For the past year or so, several content delivery network providers have been at odds in the courts. The players involved were Akamai, Cable & Wireless (formerly Digital Island) and Speedera - but now Mirror Image is jumping in.

The whole legal flap started when Akamai sued Digital Island for patent infringement in 2000. Digital Island fired back with a patent infringement claim of its own. Since then there have been jury rulings, debates over whether infringing technology was still in use, requests for injunctions to shut down service, and new patents awarded.

Last year Speedera got pulled into the imbroglio when Akamai accused Speedera executives of illegally hacking into a protected database to get Akamai customer information. Claims of unfair competition were also traded.

The whole thing turned into a kind of sour wrapping for the CDN market that has been trying to pull itself out of a tough economic situation. Things have gotten better for the CDN business, and the patent factor faded into the background after reaching a peak last fall.

But now, the patent issue has raised its head again. This time it's Mirror Image, which had so far stayed out of the patent fray:
http://www.nwfusion.com/news/2003/0630cdnpatent.html

Last month Mirror Image announced it had secured a patent covering its core technology, which includes transparent caching. Plus, it covers cache aggregation technology to combine multiple caches into a single entity that not only caches content, but also handles storage and transaction processing, Mirror Image execs say.

They say the patent covers technology currently in use by other service providers and caching companies. I smell a whole new round of patent litigation brewing. What do you think? Let me know at mailto:jmears@nww.com

Ann Bednarz is associate news editor at Network World.