US 7,526,533 B1
Active call context reconstruction for primary/backup resource manager servers
Brian Lo Bue, Irvine, Calif. (US); Darrell Myers Shively, II, Irvine, Calif. (US); and Larry Nadeau, Irvine, Calif. (US)
Assigned to Cisco Technology, Inc., San Jose, Calif. (US)
Filed on Nov. 30, 1999, as Appl. No. 9/452,285.
Int. Cl. G06F 13/00 (2006.01)
U.S. Cl. 709—220  [709/224; 709/226; 714/4; 714/6] 26 Claims
OG exemplary drawing
 
1. A backup server for enabling a data communications network to recover from a local server failure, the backup server comprising:
an information packet requester configured to request an information packet from a memory associated with the a network access server (NAS) in response to a call received from the NAS, if the call information is not available to the backup server, the information packet associated with an ongoing call placed by a call-in user via the NAS, the information packet containing call information for maintaining connection of the ongoing call if the local server fails;
an encoder associated with the local server and configured to generate an information packet associated with an ongoing call placed by the call-in user via the NAS, wherein the information packet containing call information for maintaining connection of the ongoing call if the local server fails;
a sender configured to transmit for transmitting the information packet from the encoder to a memory associated with the NAS, the information packet being stored in the memory;
a call coupler associated with the NAS and configured to couple for coupling the call to the local server if the local server does not fail, the call coupler further configured to couple and for coupling the call to the backup server if the local server fails;
an information packet receiver responsive to the local server failure, the information packet receiver receiving the information packet from a memory associated with a network access server (NAS), the NAS configured to couple capable of coupling a call placed from the call-in user to the data communications network and providing a network connection to the local server; and
a parser configured to reconstruct for reconstructing the call information from the information packet, such that the backup server maintains the ongoing call to the data communications network.