JP3552953B2 - Reserve VP design apparatus, reserve VP design method, and recording medium - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
According to the present invention, when a TP (transmission path) accommodating a working VP (virtual path) of an ATM (asynchronous transfer mode) network fails, the failure is caused by switching to a spare VP accommodated in another available TP. The present invention relates to a backup VP design technique for setting a backup VP route in advance to rescue a user who is using a VP.
[0002]
[Prior art]
Conventionally, when a TP accommodating a VP of an ATM network fails and a user who uses a failed VP is rescued by switching to a spare VP accommodated in another available TP, each active TP is used. A VP is treated without distinction, and a route that does not pass through the same geographical location as the fault location is uniformly selected to determine a backup route.
[0003]
For example, it is described in a paper by Yahara and Kawamura, "Study on Self-Healing System for ATM Network Realizing Multiple Reliability" (IEICE Technical Report of IEICE, IN96-96, pp. 59-64, November 1996). In this method, the backup VP is set by a path that is independent of the active VP, that is, a path that does not use any TP that passes through the same geographical position.
[0004]
In practice, if there are multiple physical systems passing through the same geographical location, and some of them fail, the TPs contained in other physical systems may be usable. However, it is not possible to predict a wide variety of possible accidents or failures, and it is not possible to determine a TP that can be used as a backup route in such cases. Therefore, as in the above example, the only safe and secure route setting method is to set a spare route on an independent route that does not pass through the same geographical location as the fault location. According to this method, if facilities are insufficient, spare facilities must be immediately added, and if that is not possible, spares cannot be set during that time. Therefore, there is a problem that routes that can accommodate the backup VP are limited, the backup routes are concentrated on independent routes, and the cost increases. Further, if the constraint on the independent path is simply removed, there is a problem that it is not possible to specify which VP is to be designed in consideration of what reliability.
[0005]
Further, as described above, since it is impossible to predict a wide variety of actual accidents or failures, VPs that cannot be relieved due to the failure when a plurality of physical systems actually fail. It was difficult to keep track of the problem, and there was a problem in securing reliability.
[0006]
[Problems to be solved by the invention]
An object of the present invention is to switch to another usable TP when a TP accommodating a VP of an ATM network fails, so that a spare VP can be economically selected in advance while maintaining high reliability. It is to provide a VP design technique.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, the spare VP design apparatus of the present invention switches the spare VP accommodated in another available TP when the TP accommodating the active VP of the ATM network fails. In a backup VP design apparatus for setting a backup VP route in advance, whether or not there is an empty TP having no portion passing through the same geographical position as the TP in which the working VP is accommodated And a route selecting means for selecting a spare route consisting only of the TPs when there is a vacancy, and selecting a spare route from all other TPs when there is no vacancy. It is characterized.
[0008]
The backup VP design apparatus of the present invention may further include a unit for assigning a priority to the VP, and the backup route selection unit may select a backup route sequentially from a VP having a higher priority. If the spare route selection means does not have a free TP having no portion passing through the same geographical position as the TP accommodating the working VP, the spare route selecting means selects the working TP among all other TPs. The backup route may be selected from among those excluding the TP contained in the physical system containing the VP containing the VP. Further, a means may be provided for outputting, as a list, VPs in which TPs having a portion passing through the same geographical position as the TP accommodating the active VP are selected.
[0009]
In the spare VP designing device of the present invention, the means for assigning a priority to the VP assigns one of two priorities of a high priority and a low priority to each VP, and the spare route selecting means If there is an available TP that has no part passing through the same geographical position as the TP accommodating the active VP, the backup route is selected in order from the high-priority VP. If not, a backup route is selected from all the other TPs, and the low-priority VP is accommodated in the physical system in which the TP accommodating the active VP is accommodated among all the TPs. The backup route may be selected from among those excluding the existing TP.
[0010]
In addition, the backup VP design method of the present invention is to switch the route of the backup VP in advance in order to switch to the backup VP stored in another available TP when the TP containing the active VP of the ATM network fails. In the backup VP design method for setting, if there is an available TP that does not have a portion passing through the same geographical position as the TP in which the working VP is accommodated, as the backup VP route It is characterized in that a backup route consisting only of these is selected, and if there is no free space, a backup route is selected from all other TPs.
[0011]
In the backup VP design method of the present invention, a priority may be further given to the VP, and the backup route may be selected sequentially from the VP with the highest priority. Further, when there is no TP free having no portion passing through the same geographical position as the TP accommodating the active VP, of all the other TPs, the TP accommodating the active VP is included. The backup route may be selected from among those excluding the TP contained in the physical system in which is stored. Further, a list of VPs that select a TP having a portion passing through the same geographical position as the TP accommodating the active VP may be output as a list.
[0012]
The backup VP design method according to the present invention also includes assigning one of two priorities, a high priority and a low priority, to each VP, selecting a backup route sequentially from the high priority VP, and If there is an available TP that does not have a portion passing through the same geographical position as the TP that contains the working VP, a spare route is selected from the available TPs. A backup route is selected from TPs, and low-priority VPs are selected from all TPs excluding TPs contained in the physical system containing the TPs containing the active VPs. A backup route may be selected.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a diagram for explaining a configuration of a backup VP design apparatus according to an embodiment of the present invention. In FIG. 1, 1 is a communication network, 2 is a communication network management system for managing the communication network 1, and 3 is a backup VP design device. Here, the management system 2 grasps the accommodation status of the VP, TP, and physical system as the communication network configuration information.
[0014]
The backup VP design device 3 includes VP list information 4, a VP selection unit 5, a routing unit 6, and an accommodation instruction unit 7. The backup VP design device 3 grasps the VP list information 4 and manages each VP by assigning a priority. The VP selection unit 5 selects an appropriate VP according to the priority, and the routing unit 6 provides necessary information such as accommodation of the VP in the TP, accommodation of the TP in the physical system, and geographical position of the physical system. Give information. The routing unit 6 determines a route, and provides the determined route information to the accommodation instruction unit 7. The accommodation instruction unit 7 instructs the communication network management system 2 to set accommodation based on the data.
[0015]
FIG. 2 is a diagram for explaining an example of a case where a spare VP is assigned by the spare VP designing apparatus of the present invention. In FIG. 2, 11-14 is a VP switching node, 21-26 is a physical system that accommodates a TP, 31-36 is a TP that is accommodated in a physical system 21-26 and accommodates a VP, 41 is a VP, and 42-44. Is a route that can be used as a backup for the VP41. Hereinafter, a method of setting a backup VP while using the VP 41 as a working will be described. However, the physical systems 21 and 22 pass through the same physical route, and the other physical systems pass through different locations.
[0016]
FIG. 3 is a flowchart for explaining a procedure for assigning a backup VP in the embodiment of the present invention. First, an arbitrary VP is selected from the VPs having the highest priority (step 51), and the destination node of the selected VP is checked (step 52). The system and all physical systems passing through the same route are excluded from the network configuration information (step 53), and a route search is performed to determine a backup VP route (step 54).
[0017]
In this case, the route search is performed by using, for example, Dijkstra's shortest route search method, and when there is a sufficient band for accommodating the backup VP, the route is used as it is, and when there is not enough band, the portion is omitted. Then, the shortest route search can be performed again. By this route search, a VP with a high priority can be searched for from a backup VP that passes through a route different from the active system. Therefore, even when it is assumed that a plurality of physical systems passing through the same geographical position as the TP in which the working VP is housed fail, a path using only the TP that can be used can be found. That is, in the example of FIG. 2, the VP 43 or the VP 44 is designated as the VP backup route. If there is a route (step 55), the communication network management system 2 is instructed to set a backup route and set the route (step 60).
[0018]
On the other hand, if the searched route does not exist (step 55), the VP is left as a list (step 56), and the destination node of the selected VP is checked (step 57), and the TP containing the active VP is checked. Is excluded from the network configuration information (step 58), and a route search is performed. In this case, as the route search, the TP of the physical system passing through the same geographical position as the physical system accommodating the TP accommodating the active VP is determined as the backup route (step 59). Proceed to step 60. That is, in the example of FIG. 2, the VP 42 is designated as a VP backup route. In this case, if the TP designated as the backup path also fails at the same time, the active VP cannot be switched.
[0019]
For a VP with a high priority, the setting conditions of such a backup route may be insufficient. Such a VP is left as a list (step 56). For example, after the preliminary design, the list is referred to, measures such as adding a TP used as a spare are performed, and it is assumed that a plurality of physical systems fail. In this case, it is possible to reset the route to use only the usable TP. After the above steps are repeated to complete the setting of the backup VPs for all the VPs with a high priority (Step 61), if there are remaining VPs with a low priority (Step 62), the VPs among the VPs with a low priority are , An arbitrary VP is selected (step 63), and step 57 and subsequent steps are repeated for the selected VP. When the setting of the backup VP is completed for all the VPs (step 62), this procedure ends.
[0020]
【The invention's effect】
As described above, according to the spare VP design technique of the present invention, the required fault tolerance is set for the high-priority VP that requires high reliability, and the highest possible fault is set for the low-priority VP. By setting the resistance, an economical preliminary setting can be performed. Further, when a necessary fault tolerance cannot be set for a VP having a high priority, a list thereof is created, thereby facilitating a response at the time of a fault and making it possible to use the data at the time of additional facilities.
[Brief description of the drawings]
FIG. 1 is a diagram for explaining a configuration of a backup VP design apparatus according to an embodiment of the present invention.
FIG. 2 is a diagram for explaining an example of a case where a spare VP is assigned by a spare VP designing apparatus of the present invention.
FIG. 3 is a flowchart illustrating a procedure for assigning a backup VP in the embodiment of the present invention.
[Explanation of symbols]
Reference Signs List 1 communication network 2 communication network management system 3 backup VP design device 4 VP list information 5 VP selection unit 6 routing unit 7 accommodation instruction units 11, 12, 13, 14 VP switching nodes 21, 22, 23, 24, 25, 26 Physical System 31, 32, 33, 34, 35, 36 TP
41, 42, 43, 44 VP

Claims (18)

A backup VP design apparatus for setting a route of a backup VP in advance in order to switch to a backup VP accommodated in another available TP when a TP containing a working VP of an ATM network fails. ,
Means for determining whether there is a vacancy of a TP that does not have a portion passing through the same geographical position as the TP in which the working VP is accommodated, and, if there is a vacancy, a spare route including only those vacancies And a backup route selecting means for selecting a backup route from all the other TPs when there is no free space. 2. The spare VP designing apparatus according to claim 1, further comprising means for assigning a priority to the VP, wherein the spare route selecting means sequentially selects a spare route from a VP having a higher priority. If the spare route selecting means does not have a TP having no portion passing through the same geographical position as the TP accommodating the working VP, the spare route selecting means sets the working VP among all other TPs. 3. The spare VP design apparatus according to claim 2, wherein a spare route is selected from among the TPs contained in the physical system in which the contained TPs are contained. 3. The apparatus according to claim 2, further comprising means for outputting, as a list, VPs that select TPs having a portion passing through the same geographical position as the TP accommodating the active VP. Reserve VP design equipment. 4. The apparatus according to claim 3, further comprising means for outputting, as a list, VPs that select TPs having a portion passing through the same geographical position as the TP accommodating the active VP. Reserve VP design equipment. Means for assigning a priority to the VP assigns one of two priorities, a high priority and a low priority, to each VP,
The backup route selecting means sequentially starts from the high-priority VP, if there is an available TP which does not have a portion passing through the same geographical position as the TP accommodating the working VP, and then proceeds to the backup route. Is selected, and if there is no free space, a backup route is selected from all the other TPs, and among the low-priority VPs, of all the TPs, the physical TP that houses the active VP is stored. 4. The backup VP designing apparatus according to claim 3, wherein a backup route is selected from among those excluding TPs accommodated in the dynamic system. In order to switch to a spare VP accommodated in another available TP when a TP accommodating a working VP of the ATM network fails, a spare VP design method for setting a route of the spare VP in advance ,
Determining whether or not there is a TP having no portion passing through the same geographical position as the TP in which the working VP is accommodated as a route of the backup VP;
A spare VP design method comprising the steps of: selecting a spare route consisting of only the spare TPs if there is a vacancy; and selecting a spare route from all other TPs if there is no vacancy. . A computer-readable recording medium on which a program for causing a computer to execute the steps according to claim 7 is recorded. 8. The backup VP designing method according to claim 7, further comprising the step of assigning a priority to the VP and the step of sequentially selecting a backup route from the VP having the highest priority. A computer-readable recording medium on which a program for causing a computer to execute the steps according to claim 9 is recorded. Further, when there is no TP free having no portion passing through the same geographical position as the TP accommodating the active VP, of all the other TPs, the TP accommodating the active VP is included. 10. The backup VP design method according to claim 9, further comprising the step of selecting a backup route from among those excluding TPs stored in the physical system in which the VPs are stored. A computer-readable recording medium on which a program for causing a computer to execute the steps according to claim 11 is recorded. 10. The spare according to claim 9, further comprising the step of outputting a list of VPs that have selected a TP having a portion passing through the same geographical position as the TP containing the active VP. VP design method. A computer-readable recording medium on which a program for causing a computer to execute the steps according to claim 13 is recorded. 12. The spare according to claim 11, further comprising a step of outputting a list of VPs that have selected a TP having a portion passing through the same geographical position as the TP accommodating the active VP. VP design method. A computer-readable recording medium on which a program for causing a computer to execute the steps according to claim 15 is recorded. And assigning one of two priorities, high priority and low priority, to each VP.
The backup route is sequentially selected from the VPs with the highest priority, and at this time, if there is an available TP having no portion passing through the same geographical position as the TP accommodating the working VP, then, Selecting a backup route and selecting a backup route from all other TPs when there is no free space; and, among low-priority VPs, among all TPs, a TP containing a working VP is stored. 12. The backup VP design method according to claim 11, further comprising the step of selecting a backup route from among those excluding TPs housed in the physical system. A computer-readable recording medium on which a program for causing a computer to execute the steps according to claim 17 is recorded.

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