Patent · US Expired

Computer systems, in particular virtual private networks

US7000121B2 · kind B2 · utility

44Cited by
4References
7Claims
0Family size

Assignee

Inventor

Key dates

Filing dateMay 22, 2001
Grant dateFeb 14, 2006
Priority date
Expiry dateNov 30, 2023

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH04L63/06
  • WIPO fieldDigital communication
  • WIPO sectorElectrical engineering

Abstract

A first node (client) (1) is in communication with one of a plurality of second nodes (5, 6, 7) connected to a local area network (LAN) (4) via a virtual private network including a link (3), such as the Internet, and a selected one of a plurality of third nodes (gateway servers) (21, 22, 23). Communication between the first node (1) and the third nodes (21, 22, 23) is encrypted, whereas communication between the third nodes and the second nodes (5, 6, 7) is unencrypted. Communication from the first node (1) to one of the second nodes (5, 6, 7) is initially set up via a selected one of the third nodes after suitable authentication. If that third node should subsequently fail, an alternative third node can be used. To detect the failure of a third node, the first node (1) sends a “heartbeat” packet (failure detection signal) to it. An operational third node responds with an answer, indicating that all is well. If no answer is received within a predetermined time interval, the first node sends another “heartbeat” packet. If there is still no answer, another third node is selected for use. This other third node can be one that was previously authenticated, or alternatively one that mu…

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.