Having just an otf file is not sufficient. Different web browsers require different file formats, and as always, IE is the troublemaker.
@font-face{
font-family: 'YourFont';
src: url('../fonts/YourFont.eot');
src: url('../fonts/YourFont.eot?#iefix') format('embedded-opentype'),
url('../fonts/YourFont.woff') format('woff'),
url('../fonts/YourFont.ttf') format('truetype'),
url('../fonts/YourFont.svg#webfont') format('svg');
font-weight: normal;
font-style: normal;
}
A valuable tool for generating both the code and the necessary files can be found at
Enjoy the process!