gw xxx.xxx.xxx.xxx

I changed it (fat and underlined).