High-speed dialup, sometimes advertised as broadband dialup, is an Internet service provider (ISP) feature that speeds up data transfer by using a special server, called an acceleration server, to act as a bridge between the user's dialup connection and a Web page. The acceleration server uses a fast broadband connection to request the Web page on behalf of the dial-up user. When the acceleration server receives the data it requested, it caches the page, compresses the data, and filters out any popup ads before sending the Web page on to the dialup user. To the average user browsing the Internet, the caching, compression, and filtering techniques can make a dialup connection seem up to five times faster than normal.
Because an acceleration server compresses data and not all data can be compressed with current technology, some kinds of Web content can not be brought in faster by using high-speed dialup. Currently, these data types include streaming media, secure Web pages, downloads and multi-media email attachments.