JP3689061B2 - Upper node, network, program and recording medium - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an optical cross-connect, a router, and an SDH (Synchronous Digital
Hierarchy) It is used for a multi-layer network that can control devices and the like centrally. In particular, GMPLS (Generalized Multi Protocol
Label Switching).
[0002]
[Prior art]
In a multi-layer network, an optical cross-connect, a router, an SDH device, and the like can be controlled centrally. An example of such a multi-layer network is shown in FIG. In the example of FIG. 27, a lower network composed of a plurality of optical cross-connects is connected between the routers. Each router holds network topology information. However, this topology information does not include the topology information related to the lower level network, and the lower level network is simply treated as one transmission path. That is, as shown in FIG. 28, the topology information held by the routers is the topology information between the routers, and each router does not recognize the existence of the optical cross-connects constituting the lower network.
[0003]
Each node such as an optical cross-connect, a router, and an SDH device in such a multi-layer network is a protocol for sending an LSA (Link State Advertisement) packet to a peripheral node equally when any of the nodes detects a failure. When the router receives this LSA packet, it updates the topology information held by itself and sets a route that bypasses the failure location.
[0004]
[Problems to be solved by the invention]
In such a lower layer network of the multilayer network, when a failure occurs, a failure recovery measure such as setting a route that bypasses the failure portion can be quickly executed. However, since the router cannot recognize the execution status of such a failure recovery measure in the lower network, when the LSA packet arrives, it updates the topology information held by itself immediately and sets a detour route.
[0005]
However, in the lower network, the failure recovery measure is promptly executed, and an LSA packet indicating the failure recovery completion is transmitted. Upon receiving this LSA packet, the router again updates the topology information held by itself and sets the route.
[0006]
As described above, when the conventional failure recovery control technology is directly applied to the multilayer network, the router has an increased opportunity to update invalid topology information and set a detour route, resulting in an increase in processing load. . In particular, the load required for route calculation is large, and while performing route calculation, there are concerns about adverse effects such as a decrease in the processing speed of other processing, and the control mode that makes such route calculation invalid is improved. It is desirable that Therefore, it is desirable to apply a new failure recovery control technology different from the conventional failure recovery control technology in the multilayer network.
[0007]
The present invention has been made in such a background, and provides a failure recovery control technique suitable for a multi-layer network, and an upper node, a network, a program, and a recording medium capable of effectively using network resources. The purpose is to provide.
[0008]
[Means for Solving the Problems]
The most important feature of the present invention is that an upper node that detects a failure in the lower network holds the update of its own topology information for a predetermined time. The present invention proposes a protocol for deferring topology information update.
[0009]
A first aspect of the present invention is a device connected to a lower network composed of a plurality of lower nodes and transmission paths provided with a failure recovery means, and detects a failure occurrence of a transmission path accommodated by itself. Detection results as fault information Wide Means for reporting, means for maintaining network topology information, Wide Means for updating the topology information held by the device according to the reported failure information or the failure information detected by the device; Wide Report the reported failure information to other upper nodes Wide Tell Wide It is an upper node provided with a notification transfer means.
[0010]
Here, the present invention is characterized in that the updating means includes means for holding the update of topology information for T time from the time when the occurrence of failure is detected by the detecting means.
[0011]
In this way, the upper node is invalidated by holding the topology information update for a certain period of time in anticipation of prompt recovery of the lower network, instead of immediately updating the topology information when a failure occurs in the lower network. Route calculation can be avoided.
[0012]
Predictive time information holding means for holding information on the predicted time required for failure recovery of the lower network is provided, Wide The reporting means is the first immediately after the detecting means detects a failure of the lower network. Wide The first to make a report Wide Notification means and this first Wide Said first by reporting means Wide Notice Wide The second time when the failure recovery of the transmission path is not realized even if the predicted time held in the predicted time information holding means elapses from the notified time. Wide Second to make a notification Wide Notification means, and the means for holding is the first Wide The second time from the time the notification was received Wide Means for setting the time until the time of receiving the notification as the T time may be provided.
[0013]
In other words, when a failure occurs, Wide The other upper nodes recognize the occurrence of the failure. At this point, the other upper node can take an autonomous failure avoidance measure in consideration of the importance of communication handled by itself. For example, if the communication handled by you is less important, Wide Ignore the notification and second Wide It is only necessary to implement obstacle avoidance measures when the notification is made. Or, if the communication that you handle is very important, Wide At the time of notification, the topology information should be updated promptly and a fault detour route may be calculated. Thereby, invalid route calculation can be avoided.
[0014]
Priority holding means for holding recovery priority information at the time of failure recovery of the transmission path of the lower network is provided, Wide Means for notifying the plurality of transmission lines in which failures have occurred almost simultaneously. Wide Second time from the notification time Wide It is also possible to provide means for setting the length of time until the notification time in inverse proportion to the restoration priority held in the priority holding means.
[0015]
That is, when failures occur in a plurality of transmission lines almost simultaneously, it is difficult to restore these transmission lines simultaneously. Therefore, a restoration priority is set for each transmission line, and restoration is performed in order from the highest priority. In this case, first Wide Second after making a report Wide It is preferable to set the length of time until the notification is made in inverse proportion to the priority order. As a result, for transmission lines that can be promptly restored, Wide Second from notification Wide The time until notification is set long, and the update of the topology information by other upper nodes is put on hold, and the recovery is completed in the meantime. For transmission lines that cannot be promptly restored, first Wide Second from notification Wide The time until notification is set short, and the update of the topology information by other upper nodes is urged to set the detour route. Thereby, invalid route calculation can be avoided.
[0016]
Predictive time information holding means for holding information on the predicted time required for failure recovery of the lower network is provided, Wide A means for notifying means for acquiring the information on the predicted time required for the recovery by referring to the detection result of the means for detecting and the predicted time held in the predicted time information holding means; and means for acquiring the information Contains information on the estimated time obtained by Wide Means for making a notification, and the means for holding Wide It is also possible to provide means for setting the predicted time included in the notification as the T time.
[0017]
That is, since the upper node that detects the failure informs the other upper nodes of the estimated time required for the recovery of the failure, Wide It is only necessary to hold the update of the topology information according to the predicted time information included in the notification, and autonomous determination is not required. Since the upper node, which is the party that detected the failure, can most accurately grasp the predicted time for failure recovery, other upper nodes can set an appropriate hold time.
[0018]
Said Wide The notification transferring means sends the holding means to the other upper node until the holding time of the holding means elapses. Wide Suspend notification Wide Notification holding means can also be provided.
[0019]
In other words, the upper node directly connected to the lower network where the failure occurred Wide Hold the notification for T hours. As a result, other upper nodes that are not directly connected to the failed lower network are connected to the upper node that is directly connected to the failed lower network after T hours. Wide As a result, the update of the topology information is suspended for 2T time. Therefore, it is possible to make a difference in the holding time between the upper node directly connected to the lower network where the failure has occurred and the other upper node that is not. As a result, after the upper node directly connected to the failed lower network updates the topology information after T time and starts a failure avoiding measure such as setting of a detour route, the other upper nodes are further connected to T If the failure of the lower level network is recovered during this time, the topology information is restored only for the upper level node directly connected to the failed lower level network. Therefore, it is possible to prevent the oscillation of the topology information update from spreading to the entire network in two stages.
[0020]
Alternatively, when a higher-order node having a means for deferring topology information and other upper-level nodes that do not have a mixture exist in the network, the upper-level node having means for deferring topology information is To other upper nodes that do not have a means of deferring information updates Wide By providing a means for holding notifications together, other upper nodes that do not have means for holding updates of topology information can behave in the same manner as upper nodes having means for holding updates of topology information. become. For this reason, even a network in which an upper node having a means for deferring topology information updating and another upper node not provided can operate as the network of the present invention.
[0021]
Predictive time information holding means for holding information of predicted time required for failure recovery of the lower network is provided, and the means for holding refers to the failure information and the predicted time held in the predicted time information holding means Then, it is possible to provide means for acquiring information on the predicted time required for the recovery and means for setting the predicted time acquired by the acquiring means to the T time.
[0022]
That is, all the upper nodes grasp the estimated time for failure recovery and set the pending time for updating the topology information.
[0023]
Said Wide The means for reporting is a constant cycle during the detection of the fault by the means for detecting. Wide Means for making a notification, and the means for holding is a predetermined number of times. Wide It is also possible to provide means for setting the time until the notification is received as the T time.
[0024]
In other words, the upper node simply sends a failure occurrence to other upper nodes at a fixed cycle. Wide It is only necessary to notify the other upper nodes. Wide It is only necessary to hold the update of the topology information until the notification is received, and the processing load can be reduced without requiring complicated processing in the upper node and other upper nodes. It is suitable for the desire to simplify the upper node and other upper nodes. At this time, the other upper nodes consider the importance of the communication handled by themselves and other factors in consideration of the above. Wide You may change suitably the frequency | count of receiving notification.
[0025]
Means for analyzing the failure status according to the detection result of the means for detecting, and means for ranking the degree of failure according to the analysis result of the means for analyzing as representing a severe failure with a higher possibility of recovery as the rank is higher Is provided Wide The means for reporting refers to the ranking result of the means for ranking, and for faults above a predetermined rank. Wide Conditional to make a notification Wide It is also possible to provide a reporting means.
[0026]
In other words, for low-rank failures that can be recovered in a short time, Wide Do not make a notification. As a result, other upper nodes do not even know that a failure has occurred, and the processing load on the upper nodes can be reduced.
[0027]
Means for analyzing the failure status according to the detection result of the means for detecting, and means for ranking the degree of failure according to the analysis result of the means for analyzing as representing a severe failure with a higher possibility of recovery as the rank is higher A predicted time information holding means for holding information of a predicted time required for failure recovery of the lower network, Wide The reporting means refers to the ranking result of the ranking means, and for failures below a predetermined rank, it is limited to the upper node directly related to the failure lower network. Wide Limited including limited information to notify Wide The means of issuing notifications and this limitation Wide When the predicted lower level network does not recover after the predicted time held in the predicted time information holding means from the issuance of the notification, the limitation is lifted. Wide Means for issuing a notification Wide When the notification is received, it is sent to the other upper node according to the limited information. Wide Ban on the above notice Wide It is possible to provide a means for prohibiting until a notice is received.
[0028]
In other words, even if a failure can be expected to be recovered in a short time, other upper nodes directly related to the failure Wide Make a notification. However, other upper nodes that are not directly related to the failure Wide Do not forward notifications. As a result, the occurrence of a failure that can be expected to be recovered in a short time Wide By the notification, it is possible to avoid the vibration of the topology information update from spreading to the entire network. further, Wide Other higher-level nodes that receive notifications can take measures to avoid failures in the event that failure recovery is not realized in a short time against expectations. For example, they handle highly important communications. Useful for other upper nodes.
[0029]
The means for analyzing the failure status may comprise means for detecting the number of transmission lines in which failures have occurred almost simultaneously, and the ranking means may comprise means for assigning a rank based on this number. The means for detecting the number divides the failure factors into groups, and a table in which transmission paths that are interrupted in response to the failure occurrence of the failure factors belonging to each group are recorded, and the failure is detected almost simultaneously with reference to this table. And a means for detecting the number of the generated transmission lines.
[0030]
That is, when ranking the degree of failure, it is possible to rank according to the number of transmission lines in which failures occur almost simultaneously. According to this, it becomes a rank so high that a failure occurs in a large number of transmission paths almost simultaneously and recovery cannot be expected, and a failure avoidance measure that depends on other upper nodes such as setting a detour route in other upper nodes is required. Represents what to do.
[0031]
Priority holding means for holding recovery priority information at the time of failure recovery of the transmission path in the lower network is provided, and the means for analyzing the failure status is the priority holding means for the transmission path in which a failure has occurred. Means for obtaining information on the restoration priority stored in the ranking, and the ranking means ranks higher in inverse proportion to the priority order, indicating that the higher the rank, the lower the possibility of restoration. It is also possible to provide means for
[0032]
In other words, when ranking the degree of failure, the rank is so high that recovery cannot be preferentially expected, and failure avoidance measures depending on other upper nodes such as setting of a detour route in other upper nodes are required. Represents.
[0033]
The means for analyzing the failure situation comprises means for detecting the degree of congestion of network resources by referring to the topology information of the lower network where the failure has occurred, and the ranking means has a possibility of recovery as the rank increases Means for ranking higher in inverse proportion to the degree of congestion may be provided as representing a low severity obstacle.
[0034]
In other words, when ranking the degree of failure, it is difficult to set a detour route where the degree of congestion of network resources is low, and it is difficult to expect short-term recovery. This indicates that a failure avoidance measure depending on the upper node such as route setting is required.
[0035]
The predicted time information holding means is means for holding link state information relating to a detailed configuration of the lower network, and a detour path included in each of the transmission paths estimated from the link state information held in the holding means. Means for calculating the predicted time for each of the transmission paths based on the setting capability of the transmission line.
[0036]
For example, the means for calculating the predicted time calculates, as the setting capability of the detour path, the transmission path during duplex operation with the predicted time being almost zero and the transmission path is in a single operation during failure. A means for re-recognizing as a transmission path, or a means for calculating the predicted time, as the setting capability of the detour path, the presence / absence of a detour path to both ends of the faulty transmission path and the vacancy of the detour path Means for calculating the predicted time based on the situation.
[0037]
Alternatively, the predicted time information holding means is configured to calculate the predicted time between the two nodes for which a working and backup route is set, and a route having a free bandwidth near the working and backup routes, respectively. The time required for the path to be switched from the virtual working path to the virtual backup path when a failure is simulated for the virtual working path as a working and backup path. Means for calculating the predicted time can also be provided.
[0038]
That is, in order to set a virtual working path and a standby path in normal times, cause a simulated failure in the virtual working path, and switch the path from the virtual working path to the virtual backup path By examining the time required, the estimated time required for failure recovery can be calculated. Virtual working and protection paths are set in the vicinity of the actual working and protection paths, failure detection → failure Wide In accordance with an actual process such as notification → switching a backup route, it is possible to obtain a highly accurate predicted failure recovery time that reflects actual network conditions.
[0039]
Alternatively, the predicted time information holding means uses the predicted time between two nodes for which a route has already been set as a virtual route that has a free bandwidth near the route, and this virtual route. When a failure is simulated, a detour route for the virtual route is searched, and a time required for the route to switch from the virtual route to the detour route is calculated as the predicted time. It is also possible to provide means for
[0040]
In other words, a virtual route is set at normal times, a failure is simulated on this virtual route, and failure detection → failure Wide It is possible to simulate the process of notification → bypass route search → bypass route setting → bypass route switching, and obtain a highly accurate failure recovery prediction time reflecting actual network conditions.
[0041]
According to a second aspect of the present invention, there is provided a network including the higher order node of the present invention.
[0042]
According to a third aspect of the present invention, transmission installed in the information processing apparatus is connected to the information processing apparatus and connected to a lower network composed of a plurality of lower nodes and transmission paths having a failure recovery function. A function that detects the occurrence of a road fault and the detection result of this function as fault information Wide A function to notify, a function to hold network topology information, Wide A function of updating the topology information held by the device according to the reported failure information or the failure information detected by the device; Wide Report the reported failure information to other upper nodes Wide Tell Wide This is a program for realizing a function corresponding to a device for controlling an upper node having a notification transfer function.
[0043]
Here, the feature of the present invention is that, as the updating function, a function of holding the update of topology information for T time from the time when the occurrence of a failure is detected by the detecting function is realized.
[0044]
Realizing a predicted time information holding function for holding information of a predicted time required for failure recovery of the lower network, Wide As the function to notify, the first function immediately after the detecting function detects the failure of the lower network. Wide The first to make a report Wide Notification function and this first Wide The first by the notification function Wide Notice Wide The second time when the failure recovery of the transmission path is not realized even if the predicted time held in the predicted time information holding function has elapsed from the notified time. Wide Second to make a notification Wide Notification function, and as the function to hold, the first Wide The second time from the time the notification was received Wide It is also possible to realize a function of setting the time until the time of receiving the notification as the T time.
[0045]
Realizing a priority holding function for holding information on recovery priority at the time of failure recovery of the transmission path of the lower network, Wide As a function of reporting, a plurality of the transmission lines in which failures occur almost simultaneously, the first Wide Second time from the notification time Wide It is also possible to realize a function of setting the length of time until the notification time in inverse proportion to the restoration priority held in the priority holding function.
[0046]
Realizing a predicted time information holding function for holding information of a predicted time required for failure recovery of the lower network, Wide A function to acquire the information on the predicted time required for the recovery by referring to the detection result of the function to be detected and the predicted time held in the predicted time information holding function, and the function to acquire Contains information on the estimated time acquired by Wide And a function for holding the Wide It is also possible to realize a function of setting the predicted time included in the notification as the T time.
[0047]
Said Wide As a notification transfer function, until the hold time of the hold function elapses, Wide Suspend notification Wide A notification hold function can also be realized.
[0048]
Realizing a predicted time information holding function for holding information on a predicted time required for recovery from a failure in the lower network, and referring to the failure information and the predicted time held in the predicted time information holding function as the holding function Thus, it is possible to realize a function of acquiring information of the predicted time required for the recovery and a function of setting the predicted time acquired by the acquired function as the T time.
[0049]
Said Wide As a function to notify Wide The function to make a notification is realized, and as the function to hold, a predetermined number of times Wide It is also possible to realize a function of setting the time until the notification is received as the T time.
[0050]
A function of analyzing the failure status according to the detection result of the function to be detected, and a function of ranking the degree of failure according to the analysis result of the function to be analyzed as representing a severe failure with a higher possibility of recovery as the rank is higher And realize the above Wide Refer to the ranking results of the ranking function as a function to notify Wide Conditional to make a notification Wide The notification function can also be realized.
[0051]
A function of analyzing the failure status according to the detection result of the function to be detected, and a function of ranking the degree of failure according to the analysis result of the function to be analyzed as representing a severe failure with a higher possibility of recovery as the rank is higher Realizing a predicted time information holding function for holding information of a predicted time required for failure recovery of the lower network, Wide As a function to report, referring to the ranking result of the function to be ranked, the failure below a predetermined rank is limited to the upper node directly related to the failure lower network. Wide Limited including limited information to notify Wide The function to issue notifications and this limitation Wide When the failure lower network does not recover after the prediction time held in the prediction time information holding function has elapsed since the issue of the notification, the restriction is lifted Wide The function to issue a notification Wide When the notification is received, it is sent to the other upper node according to the limited information. Wide Ban on the above notice Wide You can also implement a function that is prohibited until a notification is received.
[0052]
As a function of analyzing the failure status, a function of detecting the number of the transmission lines in which a failure has occurred almost simultaneously can be realized, and as a function of ranking, a function of assigning a rank based on this number can be realized.
[0053]
As a function of detecting the number, a function corresponding to a table in which failure factors are grouped and a transmission path that is disconnected in response to the occurrence of a failure of each failure factor is recorded, and a function corresponding to this table The function of detecting the number of the transmission lines in which a failure has occurred almost simultaneously can also be realized.
[0054]
As a function of realizing a priority holding function for holding restoration priority information at the time of failure recovery of the transmission path in the lower network and analyzing the failure status, the priority holding means for the transmission path in which a failure has occurred The function of obtaining the information of the restoration priority stored in the list is realized, and as the function of ranking, the higher the rank, the higher the probability that the possibility of restoration is low and the higher the ranking is inversely proportional to the priority. It is also possible to realize the function of performing.
[0055]
As a function of analyzing the failure status, a function of detecting the degree of congestion of network resources by referring to topology information of the lower network where the failure has occurred is realized, and as the function of ranking, the higher the rank, the higher the possibility of recovery It is also possible to realize a function that ranks high in inverse proportion to the degree of congestion, assuming that it represents a low severity obstacle.
[0056]
As the predicted time information holding function, a function of holding link state information relating to the detailed configuration of the lower network, and a detour path included in each of the transmission paths estimated from the link state information held in the held function It is also possible to realize a function of calculating the predicted time for each of the transmission paths based on the setting capability.
[0057]
As a function of calculating the predicted time, as a setting capability of the detour path, for a transmission line in duplex operation, the calculation time is calculated with the prediction time being almost zero and the transmission line is in a single operation during a failure. It is possible to realize the function of re-recognizing as
[0058]
As the function of calculating the predicted time, the function of calculating the predicted time based on the presence / absence of a bypass path at both ends of the faulty transmission path and the status of vacancy of the bypass path is realized as the setting capability of the bypass path You can also
[0059]
As the predicted time information holding function, the predicted time between the two nodes where the working and backup paths are set, the path having a free band near the current and backup paths, the virtual working and Estimate the time required for the path to switch from the virtual working path to the virtual backup path when a failure is simulated for the virtual working path as a backup path. It is also possible to realize a function for calculating time.
[0060]
As the predicted time information holding function, the predicted time between the two nodes for which a route has already been set is defined as a virtual route that has a free bandwidth in the vicinity of the route. A function that, when a failure is simulated, a detour route for the virtual route is searched, and a time required for the route to be switched from the virtual route to the detour route is calculated as the predicted time Can also be realized.
[0061]
The third aspect of the present invention is the information processing apparatus-readable recording medium on which the program of the present invention is recorded. By recording the program of the present invention on the recording medium of the present invention, the information processing apparatus can install the program of the present invention using this recording medium. Alternatively, the program of the present invention can be directly installed in the information processing apparatus via a network from a server holding the program of the present invention.
[0062]
Accordingly, it is possible to provide a failure recovery control technique suitable for a multi-layer network using an information processing apparatus such as a computer apparatus, and to realize an upper node and a network capable of effectively using network resources.
[0063]
DETAILED DESCRIPTION OF THE INVENTION
(First Example)
The network of the first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a conceptual diagram of a network according to this embodiment. FIG. 2 is a configuration diagram of the optical cross-connect of this embodiment. FIG. 3 is a block diagram of the failure recovery control apparatus of the first embodiment. FIG. 4 is a block diagram of the router of the first embodiment.
[0064]
The first embodiment includes a plurality of nodes and transmission lines installed between the plurality of nodes, and the plurality of nodes include routers 1 to 8 as upper nodes and optical cross-connects 10 as lower nodes. 26, and at least two routers are connected by a lower network composed of a plurality of optical cross-connects and transmission paths, and the plurality of optical cross-connects cooperate with this lower-level network to perform failure recovery. A control device 30 is provided in each of the optical cross-connects 10 to 26, and the failure recovery control device 30 of the routers 1 to 8 and the optical cross-connects 10 to 26 detects a failure occurrence that detects the failure of the transmission path accommodated by itself. Unit 31 and 41 and the detection results of the failure occurrence detection units 31 and 41 as failure information Wide Tell Wide The routers 1 to 8, the topology information holding unit 43 for holding the network topology information, Wide A topology information update unit 46 for updating the topology information held by the device according to the reported failure information or the failure information detected by the device; Wide Report the reported failure information to other routers 1-8 Wide Tell Wide This is a network including a notification transfer unit 47.
[0065]
Here, the feature of the present invention is that the topology information update unit 46 includes an alarm protection unit 48 that holds the update of the topology information for T time from the time when the occurrence of the failure is detected.
[0066]
In the routers 1 to 8, when the failure detection unit 41 detects the occurrence of a failure, Wide Although the failure occurrence may be detected by notification, the failure detected by the failure occurrence detection unit 41 is a higher-level network failure including the routers 1 to 8 shown in FIG. In contrast, from the lower network Wide The failure detected by the notification is a failure at the lower network level composed of the optical cross-connects 10 to 26 shown in FIG.
[0067]
That is, the failure detected by the failure occurrence detection unit 41 is a serious failure in which the lower-level network between routers is almost completely disconnected, and is a failure for which immediate recovery is hardly expected. In contrast, from the lower network Wide The failure detected by the notification is a minor failure in which a part of the lower network is disconnected, and is a failure that can be expected to be recovered quickly such as setting a detour route.
[0068]
In the present embodiment, a description will be given with respect to the occurrence of a failure at a lower network level where rapid recovery can be expected.
[0069]
In this embodiment, it is from the lower network. Wide The failure is detected by the notification, but the failure of the lower network is also detected by the error monitoring of the link keep-alive signal transmitted from the routers 1 to 8 itself or the K1 / K2 byte of SDH. According to the LSA packet described in this embodiment. Wide The present embodiment can be similarly explained by using such a failure occurrence detection method instead of the notification.
[0070]
The failure recovery control device 30 is provided with a predicted time information holding unit 34 that holds information of a predicted time required for failure recovery of the lower network. Wide The reporting unit 32 refers to the detection result of the failure occurrence detection unit 31 and the predicted time held in the predicted time information holding unit 34, acquires the information on the predicted time required for the recovery, and acquires the acquired Contains estimated time information Wide Make a notification. The alarm protection unit 48 of the routers 1 to 8 Wide The predicted time included in the notification is set as the T time. In the network configuration diagram, the illustration of the failure recovery control device 30 is omitted.
[0071]
(Second embodiment)
A second embodiment of the present invention will be described with reference to FIG. FIG. 5 shows the second embodiment. Wide It is a block block diagram of a notification transfer part.
[0072]
In the second embodiment, the routers 1 to 8 Wide The notification transfer unit 47 sends to other routers until the holding time of the alarm protection unit 48 elapses. Wide Suspend notification Wide A notification holding unit 49 is provided.
[0073]
According to the second embodiment, the upper nodes 7 and 8 directly connected to the lower network where the failure has occurred Wide The update of topology information is suspended for T time. On the other hand, the upper nodes 1 to 6 that are not directly connected to the failed lower network are connected to the upper nodes 7 and 8 after T time. Wide As a result, the update of the topology information is suspended for 2T time. Therefore, it is possible to make a difference in the holding time between the upper nodes 7 and 8 directly connected to the lower network where the failure has occurred and the upper nodes 1 to 6 that are not. As a result, after the upper nodes 7 and 8 directly connected to the lower network in which the failure has occurred update the topology information after T time and start failure avoiding measures such as setting a detour route, the other upper nodes 1 to 1 6 further holds the update of the T-time topology information. If the failure of the lower network is recovered during this period, the restoration of the topology information is directly connected to the failed lower network. Since only the upper nodes 7 and 8 are required, it is possible to prevent the oscillation of the topology information update from spreading to the entire network in two stages.
[0074]
Alternatively, according to the second embodiment, when a router with the alarm protection unit 48 and a router without the alarm protection unit 48 coexist in the network, the router with the alarm protection unit 48 includes the alarm protection unit 48. Not to other routers Wide Suspend notification Wide By providing the notification holding unit 49 together, a router that does not include the alarm protection unit 48 can behave in the same manner as a router that includes the alarm protection unit 48. Therefore, even a network in which a router having the alarm protection unit 48 and a router not having the alarm protection unit 48 are mixed can operate as the network of the present invention.
[0075]
(Third embodiment)
A third embodiment of the present invention will be described with reference to FIGS. FIG. 6 is a block diagram of the router of the third embodiment. FIG. 7 is a block diagram of the failure recovery control apparatus of the third embodiment.
[0076]
In the third embodiment, each of the routers 1 to 8 includes a predicted time information holding unit 50 that holds information about a predicted time required for the failure recovery of the lower network. The alarm protection unit 48 refers to the failure information and the predicted time held in the predicted time information holding unit 50 to acquire information on the predicted time required for the recovery, and uses the acquired predicted time as the T time. Therefore, as shown in FIG. 7, it is not necessary to provide the predicted time information holding unit in the failure recovery control device 30 provided in the optical cross connects 1 to 25.
[0077]
(Fourth embodiment)
A fourth embodiment of the present invention will be described with reference to FIG. FIG. 8 is a diagram for explaining a holding time determination method according to the fourth embodiment.
[0078]
In the fourth embodiment, in the failure recovery control device 30 of the optical cross-connects 10 to 26 Wide The whistleblower 32 is in a constant cycle while the fault detection unit 31 detects a fault. Wide Make a notification. The alarm protection unit 48 of the routers 1 to 8 has a predetermined number of times. Wide The time until the notification is received is defined as T time.
[0079]
According to the fourth embodiment, the failure recovery control device 30 Wide The whistleblower 32 issues Wide The content of the notification itself does not require complex content and simply includes information that a failure has occurred. Wide Because it is sufficient to make a notification at regular intervals, Wide The processing load on the reporting unit 32 can be reduced.
[0080]
The configuration of the routers 1 to 8 is the configuration shown in FIG. 6, and the predicted time information holding unit 50 sets the T time and receives this T time. Wide Replace with the number of notifications.
[0081]
(Fifth embodiment)
A network according to a fifth embodiment of the present invention will be described with reference to FIG. FIG. 9 is a diagram for explaining the holding time determination method of the fifth embodiment.
[0082]
In the fifth embodiment, as shown in FIG. 3, the failure recovery control device 30 provided in the optical cross connects 10 to 26 includes a predicted time information holding unit 34. Wide The notification unit 32 immediately starts after the failure detection unit 31 detects a failure in the lower network. Wide This first Wide Notice Wide The second time when the failure recovery of the lower network is not realized even if the predicted time held in the predicted time information holding unit 34 elapses from the notified time. Wide Make a notification.
[0083]
The alarm protector 48 of the routers 1-8 is the first Wide 2nd from the time the notification was received Wide The time until the time of receiving the notification is defined as T time.
[0084]
(Sixth embodiment)
A network according to the sixth embodiment of the present invention will be described with reference to FIGS. FIG. 10 is a block diagram of a failure recovery control apparatus according to the sixth embodiment. FIG. 11 is a diagram for explaining a holding time determination method according to the sixth embodiment.
[0085]
In the sixth embodiment, as shown in FIG. 10, the failure recovery control device 30 of the optical cross-connects 10 to 26 includes a priority storage unit 35 that stores information on the recovery priority at the time of failure recovery of the transmission path of the lower network. Prepare.
[0086]
For example, as shown in FIG. 11, when the transmission path is a wavelength division multiplexing transmission path, many wavelength paths are disconnected simultaneously due to the occurrence of a failure in the transmission path. In such a case, it is actually difficult to restore all the wavelength paths at the same time, and the priority order is set and restored in order. In general, the more important the communication content handled, the higher the priority. The priority level holding unit 35 holds in advance recovery priority level information at the time of failure recovery.
[0087]
Under such circumstances, in the sixth embodiment, the failure recovery control device 30 Wide The reporting unit 32 performs the first processing on the plurality of wavelength paths in which failures occur almost simultaneously. Wide Second from the notification time Wide The length of time until the notification time is set in inverse proportion to the restoration priority stored in the priority storage unit 35.
[0088]
That is, as shown in FIG. 11, for the wavelength path λ1, which has the highest priority and can be expected to be promptly restored, the restoration of the lower network is completed promptly without the routers 1 to 8 probably setting a detour route. Based on the expectation that Wide Second from notification Wide Set a longer time until notification. In the example of FIG. Wide Recovery has been completed before the scheduled notification time, Wide The notice is not actually issued.
[0089]
On the other hand, for the wavelength path λn, which has the lowest priority and cannot be expected to be promptly restored, the first is probably based on the expectation that a failure avoidance measure by the routers 1 to 8 is necessary. Wide Second from notification Wide Set a short time to notification. As a result, trouble avoidance measures such as setting of a detour route by the routers 1 to 8 are immediately taken.
[0090]
(Seventh embodiment)
A seventh embodiment of the present invention will be described with reference to FIG. FIG. 12 is a block diagram of the failure recovery control apparatus of the seventh embodiment.
[0091]
In the seventh embodiment, the failure status analysis unit 36 that analyzes the failure status according to the detection result of the failure occurrence detection unit 31, and the higher the rank of the failure according to the analysis result of the failure status analysis unit 36, the higher the possibility of recovery. A failure ranking unit 37 that ranks as representing a low severity failure, Wide The reporting unit 32 refers to the ranking result of the failure ranking unit 37 for the failure of a predetermined rank or higher. Wide Make a notification.
[0092]
In other words, in the seventh embodiment, for low-ranking faults that can be recovered in a very short time, Wide Do not make a notification. Thereby, the processing load in the routers 1-8 can be reduced.
[0093]
(Eighth Example)
An eighth embodiment of the present invention will be described with reference to FIGS. FIG. 13 is a block diagram of the failure recovery control apparatus of the eighth embodiment. FIG. 14 is a diagram showing the contents of the LSA packet used in the network of the eighth embodiment.
[0094]
In the eighth embodiment, as shown in FIG. 12, the failure recovery control device 30 includes a failure status analysis unit 36 that analyzes a failure status according to the detection result of the failure occurrence detection unit 31, and an analysis by the failure information analysis unit 36. According to the result, a failure ranking unit 37 that ranks the failure level as representing a severe failure that has a lower probability of recovery as the rank is higher, and holding predicted time information that holds information of a predicted time required for failure recovery of the lower network Part 34 is provided, Wide The reporting unit 32 refers to the ranking result of the failure ranking unit 37 and limits failures below a predetermined rank to the routers 7 and 8 directly related to the failure lower network. Wide Limited including limited information to notify Wide An announcement is issued. In addition, this limitation Wide The restriction is lifted when the failure transmission path does not recover even after the predicted time held in the predicted time information holding unit 34 from the issue of the notification. Wide An announcement is issued.
[0095]
Routers 7 and 8 Wide The notification transfer unit 47 Wide When the notification is received, it is sent to other routers 1-6 according to the limited information. Wide Ban on the above notice Wide Prohibition until notification is received.
[0096]
That is, limited Wide As shown in FIG. 14A, “LSA” is written as the packet type, “24-22” as the failure location is written as the failure information, and “ Wide "Not prohibited" is written. Wide Routers 7 and 8 that are waiting for notification Wide Upon receiving this LSA packet, the notification transfer unit 47 writes “ Wide To the other routers 1 to 6 Wide Ban Wide Transition to the notification transfer standby state.
[0097]
Of the failure recovery control device 30 Wide In the reporting unit 32, the limitation shown in FIG. Wide If the recovery is not completed even after the failure recovery prediction time obtained by referring to the prediction time information holding unit 34 after issuing the notification, as shown in FIG. “ Wide Send LSA packet with "No ban" written in. Routers 7 and 8 Wide Upon receiving this LSA packet, the notification transfer unit 47 writes “ Wide According to "ban", to other routers 1-6 Wide Forward the notification Wide Transition to the notification transfer state.
[0098]
Alternatively, the failure recovery control device 30 Wide In the reporting unit 32, the limitation shown in FIG. Wide When the recovery is completed before the predicted failure recovery time obtained by referring to the predicted time information holding unit 34 after issuing the notification, as shown in FIG. The LSA packet in which “Recovery” is written is transmitted. Routers 7 and 8 Wide When the notification transfer unit 47 receives this LSA packet, Wide Canceling the notification transfer standby state Wide Return to the standby state.
[0099]
(Ninth Example)
A ninth embodiment of the present invention will be described with reference to FIGS. FIG. 15 is a diagram showing a part of a network for explaining the ninth embodiment. FIG. 16 is a diagram showing SRLG (Shared Risk Link Group).
[0100]
In the ninth embodiment, the failure status analysis unit 36 of the failure recovery control device 30 detects the number of transmission paths in which failures have occurred almost simultaneously, and the failure ranking unit 37 assigns a rank based on this number.
[0101]
When detecting the number of transmission lines in which a failure has occurred almost simultaneously, as shown in FIG. 16, the failure factors are divided into groups, and the transmission lines that are disconnected in response to the failure occurrence of the failure factors belonging to each group are recorded. The number of transmission lines in which a failure has occurred almost simultaneously is detected with reference to this table.
[0102]
That is, SRLG is a set of those affected simultaneously when a failure occurs in one failure factor. In the ninth embodiment, there are optical cross-connects 22 to 26 and links 80 to 85 as failure factors. There are six optical paths of wavelengths λ1 to λ6 that are affected when a failure occurs in these.
[0103]
If a failure occurs in any of the optical cross-connects 22, 24, 25 and the links 82, 83, the three optical paths having the wavelengths λ1 to λ3 are affected. Further, if any of the optical cross-connects 22, 26, 25 and the links 84, 85 fails, the two optical paths with wavelengths λ4 and λ5 are affected, so this is set as group # 2. Further, if any of the optical cross-connects 22, 23, 25 and the links 80, 81 fails, one optical path having the wavelength λ6 is affected, so this is set as group # 3. Tables shown in FIGS. 16A and 16B show this correspondence in a table.
[0104]
The failure condition analysis unit 36 includes the table shown in FIG. 16, and by identifying the failure factor from the failure information written in the LSA packet and referring to this table, the failure cause of the failure factor is generated. Correspondingly, the number of affected optical paths can be examined. In accordance with this number, the failure ranking unit 37 ranks the degree of failure. In the ninth embodiment, since there are three groups # 1, # 2, and # 3, the rank “H” is assigned to the failure occurrence of the failure factor belonging to the group # 1, and the failure factor belonging to the group # 2 is assigned. Rank “M” is assigned to the failure occurrence, and rank “L” is assigned to the failure occurrence of the failure factor belonging to group # 3.
[0105]
(Tenth embodiment)
A tenth embodiment of the present invention will be described with reference to FIG. FIG. 17 is a block diagram of a failure recovery control apparatus according to the tenth embodiment.
[0106]
In the tenth embodiment, as shown in FIG. 17, the failure recovery control device 30 is provided with a priority storage unit 35 that stores information on the recovery priority at the time of failure recovery of the transmission path of the lower network. The situation analysis unit 36 obtains information on the restoration priority stored in the priority holding unit 35 of the transmission path in which the failure has occurred, and the failure ranking unit 37 detects a severe failure that is less likely to be recovered as the rank is higher. As a representation, a high ranking is given in inverse proportion to the priority order.
[0107]
That is, as described with reference to FIG. 11 of the sixth embodiment, a plurality of transmission lines in which a failure has occurred at the same time are provided with restoration priorities, and the transmission line can be restored earliest after the failure has occurred. Is assigned the lowest rank, and the highest rank is assigned to the transmission line that is finally recovered after the failure.
[0108]
(Eleventh Example)
A network according to the eleventh embodiment of the present invention will be described with reference to FIGS. FIG. 18 is a block diagram of a failure recovery control apparatus according to the eleventh embodiment. FIG. 19 is a diagram for explaining the rank assignment method of the eleventh embodiment.
[0109]
In the eleventh embodiment, as shown in FIG. 18, the failure recovery control device 30 is provided with a link state information holding unit 38 for holding link state information relating to the detailed configuration of the lower level network. As shown in FIG. 19, the link state information holding unit 38 holds small-scale topology information limited to the lower networks to which the link state information holding unit 38 belongs.
[0110]
The failure status analysis unit 36 detects the degree of congestion of network resources with reference to the link state information regarding the detailed configuration of the lower level network where the failure has occurred, as shown in FIG. In the example of FIG. 19, when the failure locations A and B are compared, A has a higher degree of network resource congestion than B. The failure ranking unit 37 ranks higher in inverse proportion to the degree of congestion, assuming that the higher the rank is, the lower the possibility of recovery is, indicating a severe failure.
[0111]
In other words, it is easy to set a detour route at a location where network resources are dense and can be expected to recover in a short time, but it is difficult to set a detour route at a location where network resources are sparse. A short time recovery is not expected. Therefore, a high rank is assigned in inverse proportion to the degree of network resource congestion.
[0112]
(Twelfth embodiment)
A twelfth embodiment of the present invention will be described with reference to FIGS. The twelfth embodiment is an embodiment of a method for setting the predicted recovery time held by the predicted time information holding unit 34. FIG. 20 is a block diagram of the predicted time information holding unit of this embodiment. FIG. 21 is a diagram showing a transmission line during duplex operation. FIG. 22 is a diagram illustrating a transmission path having a detour path.
[0113]
The predicted time information holding unit 34 of the present embodiment is estimated from a link state information holding unit 38 that holds link state information related to the detailed configuration of the lower level network, and link state information held in the link state information holding unit 38. A recovery predicted time calculation unit 39 that calculates a predicted time for each transmission path based on the setting capability of the detour path of each transmission path of the lower network. Further, the calculation result of the recovery prediction time calculation unit 39 is recorded in the recovery prediction time information table 70.
[0114]
As shown in FIG. 21, the estimated recovery time calculation unit 39 calculates the estimated recovery time for the duplexed transmission path as almost zero as shown in FIG. 21, and unifies the transmission path during failure. Re-recognize as a transmission line during operation. That is, as shown in FIG. 21, when the same data is duplicated and transmitted using the working and backup paths, the estimated recovery time when a failure occurs in any one of the paths is regarded as zero. It's okay. However, if a failure occurs in any one of the paths, the duplexed transmission path is lost, and in such a case, the estimated recovery time is recalculated as a single transmission path.
[0115]
Alternatively, the estimated recovery time calculation unit 39 calculates the estimated recovery time based on the presence / absence of a detour path at both ends of the transmission path to be calculated and the status of air clogging of the detour path as the detour path setting capability. . That is, as shown in FIG. 22, when the transmission path to be calculated is a transmission path with optical paths of wavelengths λ1 and λ2, first, the presence or absence of the detour path is checked, and further, in the detour path Investigate the status of airwaves.
[0116]
In the example of FIG. 22, there is a detour route, and in the air-blocking situation (1), the optical paths of wavelengths λ4 and λ5 are free. Therefore, the recovery prediction time in this case is equivalent to the switching time of the optical cross-connect. In the air-blocking situation (2), all two wavelengths are blocked although two free wavelengths are required. Further, in the empty / vacant state (3), only the wavelength λ3 is vacant. In such a case, the estimated recovery time is calculated based on the occurrence probability of two free wavelengths based on statistical data from the past. In FIG. 21, the method can also be used when a failure occurs in either the working path or the backup path and the estimated recovery time is recalculated as a single transmission path.
[0117]
(Thirteenth embodiment)
A thirteenth embodiment of the present invention will be described with reference to FIGS. FIG. 23 is a block diagram of the predicted time information holding unit of the thirteenth embodiment. FIG. 24 is a diagram for explaining a method of calculating a predicted recovery time according to the thirteenth embodiment. The thirteenth embodiment is an embodiment of a method for setting the predicted recovery time held by the predicted time information holding unit 34.
[0118]
In the thirteenth embodiment, the predicted time information holding unit 34 sets the estimated recovery time between the two optical cross-connects 22 and 25 for which the working and backup paths are set, to the free space near the working and protection paths. When the path having the bandwidth is set as a virtual working path and a backup path, respectively, and a failure is simulated in the virtual working path, the path is changed from the virtual working path to the virtual backup path. A failure recovery simulation unit 71 is provided that calculates a time required for switching as a predicted recovery time. Further, the calculation result of the failure recovery simulation unit 71 is recorded in the recovery predicted time information table 70.
[0119]
That is, in the example of FIG. 24, an optical path having a wavelength λ1 is extended between the optical cross connects 22 and 25 as a working path. Further, an optical path having a wavelength λ3 is extended as a backup path. In such a situation, in order to calculate the predicted recovery time, the failure recovery simulation unit 71 sets the unused wavelength λ2 of the same link as the link on which the working route is set as a virtual working route (temporary working). In addition, the free wavelength λ4 of the same link as the link on which the backup path is extended is set as a virtual backup path (temporary backup).
[0120]
In this way, the virtual working route and the virtual backup route are respectively set, and a simulated failure is generated in the virtual working route. As a method of generating a simulated failure, for example, an LSA packet in which simulated failure information is written from any one of the optical cross-connects 22, 24, and 25 may be transmitted. As a result, the recovery predicted time can be obtained by measuring the time when the optical cross-connects 22, 23, 24, 25 cooperate to actually switch from the virtual working path to the virtual backup path. it can.
[0121]
(14th embodiment)
A fourteenth embodiment of the present invention will be described with reference to FIGS. FIG. 23 is a block diagram of the predicted time information holding unit of the fourteenth embodiment, which is common with the thirteenth embodiment. FIG. 25 is a diagram for explaining a method for calculating a predicted recovery time according to the fourteenth embodiment. The fourteenth embodiment is an embodiment of a method for setting the predicted recovery time held by the predicted time information holding unit 34.
[0122]
In the fourteenth embodiment, the predicted time information holding unit 34 has a recovery predicted time between two optical cross-connects 22 and 25 for which a path has already been set, and has a free band near the path (actual path). When a route is assumed to be a virtual route (provisional route) and a failure is simulated for this virtual route, a detour route for the virtual route is searched and the virtual route is A failure recovery simulation unit 71 is provided that calculates a time required for switching the route to the detour route as the predicted time. Further, the calculation result of the failure recovery simulation unit 71 is recorded in the recovery predicted time information table 70.
[0123]
That is, in the example of FIG. 25, an optical path having the wavelength λ1 is extended between the optical cross connects 22 and 25 as an actual path. In such a situation, in order to calculate the recovery prediction time, the failure recovery simulation unit 71 sets the free wavelength λ2 of the same link as the link on which the actual route is set as a virtual route (temporary route). To do.
[0124]
A temporary route is set in this way, and a simulated failure is generated in the temporary route. As a method of generating a simulated failure, for example, an LSA packet in which simulated failure information is written from any one of the optical cross-connects 22, 24, and 25 may be transmitted. As a result, the optical cross-connects 22, 23, 24, and 25 cooperate to set a detour route for a simulated failure of the temporary route, and measure the time for actually switching from the temporary route to the detour route. Thus, the estimated recovery time can be obtained. In the example of FIG. 25, the path of the optical cross-connect 22 ← → 23 ← → 25 is set as the bypass path # 1, and the path of the optical cross-connect 22 ← → 26 ← → 25 is set as the bypass path # 2. Is done.
[0125]
(15th Example)
The routers 1 to 8 or the failure recovery control device 30 applied to the network according to the embodiment of the present invention can be realized using a computer device that is an information processing device.
[0126]
As a function corresponding to the device that controls the routers 1 to 8, by installing a program that realizes a function corresponding to the alarm protection unit 48 that holds the update of topology information for T time from the time when the failure is detected, The computer device can be a device corresponding to the device for controlling the routers 1 to 8 of the first embodiment.
[0127]
That is, a function corresponding to the predicted time information holding unit 34 is realized, Wide As a function corresponding to the reporting unit 32, the recovery time required for the recovery by referring to the detection result of the function corresponding to the failure occurrence detection unit 31 and the predicted time held in the function corresponding to the predicted time information holding unit 34 Includes a function for acquiring information on the predicted time and information on the predicted time acquired by this function Wide By installing a program for realizing the notification function in the computer device, the computer device can be a device corresponding to the failure recovery control device 30 of the first embodiment.
[0128]
In this case, as a function corresponding to the alarm protection unit 48 of the routers 1 to 8, Wide By installing in the computer device a program that realizes the function of setting the predicted time included in the notification to the T time, the computer device becomes a device corresponding to the device that controls the routers 1 to 8 of the first embodiment. be able to.
[0129]
Or router 1-8 Wide As a function corresponding to the notification transfer unit 47, the function corresponding to the alarm protection unit 48 is transferred to another router until the holding time of the function corresponds. Wide Suspend notification Wide By installing a program for realizing the notification hold function in the computer device, the computer device can be made a device corresponding to the device for controlling the routers 1 to 8 of the second embodiment.
[0130]
Alternatively, the routers 1 to 8 realize functions corresponding to the predicted time information holding unit 50, and the functions corresponding to the alarm protection unit 48 are held in the functions corresponding to the failure information and the predicted time information holding unit 50. A program for realizing a function of acquiring information of the predicted time required for the recovery with reference to the predicted time and a function of setting the predicted time acquired by the acquired function as the T time is installed in a computer device By doing so, the computer device can be a device corresponding to the device for controlling the routers 1 to 8 of the third embodiment.
[0131]
Alternatively, the failure recovery control device 30 Wide As a function corresponding to the reporting unit 32, during the detection of a fault by the function corresponding to the fault occurrence detection unit 31, a fixed period Wide By installing a program for realizing the notification function in the computer device, the computer device can be made a device corresponding to the failure recovery control device 30 of the fourth embodiment.
[0132]
In this case, as a function corresponding to the alarm protection unit 48 of the routers 1 to 8, a predetermined number of times is set. Wide By installing in the computer device a program that realizes the function of setting the time until the notification is received as the T time, the computer device becomes a device corresponding to the device that controls the routers 1 to 8 of the fourth embodiment. Can do.
[0133]
Alternatively, a function corresponding to the predicted time information holding unit 34 is realized, Wide As a function corresponding to the reporting unit 32, a function corresponding to the failure detection unit 31 is performed immediately after detecting a failure in the lower network. Wide The first to make a report Wide Notification function and this first Wide The first by the notification function Wide Notice Wide The second time when the failure recovery of the lower network is not realized even if the predicted time held in the function corresponding to the predicted time information holding unit 34 elapses from the notified time. Wide Second to make a notification Wide By installing a program for realizing the notification function in the computer device, the computer device can be made a device corresponding to the failure recovery control device 30 of the fifth embodiment.
[0134]
In this case, as the function corresponding to the alarm protection unit 48, the first Wide The second time from the time the notification was received Wide By installing in the computer device a program that realizes the function of setting the time until the notification reception time to the T time, the computer device is made a device corresponding to the device that controls the routers 1 to 8 of this embodiment. Can do.
[0135]
Alternatively, a function corresponding to the restoration priority storage unit 35 is realized, Wide As a function corresponding to the whistleblower 32, a plurality of transmission lines that have failed almost simultaneously Wide Second from the notification time Wide By installing in the computer device a program that realizes a function for setting the length of time until the notification time in inverse proportion to the recovery priority stored in the function corresponding to the recovery priority storage unit 35, A device corresponding to the failure recovery control device 30 of the sixth embodiment can be obtained.
[0136]
Alternatively, the function corresponding to the failure status analysis unit 36 that analyzes the failure status according to the detection result of the function corresponding to the failure occurrence detection unit 31 and the level of the failure according to the analysis result of the function corresponding to the failure status analysis unit 36 The higher the rank, the lower the possibility of recovery, and the lower the possibility of recovery. Wide As a function corresponding to the reporting unit 32, referring to the ranking result of the function corresponding to the fault ranking unit 37, the fault of a predetermined rank or higher Wide Conditional to make a notification Wide By installing a program for realizing the notification function in the computer device, the computer device can be made a device corresponding to the failure recovery control device 30 of the seventh embodiment.
[0137]
Alternatively, the function corresponding to the failure status analysis unit 36 that analyzes the failure status according to the detection result of the function corresponding to the failure occurrence detection unit 31 and the level of the failure according to the analysis result of the function corresponding to the failure status analysis unit 36 Is a function corresponding to the failure ranking unit 37 that ranks as representing a severe failure that has a lower recovery possibility as the rank is higher, and a predicted time information holding unit 34 that holds information on the predicted time required for failure recovery of the lower network. And realize the function corresponding to Wide As a function corresponding to the reporting unit 32, referring to the ranking result of the function corresponding to the failure ranking unit 37, the failure below a predetermined rank is limited to the router directly related to the failure lower network. Wide Limited including limited information to notify Wide The function to issue notifications and this limitation Wide When the failure transmission path does not recover after the predicted time elapses after the notification is issued, the function corresponding to the predicted time information holding unit 34 has passed. Wide By installing a program for realizing the function of issuing a notification in a computer device, the computer device can be made a device corresponding to the failure recovery control device 30 of the eighth embodiment.
[0138]
In this case, as a function corresponding to the routers 1 to 8, the above limitation Wide Notification to other routers according to the limited information Wide Ban on the above notice Wide Prohibit until notification is received Wide By installing a program for realizing the function corresponding to the notification holding unit 49 in the computer device, the computer device can be made a device corresponding to the device for controlling the routers 1 to 8 of the eighth embodiment.
[0139]
Alternatively, as a function corresponding to the failure status analysis unit 36, a function of detecting the number of the transmission lines in which a failure has occurred almost simultaneously is realized, and a function corresponding to the failure ranking unit 37 is a function of assigning a rank based on this number. By installing the program for realizing the above into the computer device, the computer device can be made a device corresponding to the failure recovery control device of the ninth embodiment.
[0140]
In this case, the program according to the present embodiment is a table in which failure factors are grouped as a function of detecting the number, and a transmission path that is disconnected in response to the occurrence of the failure of the failure factor belonging to each group is recorded. And a function of detecting the number of the transmission lines in which a failure has occurred almost simultaneously with reference to this table.
[0141]
Alternatively, a function corresponding to the restoration priority holding unit 35 is realized, and a function corresponding to the restoration priority holding unit 35 of the transmission path in which a failure has occurred is realized as a function corresponding to the failure status analysis unit 36. As a function corresponding to the failure ranking unit 37, a function for obtaining information on recovery priority is realized, and a higher ranking is given in inverse proportion to the priority, indicating that the higher the rank, the lower the probability of recovery. By installing the program for realizing the functions in the computer device, the computer device can be made a device corresponding to the failure recovery control device 30 of the tenth embodiment.
[0142]
Alternatively, as a function corresponding to the failure status analysis unit 36, a function of detecting the degree of congestion of network resources by referring to link state information regarding the detailed configuration of the lower level network where the failure has occurred is realized. By installing a program in a computer device that realizes a function that ranks higher in inverse proportion to the degree of congestion as representing a severe failure that is less likely to be recovered as the rank is higher, A device corresponding to the failure recovery control device 30 of the eleventh embodiment can be obtained.
[0143]
Alternatively, as a function corresponding to the predicted time information holding unit 34, a function corresponding to the link state information holding unit 38 that holds link state information relating to the detailed configuration of the lower network, and a function corresponding to the link state information holding unit 38 Installed in the computer device a program that realizes the function of calculating the estimated recovery time for each transmission path based on the setting capability of the detour path of each transmission path of the lower network estimated from the link state information held in the function By doing so, it is possible to cause the computer apparatus to execute the recovery recovery time setting method of the twelfth embodiment.
[0144]
In more detail, as a function to calculate the estimated recovery time, as a bypass path setting capability, for a transmission line in duplex operation, the estimated recovery time is calculated as almost zero and the transmission line is single-operated during a failure. Realize the function to re-recognize as the transmission line inside. Alternatively, as a function for calculating the estimated recovery time, as a detour path setting capability, the estimated recovery time is calculated based on the presence / absence of a detour path at both ends of the transmission path to be calculated and the status of the vacant path of the detour path Realize the function.
[0145]
Alternatively, as a function corresponding to the predicted time information holding unit 34, the recovery predicted time between the two optical cross-connects for which the working and backup paths are set is set as the path having a free band near the working and backup paths. Are assumed to be virtual working and backup paths, respectively, and when a failure is simulated in the virtual working path, the path is switched from the virtual working path to the virtual backup path. By installing a program for realizing the function of calculating the time required for the estimated time in the computer device, the computer device can execute the method for setting the predicted recovery time in the thirteenth embodiment.
[0146]
Alternatively, as a function corresponding to the predicted time information holding unit 34, a recovery predicted time between two optical cross-connects for which a path has already been set, a path having a free bandwidth near the path as a virtual path, When a failure is simulated for this virtual route, a detour route for the virtual route is searched, and the time required for the route to switch from the virtual route to the detour route is calculated. By installing a program for realizing the function of calculating the estimated time in the computer device, the computer device can be made to execute the recovery estimated time setting method of the fourteenth embodiment.
[0147]
By recording the program of this embodiment on the recording medium of this embodiment, the computer apparatus can install the program of this embodiment using this recording medium. Alternatively, the program of this embodiment can be directly installed on the computer device from the server holding the program of this embodiment via the network.
[0148]
As a result, it is possible to provide a router 1-8 and a network that can provide a failure recovery control technique suitable for a multi-layer network and can effectively use network resources by using a computer device.
[0149]
(16th Example)
A sixteenth embodiment of the present invention will be described with reference to FIG. FIG. 26 is a diagram showing a predicted time information database and a recovery priority database according to the sixteenth embodiment.
[0150]
In the first to fourteenth embodiments, the prediction time information holding unit 34 and the recovery priority order holding unit 35 are provided in the failure recovery control device 30 and the prediction time information holding unit 50 is provided in the routers 1 to 8. In the sixteenth embodiment, as shown in FIG. 26, these are installed as independent prediction time information database 90 and recovery priority order database 91 in separate nodes in the network, respectively, and failure recovery control device 30 and routers 1-8 are installed. Is configured to retrieve each piece of information stored therein by accessing these databases.
[0151]
【The invention's effect】
As described above, according to the present invention, it is possible to provide a failure recovery control technique suitable for a multilayer network and to effectively use network resources.
[Brief description of the drawings]
FIG. 1 is a conceptual diagram of a network according to an embodiment.
FIG. 2 is a configuration diagram of an optical cross connect of the present embodiment.
FIG. 3 is a block diagram of the failure recovery control apparatus according to the first embodiment.
FIG. 4 is a block configuration diagram of a router according to the first embodiment.
FIG. 5 shows the second embodiment. Wide The block block diagram of a notification transfer part.
FIG. 6 is a block diagram of a router according to a third embodiment.
FIG. 7 is a block diagram of a failure recovery control apparatus according to a third embodiment.
FIG. 8 is a diagram for explaining a holding time determination method according to a fourth embodiment.
FIG. 9 is a diagram for explaining a holding time determination method according to a fifth embodiment.
FIG. 10 is a block diagram of a failure recovery control apparatus according to a sixth embodiment.
FIG. 11 is a diagram for explaining a holding time determination method according to a sixth embodiment;
FIG. 12 is a block diagram of a failure recovery control apparatus according to a seventh embodiment.
FIG. 13 is a block diagram of a failure recovery control apparatus according to an eighth embodiment.
FIG. 14 is a view showing the contents of an LSA packet used in the network of the eighth embodiment.
FIG. 15 is a diagram showing a part of a network for explaining a ninth embodiment.
FIG. 16 is a diagram showing SRLG (Shared Risk Link Group).
FIG. 17 is a block diagram of a failure recovery control apparatus according to a tenth embodiment.
FIG. 18 is a block diagram of a failure recovery control apparatus according to the eleventh embodiment.
FIG. 19 is a diagram for explaining a rank assignment method according to the eleventh embodiment.
FIG. 20 is a block configuration diagram of a predicted time information holding unit according to the embodiment.
FIG. 21 is a diagram showing a transmission line during duplex operation.
FIG. 22 is a diagram showing a transmission line having a detour path.
FIG. 23 is a block diagram of a predicted time information holding unit according to the thirteenth embodiment.
FIG. 24 is a diagram for explaining a method of calculating a predicted recovery time according to the thirteenth and fourteenth embodiments.
FIG. 25 is a diagram for explaining a method for calculating a predicted recovery time according to the fourteenth embodiment.
FIG. 26 is a diagram showing a predicted time information database and a recovery priority database according to the sixteenth embodiment.
FIG. 27 is a diagram illustrating an example of a multi-layer network.
FIG. 28 is a diagram showing topology information held by a router.
[Explanation of symbols]
1-8, 51-58 router
10-26, 60-76 Optical cross-connect
30 Failure recovery control device
31, 41 Fault detection unit
32, 42 Wide Prosecution Department
33 Recovery control unit
34, 50 Predictive time information holding unit
35 Recovery priority storage unit
36 Failure Situation Analysis Department
37 Disability Ranking Department
38 Link state information holding unit
39 Estimated recovery time calculator
43 Topology information holding unit
44 Routing table calculator
45 Route setting part
46 Topology information update unit
47 Wide Notification forwarding department
48 Alarm Protection Department
49 Wide Notification hold
70 Recovery Estimated Time Information Table
71 Failure recovery simulation section
80-85 links
90 Estimated time information database
91 Recovery priority database
A, B Fault location

Claims (44)

Connected to a lower network consisting of a plurality of lower nodes and transmission paths equipped with failure recovery means,
Means for detecting a failure of the transmission path itself accommodated, means for advertising a detection result of means for the detection as failure information, and means for holding the topology information of the network, advertising faults information or self in the upper node having but a means for updating the topology information itself held in accordance with the detected failure information, and advertising transferring means for advertising the trouble information advertising the other upper nodes,
The updating means comprises means for holding the update of topology information for T time from the time when the occurrence of failure is detected by the detecting means ,
Predictive time information holding means for holding information of the predicted time required for failure recovery of the lower network is provided,
The means for advertising is:
First advertising means for performing a first advertisement immediately after the detecting means detects a failure occurrence in the lower network;
The second advertisement is performed when the failure recovery of the transmission path is not realized even if the prediction time held in the prediction time information holding means elapses from the time when the first advertisement is advertised by the first advertisement means. With two advertising means
With
The means for holding comprises means for setting the time from the time when the first advertisement is received to the time when the second advertisement is received as the T time,
Priority holding means for holding recovery priority information at the time of failure recovery of the transmission path of the lower network is provided,
The means for advertising is:
Means for setting the length of time from the first advertisement time to the second advertisement time in inverse proportion to the restoration priority stored in the priority holding means for the plurality of transmission lines in which a failure has occurred almost simultaneously; upper node, characterized in that it includes. Connected to a lower network consisting of a plurality of lower nodes and transmission paths equipped with failure recovery means,
Means for detecting the occurrence of a failure in the transmission path accommodated by itself, means for advertising the detection result of the means for detecting as fault information, means for holding network topology information, and the detected fault information or self detected Means for updating the topology information held by itself according to the fault information, and advertisement transfer means for advertising the advertised fault information to other upper nodes.
In the upper node,
The means for updating comprises means for holding the update of topology information for T time from the time when the occurrence of failure is detected by the means for detecting,
Means for analyzing a failure situation according to a detection result of the means for detecting;
According to the analysis result of the means for analyzing, means for ranking the degree of failure as representing a severe failure with a lower probability of recovery the higher the rank;
Is provided,
The advertising means includes conditional advertising means for advertising a failure of a predetermined rank or higher with reference to a ranking result of the ranking means.
An upper node characterized by that . Connected to a lower network consisting of a plurality of lower nodes and transmission paths equipped with failure recovery means,
Means for detecting the occurrence of a failure in the transmission path accommodated by itself, means for advertising the detection result of the means for detecting as fault information, means for holding network topology information, and the detected fault information or self detected Means for updating the topology information held by itself according to the fault information, and advertisement transfer means for advertising the advertised fault information to other upper nodes.
In the upper node,
The means for updating comprises means for holding the update of topology information for T time from the time when the occurrence of failure is detected by the means for detecting,
Means for analyzing a failure situation according to a detection result of the means for detecting;
According to the analysis result of the means for analyzing, means for ranking the degree of failure as representing a severe failure with a lower probability of recovery the higher the rank,
Predicted time information holding means for holding information of a predicted time required for failure recovery of the lower network;
Is provided,
The means for advertising is:
A means for issuing a limited advertisement including restriction information indicating that the failure is lower than a predetermined rank with reference to the ranking result of the ranking means and that the advertisement is limited to the upper node directly related to the failure lower network. When,
Means for issuing a ban advertisement indicating that the limitation is banned when the failure lower-level network does not recover after the prediction time held in the prediction time information holding means from the issuance of the limited advertisement;
With
When the limited advertisement is received, there is provided means for prohibiting an advertisement to another higher-order node according to the limited information until the ban advertisement is received.
An upper node characterized by that . The means for analyzing the failure situation comprises means for detecting the number of the transmission lines where the failure has occurred almost simultaneously,
4. The upper node according to claim 2 , wherein the ranking means comprises means for assigning a rank based on the number . The means for detecting the number is
A table in which failure factors are grouped and a transmission path that is disconnected in response to the failure occurrence of the failure factors belonging to each group is recorded;
5. The upper node according to claim 4, further comprising means for referring to the table and detecting the number of the transmission lines in which failures have occurred almost simultaneously . Priority holding means for holding recovery priority information at the time of failure recovery of the transmission path of the lower network is provided,
The means for analyzing the failure status comprises means for obtaining information on the restoration priority held in the priority holding means of the transmission path in which a failure has occurred,
4. The upper node according to claim 2 , wherein the ranking means includes means for ranking higher in inverse proportion to the priority order, indicating that the higher the rank is, the lower the probability of recovery is . The means for analyzing the failure situation comprises means for detecting a congestion degree of network resources with reference to topology information of the lower network where the failure has occurred,
4. The upper node according to claim 2 , wherein the ranking means includes means for ranking higher in inverse proportion to the degree of congestion, assuming that the higher the rank is, the lower the probability of recovery is . The predicted time information holding means includes
Means for holding link state information relating to a detailed configuration of the lower network;
Claims and means that to calculate the estimated time for each of the transmission channel based on the setting ability of the detour path each of the transmission path is estimated from the link state information stored in means for holding has 3. Upper node described in 3 . Connected to a lower network consisting of a plurality of lower nodes and transmission paths equipped with failure recovery means,
Means for detecting the occurrence of a failure in the transmission path accommodated by itself, means for advertising the detection result of the means for detecting as fault information, means for holding network topology information, and the detected fault information or self detected Means for updating the topology information held by itself according to the fault information, and advertisement transfer means for advertising the advertised fault information to other upper nodes.
In the upper node,
The means for updating comprises means for holding the update of topology information for T time from the time when the occurrence of failure is detected by the means for detecting,
Predictive time information holding means for holding information of the predicted time required for failure recovery of the lower network is provided,
The means for advertising is:
First advertising means for performing a first advertisement immediately after the detecting means detects a failure occurrence in the lower network;
The second advertisement is performed when the failure recovery of the transmission path is not realized even if the prediction time held in the prediction time information holding means elapses from the time when the first advertisement is advertised by the first advertisement means. With two advertising means
With
The means for holding comprises means for setting the time from the time when the first advertisement is received to the time when the second advertisement is received as the T time,
The predicted time information holding means includes
Means for holding link state information relating to a detailed configuration of the lower network;
Means for calculating the estimated time for each of the transmission paths based on a setting capability of a detour path included in each of the transmission paths estimated from the link state information held in the holding means;
Upper node comprising the. Connected to a lower network consisting of a plurality of lower nodes and transmission paths equipped with failure recovery means,
Means for detecting the occurrence of a failure in the transmission path accommodated by itself, means for advertising the detection result of the means for detecting as fault information, means for holding network topology information, and the detected fault information or self detected Means for updating the topology information held by itself according to the fault information, and advertisement transfer means for advertising the advertised fault information to other upper nodes.
In the upper node,
The means for updating comprises means for holding the update of topology information for T time from the time when the occurrence of failure is detected by the means for detecting,
Predictive time information holding means for holding information of the predicted time required for failure recovery of the lower network is provided,
The means for advertising is:
Means for obtaining information of the predicted time required for the recovery with reference to a detection result of the means for detecting and the predicted time held in the predicted time information holding means;
Means for performing an advertisement including information on the predicted time acquired by the acquiring means;
With
The means for holding comprises means for setting the predicted time included in the advertisement as the T time,
The predicted time information holding means includes
Means for holding link state information relating to a detailed configuration of the lower network;
Means for calculating the estimated time for each of the transmission paths based on a setting capability of a detour path included in each of the transmission paths estimated from the link state information held in the holding means;
An upper node characterized by comprising: Connected to a lower network consisting of a plurality of lower nodes and transmission paths equipped with failure recovery means,
Means for detecting the occurrence of a failure in the transmission path accommodated by itself, means for advertising the detection result of the means for detecting as fault information, means for holding network topology information, and the detected fault information or self detected Means for updating the topology information held by itself according to the fault information, and advertisement transfer means for advertising the advertised fault information to other upper nodes.
In the upper node,
The means for updating comprises means for holding the update of topology information for T time from the time when the occurrence of failure is detected by the means for detecting,
Predictive time information holding means for holding information of the predicted time required for failure recovery of the lower network is provided,
The means for holding is
Means for acquiring information of the predicted time required for the recovery with reference to the failure information and the predicted time held in the predicted time information holding means;
Means for setting the predicted time acquired by the means for acquiring to be the T time;
With
The predicted time information holding means includes
Means for holding link state information relating to a detailed configuration of the lower network;
Means for calculating the estimated time for each of the transmission paths based on a setting capability of a detour path included in each of the transmission paths estimated from the link state information held in the holding means;
An upper node characterized by comprising: The means for calculating the predicted time is:
As a setting capability of the detour path, the transmission path during duplex operation is calculated with the estimated time being substantially zero, and a means for re-recognizing the transmission path as a transmission path during single operation during failure is provided. Item 12. An upper node according to any one of Items 8, 9, 10, and 11 . The means for calculating the predicted time includes means for calculating the predicted time based on the presence / absence of a bypass path at both ends of the faulty transmission path and the status of vacancy of the bypass path as the bypass path setting capability. The upper node according to any one of claims 8, 9, 10, and 11 . The predicted time information holding means indicates the predicted time between the two nodes for which a working path and a backup path are set, a path having a free band near the current path and the standby path, a virtual working path, and a virtual path. Estimate the time required for the path to switch from the virtual working path to the virtual backup path when a failure is simulated for the virtual working path as a backup path. 4. The upper node according to claim 3, further comprising means for calculating time . The predicted time information holding means uses the predicted time between the two nodes for which a route has already been set as a virtual route that has a free bandwidth near the route, and for this virtual route. Means for calculating a time required for a detour route for the virtual route to be searched and switching the route from the virtual route to the detour route as the predicted time when a failure is simulated. The upper node according to claim 3, further comprising: Connected to a lower network consisting of a plurality of lower nodes and transmission paths equipped with failure recovery means,
Means for detecting the occurrence of a failure in the transmission path accommodated by itself, means for advertising the detection result of the means for detecting as fault information, means for holding network topology information, and the detected fault information or self detected Means for updating the topology information held by itself according to the fault information, and advertisement transfer means for advertising the advertised fault information to other upper nodes.
In the upper node,
The means for updating comprises means for holding the update of topology information for T time from the time when the occurrence of failure is detected by the means for detecting,
Predictive time information holding means for holding information of the predicted time required for failure recovery of the lower network is provided,
The means for advertising is:
First advertising means for performing a first advertisement immediately after the detecting means detects a failure occurrence in the lower network;
The second advertisement is performed when the failure recovery of the transmission path is not realized even if the prediction time held in the prediction time information holding means elapses from the time when the first advertisement is advertised by the first advertisement means. With two advertising means
With
The means for holding comprises means for setting the time from the time when the first advertisement is received to the time when the second advertisement is received as the T time,
The predicted time information holding means indicates the predicted time between the two nodes for which a working path and a backup path are set, a path having a free band near the current path and the standby path, a virtual working path, and a virtual path. Estimate the time required for the path to switch from the virtual working path to the virtual backup path when a failure is simulated for the virtual working path as a backup path. With means to calculate as time
An upper node characterized by that . Connected to a lower network consisting of a plurality of lower nodes and transmission paths equipped with failure recovery means,
Means for detecting the occurrence of a failure in the transmission path accommodated by itself, means for advertising the detection result of the means for detecting as fault information, means for holding network topology information, and the detected fault information or self detected Means for updating the topology information held by itself according to the fault information, and advertisement transfer means for advertising the advertised fault information to other upper nodes.
In the upper node,
The means for updating comprises means for holding the update of topology information for T time from the time when the occurrence of failure is detected by the means for detecting,
Predictive time information holding means for holding information of the predicted time required for failure recovery of the lower network is provided,
The means for advertising is:
First advertising means for performing a first advertisement immediately after the detecting means detects a failure occurrence in the lower network;
The second advertisement is performed when the failure recovery of the transmission path is not realized even if the prediction time held in the prediction time information holding means elapses from the time when the first advertisement is advertised by the first advertisement means. With two advertising means
With
The means for holding comprises means for setting the time from the time when the first advertisement is received to the time when the second advertisement is received as the T time,
The predicted time information holding means uses the predicted time between the two nodes for which a route has already been set as a virtual route that has a free bandwidth near the route, and for this virtual route. Means for calculating a time required for a detour route for the virtual route to be searched and switching the route from the virtual route to the detour route as the predicted time when a failure is simulated. With
An upper node characterized by that. Connected to a lower network consisting of a plurality of lower nodes and transmission paths equipped with failure recovery means,
Means for detecting the occurrence of a failure in the transmission path accommodated by itself, means for advertising the detection result of the means for detecting as fault information, means for holding network topology information, and the detected fault information or self detected Means for updating the topology information held by itself according to the fault information, and advertisement transfer means for advertising the advertised fault information to other upper nodes.
In the upper node,
The means for updating comprises means for holding the update of topology information for T time from the time when the occurrence of failure is detected by the means for detecting,
Predictive time information holding means for holding information of the predicted time required for failure recovery of the lower network is provided,
The means for advertising is:
Means for obtaining information of the predicted time required for the recovery with reference to a detection result of the means for detecting and the predicted time held in the predicted time information holding means;
Means for performing an advertisement including information on the predicted time acquired by the acquiring means;
With
The means for holding comprises means for setting the predicted time included in the advertisement as the T time,
The predicted time information holding means indicates the predicted time between the two nodes for which a working path and a backup path are set, a path having a free band near the current path and the standby path, a virtual working path, and a virtual path. Estimate the time required for the path to switch from the virtual working path to the virtual backup path when a failure is simulated for the virtual working path as a backup path. With means to calculate as time
An upper node characterized by that . Connected to a lower network consisting of a plurality of lower nodes and transmission paths equipped with failure recovery means,
Means for detecting the occurrence of a failure in the transmission path accommodated by itself, means for advertising the detection result of the means for detecting as fault information, means for holding network topology information, and the detected fault information or self detected Means for updating the topology information held by itself according to the fault information, and advertisement transfer means for advertising the advertised fault information to other upper nodes.
In the upper node,
The means for updating comprises means for holding the update of topology information for T time from the time when the occurrence of failure is detected by the means for detecting,
Predictive time information holding means for holding information of the predicted time required for failure recovery of the lower network is provided,
The means for advertising is:
Means for obtaining information of the predicted time required for the recovery with reference to a detection result of the means for detecting and the predicted time held in the predicted time information holding means;
Means for performing an advertisement including information on the predicted time acquired by the acquiring means;
With
The means for holding comprises means for setting the predicted time included in the advertisement as the T time,
The predicted time information holding means uses the predicted time between the two nodes for which a route has already been set as a virtual route that has a free bandwidth near the route, and for this virtual route. Means for calculating a time required for a detour route for the virtual route to be searched and switching the route from the virtual route to the detour route as the predicted time when a failure is simulated. With
An upper node characterized by that . Connected to a lower network consisting of a plurality of lower nodes and transmission paths equipped with failure recovery means,
Means for detecting the occurrence of a failure in the transmission path accommodated by itself, means for advertising the detection result of the means for detecting as fault information, means for holding network topology information, and the detected fault information or self detected Means for updating the topology information held by itself according to the fault information, and advertisement transfer means for advertising the advertised fault information to other upper nodes.
In the upper node,
The means for updating comprises means for holding the update of topology information for T time from the time when the occurrence of failure is detected by the means for detecting,
Predictive time information holding means for holding information of the predicted time required for failure recovery of the lower network is provided,
The means for holding is
Means for acquiring information of the predicted time required for the recovery with reference to the failure information and the predicted time held in the predicted time information holding means;
Means for setting the predicted time acquired by the means for acquiring to be the T time;
With
The predicted time information holding means indicates the predicted time between the two nodes for which a working path and a backup path are set, a path having a free band near the current path and the standby path, a virtual working path, and a virtual path. Estimate the time required for the path to switch from the virtual working path to the virtual backup path when a failure is simulated for the virtual working path as a backup path. With means to calculate as time
An upper node characterized by that . Connected to a lower network consisting of a plurality of lower nodes and transmission paths equipped with failure recovery means,
Means for detecting the occurrence of a failure in the transmission path accommodated by itself, means for advertising the detection result of the means for detecting as fault information, means for holding network topology information, and the detected fault information or self detected Means for updating the topology information held by itself according to the fault information, and advertisement transfer means for advertising the advertised fault information to other upper nodes.
In the upper node,
The means for updating comprises means for holding the update of topology information for T time from the time when the occurrence of failure is detected by the means for detecting,
Predictive time information holding means for holding information of the predicted time required for failure recovery of the lower network is provided,
The means for holding is
Means for acquiring information of the predicted time required for the recovery with reference to the failure information and the predicted time held in the predicted time information holding means;
Means for setting the predicted time acquired by the means for acquiring to be the T time;
With
The predicted time information holding means uses the predicted time between the two nodes for which a route has already been set as a virtual route that has a free bandwidth near the route, and for this virtual route. Means for calculating a time required for a detour route for the virtual route to be searched and switching the route from the virtual route to the detour route as the predicted time when a failure is simulated. upper node comprising the. A network comprising the upper node according to any one of claims 1 to 21 . By installing on an information processing device,
Connected to a subordinate network consisting of multiple subordinate nodes and transmission paths equipped with a fault recovery function ,
A function that detects the failure of a transmission path accommodated by itself, a function that advertises the detection results of this function as fault information, a function that retains network topology information, and the advertised fault information or self-detection A function of updating the topology information held by itself according to the fault information, and an advertisement transfer function of advertising the advertised fault information to other upper nodes,
In the program that realizes the function corresponding to the device that controls the upper node,
As the function to update, realize the function to hold the update of the topology information for T time from the time when the occurrence of failure is detected by the function to detect,
Realizing a predicted time information holding function for holding information of a predicted time required for failure recovery of the lower network,
As the advertising function ,
A first advertisement function for performing a first advertisement immediately after detecting the occurrence of a failure in the lower network,
The second advertisement is performed when the failure recovery of the transmission path is not realized even if the prediction time held in the prediction time information holding function elapses from the time when the first advertisement is advertised by the first advertisement function. Two ad functions and
Realized,
As the function to hold, to realize the function of the time from the time of receiving the first advertisement to the time of receiving the second advertisement as the T time,
Realizing a priority holding function for holding recovery priority information at the time of failure recovery of the transmission path of the lower network,
As the advertising function,
A function of setting a time length from the first advertisement time to the second advertisement time in inverse proportion to the restoration priority stored in the priority holding function for each of the plurality of transmission lines in which a failure has occurred almost simultaneously. make it happen
A program characterized by that . By installing on an information processing device,
Connected to a subordinate network consisting of multiple subordinate nodes and transmission paths equipped with a fault recovery function,
A function that detects the failure of a transmission path accommodated by itself, a function that advertises the detection results of this function as fault information, a function that retains network topology information, and the advertised fault information or self-detection A function of updating the topology information held by itself according to the fault information, and an advertisement transfer function of advertising the advertised fault information to other upper nodes,
In the program that realizes the function corresponding to the device that controls the upper node,
As the function to update, realize the function to hold the update of the topology information for T time from the time when the occurrence of failure is detected by the function to detect,
A function of analyzing a failure state according to a detection result of the function to be detected;
According to the analysis result of the function to be analyzed, the degree of failure is ranked as representing a severe failure with a higher possibility of recovery as the rank increases.
Realized,
As the function to advertise, a conditional advertisement function for performing an advertisement for a failure of a predetermined rank or higher with reference to a ranking result of the ranking function is realized.
A program characterized by that . By installing on an information processing device,
Connected to a subordinate network consisting of multiple subordinate nodes and transmission paths equipped with a fault recovery function,
A function that detects the failure of the transmission path that it accommodates, a function that advertises the detection result of this function as fault information, a function that retains network topology information, and the advertised fault information or self A function of updating the topology information held by itself according to the fault information, and an advertisement transfer function of advertising the advertised fault information to other upper nodes,
In the program that realizes the function corresponding to the device that controls the upper node,
As the function to update, realize the function to hold the update of the topology information for T time from the time when the occurrence of failure is detected by the function to detect,
A function of analyzing a failure state according to a detection result of the function to be detected;
According to the analysis result of the function to be analyzed, a function that ranks the degree of failure as representing a severe failure that is less likely to be recovered as the rank increases,
A predicted time information holding function for holding information of a predicted time required for failure recovery of the lower network;
Realized,
As the advertising function,
A function for issuing a limited advertisement that includes limited information indicating that an advertisement is limited to the upper node directly related to the failure lower network with respect to a failure of a predetermined rank or less with reference to the ranking result of the ranking function. When,
A function for issuing a ban advertisement indicating that the limitation is banned when the failure lower-level network does not recover even after the prediction time held in the prediction time information holding function has elapsed since the issue of the limited advertisement;
Realized,
When the limited advertisement is received, a function for prohibiting the advertisement to other upper nodes until the ban advertisement is received according to the limited information is realized.
A program characterized by that . As a function of analyzing the failure status, realizing a function of detecting the number of the transmission lines where the failure has occurred almost simultaneously,
26. The program according to claim 24 or 25 , wherein a function of assigning a rank based on the number is realized as the function of ranking . As a function of detecting the number,
A function corresponding to a table in which failure factors are grouped, and transmission paths that are interrupted in response to failure occurrences of failure factors belonging to each group are recorded,
27. The program according to claim 26 , wherein a function for detecting the number of transmission lines in which a failure has occurred substantially simultaneously with reference to a function corresponding to the table is realized. Realizing a priority holding function for holding recovery priority information at the time of failure recovery of the transmission path of the lower network,
As a function of analyzing the failure status, a function of acquiring information on the restoration priority held in the priority holding means of the transmission path in which a failure has occurred is realized,
26. The program according to claim 24 or 25 , wherein the ranking function realizes a function of ranking higher in inverse proportion to the priority order, indicating that the higher the rank is, the lower the possibility of recovery is and indicates a severe failure . As a function of analyzing the failure status, a function of detecting the degree of congestion of network resources with reference to the topology information of the lower network where the failure has occurred is realized,
26. The program according to claim 24 or 25 , wherein, as the function of ranking, a function of ranking higher in inverse proportion to the degree of congestion is realized assuming that the higher the rank is, the lower the probability of recovery is . As the predicted time information holding function,
A function of holding link state information regarding a detailed configuration of the lower network;
Claim to realize the function of calculating the estimated time for each of the transmission channel based on the setting ability of the detour path each of the transmission path is estimated from the link state information stored in function of this holding has 25 The listed program. By installing on an information processing device,
Connected to a subordinate network consisting of multiple subordinate nodes and transmission paths equipped with a fault recovery function,
A function that detects the failure of a transmission path accommodated by itself, a function that advertises the detection results of this function as fault information, a function that retains network topology information, and the advertised fault information or self-detection A function of updating the topology information held by itself according to the fault information, and an advertisement transfer function of advertising the advertised fault information to other upper nodes,
In the program that realizes the function corresponding to the device that controls the upper node,
As the function to update, realize the function to hold the update of the topology information for T time from the time when the occurrence of failure is detected by the function to detect,
Realizing a predicted time information holding function for holding information of a predicted time required for failure recovery of the lower network,
As the advertising function ,
A first advertisement function for performing a first advertisement immediately after detecting the occurrence of a failure in the lower network,
The second advertisement is performed when the failure recovery of the transmission path is not realized even if the prediction time held in the prediction time information holding function elapses from the time when the first advertisement is advertised by the first advertisement function. Two ad functions and
Realized,
As the function to hold, to realize the function of the time from the time of receiving the first advertisement to the time of receiving the second advertisement as the T time,
As the predicted time information holding function,
A function of holding link state information regarding a detailed configuration of the lower network;
A function of calculating the predicted time for each of the transmission paths based on a setting capability of a detour path included in each of the transmission paths estimated from the link state information held in the held function;
Realize
A program characterized by that . By installing on an information processing device,
Connected to a subordinate network consisting of multiple subordinate nodes and transmission paths equipped with a fault recovery function,
A function that detects the failure of a transmission path accommodated by itself, a function that advertises the detection results of this function as fault information, a function that retains network topology information, and the advertised fault information or self-detection A function of updating the topology information held by itself according to the fault information, and an advertisement transfer function of advertising the advertised fault information to other upper nodes,
In the program that realizes the function corresponding to the device that controls the upper node,
As the function to update, realize the function to hold the update of the topology information for T time from the time when the occurrence of failure is detected by the function to detect,
Realizing a predicted time information holding function for holding information of a predicted time required for failure recovery of the lower network,
As the advertising function,
A function of obtaining information on the predicted time required for the recovery with reference to a detection result of the function to be detected and the predicted time held in the predicted time information holding function;
A function of performing an advertisement including information on the predicted time acquired by the function of acquiring;
Realized,
As the function to hold, to realize the function of the predicted time included in the advertisement as the T time,
As the predicted time information holding function,
A function of holding link state information regarding a detailed configuration of the lower network;
A function of calculating the predicted time for each of the transmission paths based on a setting capability of a detour path included in each of the transmission paths estimated from the link state information held in the held function;
Realize
A program characterized by that . By installing on an information processing device,
Connected to a subordinate network consisting of multiple subordinate nodes and transmission paths equipped with a fault recovery function,
A function that detects the failure of a transmission path accommodated by itself, a function that advertises the detection results of this function as fault information, a function that retains network topology information, and the advertised fault information or self-detection A function of updating the topology information held by itself according to the fault information, and an advertisement transfer function of advertising the advertised fault information to other upper nodes,
In the program that realizes the function corresponding to the device that controls the upper node,
As the function to update, realize the function to hold the update of the topology information for T time from the time when the occurrence of failure is detected by the function to detect,
Realizing a predicted time information holding function for holding information of a predicted time required for failure recovery of the lower network,
As the function to hold,
A function of acquiring information on the predicted time required for the recovery with reference to the failure information and the predicted time held in the predicted time information holding function;
A function of setting the predicted time acquired by the function to be acquired as the T time;
Realized,
As the predicted time information holding function,
A function of holding link state information regarding a detailed configuration of the lower network;
A function of calculating the predicted time for each of the transmission paths based on a setting capability of a detour path included in each of the transmission paths estimated from the link state information held in the held function;
Realize
A program characterized by that . As a function of calculating the predicted time,
As a setting capability of the detour path, for a transmission line in duplex operation, the calculation is performed with the predicted time being almost zero, and a function for re-recognizing the transmission line as a transmission line in single operation during a failure is realized. Item 34. The program according to any one of items 30, 31, 32, and 33 . As the function of calculating the predicted time, the function of calculating the predicted time based on the presence / absence of a bypass path with respect to both ends of the faulty transmission path and the status of air clogging of the bypass path is realized as the setting capability of the bypass path The program according to any one of claims 30, 31, 32, and 33 . As the predicted time information holding function, the predicted time between the two nodes where the working and backup paths are set, the path having a free band near the current and backup paths, the virtual working and Estimate the time required for the path to switch from the virtual working path to the virtual backup path when a failure is simulated for the virtual working path as a backup path. 26. The program according to claim 25, which realizes a function of calculating as time. As the predicted time information holding function, the predicted time between the two nodes for which a route has already been set is defined as a virtual route having a free bandwidth near the route, and the virtual route A function that, when a failure is simulated, a detour route for the virtual route is searched, and a time required for the route to switch from the virtual route to the detour route is calculated as the predicted time 26. The program according to claim 25, wherein: By installing on an information processing device,
Connected to a subordinate network consisting of multiple subordinate nodes and transmission paths equipped with a fault recovery function,
A function that detects the failure of a transmission path accommodated by itself, a function that advertises the detection results of this function as fault information, a function that retains network topology information, and the advertised fault information or self-detection A function of updating the topology information held by itself according to the fault information, and an advertisement transfer function of advertising the advertised fault information to other upper nodes,
In the program that realizes the function corresponding to the device that controls the upper node,
As the function to update, realize the function to hold the update of the topology information for T time from the time when the occurrence of failure is detected by the function to detect,
Realizing a predicted time information holding function for holding information of a predicted time required for failure recovery of the lower network,
As the advertising function ,
A first advertisement function for performing a first advertisement immediately after detecting the occurrence of a failure in the lower network,
The second advertisement is performed when the failure recovery of the transmission path is not realized even if the prediction time held in the prediction time information holding function elapses from the time when the first advertisement is advertised by the first advertisement function. Two ad functions and
Realized,
As the function to hold, to realize the function of the time from the time of receiving the first advertisement to the time of receiving the second advertisement as the T time,
As the predicted time information holding function, the predicted time between the two nodes where the working and backup paths are set, the path having a free band near the current and backup paths, the virtual working and Estimate the time required for the path to switch from the virtual working path to the virtual backup path when a failure is simulated for the virtual working path as a backup path. Realize the function to calculate as time
A program characterized by that . By installing on an information processing device,
Connected to a subordinate network consisting of multiple subordinate nodes and transmission paths equipped with a fault recovery function,
A function that detects the failure of a transmission path accommodated by itself, a function that advertises the detection results of this function as fault information, a function that retains network topology information, and the advertised fault information or self-detection A function of updating the topology information held by itself according to the fault information, and an advertisement transfer function of advertising the advertised fault information to other upper nodes,
In the program that realizes the function corresponding to the device that controls the upper node,
As the function to update, realize the function to hold the update of the topology information for T time from the time when the occurrence of failure is detected by the function to detect,
Realizing a predicted time information holding function for holding information of a predicted time required for failure recovery of the lower network,
As the advertising function ,
A first advertisement function for performing a first advertisement immediately after detecting the occurrence of a failure in the lower network,
The second advertisement is performed when the failure recovery of the transmission path is not realized even if the prediction time held in the prediction time information holding function elapses from the time when the first advertisement is advertised by the first advertisement function. Two ad functions and
Realized,
As the function to hold, to realize the function of the time from the time of receiving the first advertisement to the time of receiving the second advertisement as the T time,
As the predicted time information holding function, the predicted time between the two nodes for which a route has already been set is defined as a virtual route having a free bandwidth near the route, and the virtual route A function that, when a failure is simulated in a simulated manner, a bypass route for the virtual route is searched, and a time required for the route to be switched from the virtual route to the bypass route is calculated as the predicted time Realize
A program characterized by that . By installing on an information processing device,
Connected to a subordinate network consisting of multiple subordinate nodes and transmission paths equipped with a fault recovery function,
A function that detects the failure of a transmission path accommodated by itself, a function that advertises the detection results of this function as fault information, a function that retains network topology information, and the advertised fault information or self-detection A function of updating the topology information held by itself according to the fault information, and an advertisement transfer function of advertising the advertised fault information to other upper nodes,
In the program that realizes the function corresponding to the device that controls the upper node,
As the function to update, realize the function to hold the update of the topology information for T time from the time when the occurrence of failure is detected by the function to detect,
Realizing a predicted time information holding function for holding information of a predicted time required for failure recovery of the lower network ,
As the advertising function,
A function of obtaining information on the predicted time required for the recovery with reference to a detection result of the function to be detected and the predicted time held in the predicted time information holding function;
A function of performing an advertisement including information on the predicted time acquired by the function of acquiring;
Realized,
As the function to hold, to realize the function of the predicted time included in the advertisement as the T time,
As the predicted time information holding function, the predicted time between the two nodes where the working and backup paths are set, the path having a free band near the current and backup paths, the virtual working and Estimate the time required for the path to switch from the virtual working path to the virtual backup path when a failure is simulated for the virtual working path as a backup path. Realize the function to calculate as time
A program characterized by that . By installing on an information processing device,
Connected to a subordinate network consisting of multiple subordinate nodes and transmission paths equipped with a fault recovery function,
A function that detects the failure of a transmission path accommodated by itself, a function that advertises the detection results of this function as fault information, a function that retains network topology information, and the advertised fault information or self-detection A function of updating the topology information held by itself according to the fault information, and an advertisement transfer function of advertising the advertised fault information to other upper nodes,
In the program that realizes the function corresponding to the device that controls the upper node,
As the function to update, realize the function to hold the update of the topology information for T time from the time when the occurrence of failure is detected by the function to detect,
Realizing a predicted time information holding function for holding information of a predicted time required for failure recovery of the lower network,
As the advertising function,
A function of obtaining information on the predicted time required for the recovery with reference to a detection result of the function to be detected and the predicted time held in the predicted time information holding function;
A function of performing an advertisement including information on the predicted time acquired by the function of acquiring;
Realized,
As the function to hold, to realize the function of the predicted time included in the advertisement as the T time,
As the predicted time information holding function, the predicted time between the two nodes for which a route has already been set is defined as a virtual route having a free bandwidth near the route, and the virtual route A function that, when a failure is simulated in a simulated manner, a bypass route for the virtual route is searched, and a time required for the route to be switched from the virtual route to the bypass route is calculated as the predicted time Realize
A program characterized by that . By installing on an information processing device,
Connected to a subordinate network consisting of multiple subordinate nodes and transmission paths equipped with a fault recovery function,
A function that detects the failure of a transmission path accommodated by itself, a function that advertises the detection results of this function as fault information, a function that retains network topology information, and the advertised fault information or self-detection A function of updating the topology information held by itself according to the fault information, and an advertisement transfer function of advertising the advertised fault information to other upper nodes,
In the program that realizes the function corresponding to the device that controls the upper node,
As the function to update, realize the function to hold the update of the topology information for T time from the time when the occurrence of failure is detected by the function to detect,
Realizing a predicted time information holding function for holding information of a predicted time required for failure recovery of the lower network,
As the function to hold,
A function of obtaining information on the predicted time required for the recovery with reference to the failure information and the predicted time held in the predicted time information holding function ;
A function of setting the predicted time acquired by the function to be acquired as the T time;
Realized,
As the predicted time information holding function, the predicted time between the two nodes where the working and backup paths are set, the path having a free band near the current and backup paths, the virtual working and Estimate the time required for the path to switch from the virtual working path to the virtual backup path when a failure is simulated for the virtual working path as a backup path. Realize the function to calculate as time
A program characterized by that . By installing on an information processing device,
Connected to a subordinate network consisting of multiple subordinate nodes and transmission paths equipped with a fault recovery function,
A function that detects the failure of a transmission path accommodated by itself, a function that advertises the detection results of this function as fault information, a function that retains network topology information, and the advertised fault information or self-detection A function of updating the topology information held by itself according to the fault information, and an advertisement transfer function of advertising the advertised fault information to other upper nodes,
In the program that realizes the function corresponding to the device that controls the upper node,
As the function to update, realize the function to hold the update of the topology information for T time from the time when the occurrence of failure is detected by the function to detect,
Realizing a predicted time information holding function for holding information of a predicted time required for failure recovery of the lower network,
As the function to hold,
A function of acquiring information on the predicted time required for the recovery with reference to the failure information and the predicted time held in the predicted time information holding function;
A function of setting the predicted time acquired by the function to be acquired as the T time;
Realized,
As the predicted time information holding function, the predicted time between the two nodes for which a route has already been set is defined as a virtual route having a free bandwidth near the route, and the virtual route A function that, when a failure is simulated in a simulated manner, a bypass route for the virtual route is searched, and a time required for the route to be switched from the virtual route to the bypass route is calculated as the predicted time Realize
A program characterized by that . 44. A recording medium readable by the information processing apparatus, on which the program according to claim 23 is recorded.

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