Web/E-business /

Add some PEP to your Web site

Performance-enhancing proxies can accelerate content delivery.

By Salvatore Salamone
Network World, 06/11/01

Several companies, including BoostWorks, Fireclick, NetScaler, Speedwise and wwWhoosh, are taking new approaches to accelerating the delivery of content. The products in this ill-defined market complement, not replace, existing performance- enhancing products and services such as load-balancing switches, caching devices and content delivery networks.

These new acceleration products operate as performance-enhancing proxies (PEP), which take requests from a user's browser to a particular Web server and perform some task, such as retrieving and converting a color image on that server to gray scale for a PDA user. Some work in conjunction with Web servers and operate on all the data passing between the user's browser and a Web server.

The approaches and technologies used to speed delivery of Web pages varies greatly from company to company. However, the efforts of these vendors focus on one or more of four basic areas: data optimization for different display devices; data compression in general; taking advantage of lulls between page transmissions to send objects to the browser's cache before a page is requested; and optimizing HTTP and TCP communications.

The new products and services aim to improve the user experience by reducing wait time to view a Web page. While this is important for any site, IT managers are finding this is essential for commerce sites. Improved performance can translate into increased revenue.

That was the case for Art.com, a commercial Web site with a gallery that includes more than 30,000 prints. Art.com, which was acquired last month by Allwall.com, experienced a 30% reduction in page download times using acceleration technology. Additionally, the company saw a significant increase in the number of visitors who bought items on the site.

"We monitored conversion rates so that we'd have a good apples-to-apples comparison," says Dennis Sage, Art.com's director of development. He says the only change made was to use Fireclick's Netflame service. "When we measured the results, conversion rates improved by 10%, which is huge for us,"Sage says.

Netflame is a Fireclick service based on the company's Blueflame technology. Blueflame and Netflame use what Fireclick calls "next most likely click" caching technology to improve performance. This technology analyzes user patterns when they come to a Web site.

Once a pattern is determined, the software takes advantage of periods when less data is being transferred (for example, when a user is viewing a page) to send elements such as text or image files of the next most-likely-to-click-on page down to the user's browser cache. If the user clicks on that link, many of the page elements are already stored in the user's cache, so there is no wait for the elements to be downloaded. To a user, it seems as though they have a faster link because pages come up in a shorter period of time.

BoostWorks tackles acceleration in another way. "We optimize and compress content for a user's device," says George Moore, BoostWorks vice president of sales and marketing. For example, most PDAs, which are increasingly being used for wireless Internet access, only have gray-scale display capabilities. "Yet most content is in color," Moore says.

A network manager supporting PDA users can use the BoostWorks products to retrieve the image object file from the Web server and convert it to gray scale. This reduces the file size sent to a PDA user's browser. BoostWorks then compresses data before it is sent to the user, improving the performance of any link, but especially a low-speed dial-up or wireless connection. For the compression, BoostWorks relies on the inherent decompression capabilities of browsers, so end users do not need special software.

Another vendor in the emerging acceleration market is Speedwise. The company's family of acceleration products use a combination of content reduction and compression, as well as caching, to improve performance. Content reduction, as the name implies, reduces the amount of data that have to be transmitted to the user's browser. This is accomplished using pattern-analysis techniques on Web page images. The company claims this process typically can cut the size of an image file to one-quarter or one-fifth its original size. Similarly, the elements of a Web page are compressed before they are sent to a user. The combination of reduction and compression means less data need to be sent to display the same page. Sending less data over the same performance link means the page appears on the user's screen more quickly.

Acceleration vendor NetScaler combines content acceleration with intelligent traffic management features in its NetScaler 3000 products, which began shipping in April. The products reduce the amount of TCP and HTTP traffic between a server and a user. This reduces the number of requests a server must handle to deliver any given Web page. The NetScaler product establishes persistent connections to the Web server and lets multiple users who want access to a Web page share these persistent connections. This approach eliminates some inherent inefficiencies with TCP connections within HTTP. Specifically with HTTP, when a user wants to access a Web page, TCP sessions need to be established for each element of a Web page. A page can typically have 20 to 40 distinct objects (text, links, images and others). Each object requires that a TCP session be opened, the object retrieved and the connection closed. The Web server would have to handle the same tasks over and over for each person who accesses the same page. NetScaler off-loads these tasks from the Web server by establishing the connections once. This eliminates the time needed to establish the 20 to 40 sessions per page.

A client approach

Most of these new acceleration products run on a server and do not require any change to the client. However, WebFlight from wwWhoosh requires an end user to download a small piece of software.

At least one network manger was wary of this approach.

"In public Web applications, I'm not sure if I would want an approach that requires the user to download something, even a plug-in," says David O'Neill, network administrator at Franklin Pharmaceutical, a specialty drug manufacturer. "But if it is for internal users and the performance improvement is significant, I'd have less hesitation to at least consider the approach."

WwWhoosh officials point out there are advantages to using a proprietary client component. "To make the Internet more efficient, we need to push intelligence out to the user," says Bill Santo, wwWhoosh's CEO.

Many of these acceleration products are just coming to market, with many companies introducing new technologies to the Web acceleration arena. IT managers should look closely at these products to see if they can help accelerate performance to their Web sites.