Patent injunction could derail Longhorn

By Steve Malone

Posted on 14 Apr 2005 at 11:23

A judge has slapped an injunction on Microsoft to prevent it from using TCP technology slated for use in the next version of Windows, codenamed Longhorn, and in the Scalable Networking Pack for Windows Server 2003.

There are fears that the injunction may delay the release of Longhorn which is scheduled to appear next year.

In dispute is Microsoft's 'Chimney' TCP offload architecture which offloads the TCP protocol stack to a Network Interface Card to provide an improved network performance. US company Alacritech, which develops networking solutions, claims that 'Chimney' is based on Alacritech's SLIC Technology architecture based on two patents 6,427,171 and 6,987,868 relating to scalable networking called `Protocol Processing Stack for use with Intelligent Network Interface Device`.

Alacritech sued Microsoft in Federal District Court in August of last year. Now a US District Court has issued a temporary injunction preventing Microsoft from selling any product based on the Chimney technology.

Larry Boucher, president and CEO, Alacritech said, 'After Alacritech discovered that Microsoft Chimney is based on intellectual property that we developed, patented and own, we offered Microsoft a license. Microsoft rejected licensing terms that would be acceptable to us. We were forced to sue Microsoft to stop them from continuing to infringe, and inducing others to infringe, on our intellectual property rights. We are very pleased with the Court's decision in this matter.'

Alacritech, claims that it provided details of Dynamic TCP Offload architecture to Microsoft when the two companies met under a non-disclosure agreement in September 1998. Following the meeting, in 1999 Alacritech says it sent Microsoft a detailed document describing how its SLIC technology could work with Windows. Microsoft unveiled Chimney in 2003.