IDT (IDT) subsidiary Net2PhoneÂ sued Skype for patent infringement in the middle of last week, and somehow I missed it. Courtesy of Om Malik, here is a copy of the suit, including the patentÂ which was submitted as evidence.Â
Rich Tehrani commented that “Anyone who has been in this business long enough knows that before Skype ever existed, Net2Phone was selling VoIP service.”Â Andy Abramson asks whether EBay did sufficient due diligence before the acquisition.
This morning’sÂ Business Week asks whetherÂ the suit can ground Skype.Â Â It speculates that this is an opportunistic action, and that there is likely to be a countersuit by Skype claiming infringement of it’s patents.Â A quick search at USPTO.GOV, though, reveals more than 100 granted patents or filed applications by Net2Phone, and none that I could see by Skype.Â
The patent itself isÂ an interesting read.Â Filed in September of 1995, it contemplates a system for looking up the IP address of other voice capable clients on a network using either a database, or an email based exchange of addresses, and then permitting streams of packetized data to flow between the clients.Â Clients register, signal availability, and initiate sessions.Â It’s starkly similar to the SIP architecture, or for that matter, to DNS.
Is this the atomic bomb of VoIP patents?Â Should we expect to see suits against all SIP vendors?
It turns out that SIP, and it’s precursors, may be prior art.Â Henning Shulzrinne published the first SCIP (the precursor to SIP) draft in February of 1996, and in March of that year presented a paper titled “Personal Mobility for Multimedia Services in the Internet“, which provides details of many very similar ideas.Â Although these works were published after Net2Phone’s patent filing, 36 precursor works are cited in the references of Shulzrinne’s paper.Â
There may also be an H.323 connection.Â In May of 1996, the ITU approved the H.323v1 standard, which also contemplates a similar registration and signalling regime.Â Obviously the standard didn’t emerge fully formed in May of that year.Â It was likely several years in the making.
Dawn Kawamoto’s story on CNET also has several commenters suggesting other examples of prior art.Â
Net2PhoneÂ isn’t a patent troll, but ultimately the patent they’ve been granted may not be worth anything either. This should be interesting to watch play out.