The patent is at Delphion (free registration required) and the USPTO. Paul Vixie is listed as an inventor but probably has no ownership rights, or even the ability to collect on royalties. So don't lynch him yet...
The first base (or independent) claim is:
- A method for transferring information via the Internet, comprising the steps of:
- intercepting a message from an Internet user directed to a content provider address;
- determining whether or not the message is an information request;
- sending the message to the Internet without being affected if the message is not an information request;
- determining whether or not said information request relates to a content provider address having a corresponding alternative address, said alternative address providing at least part of the information provided at said content provider address; and
- directing said information request to said corresponding alternative address, if existing, or sending said information request to the Internet without being affected, if not.
Doesn't sound much like my understanding of how Akamai works (I didn't think Akamai "intercepted" requests -- the origin servers actually pointed to the cache servers in their img src tags). It does sound an awful lot like a transparent proxy however.
There's 36 claims, but only 3 are independent -- the rest are derived from those 3 (dependent claims). It's only the claims that are worth reading and worth worrying about. Press releases, abstracts and summaries are all irrelevant to what a patent actually covers. I find them more confusing than useful.
Let's concentrate on the 3 independent claims then. Here's the other 2:
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15. A system for transferring information via the Internet, comprising:
- first means for intercepting a message from an Internet user directed to a content provider address;
- second means for determining whether or not the message is an information request;
- third means for sending the message to the Internet without being affected if the message is not an information request;
- fourth means for determining whether or not said information request relates to a content provider address having a corresponding alternative address, said alternative address providing at least part of the information provided at said content provider address; and
- fifth means for directing said information request to said corresponding alternative address, if such a corresponding alternative address exists, or sending said information request to the Internet without being affected, if not.
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36. A method for efficiently delivering cached information to Internet users, comprising the steps of:
- intercepting a message from an Internet user directed to a content provider, the message requesting specific information;
- determining whether or not the message relates to a content provider address having a corresponding alternative address, the corresponding alternative address providing at least part of the information provided at the content provider address;
- determining whether or not the specific information is within the at least part of the information provided at the corresponding alternative address; and
- providing the at least part of the information to the Internet user, if the specific information is within the at least part of the information, or sending the message to the Internet, if not.
As you can see, the differences between these claims are very subtle. I'd need to spend more time reading those claims to understand what the patent attorneys were thinking when they drafted this. But they all seem to be getting at transparent proxies which select from multiple caches. And all three claims rely on "interception", however that may be interpreted. If you're serving pages and your URLs or img tags point directly at the cache server nearest that user, this does not seem to apply. If you're using SQUID, which does not involve determining which address from a list of alternative addresses it should grab the content from, then this does not seem to apply.
Anyway, free legal advice isn't worth the paper it's not printed on, so if you think you might be covered, get a patent lawyer. Just don't send them an e-mail saying "Help! I infringe a patent!". Instead, use the subject "innocent patent query." :-)
PS: I wrote about this once before -- but check the follow ups to that post, because I made a mistake last time. :-)