Patent Application
20170063658
Shared risk resource group, which is commonly referred to as shared risk group (SRG), is a concept in network routing that apparently diverse connections may suffer from a common failure if links share a common, but non-obvious, risk or a common SRG. There are several types of SRGs. A shared risk link group (SRLG) is a set of identifiers assigned to the links of a network model. A shared risk node group (SRNG) is a set of identifiers assigned to the nodes of a network model. Each of the identifiers correlates to some “risk” of failure. Indeed, the risk is associated with a node or link in a network based on some physical risk to the node or link that cannot be automatically detected (e.g., is non-obvious).
As an example, two nodes may be co-located such that they share the same power circuit. Therefore, the two nodes share the risk of failing should that power circuit fail. In this case, the SRNG for each node would intersect at the risk associated with the power circuit.
The links or fiber spans in a network are typically fiber optic cables that connect two nodes. In practice, the fiber optic cables may be bundled in one concrete conduit or one power/telephone pole (e.g., aerial). Therefore, the two links share the risk of failing should that concrete conduit or power/telephone pole suffer damage. In this case, the SNLG for each link would intersect at the risk associated with the concrete conduit or power/telephone pole.
Thus, an SRG failure (e.g., an SRLG failure or an SRNG failure) may undesirably result in multiple circuits going down because of the failure of a common resource those networks share and depend on for continued correct operation.
In one embodiment, the disclosure includes a method of managing risk in a network including computing a first path between a source and a destination within the network, computing a second path between the source and the destination within the network, and comparing a first location of a first network element in the first path to a second location of a second network element in the second path, the first location is based on a first location-based risk identifier assigned to the first network element prior to computation of the first path, the second location is based on a second location-based risk identifier assigned to the second network element prior to computation of the second path, and the first network element and the second network element have a shared risk when the first location is within a predetermined threshold distance of the second location.
In another embodiment, the disclosure includes a method of managing risk in a network including computing a first path between a source and a destination within the network, computing a second path between the source and the destination within the network, and comparing a first risk zone of a first network element in the first path to a second risk zone of a second network element in the second path, the first risk zone is based on a first location-based risk identifier assigned to the first network element prior to computation of the first path, the second risk zone is based on a second location-based risk identifier assigned to the second network element prior to computation of the second path, and an overlap of the first risk zone and the second risk zone indicates that the first network element and the second network element have a shared risk.
In yet another embodiment, the disclosure includes a risk management device for managing risk in a network including a processor operably coupled to a memory, and a risk management module stored in memory that, when executed by the processor, is configured to compute a first path between a source and a destination within the network, compute a second path between the source and the destination within the network, and compare a first risk zone of a first network element in the first path to a second risk zone of a second network element in the second path, the first risk zone is based on a first location-based risk identifier assigned to the first network element prior to computation of the first path, the second risk zone is based on a second location-based risk identifier assigned to the second network element prior to computation of the second path, and an overlap of the first risk zone and the second risk zone indicates that the first network element and the second network element have a shared risk.
These and other features will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings and claims.
For a more complete understanding of this disclosure, reference is now made to the following brief description, taken in connection with the accompanying drawings and detailed description, wherein like reference numerals represent like parts.
It should be understood at the outset that although an illustrative implementation of one or more embodiments are provided below, the disclosed systems and/or methods may be implemented using any number of techniques, whether currently known or in existence. The disclosure should in no way be limited to the illustrative implementations, drawings, and techniques illustrated below, including the exemplary designs and implementations illustrated and described herein, but may be modified within the scope of the appended claims along with their full scope of equivalents.
Disclosed herein is a network utilizing a shared risk link group and/or shared risk node group vicinities for the computation of risk disjoint paths through the network. As will be more fully explained below, the shared risk link group and/or shared risk node group have identifiers that contain geographic (e.g., physical location) information. Therefore, a network administrator (e.g., a person and/or computer software) is able to check for overlaps in the physical positions of traversed network elements. If, for example, a network element (e.g., nodes, links, etc.) is within the same threshold distance as another network element, then those network elements share a risk (e.g., a risk that cannot be automatically detected or discovered) that is unacceptable and, therefore, their respective geographic locations or their respective paths through the network are not considered disjoint relative to that risk. Stated another way, the two network elements permitted to share a risk as those two elements are not within, for example, a predetermined distance of each other. To reduce the probability that the network is not subject to an outage based on a shared risk, new paths that do not share the risk are computed. This minimizes the probability that a single failure/risk will result in a loss of connectivity of both a primary and a backup circuit in the network.
The network 100 also includes a plurality of shared risk groups. For example, each of the nodes 110 labeled A, B, C, D, and I is reliant upon the same power source 112. If that power source 112 happens to fail, which may be deemed Risk-A, each of the nodes 110 labeled A, B, C, D, and I will lose power and may fail, thereby potentially interrupting traffic flow through the network 100. As such, the nodes 110 labeled A, B, C, D, and I are assigned a particular identifier to indicate that these nodes share a risk that exceeds an acceptable threshold and have been grouped together into a shared risk node group corresponding to Risk-A. Likewise, each of the nodes 110 labeled E, F, G, and H is reliant upon the same power source 112. If that power source 112 happens to fail, which may be deemed Risk-B, each of the nodes 110 labeled E, F, G, and H will lose power and may fail, thereby potentially interrupting traffic flow through the network 100. As such, the nodes 110 labeled E, F, G, and H are assigned a particular identifier to indicate that these nodes share a risk that exceeds an acceptable threshold and have been grouped together into a shared risk node group corresponding to Risk-B.
The particular identifier for the shared risk node group may be beneficially utilized when two disjoint paths 102, 103 through the network 100 are calculated. For example, the first path 102 through the network may include the nodes 110 labeled A, B, C, and D. Because the node 110 labeled I shares the same particular identifier as the nodes 110 labeled A, B, C, and D, the node 110 labeled I will not be used within the second path 103 to ensure that the two paths are disjoint (e.g., do not have a shared risk above a predetermined threshold). With the node 110 labeled I eliminated from consideration due to its particular identifier, only the nodes 110 labeled E, F, G, and H are available for the second path 103.
As another example, the link 108 between the nodes 110 labeled B and C and the link 109 between the nodes 110 labeled F and G both pass through the structure 114 (e.g., a conduit, bridge, building, roadway, etc.). If that structure 114 or the surrounding area suffers damage, which may be deemed Risk C, the link 108 between the nodes 110 labeled B and C and the link 109 between the nodes 110 labeled F and G may both fail. As such, the link 108 between the nodes 110 labeled B and C and the link 109 between the nodes 110 labeled F and G are assigned a particular identifier to indicate that these links share a risk that exceeds an acceptable threshold and have been grouped together into a shared risk link group corresponding to Risk-C. The particular identifier for the shared risk link group may be beneficially utilized when two disjoint paths 102, 103 through the network 100 are calculated. For example, the first path 102 through the network may include the link 108 between the nodes 110 labeled B and C. Because the link 109 between the nodes 110 labeled F and G shares the same particular identifier as the link 108 between the nodes 110 labeled B and C, the link 109 between the nodes 110 labeled F and G will not be used within the second path 103 to ensure that the two paths are disjoint (e.g., do not have a shared risk above a predetermined threshold). With the link 109 between the nodes 110 labeled F and G eliminated from consideration due to its particular identifier, only the nodes 110 labeled E, F, G, and H are available for the second path 103.
Unlike the network 200 of
In an embodiment, the location-based risk identifiers comprise a set of coordinates. For example, a location-based risk identifier may identify the latitude and longitude of a network element, which represents the position (e.g., physical location) of the network element in two dimensions. As another example, the location-based risk identifier may identify the latitude, longitude, and altitude of a network element, which represents the position of the network element in three dimensions. Physical links may be represented using geo-fencing techniques that allow for the definition of a series of line segments (or a path) through a map.
In an embodiment, any type of coordinate system may be utilized for the network 300 so long as the coordinate system is agreed upon between the different domains . Where the discussion of conventional risk mapping above indicated that mapping from one system to another can be difficult, the use of standardized positional references may allow for a simple translation of one co-ordinate system to another. For example, the coordinate system may be a Cartesian coordinate system, a cylindrical coordinate system, and a spherical coordinate system, and so on.
In an embodiment, one of the location-based risk identifiers may have the format: (latitude, longitude, radius), which generates a two-dimensional circle when visually represented. In contrast, another of the location-based risk identifiers may have the format: (latitude, longitude, altitude, radius), which generates a three-dimensional sphere when visually represented.
The methods of risk identification or management in a network (e.g., network 300) described herein, including the threshold and risk zone comparisons and/or path computations, may be implemented on any general-purpose network equipment or device, such as a computer or router with sufficient processing power, memory resources, and network throughput capability to handle the necessary workload placed upon it. In an embodiment, the methods may be implemented with input from, for example, a network administrator managing the network equipment or device.
From the foregoing, those skilled in the art will appreciate that a network administrator (e.g., a person and/or computer software) is able to check for overlaps in the physical positions of traversed network elements even when different domains are included in the network. Because location-based risk identifiers are used, any need to cross-reference or map the identifiers of one domain in a network to dissimilar identifiers of another domain is eliminated.
While several embodiments have been provided in the present disclosure, it should be understood that the disclosed systems and methods might be embodied in many other specific forms without departing from the spirit or scope of the present disclosure. The present examples are to be considered as illustrative and not restrictive, and the intention is not to be limited to the details given herein. For example, the various elements or components may be combined or integrated in another system or certain features may be omitted, or not implemented.
In addition, techniques, systems, subsystems, and methods described and illustrated in the various embodiments as discrete or separate may be combined or integrated with other systems, modules, techniques, or methods without departing from the scope of the present disclosure. Other items shown or discussed as coupled or directly coupled or communicating with each other may be indirectly coupled or communicating through some interface, device, or intermediate component whether electrically, mechanically, or otherwise. Other examples of changes, substitutions, and alterations are ascertainable by one skilled in the art and could be made without departing from the spirit and scope disclosed herein.
