Dial-up accelerators.....

[Chuck Wintle]

How do dial up accelerators work? there are a lot of programs that claim it can "speed up" a connection but how do they do it?

[Mike Circo]

I'm not equipped to give an extensive response.

However... They work by caching pages and parts of pages to your local computer. The massive speed improvements represent a return visit to a site. The software detects that the page resided on the local computer and pulls up the majority of the graphics locally, and only pulls the updates over the dial-up line.

Downside is it takes processing and disk on your local machine.

Upside is it helps on sites you visit often.

For a lot of random visits its no help. It does not speed up downloads of software (like an update) nor does it speed the loading of content not part of an original web page (like someone's attached photograph).

Save your money and get broadband.

[Dave Shaffer]

Mike is correct. Look at the bottom right corner of this post. There is a graphic that says "Quote". There is another one at the bottom of the page that says "Post Reply". All these are graphics. There are a lot of graphics all over this page and just about any page you bring up on the web.

Every time you click a page all those graphics have to be downloaded to your browser before they can be seen on the page. What a Dial-up Accelerator does is it keeps a copy of these graphics on your computer so they dont have to be downloaded each time.

Like Mike said, just about every page here has those graphics and the dial-up accelerator will speed things up here. But if you are going to different sites with each click, the graphics are all going to be new and different so they wont be saved. They will all have to be downloaded. In that case it won t help.

[Rob Russell]

I'm gonna be a bit contrary here and dispute Mike and Dave's answers.

Your web browser almost automatically caches images like the Quote and Post Reply button GIFs. For IE, under Tools, Internet Options, click on the Temporary Internet Files Settings button. It's probably checked "Automatically", which means that it's checking to see if the images have changed before downloading a new copy of it.

What the accelerators do is compress and decompress the data stream. There is a lot of repetition in the text that goes back and forth. By compressing the data stream before transmission, the amount of "modem time" (my term) is cut. Processors are fast enough these days, that the amount of time spent compressing before transmission (on their server) and decompressing (on your PC) is less than the time spent in transmission over a dial-up line. That's also why the speed increase only applies to surfing and not image/file downloads.

Random websurfing over a dial-up connection, especially if you suppress images from downloading, should be faster with this option.

I will say that I just got a cable broadband connection 2 days ago. Even running wireless remote, the speed increase is amazing. I downloaded a 12+ meg Office update as part of the latest MicroSquish security boondoggle (the JPEG problem), and the download look less than a minute. That was sitting on the couch watching the Red Sox plaster the Angels, with the only cord hooked up being the charger. No cord stretched to the phone outlet. It would have been hours over dialup.

Rob

[Aaron Koehl]

Charles,

What has been described thus far is simple caching--which is performed by your browser whether you are on dial-up or not (depending on your settings).

Here is a simple explanation of how dial-up accelerators work:

Dial-Up accelerators work by reducing the amount of data that needs to be transmitted over your phone lines. When you make a web page request, that request is sent over your phone line to a server connected to the Internet via a high-speed connection. The server then downloads the requested files over its high speed connection (e.g, a proxy), usually into a database where the files are compressed. HTML and text-based content are then compressed (like making a .zip file), and the resulting compressed file is sent over the phone back to your computer, where it is uncompressed and rendered in your browser. The text compression techniques are lossless, but text is really not a major time-consumer on dial-up anyway. This is where the graphics compression comes in.

Graphics files are compressed in a different way. When it comes to graphics, there is a trade-off between graphics quality and file size. Dial-up accelerators compress graphics on the server (at the proxy), and send the resulting compressed graphics back to you. The quick compression techniques employed are usually lossy jpeg compressions. Depending on your accelerator settings, the server will either send you highly compressed graphics (poor quality, difficult to decipher) or lightly compressed graphics (no compression employed). The graphics with a lower compression will take longer to download, but the idea is that most of the graphics you view on the web don't need to be high quality.

Thus, you can choose to view lossy, pixelated graphics but as an advantage they take much less time to download. Most casual surfers, particularly those reading text content specifically, don't really need to download high-quality web site images.

There are other speed increasing techniques employed by the proxy itself, like caching of the images that it compresses (much like your browser). This is just a broad overview of what's going on.

[Todd Burch]

While in New Mexico recently, visiting my dad, I used his dial-up PC at his office. He uses AOL. I went to my website to show some of my work to him, and the image quality was terrible. He was using AOL 9.0 "Optimized", and the pictures that were out there as 35K to 50K bytes in size were being delivered to his PC as 6.5K bytes. They looked TERRIBLE.

I opened up IE on his PC, and showed him the pictures via that method (instead of through the AOL interface) and the pictures were, well, picture perfect.

[Dan Mages]

If you are referring to the software that is offered in pop-up ads, DO NOT install that software!! It is malicious spyware that will track your movements on the web.

Dan