JP2003258906A - Low-order node, network, program, and recording medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To effectively use network resources by providing a fault recovery control technique matching a multi-layer network. <P>SOLUTION: A low-order node which sends LSA packets suspends transmission of the LSA packets for a specified time. Namely, the low-order node does not send official announcement to a high-order node immediately once a fault occurs to a low-order network, but expects the low-order network to speedily recover and suspends the official announcement for the certain time to avoid route calculation which becomes ineffective. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical cross connect, router, SDH (Synchronous Digital Hierarchy).
It is used in a multi-layer network that can control devices, etc. Especially, GMPLS (Generalized Multi Pro)
tocol Label Switching).

[0002]

2. Description of the Related Art In a multi-layer network, optical cross-connects, routers, SDH devices, etc. can be centrally controlled. An example of such a multi-layer network is shown in FIG. In the example of FIG. 25, a lower level network including a plurality of optical cross connects is connected between the routers. Each router holds network topology information. However, this topology information includes
It does not include the topology information about the lower network, and the lower network is treated as only one transmission path. That is, as shown in FIG. 26, the topology information held by the routers is the topology information of the routers, and each router does not recognize the existence of the optical cross connect that constitutes the lower network.

Each node such as an optical cross-connect, a router, an SDH device, etc. in such a multi-layer network has the same LS when one of them detects a failure.
The rule is to send an A (Link State Advertisement) packet to a peripheral node, and when the router receives this LSA packet, it updates the topology information held by itself and sets a route that bypasses the fault location.

[0004]

When a failure occurs in a lower layer network of such a multi-layer network, failure recovery measures such as setting a route bypassing this failure point can be promptly executed. But,
Since the router cannot recognize the execution status of such a failure recovery measure in the lower network, when the LSA packet arrives, the topology information held by the router is immediately updated and the detour route is set.

However, in the lower network, the failure recovery measure is promptly executed and the LSA packet indicating the completion of the failure recovery is sent out. Upon receiving this LSA packet, the router updates the topology information held by itself again and sets the route.

As described above, when the conventional failure recovery control technique is applied to the multilayer network as it is, the router increases the chances of updating the invalid topology information and setting the detour route, and thus increases the processing load. Will result. In particular, the load required for route calculation is large, and while performing route calculation, there is concern that adverse effects such as a decrease in the processing speed of other processes may occur. It is desirable to be done. Therefore, in the multi-layer network, it is desirable to apply a new failure recovery control technology different from the conventional failure recovery control technology.

[0007] The present invention has been made against such a background, and provides a failure recovery control technique suitable for a multi-layer network and enables effective utilization of network resources. The purpose is to provide a recording medium.

[0008]

The main feature of the present invention is that the subordinate node transmitting the LSA packet suspends the transmission of the LSA packet for a predetermined time. The present invention is
It proposes a protocol for suspending the transmission of LSA packets.

That is, a first aspect of the present invention is to provide a lower network connecting at least two upper nodes with a fault recovery means for the lower network,
A lower node provided with means for detecting the occurrence of a failure in a transmission line that the self accommodates, and means for publicizing the detection result of the detecting means as failure information, wherein the feature of the present invention is that the announcement is made. The means for doing so is provided with means for holding the issuance of the announcement for T time from the time when the failure is detected by the detecting means.

As described above, in the lower node, the notification is not issued to the upper node immediately when a failure occurs in the lower network, but is held invalid by holding the notification for a certain period of time in the hope of prompt recovery of the lower network. It is possible to avoid the route calculation.

Alternatively, a first aspect of the present invention is to provide a lower network connecting at least two upper nodes, and a failure recovery means for the lower network,
A lower node provided with means for detecting the occurrence of a failure in a transmission line which the self accommodates, and means for publicizing the detection result of the detecting means as failure information, wherein the feature of the present invention is that Prediction time information holding means for holding information on a predicted time required for network failure recovery is provided, and the means for issuing a notice makes a first announcement immediately after the detecting means detects a failure occurrence in the lower network. (1) public notice means and (1) when failure recovery of the transmission line is not realized even after the predicted time held in the predicted time information holding means has elapsed from the time when the first public announcement by the first public announcement means was made. (Ii) It has a second public notice means for making public notice.

That is, when a failure occurs for the time being, the first announcement is made and the upper node recognizes the failure occurrence. At this point, the upper node can take autonomous failure avoidance measures in consideration of the importance of the communication handled by itself. For example, when the communication handled by the user is of low importance, the first notification may be ignored, and the obstacle avoidance measure may be executed for the first time when the second notification is made. Alternatively, if the communication handled by the user is of high importance, the topology information may be promptly updated at the time of the first announcement, and the fault bypass route may be calculated. This makes it possible to avoid invalid route calculation.

A priority order holding means for holding information on a restoration priority order at the time of restoration of a failure of the transmission path of the lower network is provided, and the announcement means is provided for the plurality of transmission paths in which a failure occurs at substantially the same time. Means may be provided for setting the time length from the first announcement time to the second announcement time in inverse proportion to the restoration priority order held in the priority order holding means.

That is, when failures occur in a plurality of transmission lines at substantially the same time, it is difficult to restore these transmission lines at the same time. Therefore, a restoration priority is set for each transmission path, and restoration is performed in order from the highest priority. In this case, it is preferable to set the time length from the first announcement to the second announcement in inverse proportion to the priority. As a result, for transmission lines that can be expected to be restored promptly, the time from the first announcement to the second announcement is set long, the topology information update by the upper node is suspended, and the restoration is completed during that time. To Further, for a transmission line for which rapid recovery cannot be expected, the time from the first announcement to the second announcement is set to be short, the top node updates the topology information, and a detour route is set. This makes it possible to avoid invalid route calculation.

Alternatively, a first aspect of the present invention is to provide a lower network connecting at least two upper nodes, and a failure recovery means for the lower network,
A lower node provided with means for detecting the occurrence of a failure in a transmission line which the self accommodates, and means for publicizing the detection result of the detecting means as failure information, wherein the feature of the present invention is that Prediction time information holding means for holding information on a prediction time required for network failure recovery is provided, and the means for making an announcement is the detection result of the detecting means and the prediction time held in the prediction time information holding means. With a means for acquiring the information on the predicted time required for the recovery and a means for making a public notice including the information on the predicted time acquired by the acquiring means.

That is, the lower node that has detected the failure informs the upper node of the estimated time required for recovery from the failure. According to this, the upper node can also suspend the update of the topology information according to the information of the predicted time included in the announcement.

Alternatively, a first aspect of the present invention is to provide a lower network connecting at least two upper nodes, and a failure recovery means for the lower network,
A lower node provided with means for detecting the occurrence of a failure in a transmission line that the self accommodates, and means for publicizing the detection result of the detecting means as failure information, wherein the feature of the present invention is that the announcement is made. The means for performing is to equip a means for making a public notice at a constant period during the detection of the failure by the detecting means.

That is, the lower node announces the occurrence of the failure to the upper node at a constant cycle. In response to this, the upper node can suspend the update of the time topology information until receiving a predetermined number of notifications, for example. Further, the upper node can adjust the relationship between the number of times the notification is received and the time for which the update of the topology information is suspended, in consideration of the importance of communication handled by itself and various other factors.

Alternatively, a first aspect of the present invention is to provide a lower network connecting at least two upper nodes, and a failure recovery means for the lower network,
A lower node provided with means for detecting the occurrence of a failure in a transmission line accommodated in itself, and means for publicizing the detection result of the detecting means as failure information, which is a feature of the present invention, A means for analyzing the failure situation according to the detection result of the means for measuring and a means for ranking the degree of the failure according to the analysis result of the means for analyzing as the higher the rank is, the lower the possibility of recovery is to represent the severe failure. The means for making an announcement includes a conditional announcement means for making an announcement about a failure of a predetermined rank or higher with reference to the ranking result of the means for making a ranking.

That is, the lower node does not make a public notice from the beginning regarding a failure of a low rank which can be expected to be recovered in a short time. This allows the upper node to reduce the processing load on the upper node without even knowing the occurrence of a failure.

[0021] Alternatively, a first aspect of the present invention is to provide a lower network connecting at least two upper nodes, and a failure recovery means for the lower network,
A lower node provided with means for detecting the occurrence of a failure in a transmission line accommodated in itself, and means for publicizing the detection result of the detecting means as failure information, which is a feature of the present invention, Means for analyzing the failure situation according to the detection result of the means for analyzing, and means for ranking the degree of the failure according to the analysis result of the analyzing means as the higher the rank, the lower the possibility of recovery is to represent the severe failure, and Predicted time information holding means for holding information on predicted time required for failure recovery of the lower network is provided, and the means for making an announcement refers to the ranking result of the ranking means A means for issuing a limited public notice including limited information that the public notice is limited to the upper node directly related to the faulty lower network, and the limitation. After the predicted time information holding means and the estimated time held in the emission of tell when even not restored the fault lower network is in place and means to fire a ban publication indicating that ban the limitation.

That is, even if a failure is expected to be recovered in a short time, the lower node makes a public notice to the upper node directly related to the failure. However, do not forward the announcement to other higher-level nodes that are not directly involved in the failure. As a result, it is possible to prevent the vibration of topology information update from spreading to the entire network due to the notification of the occurrence of a failure that can be expected to be recovered in a short time. Furthermore, the upper node that received the notification can take failure avoidance measures in case the failure recovery cannot be realized in a short time against expectations, for example, dealing with highly important communications. This is useful for upper nodes.

It is preferable that the means for analyzing the failure condition comprises means for detecting the number of the transmission paths in which a failure has occurred almost at the same time, and the ranking means have means for assigning a rank based on the number. . The means for detecting the number is, for example, grouping the failure factors,
It is provided with a table in which transmission lines that are cut off in response to the occurrence of a failure caused by a failure factor belonging to each group are recorded, and means for referring to this table and detecting the number of the transmission paths in which a failure has occurred at approximately the same time.

That is, when ranking the degree of failure, it is possible to rank by the number of transmission paths in which failure has occurred almost at the same time. According to this, failure occurs at many transmission lines almost at the same time and the rank is so high that recovery cannot be expected, and it means that failure avoidance measures depending on the upper node such as setting of detour route in upper node are required. .

A priority order holding means for holding information on a recovery priority order at the time of failure recovery of the transmission line of the lower network is provided, and the means for analyzing the failure status is
A means for acquiring the information on the restoration priority order held in the priority order holding means of the transmission path in which a failure has occurred, and the ranking means selects a serious failure having a lower recovery possibility as the rank becomes higher. Means may be provided to provide a high ranking inversely proportional to the priority.

That is, when ranking the degree of failure, the rank is so high that restoration cannot be expected preferentially,
Indicates that failure avoidance measures that depend on the upper node, such as the setting of detour routes in the upper node, are required.

The means for analyzing the failure status includes means for detecting the degree of congestion of network resources by referring to the topology information of the lower network in which the failure has occurred, and the means for ranking the higher the rank, the higher the recovery. Means may be provided to provide a high ranking inversely proportional to the degree of congestion as representing a less likely severe disorder.

That is, when ranking the degree of failure, it is difficult to set a detour route in a place where the degree of congestion of network resources is low, and it is a place where recovery in a short time cannot be expected. Indicates that failure avoidance measures that depend on the upper node, such as the setting of detour routes in the node, are required.

The predicted time information holding means holds the link state information relating to the detailed configuration of the lower network, and each of the lower networks estimated from the link state information held in the holding means. And a means for calculating the predicted time for each of the transmission paths based on the bypass path setting capability of the transmission path. The means for calculating the predicted time, for example, as the ability to set the detour path, for the transmission line in the duplex operation, calculates the predicted time as almost zero and at the same time during the failure during the single operation of the transmission line. A means for re-recognizing as a transmission line is provided. Alternatively, the means for calculating the predicted time includes means for calculating the predicted time based on the presence / absence of a detour path with respect to both ends of the faulty transmission line and the availability of the detour path as the detour path setting capability. Prepare

The predicted time information holding means virtually predicts the predicted time between the two nodes in which the working and protection paths are set, and the paths each having an empty band in the vicinity of the working and protection paths. Time required to switch a route from the virtual working route to the virtual backup route when a virtual fault is generated on the virtual working route. Can be provided as the predicted time.

That is, in normal times, virtual working and protection routes are set, a fault is simulated in the virtual working route, and the route is switched from the virtual working route to the virtual protection route. By investigating the time required for replacement, the estimated time required for failure recovery can be calculated. Virtual working and protection routes are set near the actual working and protection routes, and fault detection → fault notification →
It is possible to obtain a highly accurate failure recovery prediction time that reflects the actual conditions of the actual network, in accordance with the actual process of switching the backup route.

The predicted time information holding means sets the predicted time between the two nodes to which a route has already been set as a virtual route having a free band in the vicinity of the route, When a fault is simulated on a route, a detour route for the virtual route is searched for, and the time required to switch the route from the virtual route to the detour route is used as the predicted time. Means for calculating can be provided.

That is, in normal times, a virtual route is set, a fault is simulatedly generated in this virtual route, fault detection → fault notification → detour route search → detour route setting → detour route switching. By executing the simulation, it is possible to obtain a highly accurate failure recovery prediction time that reflects the actual conditions of the actual network.

A second aspect of the present invention is a network including the lower node of the present invention.

A third aspect of the present invention is that, when installed in an information processing device, the information processing device is provided in a lower network connecting at least two upper nodes, and a failure recovery function of this lower network is provided. And a program that realizes a function corresponding to a device for controlling a lower node having a function of detecting a failure occurrence in a transmission path accommodated by itself and a function of notifying a detection result of the detected function as failure information. is there.

Here, the feature of the present invention resides in that, as the notification function, a function of suspending the issuing of the notification for T time from the time when the failure is detected by the detecting function is realized.

Alternatively, the predicted time information holding function for holding the information on the predicted time required for the failure recovery of the lower network is realized, and as the function of making the announcement, immediately after the detecting function detects the failure occurrence of the lower network. And a first announcement function for making a first announcement, and a failure of the transmission path even after the estimated time held in the estimated time information holding function has elapsed from the time when the first announcement was made by the first announcement function. This is to realize the second public notice function that makes the second public notice when restoration is not realized.

Alternatively, a priority order holding function for holding information on the restoration priority order at the time of failure recovery of the transmission lines of the lower network is realized, and as a function of the announcement, a plurality of the transmission lines in which a failure has occurred almost at the same time With respect to, the function of setting the time length from the first announcement time to the second announcement time in inverse proportion to the restoration priority order held in the priority order holding function is realized.

Alternatively, the predicted time information holding function for holding the information of the predicted time required for the failure recovery of the lower network is realized, and as the function of making the announcement, the detection result of the detecting function and the predicted time information holding function are used. In order to realize the function of acquiring the information of the predicted time required for the restoration with reference to the held predicted time, and the function of making a public notice including the information of the predicted time acquired by the acquiring function. is there.

Alternatively, the function of making a public notice is to realize a function of making a public notice at a constant cycle during the detection of a failure by the detecting function.

Alternatively, it is assumed that the function of analyzing the failure status according to the detection result of the function to be detected and the degree of the failure according to the analysis result of the function to be analyzed represent a serious failure having a lower recovery possibility as the rank becomes higher. The function of ranking is realized, and as the function of making the announcement, a conditional announcement function of making an announcement about a failure of a predetermined rank or higher by referring to the ranking result of the function of making the ranking is realized.

Alternatively, it is assumed that a function of analyzing a failure status according to the detection result of the function to be detected and a failure level having a higher rank according to the analysis result of the function to be analyzed represent a serious failure having a lower recovery possibility. A function for ranking and a predicted time information holding function for holding information on a predicted time required for failure recovery of the lower network are realized, and as a function for making the announcement, refer to a ranking result of the function for ranking. For faults of a predetermined rank or less, a function to issue a limited public notice including limited information that the public notice is limited to the upper node directly related to the faulty lower network, and the predicted time information is held from the issuance of the limited public notice. If the failure lower network does not recover even after the predicted time retained in the function has elapsed, the limitation will be lifted. There is the place to be and a function to issue a ban public notice.

As a function of analyzing the failure status, a function of detecting the number of the transmission paths in which a failure occurs at substantially the same time is realized, and a function of assigning a rank based on this number is realized as the ranking function. You can

As a function of detecting the number of lines, the failure factors are divided into groups, and a function corresponding to 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 this table It is possible to realize the function of detecting the number of the transmission paths in which a failure has occurred almost simultaneously with reference.

The priority holding function for holding the restoration priority information at the time of failure recovery of the transmission line of the lower network is realized, and the priority of the transmission line in which the failure has occurred is analyzed as a function of analyzing the failure status. Realizing the function of acquiring the information of the restoration priority held in the ranking holding function, the ranking function is inversely proportional to the priority as the higher the rank is, the lower the possibility of recovery is to represent the serious failure. It is possible to realize a high ranking function.

As a function of analyzing the failure status, a function of detecting the degree of congestion of network resources is realized by referring to the topology information of the faulty lower network, and the higher the rank, the higher the rank. It is possible to realize a function of giving a high ranking in inverse proportion to the degree of congestion as representing a serious failure with low recoverability.

As the predicted time information holding function, a function of holding link state information relating to the detailed configuration of the lower network, and an individual function of the lower network estimated from the link state information held by the holding function It is possible to realize the function of calculating the predicted time for each of the transmission paths based on the bypass path setting capability of the transmission path.

As a function of calculating the predicted time, as a setting ability of the detour path, the predicted time is calculated as almost zero for a transmission line in the duplex operation, and the transmission line is in the single operation during a failure. It is possible to realize the function of re-recognizing as the transmission path of the.

As a function of calculating the predicted time, a function of calculating the predicted time based on the presence / absence of a detour path with respect to both ends of the faulty transmission line and the availability of the detour path as the detour path setting ability. Can be realized.

As the predicted time information holding function, the predicted time between the two nodes in which the working and protection paths are set is calculated by virtualizing the paths each having an empty band in the vicinity of the working and protection paths. Time required to switch a route from the virtual working route to the virtual backup route when a virtual fault is generated on the virtual working route. Can be realized as the predicted time.

As the predictive time information holding function, the predicted time between the two nodes to which a route has already been set is set as a virtual route having a free band in the vicinity of the route, and When a fault is simulated on a route, a detour route for the virtual route is searched for, and the time required to switch the route from the virtual route to the detour route is used as the predicted time. The function of calculating can be realized.

A fourth aspect of the present invention is a recording medium readable by the information processing device, in 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 installed in the information processing apparatus directly from a server holding the program of the present invention via a network.

As a result, it is possible to provide a failure recovery control technique suitable for a multi-layer network by using an information processing device such as a computer device, and to realize a lower node and a network capable of effectively utilizing network resources. .

[0054]

BEST MODE FOR CARRYING OUT THE INVENTION (First Embodiment) A network according to a first embodiment of the present invention will be described with reference to FIGS.
FIG. 1 is a conceptual diagram of the network of this embodiment. FIG. 2 is a block diagram of the optical cross connect of this embodiment. FIG. 3 is a block diagram of the failure recovery control device of the first embodiment.
FIG. 4 is a block diagram of the notification issuing unit according to the first embodiment. FIG. 5 is a block diagram of the router of the first embodiment.

The first embodiment is provided in a lower network that connects at least two routers, and a failure recovery control device 30 for performing failure recovery of this lower network.
An optical cross, which is a subordinate node, including a failure occurrence detection unit 31 that detects a failure occurrence in a transmission path that it accommodates, and a notification issuing unit 32 that notifies the detection result of the failure occurrence detection unit 31 as failure information. The connections are 10 to 26. The failure recovery control device 30 is not shown in the network configuration diagram.

Here, the feature of the first embodiment is that, as shown in FIG. 4, the notification issuing unit 32 issues the notification T time from the time when the failure detection unit 31 detects the failure. It is provided with the announcement holding unit 49 for holding.

As described above, the optical cross connects 10 to 26
The failure recovery control device 30 is invalidated by not immediately issuing a notification to the routers 1 to 8 when a failure occurs in the lower network, but by holding the notification for a certain period of time in hope of prompt recovery of the lower network. Route calculation can be avoided.

In each of the routers 1 to 8, there are cases where the failure occurrence detecting section 41 detects the failure occurrence itself and cases where the failure occurrence is detected by a notification from the lower network. The failure occurrence detecting section 41 detects the failure occurrence. Figure 2
It is an upper network level fault composed of the routers 1 to 8 shown in FIG. On the other hand, the failure detected by the notification from the lower network is the lower network level failure including the optical cross-connects 10 to 26 shown in FIG.

That is, the failure detected by the failure occurrence detecting section 41 is a serious failure such that the lower network between the routers is almost completely cut off, and an immediate recovery is hardly expected. On the other hand, the failure detected by the notification from the lower level network is a minor failure such as a part of the lower level network being cut off, and an immediate recovery such as setting a detour route is expected. is there.

In the present embodiment, description will be made for the occurrence of a failure at the lower network level, which can be expected to be restored promptly.

In the present embodiment, the description will be made assuming that the failure occurrence is detected by the announcement from the lower network.
In addition, the failure occurrence of the lower network can be detected by the error monitoring of the keep-alive signal of the link transmitted from the routers 1 to 8 itself or the K1 / K2 byte of SDH, and the LSA packet described in this embodiment. The present embodiment can be similarly described by using such a failure occurrence detection method instead of the public notice by.

The failure recovery control device 30 is provided with a predicted time information holding unit 34 which holds information on the predicted time required for the failure recovery of the lower network, and the failure recovery control device 30.
The notification issuing 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 to acquire the information of the predicted time required for the restoration, and the notification holding unit. 49 determines the holding time for the announcement based on the acquired information on the predicted time.

The routers 1 to 8 shown in FIG. 5 will be briefly described. Each of the routers 1 to 8 has a failure occurrence detection unit 41 that detects a failure occurrence in a transmission path that it accommodates, a notification issuing unit 42 that notifies the detection result of the failure occurrence detection unit 41 as failure information, and network topology information. And a topology information updating unit 46 that updates the topology information held by itself according to the notified failure information or the failure information detected by the self, and the announced failure information by another router. 1 to 8, a public notice transfer unit 47, a routing table calculation unit 44 that calculates a routing table based on the topology information held in the topology information holding unit 43, and a route that sets a route based on this routing table And a setting unit 45.

(Second Embodiment) In the second embodiment, the notification issuing unit 32 refers to the detection result of the failure occurrence detecting unit 31 and the predicted time held in the predicted time information holding unit 34 to restore the restoration. The information issuing unit 32 obtains the information on the predicted time required for, and issues the announcement including the acquired information on the estimated time.

For example, if the routers 1 to 8 are provided with a function of suspending the update of the topology information for a predetermined time after receiving the notification, the routers 1 to 8 can suspend the update of the topology information for the predicted time. .

(Third Embodiment) A third embodiment of the present invention will be described with reference to FIG. FIG. 6 is a diagram for explaining the holding time determination method of the third embodiment.

In the third embodiment, the optical cross connects 10-
Notification issuing unit 32 in the failure recovery control device 30
Makes a public announcement at regular intervals while the failure occurrence detection unit 31 is detecting a failure.

For example, if the routers 1 to 8 are provided with a function of updating the topology information after receiving a public notice a plurality of predetermined times, the routers 1 to 8 can suspend the updating of the topology information for a predetermined time. You can

(Fourth Embodiment) A network according to the fourth embodiment of the present invention will be described with reference to FIG. FIG. 7 is a diagram for explaining the holding time determination method of the fourth embodiment.

In the fourth embodiment, the notification issuing unit 32 makes the first notification immediately after the failure occurrence detecting unit 31 detects the occurrence of the failure in the lower network, and the predicted time from the time when the first announcement is announced. The second public notice is issued when the failure recovery of the lower network is not realized even after the estimated time stored in the information storage unit 34 has elapsed.

For example, if the routers 1 to 8 are provided with a function of suspending the update of the topology information for the time from the time when the first announcement is received to the time when the second announcement is received, the routers 1 to 8 can make the first announcement. Update of the topology information for the time from the announcement to the second announcement can be put on hold.

(Fifth Embodiment) A network according to a fifth embodiment of the present invention will be described with reference to FIGS. 8 and 9. FIG. 8 is a block diagram of the failure recovery control device of the fifth embodiment.
FIG. 9 is a diagram for explaining the holding time determination method of the fifth embodiment.

In the fifth embodiment, as shown in FIG. 8, the priority recovery holding device 30 of the optical cross-connects 10 to 26 holds the recovery priority information at the time of recovery from the failure of the transmission path of the lower network. The unit 35 is provided.

The restoration priority is, for example, as shown in FIG. 9, when a transmission line is a wavelength division multiplex transmission line, many wavelength paths are interrupted at the same time due to the failure of the transmission line. In such a case, it is actually difficult to restore all the wavelength paths at the same time, and a priority order is set and restoration is performed in order. Generally, the more important the communication content to be handled, the higher the priority. The priority order storage unit 35 holds in advance recovery priority order information at the time of failure recovery.

In such a situation, in the fifth embodiment, the notification issuing unit 32 of the failure recovery control device 30 operates from the first announcement time to the second announcement time for a plurality of wavelength paths in which failures occur almost at the same time. Is set in inverse proportion to the restoration priority order held in the priority order holding unit 35.

That is, as shown in FIG. 9, for the wavelength path λ1 which has the highest priority and is expected to be restored promptly, it is likely that the routers 1 to 8 do not set the detour route, and the lower network immediately Based on the expectation that the recovery will be completed, set the time from the first announcement to the second announcement longer. In the example of FIG. 9, the restoration is completed before the scheduled issue time of the second public notice, and the second public notice is not actually issued.

On the other hand, the wavelength path λn, which has the lowest priority and cannot be expected to be recovered promptly, is supposed to require the failure avoidance measures by the routers 1 to 8, and therefore the first public notice to the second public notice. Set a shorter time. As a result, trouble avoidance measures such as detour route setting by the routers 1 to 8 are promptly taken.

(Sixth Embodiment) A sixth embodiment of the present invention is shown in FIG.
Will be described with reference to. FIG. 10 is a block diagram of the failure recovery control device of the sixth embodiment.

In the sixth embodiment, the failure status analysis section 36 for analyzing the failure status according to the detection result of the failure occurrence detection section 31, and the higher the rank of the failure according to the analysis result of the failure status analysis section 36, the higher the rank. A failure ranking unit 37 that ranks as a serious failure with low recoverability
The notification issuing unit 32 refers to the ranking result of the failure ranking unit 37, and publicizes the failure of a predetermined rank or higher.

That is, in the sixth embodiment, no public notice is given from the beginning for a low-rank failure that can be expected to be recovered in a very short time. As a result, the processing load on the routers 1 to 8 can be reduced.

(Seventh Embodiment) The seventh embodiment of the present invention is shown in FIG.
And it demonstrates with reference to FIG. FIG. 11 is a block diagram of the failure recovery control device of the seventh embodiment. FIG. 12 is a diagram showing the contents of LSA packets used in the network of the seventh embodiment.

In the seventh embodiment, as shown in FIG. 11, the failure recovery control device 30 includes a failure situation analysis unit 36 for analyzing the failure situation according to the detection result of the failure occurrence detection unit 31.
And a failure ranking section 37 that ranks the degree of failure according to the analysis result of the failure information analysis section 36 as representing a severe failure with a higher possibility of recovery with a higher rank.
An estimated time information holding unit 34 that holds information on an estimated time required for failure recovery of the lower network is provided, and the notification issuing unit 32 refers to the ranking result of the failure ranking unit 37 to check for failures of a predetermined rank or lower. Issues a limited public notice including limited information that the public notice is limited to the routers 7 and 8 directly related to the faulty lower network. Further, if the faulty transmission line is not restored even after the predicted time held in the predicted time information holding unit 34 has elapsed from the issuance of the limited public notice, a forbidden public notice for releasing the limit is issued.

For example, the announcement transfer unit 4 of the routers 7 and 8
If the configuration is such that when the limited advertisement is received, the advertisements to the other routers 1 to 6 are prohibited according to the limited information until the removal announcement is received.
Can hold the update of the topology information until the public notice is lifted.

That is, in the limited announcement, "LSA" is written as the packet type, as shown in FIG.
"24-22", which is the fault location, is written as the fault information, and "publication prohibition" is written as an incidental item. The announcement transfer unit 47 of the routers 7 and 8 in the announcement waiting state
When the LSA packet is received, the state transitions to the announcement transfer standby state in which the announcement to the other routers 1 to 6 is prohibited according to the “prohibition of announcement” written in the supplementary items.

The notification issuing unit 32 of the failure recovery control device 30 has passed the failure recovery predicted time obtained by referring to the predicted time information holding unit 34 after issuing the limited notification shown in FIG. 12 (a). Even if the restoration is not completed yet, as shown in FIG. 12B, the LSA packet in which "publication ban" is written in the additional matter is transmitted. When the notification transfer unit 47 of the routers 7 and 8 receives this LSA packet,
According to the “ban on public announcement” written in the supplementary items, the state transits to the public announcement transfer state in which the announcement is transferred to the other routers 1 to 6.

Alternatively, the public notice issuing unit 32 of the fault recovery control device 30 may predict the fault recovery time obtained by referring to the estimated time information holding unit 34 after issuing the limited public notice shown in FIG. 12A. When the recovery is completed before the elapse, the LSA packet in which "recovery" is written in the failure information is transmitted as shown in FIG. 12 (c). Upon receiving this LSA packet, the announcement transfer unit 47 of the routers 7 and 8 releases the announcement transfer standby state and returns to the announcement waiting state.

(Eighth Embodiment) FIG. 13 shows the eighth embodiment of the present invention.
And FIG. 14 will be described. FIG. 13 is a diagram showing a part of a network for explaining the eighth embodiment.
FIG. 14 is a diagram showing SRLG (Shared Risk Link Group).

In the eighth embodiment, the failure status analysis unit 36 of the failure recovery control device 30 detects the number of transmission paths in which a failure has occurred almost at the same time, and the failure ranking unit 37 assigns a rank based on this number. .

When detecting the number of transmission lines in which a failure has occurred almost at the same time, as shown in FIG. 14, the failure factors are divided into groups, and the transmissions are interrupted in response to the failure occurrence of the failure factors belonging to each group. With a table where the road is recorded,
By referring to this table, the number of transmission lines in which a failure has occurred is detected almost at the same time.

That is, SRLG is a set of things which are affected at the same time when a failure occurs in one failure factor. In the eighth embodiment, the optical cross-connects 22 to 26 and the links 80 to 80 are the failure factors. 85, and there are six optical paths of wavelengths λ1 to λ6 that are affected by failures when they occur.

If a failure occurs in any of the optical cross-connects 22, 24, 25 and the links 82, 83, three optical paths of wavelengths λ1 to λ3 are affected, so this is designated as group # 1. Also, optical cross connect 2
If a failure occurs in any one of the links 2, 26, 25 and the links 84, 85, the two optical paths of the wavelengths λ4, λ5 are affected, so this is designated as group # 2. Also,
Optical cross connect 22, 23, 25 and link 80,
If a failure occurs in any of 81, one optical path of wavelength λ6 is affected, so this is designated as group # 3. FIG. 14 shows a table of this correspondence.
It is a table shown to (a) and (b).

The failure status analysis unit 36 is provided with the table shown in FIG. 14, and by identifying the failure factor from the failure information written in the LSA packet and referring to this table, the failure factor of the failure factor is identified. The number of affected optical paths can be checked in response to the occurrence of a failure. The failure ranking unit 37 ranks the degree of failure according to the number. In the eighth embodiment, three groups # 1, #
Since there are 2 and # 3, rank “H” is assigned to the failure occurrence of the failure factor belonging to the group # 1, and the group #
Rank "M" for failure occurrence of failure factors belonging to 2
And the rank “L” is assigned to the failure occurrence of the failure factor belonging to the group # 3.

(Ninth Embodiment) The ninth embodiment of the present invention is shown in FIG.
Will be described with reference to. FIG. 15 is a block diagram of the failure recovery control device of the ninth embodiment.

In the ninth embodiment, as shown in FIG. 15, the failure recovery control device 30 is provided with a priority order holding section 35 for holding information on the recovery priority order at the time of failure recovery of the transmission path of the lower network. And failure situation analysis unit 36
Acquires the restoration priority information held in the priority holding unit 35 of the faulty transmission path, and the fault ranking unit 37 indicates that the higher the rank is, the lower the possibility of restoration is, and the lower the priority is. Give a high ranking in inverse proportion to.

That is, as described with reference to FIG. 9 of the fifth embodiment, a plurality of transmission lines in which a failure has occurred almost at the same time are given priorities for their recovery so that the recovery can be performed earliest after the failure occurs. The lowest rank is assigned to the established transmission path, and the highest rank is assigned to the transmission path that is finally restored after the failure occurs.

(Tenth Embodiment) A network according to the tenth embodiment of the present invention will be described with reference to FIGS. 16 and 17. Figure 1
6 is a block diagram of the failure recovery control device of the tenth embodiment. FIG. 17 is a diagram for explaining the rank allocation method of the tenth embodiment.

In the tenth embodiment, as shown in FIG. 16, the failure recovery control device 30 is provided with a link state information holding unit 38 which holds the link state information regarding the detailed configuration of the lower network. As shown in FIG. 17, the link state information holding unit 38 holds small-scale topology information limited to the lower network to which it belongs.

The failure status analysis unit 36 detects the degree of congestion of network resources by referring to the link state information on the detailed configuration of the lower network in which a failure has occurred, as shown in FIG. In the example of FIG. 17, comparing failure points A and B,
A has a higher density of network resources than B. The failure ranking unit 37 gives a higher rank in inverse proportion to the congestion degree, as a higher rank represents a serious failure having a lower possibility of recovery.

That is, if the network resources are dense, the detour route can be set easily and recovery can be expected in a short time. However, if the network resources are sparse, the detour route should be set. It is difficult, and short-term recovery cannot be expected. Therefore, a high rank is assigned in inverse proportion to the density of network resources.

(Eleventh Embodiment) An eleventh embodiment of the present invention will be described with reference to FIGS. The eleventh embodiment is an embodiment of a method of setting the predicted recovery time stored in the predicted time information storage unit 34. FIG. 18 is a block diagram of the prediction time information holding unit of this embodiment. FIG. 19 is a diagram showing a transmission line during duplex operation. FIG. 20 is a diagram showing a transmission line having a bypass route.

The predicted time information holding unit 34 of this embodiment includes a link state information holding unit 38 holding the link state information regarding the detailed configuration of the lower network, and the link state information held in the link state information holding unit 38. And a predicted recovery time calculation unit 39 that calculates a predicted time for each transmission path based on the detour path setting capability of each transmission path of the lower network estimated from the above. Further, the calculation result of the estimated recovery time calculation unit 39 is recorded in the estimated recovery time information table 70.

As shown in FIG. 19, the predicted recovery time calculation unit 39 calculates the predicted recovery time as almost zero for a transmission line during duplex operation as shown in FIG. Is re-recognized as a transmission line during single operation. That is, as shown in FIG. 19, when the same data is duplicated and transmitted using the working and protection routes, the recovery prediction time is assumed to be zero when a failure occurs in one of the routes. You may However, if a failure occurs in one of the paths, the redundant transmission path is lost. In such a case, the recovery predicted time is recalculated as one transmission path.

Alternatively, the estimated recovery time calculation unit 39 determines the estimated recovery time based on the presence / absence of a bypass route to both ends of the transmission line to be calculated and the availability of the bypass route as the capability to set the bypass route. To calculate. That is, as shown in FIG. 20, when the transmission line to be calculated is a transmission line having optical paths of wavelengths λ1 and λ2, first, the presence or absence of the detour route is checked, and further, in the detour route, Examine the wavelength blockage situation.

In the example of FIG. 20, there is a bypass route, and in the air blockage situation (1), optical paths of wavelengths λ4 and λ5 are free. Therefore, the estimated recovery time in this case is equal to the switching time of the optical cross connect. In the air blockage situation (2),
I need two free wavelengths, but they are all blocked. Further, in the air block condition (3), only the wavelength λ3 is vacant. In such a case, the predicted recovery time is calculated based on the occurrence probabilities of two vacant wavelengths based on statistical data from the past. Note that, in FIG. 19, the method can also be used when a failure occurs in either the working path or the backup path and the predicted recovery time is recalculated as one transmission path.

(Twelfth Embodiment) A twelfth embodiment of the present invention will be described with reference to FIGS. FIG. 21 is a block diagram of the predicted time information holding unit according to the twelfth embodiment.
FIG. 22 is a diagram for explaining the method for calculating the predicted recovery time according to the twelfth embodiment. The twelfth embodiment is an embodiment of a method of setting the predicted recovery time held by the predicted time information holding unit 34.

In the twelfth embodiment, the estimated time information holding unit 3
Reference numeral 4 indicates the estimated recovery time between the two optical cross-connects 22 and 25 in which the working and protection paths are set, and the virtual working and protection paths for the paths having free bands near the working and protection paths, respectively. And the route
Failure recovery simulation that calculates the time required for a route to switch from a virtual working route to a virtual backup route when a fault is simulated on this virtual working route It includes a torso portion 71. further,
The calculation result of the failure recovery simulation unit 71 is recorded in the recovery estimated time information table 70.

That is, in the example of FIG. 22, an optical path of wavelength λ1 is set up between the optical cross connects 22 and 25 as a working path. An optical path of wavelength λ3 is set up as a backup path. Under these circumstances, the failure recovery simulation unit 71 calculates the estimated recovery time.
Is the vacant wavelength λ2 of the same link as the link to which the working route is set as a virtual working route (temporary working), and the vacant wavelength λ of the same link as the link to which the backup route is set.
4 is set as a virtual backup path (temporary backup).

In this way, the virtual working route and the virtual protection route are set respectively, and a simulated failure is generated in the virtual working route. As a method of generating a simulated failure, for example, the optical cross connects 22, 2
L written with simulated fault information from either 4 or 25
It suffices to send the SA packet. Thereby, the recovery expected time can be obtained by measuring the time when the optical cross-connects 22, 23, 24, 25 cooperate with each other to actually switch the virtual working route to the virtual protection route. it can.

(Thirteenth Embodiment) A thirteenth embodiment of the present invention will be described with reference to FIGS. FIG. 21 is a block configuration diagram of the predicted time information holding unit according to the thirteenth embodiment,
This is common to the twelfth embodiment. FIG. 23 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 of setting the predicted recovery time held by the predicted time information holding unit 34.

In the thirteenth embodiment, the estimated time information holding unit 3
4 is a predicted recovery time between the two optical cross-connects 22 and 25 in which a route has already been set, and a route having an empty band near the route (actual route) is set as a virtual route (temporary route), When a fault is simulated on this virtual route, a detour route for the virtual route is searched for, and the time required to switch the route from the virtual route to the detour route is set. A failure recovery simulation unit 71 for calculating the predicted time is provided. Further, the calculation result of the failure recovery simulation section 71 is recorded in the recovery estimated time information table 70.

That is, in the example of FIG. 23, an optical path of wavelength λ1 is set up as an actual path between the optical cross connects 22 and 25. Under such circumstances, in order to calculate the predicted recovery time, the failure recovery simulation unit 71 uses the vacant wavelength λ2 of the same link as the link on which the actual route is set.
Is set as a virtual route (temporary route).

The temporary route is set in this way, and a simulated fault is generated in the temporary route. As a method of generating a simulated failure, for example, the optical cross connect 22,
The LSA packet in which the simulated failure information is written may be sent from either 24 or 25. As a result, the optical cross-connects 22, 23, 24, 25 cooperate with each other to set a detour route for a simulated failure of the tentative route, and measure the time when the tentative route is actually switched to the detour route. As a result, the estimated recovery time can be obtained. In the example of FIG. 23, the route of the optical cross connect 22 ← → 23 ← → 25 is set as the detour route # 1, and the optical cross connect 22 ← → 26 ← → 25 is set as the detour route # 2.
The route of is set.

(Fourteenth Embodiment) The failure recovery control device 30 applied to the network of the present invention can be realized by using a computer device which is an information processing device. That is, by installing in a computer device, the computer device is provided with a function corresponding to a recovery control unit 33 provided in a lower network connecting at least two routers and performing failure recovery of the lower network, and the self device. Failure recovery having a function corresponding to the failure occurrence detection unit 31 that detects a failure occurrence in the accommodated transmission path and a function corresponding to the notification issuing unit 32 that announces the detection result of the failure occurrence detection unit 31 as failure information. It is a program that realizes a function corresponding to the control device 30, and as a function corresponding to the notification issuing unit 32, the notification is issued from the time when the failure is detected by the function corresponding to the failure occurrence detecting unit 31 for T time. By installing a program that realizes the function of It can be a device corresponding to the fault recovery control unit 30 of the present embodiment the location.

More specifically, by installing in a computer device, the computer device is provided in a lower network connecting at least two routers, and as shown in FIG. A function corresponding to the restoration control unit 33, a function corresponding to the failure occurrence detection unit 31 that detects a failure occurrence in the transmission path that the self accommodates, and a notification that publicizes the detection result of the failure occurrence detection unit 31 as failure information. A program for realizing a function corresponding to the failure recovery control device 30 having a function corresponding to the issuing unit 32, which is stored in a predicted time information holding unit 34 that holds information about a predicted time required for failure recovery of the lower network. As a function corresponding to the notification issuing unit 32, the failure occurrence detecting unit 31 is configured to realize the corresponding function, and A first public notice function of performing a first public notice immediately after detecting the failure of the click, the predicted time information holding unit 3 from the time when the first publication has been published by this first publication function
By installing a program that realizes a second notification function for making a second notification when the failure recovery of the transmission path is not realized even after the estimated time stored in 4 has passed, It can be a device corresponding to the failure recovery control device 30 of the first embodiment.

Alternatively, by being installed in a computer device, the computer device is provided in a lower network that connects at least two routers, and as shown in FIG. 8, a recovery control for performing failure recovery of this lower network. A function corresponding to the unit 33 and a failure occurrence detection unit 31 that detects a failure occurrence in the transmission path that the self accommodates
Is a program that realizes a function corresponding to the failure recovery control device 30 having a function corresponding to the above, and a function corresponding to the notification issuing section 32 that notifies the detection result of the failure occurrence detection section 31 as failure information. A function corresponding to the restoration priority holding unit 35 that holds information on the restoration priority when the transmission path of the lower network is restored is realized, and a failure occurs at substantially the same time as a function corresponding to the notification issuing unit 32. A computer device having a program for realizing a function of setting the time length from the first announcement time to the second announcement time in inverse proportion to the restoration priority held in the priority holding function for each of the plurality of transmission paths. Installed in the computer, the computer device becomes a device corresponding to the failure recovery control device 30 of the fifth embodiment. Can.

Alternatively, by installing in a computer device, the computer device is provided in a lower network that connects at least two routers, and as shown in FIG. 3, the failure recovery of the lower network is performed. A function corresponding to the control device 30, a function corresponding to the failure occurrence detection unit 31 that detects the occurrence of a failure in the transmission path that the self device accommodates, and a notification issuing unit that notifies the detection result of the failure occurrence detection unit 31 as failure information. A program that realizes a function corresponding to the failure recovery control device 30 having a function corresponding to 32, and corresponds to a predicted time information holding unit 34 that holds information about a predicted time required for failure recovery of the lower network. As a function that realizes the function and corresponds to the notification issuing unit 32, the detection result of the failure occurrence detecting unit 31 and the prediction time A function of referring to the predicted time held in the information holding unit 34 to acquire information of the predicted time required for the recovery, and a function of issuing a notification including the predicted time information acquired by the acquiring function. By installing a program for realizing the above in a computer device, the computer device can be made to correspond to the failure recovery control device 30 of the second embodiment.

Alternatively, by installing in a computer device, the computer device is provided with a lower network connecting at least two routers, and a function corresponding to the recovery control unit 33 for performing failure recovery of the lower network, and a self-control function. A failure having a function corresponding to the failure occurrence detection unit 31 that detects the occurrence of a failure in the transmission path accommodated by the user and a function corresponding to the notification issuing unit 32 that announces the detection result of the failure occurrence detection unit 31 as failure information. A computer that realizes a function corresponding to the recovery control device 30 and that realizes a function of performing a notification in a constant cycle during the detection of a failure by the failure occurrence detection unit 31 as a function corresponding to the notification issuing unit 32 By installing the computer device in the device, the failure recovery of the third embodiment It can be a device corresponding to control apparatus 30.

Alternatively, by being installed in a computer device, the computer device is provided in a lower network connecting at least two routers, and as shown in FIG. A function corresponding to the unit 33, and a failure occurrence detection unit 3 that detects a failure occurrence in a transmission path that the self accommodates.
A program that realizes a function corresponding to the failure recovery control device 30 having a function corresponding to 1 and a function corresponding to the notification issuing section 32 that notifies the detection result of the failure occurrence detection section 31 as failure information. The function corresponding to 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 function corresponding to the failure ranking unit 37 for ranking as a low severity failure is realized, and a function corresponding to the notification issuing unit 32 is implemented as the failure ranking unit 37.
By installing a program that realizes a conditional announcement function for making an announcement about a failure of a predetermined rank or more by referring to the ranking result of the above, the failure recovery control apparatus 3 of the sixth embodiment is installed in the computer apparatus.
It can be a device corresponding to 0.

Alternatively, by being installed in a computer device, the computer device is provided in a lower network that connects at least two routers, and as shown in FIG. 11, a recovery control for performing failure recovery of this lower network. A function corresponding to the unit 33, and a failure occurrence detection unit 3 that detects a failure occurrence in a transmission path that the self accommodates.
A program that realizes a function corresponding to the failure recovery control device 30 having a function corresponding to 1 and a function corresponding to the notification issuing section 32 that notifies the detection result of the failure occurrence detection section 31 as failure information. The function corresponding to 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 function corresponding to the failure ranking unit 37 for ranking as a low severity failure and a function corresponding to the predicted time information holding unit 34 for holding information on the predicted time required for failure recovery of the lower network are realized. As a function corresponding to the notification issuing unit 32, the failure ranking unit 3
With reference to the ranking result of No. 7, for a failure of a predetermined rank or less, a function to issue a limited public notice including limited information that the public notice is limited to the router directly related to the faulty subordinate network, and the limited public notice A program is installed in a computer device that realizes a function of issuing a public notice of banning the limitation when the faulty lower network is not restored even after the lapse of the estimated time held in the estimated time information holding unit 34 from the issuance. As a result, the computer device can be made to correspond to the failure recovery control device 30 of the seventh embodiment.

As a function corresponding to the failure status analysis unit 36, a function of detecting the number of the transmission paths in which a failure has occurred at substantially the same time is realized, and a function corresponding to the failure ranking unit 37 is assigned a rank based on this number. Realize the function. At this time, as shown in FIG. 14, as a function of detecting the number, the failure factors are divided into groups, and a table in which the transmission paths to be interrupted corresponding to the failure occurrence of the failure factors belonging to each group are recorded in a table. A corresponding function and a function of referring to this table and detecting the number of the transmission lines in which a failure has occurred almost simultaneously are realized.

Alternatively, as shown in FIG. 15, a function corresponding to the recovery priority holding unit 35 which holds information on the recovery priority when the transmission line of the lower network is recovered from the failure is realized, and the failure status analysis unit is realized. As a function corresponding to 36, a function for acquiring the information on the restoration priority order held in the restoration priority order holding section 35 of the transmission path in which a failure has occurred is realized, and as a function corresponding to the failure ranking section 37, The higher the value is, the lower the possibility of recovery is, and the more serious the failure is.

Alternatively, as shown in FIGS. 16 and 17, as the function corresponding to the failure status analysis unit 36, the failure state stored in the function corresponding to the link state information holding unit 38 is the topology information of the lower network. To realize the function to detect the degree of congestion of network resources,
As a function corresponding to the failure ranking unit 37, a function of performing a high ranking in inverse proportion to the congestion degree is realized as a higher rank represents a serious failure with a lower possibility of recovery.

Alternatively, as a function corresponding to the predicted time information holding unit 34, as shown in FIG. 18, a function corresponding to the link state information holding unit 38 that holds the link state information regarding the detailed configuration of the lower network,
Restoration for calculating the predicted time for each transmission line based on the detour path setting capability of each transmission line of the lower network estimated from the link state information held in the link state information holding unit 38 The function corresponding to the predicted time calculation unit 39 is realized.

At this time, as a function corresponding to the predicted recovery time calculation unit 39, as shown in FIG. 19, as the setting capacity of the bypass path, the predicted time is set to almost zero for the transmission path in the duplex operation. A function for calculating and re-recognizing the transmission line as a transmission line in a single operation during a failure is realized. Alternatively, as shown in FIG. 20, as a function corresponding to the predicted recovery time calculation unit 39, as the setting ability of the detour route, the presence / absence of the detour route for both ends of the faulty transmission line, and the status of the detour route being occluded. The function of calculating the predicted time is realized based on

Alternatively, as a function corresponding to the prediction time information holding section 34, as shown in FIGS. 21 and 22, the failure recovery prediction time between two nodes in which the working and protection paths are set is And a route having an empty band in the vicinity of the backup route as a virtual working route and a backup route, respectively, and the virtual working route is generated when a fault is simulated in the virtual working route. To a virtual recovery route, the function corresponding to the failure recovery simulation unit 71 that calculates the time required for switching the route to the virtual backup route is realized.

Alternatively, as a function corresponding to the prediction time information holding unit 34, as shown in FIGS. 21 and 23, the failure recovery prediction time between two nodes for which a route has already been set is calculated as When a route having a vacant bandwidth is set as a virtual route and a fault is simulated in the virtual route, a detour route for the virtual route is searched for, and the virtual route is searched from the virtual route. A function corresponding to the failure recovery simulating unit 71 that calculates the time required for switching the route to the detour route as the predicted time is realized.

By recording the program of this embodiment on the recording medium of this embodiment, the computer device can install the program of this embodiment using this recording medium. Alternatively, the program of this embodiment can be directly installed in a computer device from a server holding the program of this embodiment via a network.

As a result, using the computer device,
It is possible to provide a failure recovery control technique suitable for a multi-layer network and realize a failure recovery control device 30 and a network that can effectively use network resources.

(Fifteenth Embodiment) A fifteenth embodiment of the present invention will be described with reference to FIG. FIG. 24 is a diagram showing a predicted time information database and a recovery priority database of the fifteenth embodiment.

In the first to thirteenth embodiments, the predicted time information holding unit 34 and the recovery priority order holding unit 35 are provided in the failure recovery control device 30, but in the fifteenth embodiment, it is shown in FIG. As described above, these are provided to independent nodes in the network, respectively, and the prediction time information database 9
0 and set as recovery priority database 91,
The fault recovery control device 30 is configured to retrieve each information stored therein by accessing these databases.

[0131]

As described above, according to the present invention,
It is possible to provide a failure recovery control technology suitable for a multi-layer network and to effectively use network resources.

[Brief description of drawings]

FIG. 1 is a conceptual diagram of a network according to this embodiment.

FIG. 2 is a configuration diagram of an optical cross connect according to the present embodiment.

FIG. 3 is a block configuration diagram of a failure recovery control device according to the first embodiment.

FIG. 4 is a block configuration diagram of a notification issuing unit according to the first embodiment.

FIG. 5 is a block configuration diagram of a router of this embodiment.

FIG. 6 is a diagram for explaining a holding time determination method according to the third embodiment.

FIG. 7 is a diagram for explaining a holding time determination method according to a fourth embodiment.

FIG. 8 is a block configuration diagram of a failure recovery control device of a fifth embodiment.

FIG. 9 is a diagram for explaining a holding time determination method according to a fifth embodiment.

FIG. 10 is a block configuration diagram of a failure recovery control device according to a sixth embodiment.

FIG. 11 is a block configuration diagram of a failure recovery control device of a seventh embodiment.

FIG. 12 is a diagram showing the contents of an LSA packet used in the network of the seventh embodiment.

FIG. 13 is a diagram showing a part of a network for explaining an eighth embodiment.

FIG. 14 is a diagram showing SRLG (Shared Risk Link Group).

FIG. 15 is a block configuration diagram of a failure recovery control device of a ninth embodiment.

FIG. 16 is a block configuration diagram of a failure recovery control device of a tenth embodiment.

FIG. 17 is a diagram for explaining a rank allocation method according to the tenth embodiment.

FIG. 18 is a block configuration diagram of a predicted time information holding unit according to the present embodiment.

FIG. 19 is a diagram showing a transmission line during duplex operation.

FIG. 20 is a diagram showing a transmission line having a bypass route.

FIG. 21 is a block configuration diagram of a predicted time information holding unit according to the twelfth and thirteenth embodiments.

FIG. 22 is a diagram for explaining a method of calculating a predicted recovery time according to the twelfth embodiment.

FIG. 23 is a diagram for explaining a method of calculating a predicted recovery time according to the thirteenth embodiment.

FIG. 24 is a diagram showing a predicted time information database and a recovery priority database of the fifteenth embodiment.

FIG. 25 is a diagram showing an example of a multi-layer network.

FIG. 26 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 Failure occurrence detection unit 32, 42 Public Notice Department 33 Recovery control unit 34 Estimated time information holding unit 35 Recovery priority holding unit 36 Failure situation analysis section 37 Disability Ranking Section 38 Link state information holding unit 39 Recovery Estimated Time Calculation Unit 43 Topology information holding unit 44 Routing table calculator 45 Route setting section 46 Topology information update unit 47 Public Notice Transfer Department 49 Public notice holding section 70 Recovery estimated time information table 71 Failure recovery simulation section 80-85 links 90 Predicted time information database 91 Recovery Priority Database A, B fault location

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Kohei Shiomoto             2-3-1, Otemachi, Chiyoda-ku, Tokyo             Inside Telegraph and Telephone Corporation F term (reference) 5K030 GA12 JA07 KA01 KX30 LB08                       MB01 MD02                 5K051 AA01 BB02 CC13 EE01 EE02                       FF01 GG11 LL02

Claims (34)

[Claims] 1. A fault recovery means provided in a lower network for connecting at least two higher nodes, a fault recovery means for the lower network, a means for detecting a fault occurrence in a transmission line accommodated therein, and a means for detecting this. In a lower node provided with means for publishing a detection result as failure information, the means for advertising comprises means for holding the issuance of the notification for T time from the time when the failure is detected by the detecting means. The subordinate node to be characterized. 2. A fault recovery means provided in a lower network for connecting at least two higher nodes, a fault recovery means for the lower network, a means for detecting a fault occurrence in a transmission path accommodated by itself, and a means for detecting this. In a lower node provided with means for publishing a detection result as failure information, a prediction time information holding means for holding information on a predicted time required for failure recovery of the lower network is provided, and the announcement means detects the The first announcement means for making the first announcement immediately after the means detects the occurrence of the failure of the lower network, and the first announcement means held the estimated time information holding means from the time when the first announcement was made. A second announcement means for making a second announcement when failure recovery of the transmission line is not realized even after the estimated time has passed. Over de. 3. A priority order holding means for holding information on a recovery priority order at the time of failure recovery of the transmission path of the lower network is provided, and the announcement means is a plurality of the transmission paths in which a failure occurs at substantially the same time. about,
3. The lower node according to claim 2, further comprising means for setting a time length from the first announcement time to the second announcement time in inverse proportion to the restoration priority order held in the priority order holding means. 4. A fault recovery means for the lower network, which is provided in a lower network connecting at least two upper nodes, a means for detecting the occurrence of a failure in a transmission path accommodated by itself, and a means for detecting this. In a lower node provided with means for publishing a detection result as failure information, a prediction time information holding means for holding information on a predicted time required for failure recovery of the lower network is provided, and the announcement means detects the Means for acquiring the information on the predicted time required for the restoration by referring to the detection result of the means and the predicted time held in the predicted time information holding means, and the information on the predicted time acquired by the acquiring means A subordinate node comprising means for making a public notice including. 5. A fault recovery means for the lower network, which is provided in a lower network connecting at least two upper nodes, a means for detecting the occurrence of a failure in a transmission path accommodated by itself, and a means for detecting this. A lower node provided with means for publishing a detection result as failure information, wherein the means for issuing notification comprises means for issuing a notification at a constant cycle during the detection of the failure by the detecting means. . 6. A fault recovery means provided in a lower network for connecting at least two higher nodes, a fault recovery means for the lower network, a means for detecting a fault occurrence in a transmission path accommodated in itself, and a means for detecting this. In a lower node provided with means for publishing a detection result as failure information, means for analyzing a failure situation according to the detection result of the detecting means, and a high degree of failure according to the analysis result of the analyzing means And a means for ranking as a serious failure having a low recoverability is provided, and the means for announcing is a condition for announcing an obstacle of a predetermined rank or higher by referring to the ranking result of the ranking means. A subordinate node characterized by being provided with a notification means. 7. A fault recovering means for the lower network, which is provided in a lower network connecting at least two upper nodes, a means for detecting the occurrence of a failure in a transmission path accommodated by itself, and a means for detecting this. In a lower node provided with means for publishing a detection result as failure information, means for analyzing a failure situation according to the detection result of the detecting means, and a high degree of failure according to the analysis result of the analyzing means A means for ranking as a serious failure having a low recovery possibility, and a predicted time information holding means for holding information on a predicted time required for failure recovery of the lower network are provided, and the means for making an announcement, Refer to the ranking result of the ranking means and directly report to the faulty subordinate network the faults below a predetermined rank. Means for issuing a limited public notice including limited information indicating that the public notice is limited to the above-mentioned upper node involved, and the failure even after the estimated time held in the estimated time information holding means from the issuance of the limited public notice A lower node, comprising means for issuing a public notice of banning the limitation when the lower network is not restored. 8. The means for analyzing the failure status comprises means for detecting the number of transmission paths in which a failure has occurred almost at the same time, and the ranking means includes means for assigning a rank based on this number. The lower node according to claim 6 or 7. 9. The table for detecting the number of lines is provided with a table in which the failure factors are divided into groups, and the transmission paths that are cut off in response to the occurrence of the failure factors belonging to each group are recorded, and this table is referred to. 9. The lower node according to claim 8, further comprising means for detecting the number of the transmission paths in which a failure has occurred almost simultaneously. 10. A priority order holding means for holding information on a recovery priority order at the time of failure recovery of the transmission path of the lower network is provided, and the means for analyzing the failure status is for the transmission path in which a failure has occurred. A means for obtaining the information on the restoration priority order held in the priority order holding means is provided, and the ranking means is inversely proportional to the priority order as a higher rank represents a serious failure having a lower recovery possibility. 6. The method according to claim 6 or 7, further comprising means for making a high ranking.
Listed subordinate node. 11. The means for analyzing the failure status comprises means for detecting the degree of congestion of network resources with reference to the topology information of the lower network in which the failure has occurred, and the means for ranking has a high rank. 8. The subordinate node according to claim 6 or 7, further comprising means for giving a high ranking in inverse proportion to the degree of congestion as representing a serious failure having a low possibility of recovery. 12. The predicted time information holding unit holds a link state information regarding a detailed configuration of the lower network, and a lower network estimated from the link state information held in the holding unit. 8. The lower node according to claim 2, further comprising means for calculating the predicted time for each of the transmission lines based on a bypass route setting capability of each of the transmission lines. 13. The means for calculating the predicted time calculates the predicted time as almost zero for a transmission line during duplex operation as the setting ability of the detour route, and unifies the transmission line during a failure. 13. The lower node according to claim 12, further comprising means for re-recognizing the transmission path during operation. 14. The means for calculating the predicted time calculates the predicted time based on the presence / absence of a detour path with respect to both ends of the faulty transmission path and the availability of the detour path as the detour path setting ability. Claim 1 comprising means for
The lower node described in 2. 15. The predicted time information holding means calculates the predicted time between two nodes in which a working path and a protection path are set, and a path having an empty band in the vicinity of the working and protection path, respectively. In order to switch the route from the virtual working route to the virtual standby route when a virtual fault is created as a virtual working route and a backup route and a simulated fault occurs in the virtual working route. 8. The lower node according to claim 2, further comprising means for calculating a required time as the predicted time. 16. The predicted time information holding means sets the predicted time between the two nodes to which a route has already been set as a virtual route having a free band in the vicinity of the route, When a fault is artificially generated for a virtual route, a detour route for the virtual route is searched, and the time required for switching the route from the virtual route to the detour route is predicted. 8. The lower node according to claim 2, further comprising means for calculating the time. 17. A network comprising the subordinate node according to claim 1. Description: 18. When installed in an information processing device, the information processing device is provided in a lower network that connects at least two upper nodes, and a failure recovery function of this lower network and transmission that it accommodates. In a program that realizes a function corresponding to a device that controls a lower node having a function of detecting the occurrence of a road failure and a function of notifying the detection result of the function to be detected as failure information, as the function of notifying, A program that realizes a function of suspending the issuance of the announcement for T time from the time when the failure is detected by the detecting function. 19. When installed in an information processing device, the information processing device is provided in a lower network that connects at least two upper nodes, and the failure recovery function of this lower network and the transmission accommodated by itself. In a program that realizes a function corresponding to a device that controls a lower node having a function of detecting the occurrence of a road failure and a function of notifying the detection result of the detected function as failure information, a failure recovery of the lower network Realizing a predicted time information holding function for holding information of predicted time required for, as the function of the public notice, the first public notice function to perform the first public notice immediately after the detecting function detects the failure occurrence of the lower network and The predicted time information holding function is held from the time when the first notification is announced by the first notification function. A program that realizes a second announcement function of making a second announcement when failure recovery of the transmission path is not realized even after the estimated time has elapsed. 20. When installed in an information processing device, the information processing device is provided in a lower network that connects at least two upper nodes, and the failure recovery function of this lower network and the transmission accommodated by itself. In a program for realizing a function corresponding to a device for controlling a lower node having a function of detecting the occurrence of a road failure and a function of notifying a detection result of the detected function as failure information, the transmission of the lower network The priority holding function that holds the information of the restoration priority at the time of the restoration of the failure of the path is realized,
A program that realizes a function of setting a time length from the first announcement time to the second announcement time in inverse proportion to the restoration priority held in the priority holding function. 21. When installed in an information processing device, the information processing device is provided in a lower network that connects at least two upper nodes, and the failure recovery function of this lower network and the transmission it accommodates In a program that realizes a function corresponding to a device that controls a lower node having a function of detecting the occurrence of a road failure and a function of notifying the detection result of the detected function as failure information, a failure recovery of the lower network To realize a predicted time information holding function for holding information of the predicted time required for, as the function of the announcement, with reference to the detection result of the function to detect and the predicted time held in the predicted time information holding function A function for acquiring information on the predicted time required for the restoration and the prediction time acquired by the function for acquiring A program that realizes a function of making a public notice including information between the two. 22. When installed in an information processing device, the information processing device is provided in a lower network that connects at least two upper nodes, and the failure recovery function of this lower network and the transmission that it accommodates. In a program that realizes a function corresponding to a device that controls a lower node having a function of detecting the occurrence of a road failure and a function of notifying the detection result of the function to be detected as failure information, as the function of notifying, A program that realizes a function of making a public announcement at a constant cycle while the failure is detected by the detecting function. 23. When installed in an information processing device, the information processing device is provided in a lower network that connects at least two upper nodes, and the failure recovery function of this lower network and the transmission that it accommodates. In a program that realizes a function corresponding to a device that controls a subordinate node having a function of detecting a road failure occurrence and a function of notifying a detection result of the detected function as failure information, detection of the detected function The function of analyzing the failure situation according to the result and the function of ranking the degree of failure according to the analysis result of the analyzing function as the higher the rank is, the lower the possibility of recovery is to represent the severe failure, are realized. Refer to the ranking result of the ranking function as a function to A program characterized by realizing the conditional public notice function for tell. 24. When installed in an information processing device, the information processing device is provided in a lower network that connects at least two upper nodes, and the failure recovery function of this lower network and the transmission that it accommodates. In a program that realizes a function corresponding to a device that controls a subordinate node having a function of detecting a road failure occurrence and a function of notifying a detection result of the detected function as failure information, detection of the detected function A function to analyze the failure situation according to the result, a function to rank the degree of the failure according to the analysis result of the analyzing function as a higher rank represents a severe failure with lower recovery possibility, and a failure of the lower network A device that realizes a predicted time information holding function that holds information on the predicted time required for restoration, As a function, referring to the ranking result of the function to be ranked, for a failure of a predetermined rank or less, a limited public notice including limited information that the public information is limited to the upper node directly related to the failure lower network is issued. The function of issuing a limited public announcement and the function of issuing a public notice that the restriction is lifted if the faulty subordinate network does not recover even after the predicted time held in the predicted time information holding function from the issuance of the limited public announcement. A program characterized by realization. 25. As a function of analyzing the failure situation,
25. The program according to claim 23, wherein a function of detecting the number of the transmission lines in which a failure has occurred at substantially the same time is realized, and a function of assigning a rank based on the number is realized as the ranking function. 26. As a function of detecting the number of lines, a function corresponding to a table in which failure factors are divided into groups, and transmission paths which are cut off in response to the failure occurrence of the failure factors belonging to each group are recorded, 26. A function for detecting the number of the transmission paths in which a failure has occurred almost simultaneously with reference to a table is realized.
The listed program. 27. A priority order holding function for holding recovery priority information at the time of failure recovery of the transmission path of the lower network is realized, and as a function of analyzing the failure status, the failure of the transmission path where the failure has occurred The function of acquiring the restoration priority information held in the priority holding function is realized, and the ranking function is inversely proportional to the priority as the higher the rank, the lower the possibility of recovery is to represent the serious failure. 3. The function of achieving high ranking is realized by the method of claim 2.
The program according to 3 or 24. 28. As a function of analyzing the failure situation,
The function of detecting the degree of congestion of network resources is realized by referring to the topology information of the lower network in which a failure has occurred, and as the ranking function, the higher the rank, the lower the possibility of recovery is to represent the severe failure. 25. The program according to claim 23 or 24, which realizes a function of performing high ranking in inverse proportion to the degree of congestion. 29. As the predicted time information holding function, a function of holding link state information related to a detailed configuration of the lower network, and a function of the lower network estimated from the link state information held in the holding function. The program according to any one of claims 19, 21, and 24, which realizes a function of calculating the predicted time for each of the transmission lines based on a bypass route setting capability of each of the transmission lines. 30. As a function for calculating the predicted time, as a setting ability of the detour route, the predicted time is calculated as almost zero for a transmission line in a duplex operation, and the transmission line is singled during a failure. 30. The program according to claim 29, which realizes a function of re-recognizing the transmission path during operation. 31. As a function of calculating the predicted time,
30. The program according to claim 29, which realizes a function of calculating the predicted time based on the presence / absence of a detour route with respect to both ends of the fault transmission path and the status of the air blocking of the detour route as the ability to set the detour route. 32. The predicted time information holding function includes the predicted time between two nodes having working and protection paths set, and a path having an empty band near each of the working and protection paths. In order to switch the route from the virtual working route to the virtual standby route when a virtual fault is created as a virtual working route and a backup route and a simulated fault occurs in the virtual working route. The program according to any one of claims 19, 21, and 24, which realizes a function of calculating a required time as the predicted time. 33. As the predictive time information holding function, the predictive time between the two nodes to which a route has already been set is set as a virtual route having a free band in the vicinity of the route, and Of a detour route to the virtual route when a failure is artificially generated on the virtual route, and the time required for switching the route from the virtual route to the detour route is predicted. The function for calculating as time is realized, claim 21, 21, 24.
The program described in any of. 34. A recording medium readable by the information processing device, in which the program according to claim 18 is recorded.