US 7,467,321 B1
	Fast software fault detection and notification to a backup unit
Neeraj Khurana, Sunnyvale, Calif. (US); Alain Jebara, Milpitas, Calif. (US); Neil Joffe, Mountain View, Calif. (US); and Venkatram Krishnamoorthi, San Jose, Calif. (US)
Assigned to Cisco Technology, Inc., San Jose, Calif. (US)
Filed on Nov. 26, 2003, as Appl. No. 10/723,234.
Int. Cl. G06F 11/00 (2006.01)

U.S. Cl. 714—4  [714/11; 714/13; 714/30; 714/43; 714/48]

23 Claims

1. In a system that includes a first unit and a backup unit, said first unit and said backup unit being adapted to communicate via a packet network, said first unit including an operating system, an exception handler and a network interface unit, said exception handler being activated when said operating system suffers a fault, the improvement which includes a notification program that operates when the exception handler is activated, said notification program being adapted to send a control packet to the backup unit via said network interface unit without utilizing said operating system software, said control packet being configured to indicate that said operating system suffered a fault, whereby said backup unit can be notified immediately when said first unit suffers a software fault.