A lot of Gartner Invest clients are calling to ask about the AT&T deal with Cotendo. Since I’m swamped, I’m doing a blog post, and the inquiry coordinators will try to set up a single conference call.

I’ve known about this deal for a long time, but I’ve been respecting AT&T and Cotendo’s request to keep it quiet despite the fact that it’s not under formal nondisclosure. Since the deal was noted in my recently-published Who’s Who in Content Delivery Networks, 2010, someone else has now blogged about it publicly, and I’m being asked explicitly about it, though, I’m going to go ahead and talk about it on my blog.

There are now three vendors in the market who claim true dynamic site acceleration offerings: Akamai, CDNetworks, and Cotendo. (Limelight’s recently-announced accelerator offerings are incremental evolutions of LimelightSITE.) CDNetworks has not gained any significant market traction with their offering since introducing it six months ago, whereas these days, I routinely see customers bid Cotendo along with Akamai.

However, to understand the potential impact of Cotendo, one has to understand what they actually deliver. It’s important to note that while Cotendo positions its service identically to Akamai’s, even calling it Dynamic Site Accelerator (just like Akamai brands it), it is not, from a technical perspective, like Akamai’s DSA.

Cotendo’s DSA offering, at present, consists of TCP multiplexing and connection pooling from their edge servers. Both of these technologies are common features in application delivery controllers (or, in more colloquial terms, load-balancers, i.e., F5′s LTM, Citrix’s NetScaler, etc.). If you’re not familiar with the benefits of either, F5′s DevCentral provides good articles on multiplexing and persistent connections, as does Network World (2001, but still relevant).

By contrast, Akamai’s DSA offering — the key technology acquired when they bought Netli — is sort of like a combination of functionality from an ADC and a WAN optimization controller (WOC, like Riverbed), offered as a service in the cloud (in the old-fashioned meaning, i.e., “somewhere on the Internet”). In DSA, Akamai’s edge servers essentially behave like bidirectional WOCs, speaking an optimized protocol between them; it’s coupled with Akamai’s other acceleration technologies, including pre-fetching, compression, and so on.

Engineering carrier-scale WOC functionality is hard. Netli succeeded. There have been other successes in the hardware market — for instance, Ipanema, which targets carriers. Both made significant sacrifices in the complexity of functionality in order to achieve scale. Enterprise WOC vendors have had a hard time scaling past more than a few dozen sites, and the bar is still pretty low (at Gartner, we use “scale to over a hundred sites” on our vendor evaluation, for instance). A new CDN entrant offering WOC-style, Akamai/Netli-style functionality would be a big deal — but that’s not what Cotendo actually has.

Akamai’s DSA service competes to some extent with unidirectional ADC-based acceleration (F5′s WebAccelerator, for instance), but there are definitely benefits to middle-mile bidirectional acceleration, resulting in a stacked benefit if you use an ADC plus Akamai; moreover, this kind of acceleration is not a baseline feature in ADCs. Cotendo overlaps directly with baseline ADC functionality. That means the two companies have distinctly different services, serving different target audiences.

Cotendo is offering pretty good performance in the places where they have footprint — enough to be competitive. Like all CDN performance, customers care about “good enough” rather than “the very best”, but in transactional sites, there’s usually a decent return curve for more performance before you finally hit “fast enough that faster makes no difference”. This is still dependent upon the context, though. Electronics shoppers, for instance, are much less patience than people shopping for air travel. And the baseline site performance (i.e., your application response time in general) and construction, will also determine how much site acceleration will get you in terms of ROI.

The deal with AT&T is significant for the same reason that it was significant for Akamai to have signed Verizon and IBM as resellers years ago — because larger companies can be much more comfortable buying on the paper of a big vendor they already have a relationship with. And since AT&T’s CDN wins are often add-ons to hosting deals — where you typically have a complex transactional site — selling a dynamic acceleration service over a pure static caching one is definitely preferable. AT&T has tried to get around that deficiency in the past by selling multi-data-center and managed F5 WebAccelerator solutions, but those solutions aren’t as attractive. This partnership benefits both companies, but it’s not a game-changer in the CDN industry.

Since everyone’s asking, no, I don’t see Cotendo price-pressuring Akamai at the moment. (I see as many as 15 CDN deals a week, so I feel very comfortable with my state of pricing knowledge, especially in this transactional space.) What I do see is the incredibly depressed price of static object delivery affecting what anyone can realistically charge for dynamic acceleration, because the price/performance delta gets too large. I certainly do see Cotendo winning smaller deals, but it’s important that the wins aren’t coming from just undercuts in price — for instance, my clients cite the user-friendly, attractive portal as a reason to choose Cotendo over Akamai.

I have plenty more to say on this subject, but I’ve already skimmed the edge of how much I can say in my blog vs. when I should be writing research or answering inquiry, so: If you’re a client, please feel free to make an inquiry.

Interesting side note: Since publishing my Who’s Who note a week and a half ago, my CDN inquiry from customers has suddenly started to include a lot more multi-vendor inquiry about the smaller vendors. That probably says that other CDNs could still do a lot to build brand awareness. (SEO is key to this, these days.)