Web Acceleration - How it works

If you're still using dial-up Internet access because Broadband DSL or Cable is not an option for you, you've probably faced the frustration of how sloooow the Internet can be, and sometimes it seems like it's getting slower and slower all the time.

The connection speed of dial-up is limited by the bandwidth of phone lines, yet file sizes on the web are getting larger and larger. Broadband connections handle these files fine, but for those people stuck with dial-up just downloading a web page can mean taking a break to grab a cup of coffee or read the newspaper while waiting for the page to display.

New technology, called web acceleration, is now available to increase dial-up speeds. Many of the Internet Service Providers reviewed on this web site are now offering web acceleration for a small additional monthly fee. They advertise connection speeds that are up to five times faster than traditional dial-up service. We have also found a couple "stand-alone" accelerator services that you can use with your current Internet service.

Faster Connections
With an accelerated service, the first thing that gets speeded up is your connection time, or the Handshake between your computer and your ISP. High-speed dial-up allows your computer to establish a connection with your ISP in a fraction of the time it takes with standard dial-up by memorizing certain data and shortening the back and forth conversations between your computer and your ISP.

When your computer is connected to the Internet, via your ISP you can request data from the Web. Your request is routed though a series of machines along the way before it reaches the server that holds the page you're looking for. Once this connection is made, data can flow freely from the server to your computer, but when it hits your 56k dial-up connection it gets bogged down.

Highspeed dial-up providers have come up with a solution to this bottleneck. They have loaded software on their machines so that when the data is being fed back to you and hits their machine, it can be speeded up considerably.

Now when you request a web page the request is going through the ISP's acceleration server and that machine is requesting the page on your behalf from the Internet. The accelerated server uses a broadband connection to quickly search the Internet for the page you want and sends it to your machine. The server uses several techniques to speed up the data transfer including:

Compression
Compression is the key element of high-speed dial-up Internet. Some files can be compressed and therefore accelerated and others cannot. Those that can include html/java based web pages, text, jpg/gif graphics, and email. Those that cannot be compressed include streaming media (audio or video), secure web pages, music/photos sent as email attachments, and downloads.

Photos and graphics can be transmitted using lossy compression. When these files are uncompressed on your computer they are not quite as high quality as the original because they lose some data during the process. This loss in quality is usually not too important to the user when compared to the increased speed that is gained in the process. Some accelerated services allow the user to control how much compression is used on photos and certain sites. In general, text files are usually compressed at least 50% and image files anywhere from 50% to 90%.

Filters
Many pages you request have pop-up advertising programmed into the page. These pop-up ads take up valuable bandwidth and slow down the transmission of data to your computer. Highspeed Internet providers have incorporated a pop-up blocker into the software they provide to their users. The pop-up blocker recognizes the advertising code and rejects the request to display the ad. This amounts to less information being sent across the phone line to your computer, so you get a faster load time.

Caching
Every time you load a new web page, your browser has to load the page text and images. The browser saves the images and text and the next time you request that same page your browser looks to see if there are any changes. If there are none, it doesn't have to download that page again; it serves it from memory. This process is called caching.

With highspeed dial-up, caching is a combination of server side caching and client side caching and saves time by avoiding unnecessary data transmission. By memorizing your surfing habits the accelerated server and your computer can "learn" to streamline your connection process

Client side caching occurs when browsers like Internet Explorer or Netscape cache (or save) frequently viewed pages to cut down on load times. These files are stored on your computer's hard disk and highspeed dial-up software enhances this feature. For pages that change regularly, the software looks for elements of frequently viewed pages that don't change and saves only those portions. Then it only has to load what has actually changed each time you request the page.

With server side caching, the accelerated server takes note of what pages all the users of the service are requesting and instead of requesting the pages over and over again, it saves a copy of the page in its memory to send to each person who requests it. This saves time by eliminating redundant requests.

In Conclusion
The combination of compression, filtering and caching are the key techniques used by web accelerators to speed up dial-up connections. This combination has helped to overcome some of the hassles of dial-up and will certainly prolong the life of dial-up Internet service and provide an alternative for those who are tired of standard dial-up, but not ready to jump to broadband.