Peer-to-Peer Firms Try to Shake Up Content Delivery Market
CenterSpan Communications Corp on Friday added one of the finishing touches to its peer-to-peer content delivery network technology, with the acquisition of the intellectual property assets of Supertracks Inc. For $750,000 in shares, CenterSpan will get software that allows users to receive media streamed locally on their PCs.
The purchase will allow CenterSpan to launch its C-span network and join the emerging P2P CDN market. A handful of companies, including Kontiki Inc and OpenCola Inc, hope to rattle the cages of "traditional" CDNs like Akamai Technologies Inc and Digital Island Inc, by claiming to offer bandwidth saving to providers of heavy media content.
Regular CDNs store content on a system of edge-of-internet caching appliances, using a backbone performance measurements to figure out where best to serve content to a user from. One of the benefits they offer customers, apart from the ability to offer users a faster service, is reduced infrastructure and bandwidth costs at the origin web site, by offloading traffic and CPU time to the edge.
The new P2P CDN firms go one step further, actually leveraging the bandwidth of the end user to move content around the internet. Instead of co-locating pricey caching appliances at the data centers, firms such as CenterSpan have end users install software on their PCs that caches content, gathers bandwidth data, and uploads data to subsequent users.
CenterSpan calls the model of its C-star offering a "mediated, gated peer-to-peer network." The firm operates a number of "seeding" peers, where its clients' content is injected into the network. The first wave of end users download this content from the seeds through their client software.
Subsequent waves that hit these seed peers are directed to download from their peers. CenterSpan's software figures out the 10 best peers to download from, based on which network they are on, and the relative available bandwidth of downloader and uploader. The requested file is split into chunks, which are downloaded simultaneously, reassembled, and then streamed from the CenterSpan client software to a media player application.
"We're all about cost savings," said CenterSpan CTO and former SuperTracks employee Michael Hudson. He said that beta tests show files delivered over C-star are a ninth the cost of client-server streaming, which requires latency to be coordinated across the internet, and a third the cost of providing file downloads. Hudson said the company does not have a comparison to streaming or download services offered by other CDNs, but "we believe we have cost advantages," he said.
CenterSpan's will implement consumer- and business-focused services. The consumer implementation of C-star, Scour, has been online for some months, and the firm will shortly offer comparable services to entertainment content providers, ISPs and other companies.
CenterSpan closest rival will be Kontiki, which is also set to launch shortly. Kontiki's Delivery Network (KDN) is pretty similar to C- star, except Kontiki will offer the P2P delivery system as one of three bandwidth-saving products.
Another portion of the service allows companies to deliver files from multiple servers simultaneously, with the best-performing servers picking up the bulk of the load. It will also offer time- shifted delivery, so companies can take advantage of cheap nighttime bandwidth. Kontiki also has a split focus - it will target enterprises that want to distribute heavy content over their extranets, as well as entertainment companies.
A third player, OpenCola, will not offer a managed service, rather a set of software that allows companies to implement their own P2P CDNs. Like Kontiki and CenterSpan, OpenCola's Swarmcast breaks content into chunks to speed delivery. Unlike its rivals, it uses "forward error correction" technology to speed up the delivery.
Forward error correction, according to OpenCola technologists, breaks a file up into many more pieces than are necessary to reconstruct the file. The size of all the pieces could be up to eight times the size of the assembled file. These are fired at the downloader's PC, which uses the Swarmcast client to reconstruct the file.
While this may slightly increase the speed, the increased bandwidth makes the system not economical, says CenterSpan's Hudson. "It sounds like a good idea, but the overhead is too big," he said. "I don't see how it makes economic sense. I see huge redundancies."
CenterSpan is a little more vague as to how it compares itself to Kontiki, except that the rival firm is targeting a slightly different customer base and that Kontiki doesn't really market itself as a P2P firm.
While the new P2P CDNs are certainly taking on the likes of Akamai in a subset of their market (Akamai has streaming and digital parcel delivery services), they reckon they can also be cooperative. Hudson says C-star can work in conjunction with edge caching. But
Akamai clearly sees the services as competitors. According to a strict definition, Akamai's network is P2P, the company said in a statement. It's a different kind of P2P, of course, using what would normally be called servers, rather than clients.
"Desktop based P2P approaches may be fine for the sharing of music files but don't rise to the mission-critical standards of today's enterprise," the company said, giving security, performance and reliability as examples of where it thinks it outperforms its upstart rivals.
Akamai launched in quite a different market, where companies had lots of money to throw at their web sites' performance. Since the dot-com blowout, companies are looking more toward cost savings, and while Akamai is now pitching that story too, it has rivals that may or may not prove to have a better one.