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US5014262A Expired / Lapsed US ⏱️ 0.0 years remaining

Apparatus and method for detecting and eliminating call looping in a node-by-node routing network

Assignee: Nokia Bell Labs
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Filing: 1990-01-02
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Granted: 1991-05-07
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Expires: 2010-01-02
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Abstract

Abstract An apparatus and method for effectively managing a switched virtual circuit network by detecting and resolving call routing problems occurring in the routing pattern of the network is provided. Detecting the call routing problems is advantageously achieved by a first process contained in a network management center which has access to all nodes in the network and performs routing table verification for each node whenever there are changes in the routing tables caused by changes in the network, such as an addition of nodes, links and the like. Otherwise, call looping may occur during call set-up as a result of any undiscovered or uncorrected errors in one or more routing tables in the network. Detection of call loops is achieved by the first process through use of a plurality of processing modules that recognizes and excludes in their analysis of the network certain network components that can not be involved in call looping. Identified routing problems are resolved by a second process which provides alternative recommendations as to how best to modify the routing tables in the nodes of the network. A selected one of the alternative recommendations is coupled from the network management center to the nodes in the network for changing the routing tables located at the respective nodes.

Inventors

  • 👤 Paramasiv Harshavardhana

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-24 10:00
CPC Classifications
H; H04; H04L; H04L45/00; H04L45/42; H04L45/02; H04L45/10; H04L45/18; H04Q; H04Q3/00; H04Q3/64; H04Q3/66; Y; Y10; Y10S; Y10S379/00; Y10S379/901

Claims Analysis

Total Claims: 25
Claim 1
Independent Claim 105 words
Apparatus for detecting call looping in a node-by-node data routing network including a plurality of nodes for routing data calls, each node having routing information for directing data calls over multiple paths to multiple destinations, said apparatus comprising: means for identifying those nodes in the network that are involved in call looping for data calls directed to specific destinations; and means for modifying the routing information in at least one node involved in the call looping, the modifying means altering a routing path for a data call to a specific destination in a manner that prevents the data call from looping among the identified nodes.
Claim 2
Dependent Claim 105 words
Apparatus for detecting call looping in a node-by-node data routing network including a plurality of nodes for routing data calls, each node having routing information for directing data calls over multiple paths to multiple destinations, said apparatus comprising: means for identifying those nodes in the network that are involved in call looping for data calls directed to specific destinations; and means for modifying the routing information in at least one node involved in the call looping, the modifying means altering a routing path for a data call to a specific destination in a manner that prevents the data call from looping among the identified nodes.
Claim 3
Dependent Claim 61 words
The apparatus for detecting call looping as in claim 1 wherein the identifying means further comprises means for identifying those nodes in the network that are configured in a manner such that they are potentially involved in call looping and identifying those nodes in the network that are configured in a manner such that they are not involved in call looping.
Claim 4
Dependent Claim 26 words
The apparatus for detecting call looping as in claim 2 wherein those nodes that are potentially involved in call looping comprise nodes configured as tandem nodes.
Claim 5
Dependent Claim 38 words
The apparatus for detecting call looping as in claim 2 wherein the identifying means further comprises means for determining a number of call loops in the routing network and the direction of travel between nodes for each loop.
Claim 6
Dependent Claim 47 words
The apparatus for detecting call looping as in claim 4 further comprising means for detecting circuitous routing, the circuitous routing detecting means providing an indication when the number of nodes provided in a routing pattern for a primary path to the specific destination exceeds a predetermined number.
Claim 7
Dependent Claim 58 words
The apparatus for detecting call looping as in claim 5 further comprising means for detecting dead-end routing, the dead-end routing detecting means providing a means for comparing information in routing tables in the nodes of the network with that in a network database and providing an indication if any information is detected as missing from the routing tables.
Claim 8
Independent Claim 105 words
A method of detecting call looping in a node-by-node data routing network including a plurality of nodes for routing data calls, each node having routing information for directing data calls over multiple paths to multiple destinations, the method comprising the steps of: identifying those nodes in the network that are involved in call looping for data calls directed to specific destinations; and modifying the routing information in at least one node involved in the call looping, the modifying step altering a routing path for a data call to a specific destination in a manner that prevents the data call from looping among the identified nodes.
Claim 9
Independent Claim 105 words
A method of detecting call looping in a node-by-node data routing network including a plurality of nodes for routing data calls, each node having routing information for directing data calls over multiple paths to multiple destinations, the method comprising the steps of: identifying those nodes in the network that are involved in call looping for data calls directed to specific destinations; and modifying the routing information in at least one node involved in the call looping, the modifying step altering a routing path for a data call to a specific destination in a manner that prevents the data call from looping among the identified nodes.
Claim 10
Dependent Claim 69 words
The method of detecting call looping in a node-by-node data routing network as in claim 7 wherein the identifying step further comprises the steps of identifying those nodes in the network that are configured in a manner such that they are potentially involved in call looping and identifying those nodes in the network that are configured in a manner such that they can not be involved in call looping.
Claim 11
Dependent Claim 32 words
The method of detecting call looping in a node-by-node data routing network as in claim 8 wherein those nodes that are potentially involved in call looping comprise nodes configured as tandem nodes.
Claim 12
Dependent Claim 40 words
The method of detecting call looping in a node-by-node data routing network as in claim 8 further comprising the step of determining a number of call loops in the network and the direction of travel between nodes for each loop.
Claim 13
Dependent Claim 82 words
The method of detecting call looping in a node-by-node data routing network as in claim 10 wherein the information modifying step further comprises the steps of: determining the routing paths that are involved in the highest number of loops in a routing pattern for the data call to the specific destination, examining a series of alternative recommendations for breaking the loops in the routing pattern, and providing one of the series of alternative recommendations to the network for modifying the routing information.
Claim 14
Dependent Claim 70 words
The method of detecting call looping in a node-by-node data routing network as in claim 7 wherein the identifying step further comprises the step of generating a routing matrix for each destination from the routing information contained in each node, the routing matrix containing data reflective of a circuit connection between individual nodes and priority of a routing choice for routing calls to the specific destination over the circuit connection.
Claim 15
Dependent Claim 57 words
The method of detecting call looping in a node-by-node data routing network as in claim 12 wherein the identifying step further comprises the step of generating an adjacency matrix for each destination from the routing matrix, the adjacency matrix containing data reflective only of the circuit connection between individual nodes for routing calls to the specific destination.
Claim 16
Dependent Claim 76 words
The method of detecting call looping in a node-by-node data routing network as in claim 13 further comprising the steps of identifying those nodes in the network that are configured in a manner such that they are potentially involved in call looping and identifying those nodes in the network that are configured in a manner such that they are not involved in call looping, the adjacency matrix providing the routing information for determining these identifying steps.
Claim 17
Dependent Claim 37 words
The method of detecting call looping in a node-by-node data routing network as in claim 14 further comprising the step of determining a number of call loops and the direction of travel between nodes for each loop.
Claim 18
Dependent Claim 51 words
The method of detecting call looping in a node-by-node data routing network as in claim 15 wherein the information modifying step further comprises the step of generating a connectivity matrix for the network, the connectivity matrix containing data reflective only of a circuit connection between individual nodes in the routing network.
Claim 19
Dependent Claim 75 words
The method of detecting call looping in a node-by-node data routing network as in claim 16 wherein the information modifying step further includes the steps of: determining the number of loops associated with each circuit connection, examining a series of alternative recommendations for breaking the loops in a routing pattern for the data call to the specific destination, and providing one of the series of alternative recommendations to the network for modifying the routing information.
Claim 20
Dependent Claim 59 words
The method of detecting call looping in a node-by-node data routing network as in claim 17 wherein a first alternative recommendation concerns breaking the circuit connection involved in the highest number of loops in the routing pattern, and a second alternative recommendation concerns breaking the circuit connection involved in the second highest number of loops in the routing pattern.
Claim 21
Dependent Claim 106 words
Apparatus for detecting call looping in a node-by-node data routing network including a plurality of nodes for routing data calls, each node having routing information for directing data calls over multiple paths to multiple destinations, said apparatus comprising: means for identifying those nodes in the network that are potentially involved in call looping for data calls directed to specific destinations; and means for modifying the routing information in at least one node involved in the call looping, the modifying means altering a routing path for a data call to a specific destination in a manner that prevents the data call from looping among the identified nodes.
Claim 22
Dependent Claim 106 words
Apparatus for detecting call looping in a node-by-node data routing network including a plurality of nodes for routing data calls, each node having routing information for directing data calls over multiple paths to multiple destinations, said apparatus comprising: means for identifying those nodes in the network that are potentially involved in call looping for data calls directed to specific destinations; and means for modifying the routing information in at least one node involved in the call looping, the modifying means altering a routing path for a data call to a specific destination in a manner that prevents the data call from looping among the identified nodes.
Claim 23
Dependent Claim 61 words
The apparatus for detecting call looping as in claim 19 wherein the identifying means further comprises means for identifying those nodes in the network that are configured in a manner such that they are potentially involved in call looping and identifying those nodes in the network that are configured in a manner such that they are not involved in call looping.
Claim 24
Dependent Claim 26 words
The apparatus for detecting call looping as in claim 20 wherein those nodes that are potentially involved in call looping comprise nodes configured as tandem nodes.
Claim 25
Dependent Claim 38 words
The apparatus for detecting call looping as in claim 20 wherein the identifying means further comprises means for determining a number of call loops in the routing network and the direction of travel between nodes for each loop.

References Cited (Backward Citations)

US4736363A Cited
US4825206A Cited
US4748658A Cited
US4773069A Cited
US4873517A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1994-05-06 1994-11-05 1995-05-07 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1998-05-06 1998-11-05 1999-05-07 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2002-05-06 2002-11-05 2003-05-07 $7700.00 Window Closed / Lapsed

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