The CDN explosion

For a long time the CDN market could be summed up in one brand: Akamai. The overwhelming leader in the CDN space, Akamai still has the broadest reach and infrastructure by far, with more than 20,000 servers at more than 2,800 sites in more than 70 countries, 660 cities, and 1,000 individual networks.

But the market has expanded and segmented, with a number of companies focusing on Web application delivery. NetLi competed with Akamai in the application delivery space by using its own application-friendly network protocol in place of TCP. Internap also uses a proprietary protocol and does its own intelligent routing. The company's acquisition of VitalStream adds a CDN to the equation, although not with the reach of Akamai (which acquired Netli).

In fact, the importance of reach is a matter of heated debate in the CDN space. "It's a religious debate," says Melanie Posey, IDC research director for telecom markets. "Do you really need to be in every ISP and every geography on earth?"

Forrester's Whiteley agrees: "If your financial services portal is accessed by users in 12 major cities, do you really care that Akamai is in every country?"

Philip Kaplan, CEO of VitalStream, doesn't think so. "Akamai's technology was designed in the mid-'90s when people worried that the backbone itself would become congested, but fiber proliferated, and it never happened," he observes. "We designed our CDN from 2000 to 2002 with the idea that we could optimize the Internet and therefore wouldn't need to be in every hamlet, just close enough that the audience experience would be good."

Akamai counters that wide reach remains essential, because the problem lies in the cloud. "You have to be close to the user, or you simply can't address the issues on the Internet," Taylor says. "The farther the user is from the infrastructure, the worse the experience."

To emphasize his point, Taylor points out Akamai's ability to continue delivering content in the face of the recent earthquake in Taiwan. "Akamai continually builds a real weather map of the Internet in order to route traffic around bottlenecks."

Gartner research director Lydia Leong sums it all up as performance versus cost: "Being as close as possible has performance advantages and cost disadvantages, so the real question is whether you can tolerate slightly more latency for lower cost."

Part of the package

Carriers are also getting into the CDN game -- particularly AT&T, which has offered a CDN for several years as an option with its hosting and networking services and claims that the combination yields a performance advantage over CDNs alone.

"A customer can host themselves, but we like them to be in our hosting centers, so we can better optimize their applications," says Rose Klimovich, vice president of AT&T's Global IP Network Services. "As a carrier, we can also do our own network optimization, and as a tier-one ISP, we have good connectivity to other networks. Optimizing both what's in the hosting centers and on the network is a big advantage."

Other players have started packaging a CDN with other services. Although not a carrier, NaviSite offers a CDN and ADN with nine distribution sites as part of a suite of services, including collocation, dedicated hosting, managed applications, SaaS, and application development, aimed squarely at the needs of midsize businesses. NaviSite goes beyond caching to replicate the customer's entire data source in other locations and has some routing optimization technologies of its own.

CDN vendors are starting to package other value-added services, such as DRM (digital rights management), authentication, external verification, rules- and roles-based access, content management, live event production, and account management, to help customers create, manage, and accelerate their content. Already, major providers are wrapping these services into appealing bundles.

Akamai recently acquired Nine Systems, which offers a suite of solutions aimed at the management, control, and monetization of rich content. VitalStream offers services that insert advertisements into live and on-demand streaming broadcasts to target specific listener demographics, along with ad campaign management features and ad results reporting. And Local Mirror will deliver a full range of event production, broadcasting, and video encoding and conversion services.

Ultimately, CDNs may become commodities rolled into broader service packages. What's clear to an increasing number of IT departments, however, is that building new datacenters in response to availability and latency issues isn't necessarily the best answer.

"If I had the chance to design my systems all over again, Akamai would be a much bigger part of everything," Williams says. "I'd use them to take the place of lots of local storage, Web services, and infrastructure. I might even take some J2EE-compliant applications and just run the whole thing on the edge."