Google-presentation-public.pdfMany people in the industry have been clamoring for the presentation that Dan Rayburn posted in his blog and then removed regarding Google's Global Cache and their view on the challenges of scaling a CDN.
I don't have the actual presentation but what I do have is the presentation that Google gave at the African Network Operators' Group back in June 2008 on Content Delivery Networks and the Google Global Cache. I apologize in advance for the redirected link, the truth is I never got around to implementing a file attachment feature.
Technologies may have changed between 2008 and 2011 but the same premise of networking and edge delivery still holds true. Peering is still the largest bandwidth and opex (operating expense) saver for network operators. Reading about Google's Global Cache is like turning the pages on Akamai's Content Delivery Network technical specification document. As I browse through the content I keep wondering if Google is infringing on Akamai's patents on DNS and content caching, specifically patent #6,108,703 and #6,553,413. They are pleasantly referred to as the 703 and 413 patents.
Briefly, the 413 patent is where the method of directing the object requested (by the browser usually or other end point devices) to the closest regional node with maps updated by traffic and network conditions. This is the core of the TLNS (top-level name server) and LLNS (low-level name server) methods that Akamai has used to dominate the CDN, Content Delivery Industry. The algorithm is based on a min-cost calculation.
The 703 patent is a method where algorithms are used to replicate content and serve the most popular content at unlimited nodes, globally.
A third patent, not as sensational (due to the back seat it has taken in litigious events; but it's the most significant feature that allow ISPs to save bundles of cash) is the 7,103,645 patent which allow ISPs to control traffic on its network. This allow ISPs to serve content to its local users and avoid the bandwidth/transit charges from transmitting over the WAN (tier 1 networks).
Let's examine how closely this relates to Google Global Caches' presentation. Page 10 of the Google's Content Delivery Network presentation talks about saving ISP bandwidth, ISP money and improving performance from local caching and serving of content. This exactly describes the 645 patent. Akamai's entire premise and raison d'etre is patent 645.
Page 9 of Google's CDN paper shows GGC servers deployed per ISP at 4-6 server clusters. Akamai's is 4-8 in a cluster with multiple clusters within an ISP depending on traffic sizing.
Page 7 of Google's content delivery paper shows it uses a DNS-based content director method in addition to a geo-IP database to accurately map the end-users IP to the closest Google Global Cache cluster. Akamai's 413 is exactly that. The only thing I'm uncertain of is the additional look up against the geo-IP database. I would have to dig up the 413 patent and re-read the monster. Also, there is an distinct between using the end-user IP versus the IP of the local DNS cache server, which would have to be ascertained.
Page 6 describes Google DNS resolution method which closely mirror's Akamai's DNS resolution method in the 413 patent. Content request goes from the local DNS to Google's or Akamai's DNS for a more accurate resolution, which takes the request closer to the end-user.
Page 5 is Akamai's 703 patent which describes how their edge nodes caches the request for future requests from users from that regional.
Maybe I missed a news article on Google licensing Akamai's patents. I don't know but Google's Global Cache is a Mirror Image of Akamai's CDN. Pardon the pun, on Mirror Image, it was just irresistable. By the way, Mirror Image is a CDN services company.
Enjoy the presentation. When I get a hold of the newer presentation I will be sure to post it.
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