Patent 8370623 was granted and assigned to Microsoft on February, 2013 by the United States Patent and Trademark Office.
Many secure tunnels require protocols that require special handling, authorization or security certificates, such as L2TP and PPTP. This often eliminates them for use between a corporate or agency network and outside, public networks. A secure socket tunnel protocol (SSTP) adds drivers in both the kernel and user mode to route standard protocol traffic, such as PPP, over a common HTTPS port. In the event of network interruptions, an exchange of a session cookie allows fast reconnection of the underlying HTTPS connection without affecting higher level applications.