How High-Speed Dial-Up Functions

While browsing the Internet, do you find yourself stepping away to grab a cup of coffee, read a magazine, or even retile your bathroom between page loads? If so, you’re probably using a dial-up connection, and you might be wondering: Is your connection slowing down?

It’s a bit of both. The speed of dial-up is still constrained by the bandwidth of phone lines, but at the same time, the average file size of web content continues to increase. More people are using broadband connections that can handle larger amounts of data, causing websites to become more expansive. Squeezing all that data through a dial-up connection takes a lot longer.

New technology presents a solution to the slow speeds without requiring broadband. Services like NetZero and EarthLink now provide 'high-speed dial-up.' According to their advertisements, these services promise connection speeds up to five times faster than traditional dial-up.

When you think of dial-up internet, the first thing that probably comes to mind is the distinctive, 'R2-D2 in a blender' type noise made by the modem as it connects. This sound is called the handshake protocol, and it's the initial factor that slows down dial-up internet speeds.

The handshake protocol, as its name suggests, starts the process that enables data transmission to and from your computer over the Internet. There are actually two separate handshakes involved. The first is the modem handshake, where the modem sets up the Internet connection. The second is the software handshake, which authenticates your access to the Internet Service Provider (ISP). When your computer makes those chirping noises, it is essentially introducing itself to the ISP. While high-speed dial-up services can’t speed up the modem handshake, they can improve the software handshake.

On the next page, learn about the standard software handshake and how it can be made faster.

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High-Speed Dial-Up: Acceleration Servers

The standard software handshake typically follows this sequence:

This is a simplified version, of course, but it illustrates the back-and-forth exchanges that happen in the handshake protocol before any data can be sent or received. High-speed dial-up providers have streamlined this process by creating a system that allows the machines to remember previous responses, significantly shortening the conversation:

This shortened handshake leads to significantly faster connection times. The speed improvement varies depending on the machine, but in some cases, it can reduce the handshake time by as much as 50 percent. What could take 45 seconds on a standard dial-up service might only take around 30 seconds with a high-speed service.

When you request a web page on the Internet, your request is routed through your ISP to the Web. After passing through several intermediate machines that help locate the page you're searching for, your computer finally connects to the server that hosts the requested page. Once this connection is made, data can flow freely from the web server to your computer. However, when the information leaves the web server and enters your dial-up connection, that’s where the typical Internet bottleneck begins.

High-speed dial-up providers have developed some innovative ways to overcome this bottleneck. By installing special software on a server, they transform it into what they call an acceleration server. By inserting this acceleration server into the process between your dial-up connection and the web, they can dramatically speed up the entire transaction.

When you search for a webpage using high-speed dial-up, your request is sent from your computer’s dial-up modem to your ISP’s acceleration server. The acceleration server then requests and retrieves the pages on your behalf. It uses a broadband connection to search the web for the server that hosts the page you're seeking. Once it finds the right server, the two machines begin exchanging the required information. The acceleration server then sends the data back to your computer.

Acceleration servers enhance dial-up data transfer using a variety of methods:

Now, let's explore how these acceleration servers really kick things into high gear for your dial-up connection.

High-Speed Dial-up: File Compression

The cornerstone of high-speed dial-up Internet is file compression. If you're familiar with How File Compression Works, you're already aware that file compression comes in two forms: lossy and lossless.

Text files and other types of data that need to remain unchanged during compression utilize lossless compression. After being uncompressed, these files revert to their original form.

Images and graphics can be compressed using lossy compression. Upon uncompression, these files won’t be exactly the same as before—they lose some of their original data. For example, a photo that originally had 2 million colors might only have 16 thousand after lossy compression. While the loss in quality may be noticeable, it’s often a small price to pay for the speed benefits. Services like NetZero allow users to control the level of compression applied to images and specific websites.

File compression is an ever-evolving technology and is not yet compatible with every file type. The information below will help you understand which files can and cannot be accelerated with high-speed dial-up.

Accelerated

Not Accelerated

Currently, the on-the-fly file compression used in high-speed dial-up cannot be applied to the above file types due to the nature of the data. For example, data on secure Web pages is encrypted. When transmitted, the encryption appears as random characters to ensure privacy. If this encrypted data reaches the acceleration server, it cannot be compressed: Altering even one character in the encryption would make the data unreadable.

Here’s how a typical acceleration server compresses various file types:

In the upcoming section, we’ll explore how high-speed dial-up accelerators filter out unnecessary data, further boosting speed.

High-speed Dial-up: Filtering and Caching

When you enter a URL (like www.AnyWebSite.com) into your browser’s address bar, you’re requesting a specific page. If that page contains pop-up ads, hidden pop-up parameters in its programming code trigger the ad when the page loads. These parameters tell your machine the size, placement, and other specifics of the ad. The transmission of these extra details consumes valuable bandwidth, slowing down the data flow to your machine.

To combat this slowdown, high-speed dial-up services incorporate a pop-up blocker within their software. This blocker identifies and rejects the lines of code that control the pop-up ads. By doing so, it prevents unnecessary data from being sent over the phone line, which results in faster loading times.

Caching

When your browser first loads a Web page, it has to fetch everything, including all the images. However, if the browser stores the images and text, it can check if they’ve been updated the next time you visit the page. If nothing’s changed, there’s no need to re-download the images. This process of saving files for future use is known as caching. For more details on how caching works, see How Caching Works.

High-speed dial-up employs a similar strategy for frequently accessed Web pages. Instead of repeatedly requesting the same page, the acceleration server keeps track of the most requested pages from all users. So, instead of asking the Mytour server thousands of times a day for its homepage, it only makes the request once. Afterward, the server stores the page in memory and sends it directly to any other user who asks for it. This process is known as server-side caching, which speeds up browsing by avoiding unnecessary requests.

There’s another aspect of caching—client-side caching. Web browsers like Explorer or Netscape are designed to store frequently visited pages on your computer to minimize loading times for future visits.

The browser saves cached pages on your computer's hard disk. High-speed dial-up software optimizes this feature by not only storing frequently accessed pages but also identifying elements that remain unchanged. For example, instead of caching the entire Mytour homepage, which is frequently updated, it focuses on static elements like the logo, header, navigation, and search bar. These elements are saved, and only the changed parts of the homepage are reloaded each time you visit.

Caching helps save time by preventing unnecessary data transfers. The most remarkable aspect of this tool is how it combines server-side and client-side caching to learn your browsing habits. By doing so, it streamlines the connection process more effectively with each use. The more you browse, the faster it becomes.

Compression, filtering, and caching are the three primary steps in speeding up dial-up connections. But what happens when all three methods are combined? Does performance really improve? And is the improvement noticeable?

The answer is yes, and in the next section, we will explore NetZero to test how well it actually performs with real-world Web pages.

High-speed Dial-up: The Bottom Line

Now that you have an understanding of how it works, let's take a closer look at how effective it is. We decided to test out one of the more popular high-speed dial-up providers, NetZero, to see how much it can speed up a dial-up connection.

After signing up for the service and selecting the default settings, Mytour explored the Web using both regular and high-speed dial-up connections to measure the difference in speed.

Upon logging in, we repeatedly visited some of the most visited websites on the internet. The results varied by site, but for instance, Mytour loaded three times faster with the high-speed dial-up connection.

It seems that a smart blend of fairly simple technologies has managed to smooth out some of the typical slowdowns of dial-up Internet. These innovations help extend the life of dial-up, offering a viable option for those who are fed up with traditional dial-up but aren’t quite ready to make the jump to broadband. If these innovations keep evolving, dial-up might be sticking around for quite some time.