The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 05, 2010
Filed:
Nov. 24, 2004
Paul Howard, Windham, NH (US);
Paul Howard, Windham, NH (US);
Juniper Networks, Inc., Sunnyvale, CA (US);
Abstract
A network device includes a primary control unit that establishes a network tunnel with another network device. The network device applies a silent failover technique to failover from the primary control unit to a backup control unit while maintaining the network tunnel. The network tunnel may be, for example, a Layer 2 Tunneling Protocol (L2TP) tunnel, and the network device may be an L2TP Access Concentrator (LAC) or an L2TP Network Server (LNS). The techniques may prevent abnormal termination of the network tunnel during the failover. Once the failover from the primary control unit to the backup control unit is complete, the backup control unit synchronizes sequence numbers associated with the network tunnel with sequence numbers of the non-failed network device, and resolves inconsistencies between subscriber session databases of the backup control unit and the non-failed network device.