Please be sure to know that including a TTF with @fontface is not a good practice (e.g. in terms of browser support). It’s best to generate a webfont in such cases. For instance you could use FontSquirrel’s famous generator (that, btw, lets you choose subsetting in ‘expert’ mode).
Also, for fonts that are available on Google Fonts (like Roboto), you may find it useful to use Google Fonts. It’s easier and faster.