Some internet service providers offer dialup connection using acceleration technology and call this high speed dialup internet access. They claim that this technology can help you surf up to 4x or 5x faster than regular dialup service.
Acceleration technology compresses text and graphics more efficiently to reduce the size of these files. It also uses caching to retain some web pages and page elements that you have previously viewed, so the more you have viewed certain web pages, the faster they are loaded. Accelerated dialup connection also uses techniques to maintain a persistent connection between the modem and the server so less time is wasted in re-establishing TCP/IP connection.
However, this technology cannot speed up the download of media files, secured web pages and email attachment. The result of acceleration technology may vary depending on the page elements, file types and how often you have viewed the web pages, etc.
In reality, the term high speed dialup internet service is a bit misleading. High speed internet such as DSL is capable of transmitting 256 Kbps or more regardless of file types or page elements. In contrast, accelerated dialup access does not increase the overall throughput of the line but only improves the efficiency of available bandwidth, and its performance is affected by file types, page elements and cache data.