The software, hosted on an out-of-the-way corner of the company's research and development site, is aimed at showing that a technology commonly used in Internet phone calls can be adapted to create a peer-to-peer network.
The "SIPshare" program--the name stemming from the Session Initiation Protocol technology the program is based on--is part of a larger EarthLink drive to show the flexibility of peer-to-peer networks, the site says. On the research page, the company outlines a vision of creating voice over P2P, video services using peer-to-peer, and other applications, all based on the Net-calling standard.
"EarthLink believes an open Internet is a good Internet," the site says. "An open Internet means users have full end-to-end connectivity to say to each other whatever it is they say--be that voice, video, or other data exchanges--without the help of mediating servers in the middle, whenever possible."
SIPshare might be simply a proof-of-concept piece, but it also highlights a new freedom of action for technology companies, following court decisions that recently cleared commercial peer-to-peer software companies of much liability for copyright infringement.
Development of peer-to-peer technology, most commonly associated with file-swapping programs like Napster or Kazaa, has labored under the cloud of legal liability for several years. Though it carries the potential for a wide range of applications, from chat to processor sharing, the technology has been hampered in its evolution by the fear that individuals might use it for trading MP3s, a concern that's raised the ire of the record industry.
However, last month a federal appeals court in Los Angelesthat said software companies Streamcast Networks and Grokster were not liable for copyright infringement perpetrated by people using their products.
The SIPshare site warns that the Java-based program is not a supported EarthLink product. EarthLink Vice President Tom Andrus said that the company has not decided whether to turn it into a fully developed consumer application, but that EarthLink does expect to do more with SIP.
"I think in one way (this program's release) is a very public gesture of our support for SIP," Andrus said. "The more developers we have behind it, the more interoperability we have with other companies, the better we'll be in the future."
Session Initiation Protocol has been emerging for several years as a powerful way to connect Internet phone calls without using a centralized server as a kind of digital switchboard. Vonage, a fast-growing Internet calling services company, uses the technology. MP3.com founder Michael Robertsoncalled SIPphone around the technology last year.
EarthLink's site says the file-sharing service is only a test application and that EarthLink is more broadly interested in applications such as an expansive vision of Internet calling and content sharing.
"File-sharing itself is not the point--file-sharing, of course, has been done," the site says. "EarthLink SIPshare demonstrates that it is conceivable that voice over IP, where voice is just content of a different form, itself can be implemented using SIP in a fully standards-based P2P network."