Multiplex communications – Fault recovery
Reexamination Certificate
1996-12-31
2003-04-29
Zimmerman, Brian (Department: 2635)
Multiplex communications
Fault recovery
C370S295000, C379S221030, C379S221040
Reexamination Certificate
active
06556538
ABSTRACT:
TECHNICAL FIELD
The technical field of the present invention relates generally to telecommunication networks and, more particularly, to the integration of a centralized network restoration system with a distributed network restoration system.
BACKGROUND OF THE INVENTION
Telecommunication networks, such as telephone networks, are subject to failure. Given the volume of traffic and the criticality of some of the traffic on such telecommunication networks, it is desirable to be able to restore from failures as quickly as possible. In general, restoration from a failure involves the following four steps: (1) detecting that a failure has occurred; (2) isolating the location of the failure within the network; (3) determining a restoral route that may be used by network traffic; (4) implementing the restoral route.
Approaches for restoring a telecommunications network are generally classified as either being dynamic or static. The static restoration approaches develop “pre-plans” for restoring a telecommunications network. The “pre-plans” are developed by simulating possible network failures and determining restoral routes to restore the network from the simulated network failures. The “pre-plans” are generally developed for a given segment of a network that can incur failure. When a segment fails, the associated “pre-plan” is utilized.
Dynamic restoration approaches dynamically determine restoral routes at the time of failure. The dynamic restoration approaches perform analysis of the telecommunications network at the time of failure to generate the restoral routes. Dynamic restoration approaches generally fall into two categories: centralized restoration methods and distributed restoration methods. With centralized restoration methods, a centralized computer system is responsible for receiving alarms that indicate a failure has occurred, performing analysis to isolate the location of the failure, determining an optimal restoral route and sending commands to implement the restoral route. Distributed restoration methods use the network nodes as the active agents for performing restoration. When the nodes detect a failure, they search for a restoral route by sending messages to each other and attempting various links of potential restoral routes. The distributed restoration methods have the advantage of being faster than the centralized restoration methods; however, not all failures may be resolved and restored by distributed restoration methods. Some nodes of the network are not capable of performing distributed restoration.
SUMMARY OF THE INVENTION
The present invention addresses the limitations of the prior art by integrating a centralized restoration system with a distributed restoration system. The centralized restoration system is a single computer system for restoring the network from failure, whereas the distributed restoration system is distributed among restoration nodes of the network. When a failure occurs in the network, the system will generally attempt to restore the network using the distributed restoration system. If the distributed restoration system fails to restore the network, the centralized restoration system may be utilized. In some instances, the distributed restoration system will be successful and the centralized restoration system need not be utilized.
The network may include trunks that interconnect the nodes so that the nodes may communicate with each other. Trunks may be assigned to the centralized restoration system or the distributed restoration system. When a trunk is assigned to the centralized restoration system, the restoration is performed by the centralized restoration system. In the case where a trunk is assigned to the distributed restoration system, the distributed restoration system first attempts to determine and implement a restoral route for the failure and then, if unsuccessful, asks for assistance from the centralized restoration system.
In general, the distributed restoration system may be first invoked to attempt to restore from a network failure. The distributed restoration system may more quickly restore higher priority portions of the network than the centralized restoration system. The distributed restoration system may then subsequently communicate with the centralized restoration system to indicate whether assistance is required from the centralized restoration system.
REFERENCES:
patent: 4577066 (1986-03-01), Bimonte et al.
patent: 4920529 (1990-04-01), Sasaki et al.
patent: 5187740 (1993-02-01), Swaim et al.
patent: 5335268 (1994-08-01), Kelly, Jr. et al.
patent: 5435003 (1995-07-01), Chng et al.
patent: 5459716 (1995-10-01), Fahim et al.
patent: 5463615 (1995-10-01), Steinhorn
patent: 5623481 (1997-04-01), Russ et al.
patent: 5636203 (1997-06-01), Shah
patent: 5646936 (1997-07-01), Shah et al.
patent: 5809286 (1998-09-01), McLain et al.
patent: 6018576 (2000-01-01), Croslin
patent: 6327669 (2001-12-01), Croslin
patent: 0 494 513 (1991-12-01), None
patent: WO 95/10149 (1995-04-01), None
Herzberg et al. “The Hop-Limit Approach for Spare-Capacity Assignment in Survivable Networks” IEEE Dec. 3, 1995.
Dighe, et al. “A Link Based Alternative Routing Scheme for Network Restoration under Failure” IEEE May 1995.
Grover et al. “Near Optimal Spare Capacity Planning in a Mesh Restorable Network” IEEE Jan. 1991.
Hasegawa et al. “Dynamic Reconfiguration of Digital Cross-Connect Systems with Network Control and Management” IEEE.
Bellary, et al. “Intelligent Transport Network Survivability: Study of Distributed and Centralized Control Techniques” IEEE 1990.
Shimazaki et al. “Neopilot: An Integrated ISDN Fault Management System” IEEE Feb. 1990.
Shimazaki et al. “Network Fault Management” Sep. 1992.
Newport, et al. “Network Survivability Through Connectivity Optimization” IEEE 1987.
Flanagan et al. “Principles and Technologies for Planning Survivability-A Metropolitan Case Study”, IEEE 1989.
M. Wehr “Protection of Synchronous Transmission Networks”, Commutation and Transmission, No. 4, 1993.
Coan, et al. “Using Distributed Topology Update and Preplanned Configurations to Achieve Trunk Network Survivability” IEEE Oct. 1991.
Manione et al. “An Inconsistencies Tolerant Approach in the Fault Diagnosis of Telecommunications Networks” Feb. 14, 1994.
Bouloutas, et al. “Alarm Correlation and Fault Identification in Communication Networks” Feb. 1, 1994.
“A New Distributed Restoration Algorithm to Protect ATM Meshed Networks Against Link and Node Failures”—Nederlof, et al.; ISS 95-Internatonal Switching Symposium, Advanced Switching Technologies for Universal Telecommunications at the Beginning of the 21st Century; vol. 2, No. SYMP. 15; pp. 398-402; Apr. 23-28, 1995.
U.S. patent application Ser. No. 08/493,741 filed Jun. 22, 1995,System And Method For Reconfiguring A Telecommunications Network To Its Normal State After Repair Of Fault.
U.S. patent application Ser. No. 08/632,198 filed Apr. 15, 1996,Minimum Common Span Network Outage Detection And Isolation.
U.S. patent application Ser. No. 08/632,200, filed Apr. 15, 1996,Dynamic Network Topology Determination.
U.S. patent application Ser. No. 08/669,259, filed Jun. 21, 1996,Topology-Based Fault Analysis In Telecommunications Network.
U.S. patent application Ser. No. 08/670,872, filed Jun. 26, 1996,Segment Substitution/Swap For Network Restoration Pre-plans.
U.S. patent application Ser. No. 08/673,415, filed Jun. 28, 1996,Realtime Restoration Process.
U.S. patent application Ser. No. 08/701/514, filed Aug. 22, 1996,Enhanced Voice Services Load Balancing.
U.S. patent application Ser. No. 08/758,111, filed Nov. 25, 1996,Method And Apparatus For Determining Maximum Network Failure Spans For Restoration.
U.S. patent application Ser. No. 08/753,558, filed Nov. 26, 1996,Method And Apparatus For Deriving And Representing Physical Network Topology.
U.S. patent application Ser. No. 08/753,559, filed Nov. 26, 1996,Method And Apparatus For Isolating Network Failures By Applying Alarms To Failure Spans.
U.S. patent application Ser. No. 08/753,553, filed Nov. 26, 1996,Method And Apparatus For Identifying Restoral R
MCI Communications Corporation
Zimmerman Brian
LandOfFree
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