I used the fontinstaller and it generated 3 files within the fonts folder "fontawesome-webfont.ttf", "fontawesome-webfont.ufm" and "fontawesome-webfont.umf.php.
As a result of that, the codes(f.e.) standing for a character, disappeared but were not replaced with one of the icons of fontawesome.
what do you mean with @font-face?
thanks for the quick reply.