Method and System for Fault and Performance Recovery in Communication Networks, Related Network and Computer Program Product Therefor

• US 20080316914A1
• Filed: 07/29/2004
• Published: 12/25/2008
• Est. Priority Date: 07/29/2004
• Status: Active Grant

• Current Assignee: Telecom Italia S.p.A.
• Original Assignee: Telecom Italia S.p.A.
• Inventors: Vercellone, Vinicio, Sassi, Massimo, Faure Ragani, Alessandro, Fantolino, Luca, Alessi, Marzio
• Granted Patent: US 8,139,475 B2
• Time in Patent Office: Days
• US Class Current: 370/216
• CPC Class Codes: H04L 41/0663 Performing the actions predefined by failover planning, e.g. switching to standby network elements
• CPC Class Codes: H04L 41/0893 Assignment of logical groups to network elements
• CPC Class Codes: H04L 41/0894 Policy-based network configuration management
• CPC Class Codes: H04L 43/0811 by checking connectivity
• CPC Class Codes: H04L 43/50 Testing arrangements
• CPC Class Codes: H04L 45/00 Routing or path finding of packets in data switching networks routing or path finding in wireless networks H04W40/00
• CPC Class Codes: H04L 45/28 using route fault recovery

Abstract

A system for fault and performance recovery in a communication network includes a set of network apparatuses as well as a plurality of sites connected by means of connections having a given topology. The network also includes routers for implementing given routing policies and has associated therewith at least one database maintaining information regarding the network apparatuses. The system includes test modules for executing performance tests created automatically by exploiting the information available on the topology of the connections between the various sites and by accessing the database in question. The test modules are configured for analysing the results of the performance tests to detect possible fault and performance impairment conditions of the network. In the presence of a fault and performance impairment condition detected in the network, the routers modify the routing policy to compensate for the fault and performance impairment condition.

Claims

1-64. -64. (canceled)

65. A method of fault and performance recovery in a communication network comprising a set of network apparatuses, said network comprising a plurality of sites connected by means of connections having a given topology and adopting a given routing policy, the network having associated therewith at least one database maintaining information regarding said network apparatuses, comprising the steps of:

executing at least one set of performance tests, wherein said at least one set of performance tests is created automatically by exploiting the information available on the topology of the connections between the various sites and by accessing said at least one database;

analysing the results of said at least one set of performance tests to detect possible fault and performance impairment conditions of said network; and

modifying said routing policy to compensate for a fault and performance impairment condition in the presence of a fault and performance impairment condition detected in said network.

66. The method of claim 65, wherein said at least one set of performance tests comprises performance tests between sites of said plurality, said tests being carried out between edge routers and by associating the same performance to all the internal networks of a site.

67. The method of claim 65, wherein said network comprises at least two backbones, said at least one set of performance tests comprising performance tests carried out simultaneously on said at least two backbones.

68. The method of claim 65, wherein said network comprises at least two backbones and corresponding multibackbone sites and wherein the communications between the multibackbone sites are directed to or travel from a central site, said performance tests being limited to the stretches from a site in said plurality of sites and said central site.

69. The method of claim 65, wherein said network comprises at least two backbones and corresponding multibackbone sites and wherein said network is a full mesh network, said performance tests comprising all end-to-end connections in the network, thus configuring a complete mesh of performance tests.

70. The method of claim 65, wherein said network comprises at least two backbones and corresponding multibackbone sites and wherein said network is a partial mesh network, said performance tests comprising all end-to-end connections in a test subset in the network.

71. The method of claim 65, comprising the steps of:

generating test traffic in said network;

controlling the routing of said test traffic in both possible directions of communication by configuring the routing policies implemented by both of the sites involved in the communication, causing said test traffic between a first site and a second site of a given pair always to travel on the same backbone in both directions; and

making estimations on the connectivity referred to a routing path that selectively involves a given network backbone, both out and back (round-trip).

72. The method of claim 71, comprising the step of gaining control over said routing of the test traffic by configuring on each router two addresses that are advertised respectively on at least two backbones, whereby said addresses constitute the targets of the performance tests made, when the method is applied to a network comprising at least two backbones.

73. The method of claim 65, comprising the step of modifying the routing policy applied at a site in the network based on performance tests starting from a remote site.

74. The method of claim 65, comprising the step of implementing a mechanism of detection of performance impairment by means of at least one of:

a synchronous-polling mechanism of a periodic type; and

a mechanism of asynchronous signalling by said network apparatuses.

75. The method of claim 74, wherein said asynchronous signalling is obtained by creating asynchronous events in the network when given thresholds have been exceeded within predetermined probe configurations.

76. The method of claim 65, comprising the steps of performing in a centralized manner the steps of:

gathering statistics on reachability and associated quality between the routers of various sites in said plurality; and

in the presence of a fault and performance impairment condition detected in said network, instructing the apparatuses involved for choosing from among the routes advertised by a backbone other than the one in use, when the method is applied to networks comprising at least two backbones.

77. The method of claim 76, comprising the steps of reaching said apparatuses instructed by exploiting the interface/address connected to the best backbone at a given moment.

78. The method of claim 65, comprising at least one of the steps of:

providing service and collecting user and topology information by means of a first subsystem;

configuring and provisioning network apparatuses by means of a second subsystem; and

ensuring continuous network activity by means of a third subsystem.

79. The method of claim 78, comprising the step of providing via said second subsystem, on-demand modification of configuration parameters by configuring, starting from the information contained in said at least one database, functions for performance monitoring and routing control.

80. The method of claim 79, wherein said functions for performance monitoring and routing control comprises at least one of:

loop back interfaces and corresponding addressing operations, route-maps for outgoing and incoming advertisements, and performance tests.

81. The method of claim 80, comprising the step of providing via said third subsystem at least one of the steps of:

monitoring the different connectivity paths between sites, and deriving therefrom measurements of at least one of use and performance;

selecting best paths in said network based on at least one of data obtained during said monitoring and pre-established policies; and

imparting directives for router updating for modifying routing decisions based on selections made during said selecting.

82. The method of claim 78, comprising the step of providing via said third subsystem at least one of the steps of:

activating all previously configured performance tests;

tracing performance data from the routers;

analysing the performance tests according to service configuration; and

re-configuring routing.

83. The method of claim 65, comprising the step of optimising said set of performance tests by automatically configuring a minimum number of performance tests to guarantee performance monitoring of said network with coverage of all the communication stretches therein by configuring only one measurement for each pair of sites connected in said topology.

84. The method of claim 65, comprising the step of distributing the performance tests to be performed at said sites in said network by generating for each apparatus involved a value representative of the performance tests to be entrusted to said apparatus.

85. The method of claim 84, comprising the step of obtaining said value as a function of at least one of a first set of variables adapted to be measured statically on the apparatus, and a second set of variables assigned based on requirements of use of a respective site.

86. The method of claim 85, wherein said first set of variables comprises variables selected from the group of the type of platform, the hardware equipment, and the memory capabilities of the apparatus.

87. The method of claim 65, comprising the steps of reconfiguring the traffic leaving a site over at least two backbones according to customer, for all the sites associated with a given customer in said network, when the method is applied to a network comprising at least two backbones.

88. The method of claim 87, comprising the step of processing performance indicators corresponding to a backbone as a whole regardless of the individual site of origin and destination.

89. The method of claim 88, wherein said indicators comprise a weighted average of the data of the performance tests on the parameters of interest over a set of probes.

90. The method of claim 65, comprising the steps of reconfiguring the traffic leaving a site over at least two backbones according to customer site, irrespective of any other site possibly associated with the same customer in said network, when the method is applied to a network comprising at least two backbones.

91. The method of claim 90, comprising the step of processing performance indicators corresponding to transit on a backbone of the traffic originated by each customer site.

92. The method of claim 91, wherein said indicators comprise a weighted average of the data of the performance tests on the parameters of interest over a set of probes performed on the customer edges of the site considered.

93. The method of claim 65, comprising the step of reconfiguring the traffic leaving a site over at least two backbones selectively for different pairs sites associated with the same customer in said network, when the method is applied to a network comprising at least two backbones

94. The method of claim 93, comprising the step of processing performance indicators corresponding to the transit, on a backbone of the traffic originated by each said customer site toward any other destination sites.

95. The method of claim 94, wherein said indicators comprise weighted averages of the data of the performance tests on the parameters of interest over the set of probes made on the customer edges of each said customer site to the customer edges of any other destination sites.

128. A computer program product loadable in the memory of at least one computer and comprising software code portions capable of performing the method of claim 65

96. A system for fault and performance recovery in a communication network comprising a set of network apparatuses comprising a plurality of sites connected by means of connections having a given topology and comprising routers for implementing given routing policies, the network having associated therewith at least one database maintaining information regarding said network apparatuses, comprising:

test modules for executing at least one set of performance tests, wherein said at least one set of performance tests is created automatically by exploiting the information available on the topology of the connections between the various sites and by accessing said at least one database, said test modules being configured for analysing the results of said at least one set of performance tests to detect possible fault and performance impairment conditions of said network; and

routers configured for modifying, in the presence of a fault and performance impairment condition detected in said network, said routing policy compensating for said fault and performance impairment condition.

97. The system of claim 96, wherein said at least one set of performance tests comprises performance tests between sites of said plurality, said test modules being configured for carrying out said tests between edge routers and by associating the same performance to all the internal networks of a site.

98. The system of claim 96, wherein said network comprises at least two backbones, wherein said test modules are configured for carrying out said at least one set of performance tests as a set comprising performance tests carried out simultaneously on said at least two backbones.

99. The system of claim 96, wherein said network comprises at least two backbones and corresponding multibackbone sites, and wherein the communications between the multibackbone sites are directed to or travel from a central site, said test modules being configured for carrying out performance tests limited to the stretches from a site in said plurality and said central site.

100. The system of claim 96, wherein said network is a full mesh network, said test modules being configured for carrying out performance tests involving all end-to-end connections in the network, thus configuring a complete mesh of performance tests.

101. The system of claim 96, wherein said network is a partial mesh network, said test modules being configured for carrying out performance tests involving all end-to-end connections in a test subset in the network.

102. The system of claim 96, configured for:

generating test traffic in said network;

controlling via said routers, the routing of said test traffic in both possible directions of communication by configuring the routing policies implemented by both of the sites involved in the communication, said test modules being configured for causing said test traffic between a first site and a second site of a given pair always to travel on the same backbone, in both directions; and

making estimations on the connectivity referred to a routing path that selectively involves a given network backbone, both out and back (roundtrip).

103. The system of claim 102, wherein said routers are configured for gaining control over said routing of the test traffic, wherein on each router two addresses are configured that are advertised respectively on at least two backbones, whereby said addresses constitute the targets of the performance tests made, when the system is applied to a network comprising at least two backbones.

104. The system of claim 96, wherein said routers are configured for modifying the routing policy applied at a site in the network based on performance tests made starting from a remote site.

105. The system of claim 96, comprising a mechanism of detection of performance impairment by means of at least one of:

a synchronous-polling mechanism of a periodic type; and

a mechanism of asynchronous signalling by said network apparatuses.

106. The system of claim 105, wherein said asynchronous signalling is obtained by creating asynchronous events in the network when given thresholds have been exceeded within predetermined probe configurations.

107. The system of claim 96, comprising a centralized module configured for performing the steps of:

gathering statistics on reachability and associated quality between the routers of various sites in said plurality; and

in the presence of a fault and performance impairment condition detected in said network, instructing the apparatuses involved for choosing from among the routes advertised by a backbone other than the one in use, when the system is applied to a network comprising at least two backbones.

108. The system of claim 107, wherein said centralized module is configured for reaching said apparatuses instructed by exploiting the interface/address connected to the best backbone at a given moment.

109. The system of claim 96, comprising at least one of:

a first subsystem providing service and collecting user and topology information;

a second subsystem configuring and provisioning network apparatuses; and

a third subsystem ensuring continuous network activity.

110. The system of claim 109, wherein said second subsystem is configured for providing on-demand modification of configuration parameters by configuring, starting from the information contained in said at least one database, functions for performance monitoring and routing control.

111. The system of claim 110, wherein said functions for performance monitoring and routing control comprises at least one of:

loop back interfaces and corresponding addressing steps, route-maps for outgoing and incoming advertisements, and performance tests.

112. The system of claim 109, wherein said third subsystem is configured for performing at least one of the steps of:

monitoring the different connectivity paths between sites, and deriving therefrom measurements of at least one of use and performance;

selecting best paths in said network based on at least one of data obtained during said monitoring and pre-established policies; and

imparting directives for router updating for modifying routing decisions based on selections made during said selecting.

113. The system of claim 112, wherein said third subsystem is configured for performing at least one of the steps of:

activating all previously configured performance tests;

tracing performance data from the routers;

analysing the performance tests according to service configuration; and

re-configuring routing.

114. The system of claim 96, wherein said test modules are configured for optimising said set of performance tests by automatically configuring a minimum number of performance tests to guarantee performance monitoring of said network with coverage of all the communication stretches therein by configuring only one measurement for each pair of sites connected in said topology.

115. The system of claim 96, wherein said test modules are configured for distributing the performance tests to be performed at said sites in said network by generating for each apparatus involved a value representative of the performance tests to be entrusted to said apparatus.

116. The system of claim 115, wherein said test modules are configured for obtaining said value as a function of at least one of a first set of variables adapted to be measured statically on the apparatus, and a second set of variables assigned based on requirements of use of a respective site.

117. The system of claim 116, wherein said first set of variables comprises variables selected from the group of the type of platform, the hardware equipment, and the memory capabilities of the apparatus.

118. The system of claim 96, wherein said routers are configured for reconfiguring the traffic leaving a site over at least two backbones according to customer, for all the sites associated with a given customer in said network, when the system is applied to a network comprising at least two backbones.

119. The system of claim 118, configured for processing performance indicators corresponding to a backbone as a whole regardless of the individual site of origin and destination.

120. The system of claim 119, wherein said indicators comprise a weighted average of the data of the performance tests on the parameters of interest over a set of probes.

121. The system of claim 96, wherein said routers are configured for reconfiguring the traffic leaving a site over at least two backbones according to customer site, irrespective of any other site possibly associated to the same customer in said network, when the system is applied to a network comprising at least two backbones.

122. The system of claim 121, configured for processing performance indicators corresponding to transit on a backbone of the traffic originated by each customer site.

123. The system of claim 122, wherein said indicators include a weighted average of the data of the performance tests on the parameters of interest over a set of probes performed on the customer edges of the site considered.

124. The system of claim 96, wherein said routers are configured for reconfiguring the traffic leaving a site over at least two backbones selectively for different pairs of sites associated with the same customer in said network, when the system is applied to a network comprising at least two backbones.

125. The system of claim 124, configured for processing performance indicators corresponding to the transit, on a backbone of the traffic originated by each said customer site toward any other destination sites.

126. The system of claim 125, wherein said indicators comprise weighted averages of the data of the performance tests on the parameters of interest over the set of probes made on the customer edges of each said customer site to the customer edges of any other destination sites.

127. A communication network comprising:

a set of network apparatuses;

a plurality of sites connected by means of connections having a given topology and adopting a given routing policy; and

at least one associated database maintaining information regarding said network apparatuses;

the network having associated therewith a system according to claim 96.