CA2498037C - Root cause correlation in connectionless networks - Google Patents

Root cause correlation in connectionless networks Download PDF

Info

Publication number
CA2498037C
CA2498037C CA2498037A CA2498037A CA2498037C CA 2498037 C CA2498037 C CA 2498037C CA 2498037 A CA2498037 A CA 2498037A CA 2498037 A CA2498037 A CA 2498037A CA 2498037 C CA2498037 C CA 2498037C
Authority
CA
Canada
Prior art keywords
network
address
node
router
correlating
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Fee Related
Application number
CA2498037A
Other languages
French (fr)
Other versions
CA2498037A1 (en
Inventor
Ariel Noy
Danny Kibel
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Sheer Networks Inc
Original Assignee
Sheer Networks Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Sheer Networks Inc filed Critical Sheer Networks Inc
Publication of CA2498037A1 publication Critical patent/CA2498037A1/en
Application granted granted Critical
Publication of CA2498037C publication Critical patent/CA2498037C/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

Classifications

    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04LTRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L41/00Arrangements for maintenance, administration or management of data switching networks, e.g. of packet switching networks
    • H04L41/12Discovery or management of network topologies
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04LTRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L45/00Routing or path finding of packets in data switching networks
    • H04L45/02Topology update or discovery
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04LTRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L45/00Routing or path finding of packets in data switching networks
    • H04L45/26Route discovery packet
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04LTRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L45/00Routing or path finding of packets in data switching networks
    • H04L45/28Routing or path finding of packets in data switching networks using route fault recovery
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04LTRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L41/00Arrangements for maintenance, administration or management of data switching networks, e.g. of packet switching networks
    • H04L41/34Signalling channels for network management communication
    • H04L41/342Signalling channels for network management communication between virtual entities, e.g. orchestrators, SDN or NFV entities

Abstract

A method for correlating routing errors to link failures in a network, the method including detecting a link failure between a first and a second router in a network, associating a first node address indicated in a first routing table of the first router with a first partition of the network, where a next hop of a packet destined for the first node address is the second router, associating a second node address indicated in a second routing table of the second router with a second partition of the network, where a next hop of a packet destined for the second node address is the first router, and correlating an error notification resulting from the failed delivery of a packet with the link failure where a source address of the packet corresponds to the first node address and a destination address of the packet corresponds to the second node address.

Description

TITLE OF THE INVENTION
Root Cause Correlation in Connectionless Networks.
FIELD OF THE INVENTION
The present invention relates to computer network technology in general, and in particular to correlation of network errors to root causes in connectionless networks.
BACKGROUND OF THE INVENTION
Connectionless computer networks, such as Internet Protocol (IP) networks, are typically formed by connecting multiple routers to each other using either point-to-point connections or the Data Link Layer of the International Standard Organiaation's Open System Interconnect (ISO/OSI) network model, commonly referred to as "layer 2." One of the main features of a connectionless neturork is the ability of a network node, such as a PC, to connect directly to any of the routers and sendfreceive packetized data to/from any other network node connected to any other router. To accomplish this each node is typically uniquely identified by a unique network address, known in IP networks as an IP
address.
Routing of packets in a connectionless computer network is now described by way of example with reference to Fig. 1. When a node A sends a packet to a node B, A
must specify the address of B as the destination address of the packet. The first router Rl that accepts the packet forwards the packet to the next router R2 on the path to B, whereupon R2 forwards the packet to the next router R3 on the path to B, and so on.
When the packet reaches the router to which B is directly connected, it is forwarded to B.
It may thus be seen that, for any given destination address to which a packet is addressed, every router in the network should know the packet's next "hop," i.e., to which next router the packet is to be forwarded. Each muter typically maintains this information in a routing table which contains a mapping between addresses or address groups, such as IP
subnets, and the next hop for packets destined for these addresses.
When a link connecting two routers in a network fails, a partitioning of the network may occur. Thus in Fig. l, if the link between Rl and R2 fails, nodes A and C can still communicate with each other but not with nodes B and D, and vice versa.
Each router will typically automatically detect this situation and update its routing table accordingly, such as by eliminating entries whose next hop is unreachable. However, nodes in one partition may still try to send packets to nodes in the other partition. When this occurs, a.
"no route to destination" error is typically generated and logged by the first router to detect the problem, which then reports the problem to the network management system (NMS).
The NMS must then decide what action to take, such as tracing the error to its root cause.
In large networks where there may be many active communication sessions between nodes at one time, a single fink failure event might cause numerous "no route to destination"
notifications to be generated in every muter in one partition which receives packets that are destined for the other partition and reported to the NEVIS. Thus, where the existence of a link failure is already known to the NMS, it would be advantageous to know whether or not a routing error is caused by the link failure, as well as which nodes might be affected by the link failure, obviating the need for the NMS to take action that it would normally take.
SLJwtMfAR~ OF THE INVENTION
The present invention provides for the correlation of routing errors to link failures in a connectionless network.
In one aspect of the present invention a method is provided for correlating routing errors to link failures in a networl~ the method including detecting a link failure between a first and a second muter in a network, associating a first node address indicated in a first routing table of the first router with a first partition of the network, where a next hop of a packet destined for the first node address is the second router, associating a second node address indicated in a second routing table of the second router with a second partition of the network, where a next hop of a packet destined for the second node address is the first router, and correlating an error notification resulting from the failed delivery of a packet with the link failure where a source address of the packet corresponds to the first node address and a destination address of the packet corresponds to the second node address.
In another aspect of the present invention any of the steps are performed with respect to a connectionless network.
In another aspect of the present invention a method the correlating step includes correlating a "no route to destination" error.
In another aspect of the present invention the associating steps comprise constructing a connectivity table.
In another aspect of the present invention the method further includes suppressing the error.
In another aspect of the present invention any of the steps are performed in a distributed network management system by at least one software agent associated with either of the routers.
In another aspect of the present invention the method further includes notifying at least one other agent in the network of the associations of the nodes to the partitions, where the other agent is not associated with either of the routers.
In another aspect of the present invention a method is provided for correlating routing errors to link failures in a network, the method including identifying a path between 1 S a first node and a second node in a network, detecting a link failure in the network, determining if the link failure lay along the path, and correlating an error notification resulting from the failed delivery of a packet with the link failure where a source address of the packet corresponds to an address of the first node, where a destination address of the packet corresponds to an address of the second node, and where the link failure lay along the path.
In another aspect of the present invention the identifying step includes identifying either of a most commonly used route and a most heavily used route between the nodes in accordance with a predefined measure of use.
In another aspect of the present invention any of the steps are performed with respect to a conneetionless network.
In another aspect of the present invention the correlating step includes correlating a "no route to destination" error.
In another aspect of the present invention the method further includes suppressing the error_ In another aspect of the present invention any of the steps are performed in a distributed network management system by a software agent associated with either of the routers.
In another aspect of the present invention a system is provided for correlating routing errors to link failures in a network, the system including means for detecting a link failure between a first and a second router in a network, means for associating a first node address indicated in a first routing table of the first router with a first partition of the network, where a next hop of a packet destined for the first node address is the second router, means for associating a second node address indicated in a second routing table of the second router with a second partition of the network, where a next hop of a packet destined for the second node address is the first router, and means for correlating an error notification resulting from the failed delivery of a packet with the link failure where a source address of the packet corresponds to the first node address and a destination address of the packet corresponds to the second node address.
In another aspect of the present invention any of the means are operative with respect to a connectionless network.
In another aspect of the present invention the means for correlating is operative to correlate a "no route to destination" error.
In another aspect of the present invention the means for associating are operative to construct a connectivity table.
In another aspect of the present invention the system fitrther includes means for suppressing the error.
In another aspect of the present invention a system any of the means are operative in a distributed network management system including at least one software agent associated with either of the routers.
In another aspect of the present invention the system further includes means for notifying at least one other agent in the network of the associations of the nodes to the partitions, where the other agent is not associated with either of the routers.
In another aspect of the present invention a system is provided for correlating routing errors to link failures in a network, the system including means for identifying a path between a first node and a second node in a network, means for detecting a link failure in the network, means for determining if the link failure lay along the path, and means for correlating an error notification resulting from the failed delivery of a packet with the link failure where a source address of the packet corresponds to an address of the first node, where a destination address of the packet corresponds to an address of the second node, 5 and where the link failure lay along the path.
In another aspect of the present invention the means for identifying is operative to identify either of a most commonly used route and a most heavily used route between the nodes in accordance with a predefined measure of use.
In another aspect of the present invention any of the means are operative with respect to a connectionless network.
In another aspect of the present invention the means for correlating step is operative to correlate a "no route to destination" error_ In another aspect of the present invention the system further includes means for suppressing the error.
In another aspect of the present invention any of the means are operative in a distributed network management system including a software agent associated with either of the routers.
BRIEF DESCRIPTION OF THE DRAWII\TTGS
The present invention will be understood and appreciated more fully from the following detailed description taken in conjunction with the appended drawings in which:
Fig. 1 is a simplified pictorial illustration of a network framework, useful in understanding present invention;
Fig. 2 is a simplified pictorial illustration of a network framework supporting error correlation, constructed and operative in accordance with a preferred embodiment of the present invention;
Fig. 3 is a simplified flowchart illustration of a method of correlation of routing errors to link failures in a connectionless network, operative in accordance with a preferred embodiment of the present invention.
Fig. 4 is a simplified flowchart illustration of a method of correlation of routing errors to link failures in a connectionless network supported by a distributed network s management system, operative in accordance with a preferred embodiment of the present invention; and Fig. S is a simplified flowchart illustration of a method of identifying nodes that may be affected by link failures in a connectionless network, operative in accordance with a preferred embodiment of the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Reference is now made to Fig. 2, which is a simplified pictorial illustration of a network framework supporting error correlation, constructed and operative in accordance with a preferred embodiment of the present invention, and additionally to Fig.
3, which is a simplified flowchart illustration of a method of correlation of routing errors to link failures in a connectionless networl~ operative in accordance with a preferred embodiment of the present invention. In Fig. 2 a link 200 between two routers Rl and RZ is shown as having failed, as designated by an 'x' through link 200. Prior to the failure of link 200, a routing table 202 of router Rl shows that the next hop for packets destined for B and D is R2, while a routing table 204 of muter R2 shows that the next hop for packets destined for A
and C is Rl. It may be seen that two partitions 206 and 208 (shown in dashed lines) are thus created in that nodes A and C cannot communicate with nodes B and D via link 200, and vice versa.
A network management system (NMS) 210 preferably maintains copies of routing tables 202 and 204. Having detected a link failure between Rl and R2, may create a connectivity table 212 indicating which nodes are in each of partitions 20s and 208. Since NMS 210 knows that R2 is inaccessible to Rl via fink 200, NMS 210 may associate with partition 206 those node addresses in its copy of routing table 202 whose next hop is R2. Likewise, NMS 210 may associate with partition 208 those node addresses in routing table 204 whose next hop is Rl. Should NMS 210 receive a "no route to destination" error notification from a network router together with the source and destination addresses of the packet that could not be delivered, NMS 210 may look up the source and destination addresses in connectivity table 212 to determine whether they are from different partitions. If both the source and destination addresses are from different partitions, then the "no route to destination" error notification may be an attempt to send the packet across failed link 200. Thus, the error notification may be correlated with the link failure that is already known to NMS 210, and the error may be suppressed and need not be investigated further. Alternatively, the error notification should not be correlated with the link failure and may be investigated or otherwise acted upon by NMS
210.
Reference is now made to Fig. 4, which is a simplified flowchart illustration of a method of correlation of routing errors to link failures in a connectionless network supported by a distributed network management system, operative in accordance with a preferred embodiment of the present invention. In Fig. 4 the present invention is implemented in a distributed network management system, such as is described in U. S.
Patent Application No. 09/799,637 and published as Published Application No.
20010039577, where every router has an associated software agent which continuously monitors the state of the muter and its links. The agents monitoring Rl and R2 would thus detect the failure of link 200 and then communicate with each other to create connectivity table 212 which may then be provided to the agents of all other routers in the network.
Thus, when any router Rx encounters a "no route to destination" error, its associated agent looks up the source and destination addresses in connectivity table 212 to determine whether they are from different partitions, and action may be taken or the error notification ignored as described above.
Reference is now made to Fig. 5, which is a simplified flowchart illustration of a method of identifying nodes that may be affected by link failures in a connectionless network, operative in accordance with a preferred embodiment of the present invention. In Fig. 5 a list of virtual paths in a network is maintained, where each virtual path represents the traversal of the links, routers, and other network elements comprising the most commonly used and/or most heavily used routes between network nodes, as determined using any predefined measure of use. The virtual path list may be maintained centrally, such as by NMS 210, or in a distributed manner, such as by one or more agents in a distributed network management system. The virtual path list may be created using any conventional technique, such as by identifying common access patterns in router access lists, analyzing network failure alarms (e.g., packet lost, no route, etc.) to determine tradic flow, and determining network tomography from traffic counter patterns. When a failed link is detected, each virtual path may be checked using any known technique to determine if it is broken and, if so, which nodes and other network elements along the path are affected.
Thereafter, should a "no route to destination" error be encountered where the source address of the packet being sent belongs to the node at one end of a virtual path known to have a failed link, and the packet's destination address belongs to the node at the other end of the virtual path, the error may be correlated to the failed link and action may be taken or suppressed as described hereinabove.
It is appreciated that one or more of the steps of any of the methods described herein may be omitted or carried out in a different order than that shown, without departing from the true spirit and scope of the invention.
While the methods and apparatus disclosed herein may or may not have been described with reference to specific hardware or softuvare, it is appreciated that the methods and apparatus described herein may be readily implemented in hardware or software using conventional techniques.
While the present invention has been described with reference to one or more 1 S specific embodiments, the description is intended to be illustrative of the invention as a whole and is not to be construed as limiting the invention to the embodiments shown. It is appreciated that various modifications may occur to those skilled in the art that, while not specifically shown herein, are nevertheless within the true spirit and scope of the invention.

Claims (26)

What is claimed is:
1. A method for correlating routing errors to link failures in a network, the method comprising:
detecting a link failure between a first and a second router in a network;
associating a first node address indicated in a first routing table of said first router with a first partition of said network, wherein a next hop of a packet destined for said first node address is said second router;
associating a second node address indicated in a second routing table of said second router with a second partition of said network, wherein a next hop of a packet destined for said second node address is said first router; and correlating an error notification resulting from the failed delivery of a packet with said link failure where a source address of said packet corresponds to said first node address and a destination address of said packet corresponds to said second node address.
2. A method according to claim 1 wherein any of said steps are performed with respect to a connectionless network.
3. A method according to claim 1 wherein said correlating step comprises correlating a "no route to destination" error.
4. A method according to claim 1 wherein said associating steps comprise constructing a connectivity table.
5. A method according to claim 1 and further comprising suppressing said error.
6. A method according to claim 1 wherein any of said steps are performed in a distributed network management system by at least one software agent associated with either of said routers.
7. A method according to claim 6 and further comprising notifying at least one other agent in said network of said associations of said nodes to said partitions, wherein said other agent is not associated with either of said routers.
8. A method for correlating routing errors to link failures in a network, the method comprising:
identifying a path between a first node and a second node in a network;
detecting a link failure in said network;
determining if said link failure lay along said path; and correlating an error notification resulting from the failed delivery of a packet with said link failure where a source address of said packet corresponds to an address of said first node, where a destination address of said packet corresponds to an address of said second node, and where said link failure lay along said path.
9. A method according to claim 8 wherein said identifying step comprises identifying either of a most commonly used route and a most heavily used route between said nodes in accordance with a predefined measure of use.
10. A method according to claim 8 wherein any of said steps are performed with respect to a connectionless network.
11. A method according to claim 8 wherein said correlating step comprises correlating a "no route to destination" error.
12. A method according to claim 8 and further comprising suppressing said error.
13. A method according to claim 8 wherein any of said steps are performed in a distributed network management system by a software agent associated with either of said routers.
14. A system for correlating routing errors to link failures in a network, the system comprising:
means for detecting a link failure between a first and a second router in a network;
means for associating a first node address indicated in a first routing table of said first router with a first partition of said network, wherein a next hop of a packet destined for said first node address is said second router;
means for associating a second node address indicated in a second routing table of said second router with a second partition of said network, wherein a next hop of a packet destined for said second node address is said first router; and means for correlating an error notification resulting from the failed delivery of a packet with said link failure where a source address of said packet corresponds to said first node address and a destination address of said packet corresponds to said second node address.
15. A system according to claim 14 wherein any of said means are operative with respect to a connectionless network.
16. A system according to claim 14 wherein said means for correlating is operative to correlate a "no route to destination" error.
17. A system according to claim 14 wherein said means for associating are operative to construct a connectivity table.
18. A system according to claim 14 and further comprising means for suppressing said error.
19. A system according to claim 14 wherein any of said means are operative in a distributed network management system comprising at least one software agent associated with either of said routers.
20. A system according to claim 19 and further comprising means for notifying at least one other agent in said network of said associations of said nodes to said partitions, wherein said other agent is not associated with either of said routers.
21. A system for correlating routing errors to link failures in a network, the system comprising:
means for identifying a path between a first node and a second node in a network;
means for detecting a link failure in said network;
means for determining if said link failure lay along said path; and means for correlating an error notification resulting from the failed delivery of a packet with said link failure where a source address of said packet corresponds to an address of said first node, where a destination address of said packet corresponds to an address of said second node, and where said link failure lay along said path.
22. A system according to claim 21 wherein said means for identifying is operative to identify either of a most commonly used route and a most heavily used route between said nodes in accordance with a predefined measure of use.
23. A system according to claim 21 wherein any of said means are operative with respect to a connectionless network.
24. A system according to claim 21 wherein said means for correlating step is operative to correlate a "no route to destination" error.
25. A system according to claim 21 and further comprising means for suppressing said error.
26. A system according to claim 21 wherein any of said means are operative in a distributed network management system comprising a software agent associated with either of said routers.
CA2498037A 2002-09-09 2003-09-08 Root cause correlation in connectionless networks Expired - Fee Related CA2498037C (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
US40890602P 2002-09-09 2002-09-09
US60/408,906 2002-09-09
PCT/IL2003/000741 WO2004023719A2 (en) 2002-09-09 2003-09-08 Root cause correlation in connectionless networks

Publications (2)

Publication Number Publication Date
CA2498037A1 CA2498037A1 (en) 2004-03-18
CA2498037C true CA2498037C (en) 2010-07-06

Family

ID=31978699

Family Applications (1)

Application Number Title Priority Date Filing Date
CA2498037A Expired - Fee Related CA2498037C (en) 2002-09-09 2003-09-08 Root cause correlation in connectionless networks

Country Status (8)

Country Link
US (1) US7373563B2 (en)
EP (2) EP1953962B1 (en)
AT (2) ATE440420T1 (en)
AU (1) AU2003259541A1 (en)
CA (1) CA2498037C (en)
DE (2) DE60328929D1 (en)
DK (1) DK1537701T3 (en)
WO (1) WO2004023719A2 (en)

Families Citing this family (24)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7653008B2 (en) 2004-05-21 2010-01-26 Bea Systems, Inc. Dynamically configurable service oriented architecture
US20050273502A1 (en) * 2004-05-21 2005-12-08 Patrick Paul B Service oriented architecture with message processing stages
US20050273520A1 (en) * 2004-05-21 2005-12-08 Bea Systems, Inc. Service oriented architecture with file transport protocol
US20060080419A1 (en) * 2004-05-21 2006-04-13 Bea Systems, Inc. Reliable updating for a service oriented architecture
US20050273517A1 (en) * 2004-05-21 2005-12-08 Bea Systems, Inc. Service oriented architecture with credential management
US20060031481A1 (en) * 2004-05-21 2006-02-09 Bea Systems, Inc. Service oriented architecture with monitoring
US20060005063A1 (en) * 2004-05-21 2006-01-05 Bea Systems, Inc. Error handling for a service oriented architecture
US20050278335A1 (en) * 2004-05-21 2005-12-15 Bea Systems, Inc. Service oriented architecture with alerts
US20050273497A1 (en) * 2004-05-21 2005-12-08 Bea Systems, Inc. Service oriented architecture with electronic mail transport protocol
JP4345987B2 (en) * 2004-10-29 2009-10-14 富士通株式会社 Apparatus and method for identifying fault location in communication network
GB2431067B (en) 2005-10-07 2008-05-07 Cramer Systems Ltd Telecommunications service management
GB2432992B (en) 2005-11-18 2008-09-10 Cramer Systems Ltd Network planning
GB2433675B (en) 2005-12-22 2008-05-07 Cramer Systems Ltd Communications circuit design
GB2435362B (en) 2006-02-20 2008-11-26 Cramer Systems Ltd Method of configuring devices in a telecommunications network
US7817564B2 (en) * 2006-07-31 2010-10-19 Cisco Technology, Inc. Method and system for handling fault messages in a network
US8996394B2 (en) * 2007-05-18 2015-03-31 Oracle International Corporation System and method for enabling decision activities in a process management and design environment
US8185916B2 (en) 2007-06-28 2012-05-22 Oracle International Corporation System and method for integrating a business process management system with an enterprise service bus
US7808888B2 (en) * 2008-02-25 2010-10-05 Cisco Technology, Inc. Network fault correlation in multi-route configuration scenarios
JP5494646B2 (en) 2009-02-25 2014-05-21 日本電気株式会社 Communication network management system, method, and management computer
US7995487B2 (en) * 2009-03-03 2011-08-09 Robert Bosch Gmbh Intelligent router for wireless sensor network
EP2865133A1 (en) 2012-06-25 2015-04-29 Kni M Szaki Tanácsadó Kft. Methods of implementing a dynamic service-event management system
US9239887B2 (en) 2012-12-18 2016-01-19 Cisco Technology, Inc. Automatic correlation of dynamic system events within computing devices
US9648547B1 (en) * 2013-06-28 2017-05-09 Google Inc. Self-organizing topology management
JP7142503B2 (en) * 2018-07-06 2022-09-27 富士通株式会社 Management device, information processing device, and program

Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0948868A1 (en) * 1996-12-20 1999-10-13 BRITISH TELECOMMUNICATIONS public limited company Telecommunications network
US6353902B1 (en) * 1999-06-08 2002-03-05 Nortel Networks Limited Network fault prediction and proactive maintenance system
GB2371944B (en) 1999-09-06 2003-10-29 Ericsson Telefon Ab L M System and method for internodal information routing within a communications network
US6683865B1 (en) * 1999-10-15 2004-01-27 Nokia Wireless Routers, Inc. System for routing and switching in computer networks
US6813241B1 (en) * 1999-12-18 2004-11-02 Nortel Networks Limited Network architecture and method of providing link protection in a bidirectional data traffic network
US20020103631A1 (en) 2000-04-21 2002-08-01 Anja Feldmann Traffic engineering system and method
US6941362B2 (en) 2000-04-28 2005-09-06 Sheer Networks Inc. Root cause analysis in a distributed network management architecture

Also Published As

Publication number Publication date
AU2003259541A8 (en) 2004-03-29
DK1537701T3 (en) 2008-08-11
WO2004023719A2 (en) 2004-03-18
EP1537701B8 (en) 2008-09-10
US7373563B2 (en) 2008-05-13
ATE396563T1 (en) 2008-06-15
WO2004023719A3 (en) 2004-05-06
EP1537701B1 (en) 2008-05-21
EP1953962B1 (en) 2009-08-19
ATE440420T1 (en) 2009-09-15
EP1953962A1 (en) 2008-08-06
DE60321185D1 (en) 2008-07-03
CA2498037A1 (en) 2004-03-18
DE60328929D1 (en) 2009-10-01
US20060095815A1 (en) 2006-05-04
AU2003259541A1 (en) 2004-03-29
EP1537701A2 (en) 2005-06-08

Similar Documents

Publication Publication Date Title
CA2498037C (en) Root cause correlation in connectionless networks
US6697338B1 (en) Determination of physical topology of a communication network
JP3903437B2 (en) Reliable fault resolution in clusters
CN101517544B (en) Network routing to the socket
US7548540B2 (en) Dynamic discovery of ISO layer-2 topology
EP2119114B1 (en) Analyzing virtual private network failures
US8605603B2 (en) Route convergence based on ethernet operations, administration, and maintenance protocol
WO2014169969A1 (en) Identification of the paths taken through a network of interconnected devices
EP1964330B1 (en) Method for reducing fault detection time in a telecommunication network
US7688743B2 (en) Tracing routing differences
US8150998B2 (en) System and method for increasing optimal alternative network route convergence speed and border gateway router incorporating the same
Cisco Troubleshooting TCP/IP Connectivity
Cisco Troubleshooting TCP/IP Connectivity
Cisco Troubleshooting TCP/IP Connectivity
Cisco Troubleshooting TCP/IP Connectivity
Cisco Troubleshooting TCP/IP Connectivity
Cisco Troubleshooting TCP/IP Connectivity
Cisco Troubleshooting TCP/IP Connectivity
Cisco Troubleshooting TCP/IP Connectivity
Cisco Troubleshooting TCP/IP Connectivity
Cisco Troubleshooting TCP/IP Connectivity
Cisco Troubleshooting TCP/IP Connectivity
Cisco Troubleshooting TCP/IP Connectivity
Cisco Troubleshooting TCP/IP Connectivity
Cisco Troubleshooting TCP/IP Connectivity

Legal Events

Date Code Title Description
EEER Examination request
MKLA Lapsed

Effective date: 20220308

MKLA Lapsed

Effective date: 20200908