JP2013115465A - Path switching method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to automatically perform path switching in a unit of a communication device group such as a station building and a rack without relying on manual labor by a maintenance person.SOLUTION: A management device transmits a stop preparation request to a communication device which is an object of stop. Each communication device includes a storage unit for storing correspondence between the identifier of the communication device and the identifier of a communication group to which the communication device belongs. The communication device having received the stop preparation request detects paths going through the own communication device, and for each of the detected paths, transmits a path switching request including the identifier of the communication group, to which the own communication device belongs, to a communication device which is a starting point of the path. The communication device having received the path switching request switches the path which is requested to be switched by the path switching request to a path which has the same starting point and end point as the path and which does not go through the communication device belonging to the communication group included in the path switching request.

Description

  The present invention relates to a path switching method in a network capable of performing path setting and disconnection in an autonomous and distributed manner.

  Networks with autonomous distributed control functions that can set and disconnect (release) paths in an autonomous distributed manner such as GMPLS (Generalized Multi-Protocol Label Switching) / ASON (Automatically Switched Optical Network) ), It is possible to easily set and disconnect a path as follows.

  When setting the path, the maintenance person sets the device ID of the start point communication device and the device ID of the communication device (end point communication device) as the end point of the path for the communication device (start point communication device) as the start point of the path. And enter the path ID. When these pieces of information are input, the start point communication device sends a path setting request to the end point communication device. This path setting request includes the device ID of the start point communication device, the device ID of the end point communication device, and the path ID. The path setting request may further include route information.

  The adjacent communication device that has received the path setting request from the start point communication device transmits the path setting request to an adjacent communication device different from the transmission source of the path setting request. Here, if the path information is included in the path setting request, the transfer destination communication device is determined accordingly, and if it is not included, the transfer destination communication is performed using the topology information held by the own device. Determine the device. Such transfer processing is repeatedly performed, and the path setting request reaches the end point communication device.

  When receiving the path setting request, the end point communication apparatus transmits a response to the path setting request through a path opposite to the path through which the path setting request has been sent. This response includes a device ID of the start point communication device, a device ID of the end point communication device, a path ID, a label (a fixed length label attached to the packet, a time slot, a wavelength, and the like). The adjacent communication device that has received the response performs label reservation, switch setting, and the like, and transfers the response to an adjacent communication device different from the communication device that has transmitted the response. Such transfer processing is repeatedly performed, and a response to the path setting request reaches the start point communication device. As a result, the path requested by the path setting request is set between the start point communication apparatus and the end point communication apparatus.

  When disconnecting (releasing) a path that has already been set, the maintainer, for the path start point communication apparatus, the apparatus ID of the start point communication apparatus, the apparatus ID of the end point communication apparatus, and the path ID of the path to be disconnected Enter. As a result, a path disconnection request is transmitted from the start point communication device to the end point communication device. This path disconnection request includes the device ID of the start point communication device, the device ID of the end point communication device, and the path ID of the path to be disconnected. The path disconnection request transmitted from the start point communication device is sequentially transferred from the communication device existing upstream on the path specified by the path ID to the communication device existing downstream. When each communication apparatus receives a path disconnection request, it performs a path disconnection process specified by the path ID included therein.

  By the way, in a network that is in operation, some communication devices through which a path passes may be stopped to continue operation. In such a case, the maintenance person searches for a path passing through the communication device to be stopped, sets a switching destination path for each path, and then signals from the switching source path to the switching destination path. It is necessary to switch. For this reason, as the number of paths passing through the communication device to be stopped increases, the work amount and work time of the maintenance person increase. Therefore, the present inventor has proposed a path switching method for solving such a problem (see, for example, Patent Document 1).

  In the path switching method described in Patent Document 1, when a maintenance person transmits a predetermined request, which is a removal preparation request, to a communication apparatus to be stopped, the communication apparatus that has received the request first selects a path that passes through the communication apparatus. To detect. Next, for each detected path, the communication apparatus transmits a path switching request to the communication apparatus at the start point of the path. This path switching request includes a path ID, a device ID of the start communication device, a device ID of the end communication device, and a device ID of the own communication device to be stopped. The communication device that has received the path switching request uses the autonomous distributed control function of the network, and the path whose switching is requested by the path switching request has the same start point and end point as the path and the communication to be stopped. Switch to a path that does not pass through the device.

  On the other hand, as another technique related to the present invention, one or more paths for setting a plurality of grouped transfer communication paths for the received traffic and accommodating the plurality of transfer communication paths are set. The lower communication channel is set, and when a trigger signal is received from one of the lower communication channels, the transfer communication channel accommodated in the lower communication channel is changed to be accommodated in another lower communication channel. There is a technology (see, for example, Patent Document 2).

JP 2010-154383 A JP 2009-111477 A

  In a network that is in operation, when a maintenance or construction of a station or rack, construction, or a rotating power failure occurs, all communication devices accommodated in the same station or rack must be stopped. However, since the technology described in Patent Document 1 may pass through other communication devices to be stopped in the same station or rack, the path to be switched to may be used in units of communication devices such as stations and racks. It is difficult to apply to path switching. Furthermore, since the technique described in Patent Document 2 may cause another lower communication path to be switched to pass through another communication device to be stopped other than the same station or rack, the communication device such as a station or rack is also used. It is difficult to apply to path switching for each group. For this reason, the current situation is that it is unavoidable to manually perform path switching by a maintenance person.

  An object of the present invention is to provide a path switching method that solves the above-described problem, that is, the path switching for each group of communication devices such as a station building or a rack must be relied on by a manual operation by a maintenance person. It is to provide.

A path switching method according to an aspect of the present invention includes:
A path switching method in a network comprising a management device and a plurality of communication devices, and having a storage unit for storing correspondence between the identifier of the communication device and the identifier of the communication group to which the communication device belongs,
The management device transmits a stop preparation request to the communication device to be stopped,
The communication device that has received the stop preparation request detects a path that passes through the communication device, and for each detected path, the communication group to which the communication device belongs belongs to the communication device at the start point of the path. Send a path switch request including the identifier,
The communication apparatus that has received the path switching request corresponds to the communication group identifier that has the same start point and end point as the path and that is included in the path switching request. Thus, a configuration is adopted in which the path is switched to a path that does not pass through the communication apparatus having the identifier of the communication apparatus stored in the storage unit.

  Since the present invention has the above-described configuration, path switching can be automated for each group of communication devices such as a station building and a rack.

It is a block diagram which shows an example of the network structure concerning the 1st Embodiment of this invention. It is a block diagram which shows an example of the network structure concerning the 2nd Embodiment of this invention. It is a legend about the symbol etc. which are shown in FIG. It is a block diagram which shows the structural example of the communication apparatus in the 2nd Embodiment of this invention. It is a block diagram which shows the structural example of EMS in the 2nd Embodiment of this invention. It is a flowchart which shows an example of the procedure of the path | pass switching process in the 2nd Embodiment of this invention. It is a block diagram which shows the structural example of EMS in the 3rd Embodiment of this invention. It is a figure which shows the example of the content of the communication group information table memorize | stored in the communication apparatus group information storage part. It is a figure which shows the example of the content of the path information table memorize | stored in the path information storage part.

Next, embodiments of the present invention will be described in detail with reference to the drawings.
[First embodiment]
Referring to FIG. 1, the network according to the first embodiment of the present invention includes communication devices A1 to A3, B1 to B3, C1 to C3, S1, and D1. Further, the communication device A1 and the communication device A2, the communication device A1 and the communication device A3, the communication device A2 and the communication device A3, the communication device B1 and the communication device B2, the communication device B1 and the communication device B3, the communication device B2 and the communication device B3, Communication device C1 and communication device C2, Communication device C1 and communication device C3, Communication device C2 and communication device C3, Communication device A2 and communication device C1, Communication device A3 and communication device B1, Communication device B2 and communication device C3, Communication device B3 and the communication device D1, and the communication device C2 and the communication device S1 are connected by links.

  Furthermore, the communication devices A1, A2, and A3 belong to the communication device group A, the communication devices B1, B2, and B3 belong to the communication device group B, and the communication devices C1, C2, and C3 belong to the communication device group C. Belongs to.

  A path having a path name = ADP001, where the communication apparatus S1 is a start communication apparatus, the communication apparatus D1 is an end communication apparatus, and the communication apparatuses C2, C1, A2, A1, A3, B1, and B3 are relay communication apparatuses. Is set.

  In such a network, when a maintenance device stop preparation request is transmitted from the maintenance person to the communication device A2 through the EMS, the following path switching operation is performed.

  Receiving the communication device stop preparation request, the communication device A2 detects the path ADP001 passing through the communication device, and designates the communication group A to which the communication device A2 belongs to the communication device S1 at the start point of the detected path. The path switching request is sent.

  The communication device S1 that has received the path switch request has the same start point and end point as the path ADP001 requested to be switched by the path switch request, and belongs to the communication group A specified by the path switch request. , A2, and A3 are not switched, and the path is switched to a path having path name = ADP002.

  In the above operation, the communication device S1 stores which communication device belongs to the communication group A in correspondence with the ID of the communication device and the ID of the communication device group to which the communication device belongs. To determine. Such a storage unit may exist locally in the communication device S1, or may exist in a remote location accessible from the communication device S1.

  The calculation of the path from the start communication device S1 to the end communication device D1 without passing through the communication devices A1, A2, and A3 belonging to the communication group A may be performed by the communication device S1. You may make it carry out with the other apparatus which can be accessed from S1, for example, EMS.

  As described above, the maintenance person transmits any communication device A2 preparation request to the communication device A2 through the EMS, so that all the communication devices A1 that belong to the communication device group A, all of the paths that pass through the communication device A2. A path that does not pass through A2 and A3 can also be switched. Similarly, the maintenance person transmits any communication device stop preparation request to the communication devices A1 and A3 through the EMS, so that all of the paths that pass through the communication device A2 pass through any communication device A1 belonging to the communication device group A. A path that does not pass through A2 and A3 can also be switched. Accordingly, when the communication device group A is a group of communication devices accommodated in the same station building or rack, path switching in units of communication device groups such as a station building or a rack can be automated.

  The order and timing at which the maintenance person transmits the communication device stop preparation request to a plurality of communication devices belonging to the same communication device group may be arbitrary. For example, in the case of the communication device group A, a communication device stop preparation request is first transmitted to the communication device A2, and all paths that pass through the communication device A2 are switched to other paths that do not pass through the communication device group A. After confirming the above, a communication device stop preparation request may be transmitted to the next communication device A1 or A3. Alternatively, a communication device stop preparation request may be transmitted simultaneously or successively to a plurality of communication devices belonging to the same communication device group without performing such confirmation. In this case, a path switching request message is transmitted from a plurality of communication apparatuses to the same start point communication apparatus for the same path ID. At this time, for example, in the communication device at the starting point, all the plurality of path switching request messages with the same path ID are accepted, processing is performed as if there was one path switching request, and the processing result is returned to the plurality of request sources. You can do it.

[Second Embodiment]
[Overview of this embodiment]
In this embodiment, when a station or rack that accommodates a plurality of communication devices is stopped in an operating network for autonomous distributed control such as GMPLS / ASON, there is a path that has already been set for the station or rack to be stopped. When passing through communication devices accommodated in a station or rack to be stopped, it is possible to continue the service by switching all the target paths while avoiding those communication devices. Further, the present invention is characterized in that the workload of maintenance personnel accompanying switching and the load on the CPU and memory of an EMS (Element Management System) are reduced.

  The EMS issues a communication device stop preparation request to all the communication devices accommodated in the station or rack to be stopped designated by the maintenance person. The communication device that has received this request transmits a path switching request to all the start point communication devices of the set path. The start-point communication device that has received the path switching request switches a large number of configured paths in an autonomous distributed manner, avoiding communication devices accommodated in a station or rack to be stopped. For example, as in the embodiment shown in FIG. 1, the autonomous distributed control path ADP001 is switched to ADP002 in order to stop the station and rack of the communication group A. ADP002 is a route that avoids A1, A2, or A3, which are communication devices accommodated in communication device group A.

[Configuration of this embodiment]
Referring to FIG. 2, as a second embodiment of the present invention, there is shown a configuration example of a network (sometimes referred to as an autonomous distributed control compatible network) that supports autonomous distributed control such as GMPLS / ASON. Further, referring to FIG. 3, legends of symbols and line segments appearing in FIG. 2 are shown.

  The network corresponding to autonomous distributed control is a network configured by communication devices (also referred to as autonomous distributed control compatible communication devices) NE201 to NE207 corresponding to autonomous distributed control such as GMPLS / ASON and communication links. When setting a path in a network supporting autonomous distributed control, each communication device NE201 to NE207 executes route control and signaling by autonomous distributed control according to an instruction from a maintenance person, and label reservation / switch setting of each communication device NE201 to NE207 To set a path between the specified start / end communication devices. In the network assumed by the present invention, an end-to-end path is provided by a communication technique such as packet, TDM (time division multiplexing), or WDM (wavelength multiplexing).

  The communication devices NE201 to NE207 perform cross-connection or switching based on information on labels (identifiers such as fixed-length labels of packets, time slots, and wavelengths). In addition, the communication devices NE201 to NE207 perform route control and path management (path setting / maintenance / disconnection) of an autonomous distributed control path (also simply referred to as a path) by an autonomous distributed control protocol such as GMPLS / ASON.

  The communication devices NE201 to 207 are connected by a communication link such as one or more optical fibers. The communication devices NE201 to 207 are connected by a control message exchange link. The communication link is a link through which user information passes, whereas the control message exchange link is a link used for exchanging control information between the communication devices NE201 to NE207. Depending on the network operation method, the communication link and the control message exchange link may share the same physical link.

  The EMS 1 has a function of monitoring and maintaining the communication devices NE 201 to 207 of the entire network (for example, path setting / disconnection request, communication device removal management), and provides a maintenance person with an interface function with the network. The EMS 1 and the communication devices NE 201 to 207 are connected by management links ML 401 to ML 407 (some of which are not shown), and the EMS 1 monitors and maintains the communication devices NE 201 to 207 via the management link.

  FIG. 4 shows a functional block diagram of the communication device NE. The communication devices NE201 to 207 have the same configuration as the communication device NE shown in FIG.

(1) Storage Unit of Communication Device NE The communication device NE is connected to the EMS and other communication devices, and includes a communication device group information storage unit 221, a path information storage unit 222, and various other information storage units 223. These storage units are constituted by a semiconductor memory, a magnetic disk, or the like.

  The communication device group information storage unit 221 is a storage unit that stores communication device group IDs of all communication devices in the network. A configuration example of a communication group information table stored in the communication device group information storage unit 221 is shown in FIG. In FIG. 8, the communication device ID indicates the identifier of the communication device, and the communication device group ID indicates the communication device group to which the communication device belongs. In the present embodiment, the same communication group ID is assigned to a plurality of communication devices accommodated in the same station, and different communication group IDs are assigned to a plurality of communication devices different in the accommodated buildings. Therefore, in the case of FIG. 8, three communication devices with communication device IDs A1, A2, and A3 are accommodated in the same station, and three communication devices with communication device IDs B1, B2, and B3 are accommodated in the same station. The three communication devices having communication device IDs C1, C2, and C3 are accommodated in the same station. Here, the communication group ID is assigned to each communication device based on the house accommodated, but the communication group ID may be assigned to each communication device based on the rack accommodated. Further, a communication group ID may be assigned to each communication device according to other arbitrary criteria, and a plurality of communication group IDs may be assigned to each communication device according to a plurality of different criteria.

  The path information storage unit 222 is a storage unit that stores information related to an autonomous distributed control path that uses its own communication device NE. A configuration example of a path information table stored in the path information storage unit 222 is shown in FIG. In FIG. 9, a path ID indicates a path identifier, and a transmission source node and a transmission destination node indicate address information of a start point communication device and an end point communication device of the path. The other path related information indicates information related to other arbitrary paths.

  Various other information storage units 223 represent storage units that store information other than the information recorded in the communication device group information storage unit 221 and the path information storage unit 222.

(2) Processing Unit of Communication Device NE The communication device NE includes a communication device stop processing unit 211, a routing processing unit 212, a path management processing unit 213, a path switching processing unit 214, a notification processing unit 215, and a device control processing unit 216. It has a processing part. These are realized by, for example, a computer and a program. The program is recorded on a computer-readable recording medium such as a semiconductor memory or a magnetic disk, and is read by the computer when the computer is started up, etc., and controls each operation described above on the computer by controlling the operation of the computer. Realize the part.

  The communication device stop processing unit 211 is a processing unit that requests the start point communication device of each path to make a request to switch all the paths set in the communication device NE in order to stop the communication device NE. When the communication device stop processing unit 211 receives the communication device stop preparation request message from the EMS, the communication device stop processing unit 211 refers to the path information table in the path information storage unit 222 and searches for an autonomous distributed control path passing through its own communication device NE. It has a function. In addition, the communication device stop processing unit 211 has a function of transmitting a switching request message to the communication device that is the starting point of the path for each autonomous distributed control path that passes through its own communication device NE. This switching request message includes the path ID and information on the communication device group to which the own communication device NE belongs.

  The routing processing unit 212 represents a processing unit that performs link information exchange and route calculation. The routing processing unit 212 has a function of calculating a switching destination path in accordance with a switching request message received for a path that is the starting point of its own communication device NE. At that time, the routing processing unit 212 selects a route that avoids the communication devices belonging to the communication device group specified by the communication device group ID in the switching request message. In other words, the routing processing unit 212 selects a route that avoids all communication devices accommodated in the station or rack to be stopped. All communication devices accommodated in the station or rack to be stopped are identified by the communication device group ID as described above.

  The path management processing unit 213 represents a processing unit that performs path setting / maintenance / disconnection.

  The path switching processing unit 214 represents a processing unit that performs signal switching from the switching source path to the switching destination path.

  The notification processing unit 215 represents a processing unit that notifies the EMS of various types of information on the communication device.

  The device control processing unit 216 represents a processing unit that distributes a message received from an EMS or another communication device to each processing unit, or transmits a message from each processing unit to the EMS or another communication device. The device control processing unit 216 has a function of transferring a message between the processing units.

  FIG. 5 shows a functional block diagram of the EMS.

(1) Storage Unit of EMS The EMS is connected to a communication device and includes a communication device group information storage unit 111 and an existing EMS information storage unit 112. These storage units are constituted by a semiconductor memory, a magnetic disk, or the like.

  The communication device group information storage unit 111 is a storage unit that stores communication device group IDs of all communication devices NE in the network. The communication device group information storage unit 111 records information equivalent to the communication device group information storage unit 111 included in the communication device NE.

  The existing EMS information storage unit 112 is a storage unit that stores information of a general EMS.

(2) EMS Processing Unit The EMS has processing units such as a station / rack stop processing unit 121, an existing EMS processing unit 122, and an EMS control processing unit 123. These are realized by, for example, a computer and a program. The program is recorded on a computer-readable recording medium such as a semiconductor memory or a magnetic disk, and is read by the computer when the computer is started up, etc., and controls each operation described above on the computer by controlling the operation of the computer. Realize the part.

  The station / rack stop processing unit 121 is a processing unit that causes the communication device accommodated in the station / rack to stop (request to stop) when stopping the station / rack. A message sent when the communication apparatus is stopped to the communication apparatus is called a communication apparatus stop preparation request.

  The existing EMS processing unit 122 is a processing unit having a function of a general EMS.

  The EMS control processing unit 123 represents a processing unit that distributes a message received from a communication device to each processing unit or transmits a message from each processing unit to the communication device. The EMS control processing unit 123 has a function of transferring a message between the processing units.

[Operation of this embodiment]
The operation of this embodiment when the station / rack is stopped will be described.

  FIG. 6 shows a flowchart classified by EMS, stop target communication device, and start point communication device of the autonomous distributed control path. The operation of this embodiment will be described below with reference to FIG. Note that the example in the description is the same as the embodiment shown in FIG.

(1) Step F01:
The station / rack stop processing unit 121 of the EMS refers to the communication device group information table of the communication device group information storage unit 111 and searches for a communication device having a communication device group ID to be stopped input from the maintenance person, Identify the communication device to be stopped. For example, when the communication device group ID = A is designated by the maintenance person, referring to FIG. 8, the communication devices with communication device IDs A1, A2, and A3 are communication devices to be stopped.

(2) Step F02:
The EMS transmits a communication device stop preparation request to all the stop target communication devices specified in step F01. That is, in the example of FIG. 1, a communication device stop preparation request is transmitted to the communication devices A1, A2, and A3. At this time, the EMS activates the communication device stop preparation result timer.

(3) Step F11:
The communication device stop processing unit 211 of the communication device to be stopped receives the communication device stop preparation request from the EMS.

(4) Step F12:
The communication device stop processing unit 211 of the communication device to be stopped refers to the path information table in the path information storage unit 222 and searches for an autonomous distributed control path that passes through its own communication device. For example, if the content of the path information storage unit 222 included in the communication device A1 is as shown in FIG. 9, it can be seen that the path passing through the communication device A1 is a path having a path ID = ADP001. Although there is only one path in this example, there are generally a plurality of paths in the communication apparatus.

(5) Step F13:
The communication device stop processing unit 211 of the communication device to be stopped transmits a switching request message to the starting communication devices of all autonomous distributed control paths that pass through the self communication device searched in Step F12. For example, in the case of the communication device A1, a switch request message is transmitted to the path start point communication device S1 of path ID = ADP001 (if there are two or more paths, switch to the start point communication device of each path. Send request message). In the switching request message, the path ID of the switching target path and the communication device group ID of the own communication device are recorded. For example, path ID = ADP001 and communication device group ID = A are recorded in the switching request message transmitted by communication device A1. The communication device stop processing unit 211 starts a switching completion waiting timer after transmitting the switching request message.

(6) Step F21:
The starting point communication device of the autonomous distributed control path receives the switching request message. For example, S1 which is the starting point communication device of the autonomous distributed control path ADP001 receives a path switching request message with path ID = ADP001.

(7) Step F22:
The routing processing unit 212 of the starting communication device of the autonomous distributed control path searches for a route that avoids all communication devices having the communication device group ID to be stopped. For example, the communication device S1 searches for a route that does not pass through the communication devices A1, A2, and A3, which are communication devices belonging to A, as a route from the own communication device S1 to the end communication device D1, for example, S1- Discover the route of C2-C3-B2-B3-D1. In the route search in Patent Document 1, for example, a route of S1-C2-C1-A2-A3-B1-B3-D1 is selected in order to search for a route that avoids the communication device A1 that has transmitted the switching request message. . Since this route passes through the communication devices A2 and A3 that are to be stopped, as a result, the communication devices in the communication device group A cannot be stopped.

(8) Step F23:
The path switching processing unit 214 of the starting point communication device of the autonomous distributed control path switches the path to the route searched in step F22. For example, the communication device S1 switches the path of path ID = ADP001 to ADP001 with the path of S1-C2-C3-B2-B3-D1 (in FIG. 1, the switched path is expressed as ADP002). In the path switching indicated in the present embodiment, the path switching processing unit 214 sets the switching destination path in the path management processing unit 213 and switches the signal from the path switching source to the switching destination. , Requesting disconnection of the switching source path. The switching process itself uses an existing autonomous distributed control switching process such as GMPLS / ASON. That is, the path management processing unit 213 of the start point communication device sends a path setting request including the device ID of the start point communication device, the device ID of the end point communication device, the path ID, and the route information retrieved in Step F22. The destination path is set by sending it to the end point communication device. Then, after the signal is switched from the switching source path to the switching destination path, the switching source path is disconnected.

(9) Step F24:
When the path switching processing unit 214 of the start point communication device of the autonomous distributed control path is completed, the switching completion message is transmitted to the stop target communication device that has transmitted the switching request message. For example, in the example of FIG. 1, the communication device S1 transmits a switching completion message to the communication device A1. The switching completion message includes information indicating whether the starting communication device of the autonomous distributed control path has succeeded or failed in switching the autonomous distributed control path.

(10) Step F14:
The communication device to be stopped receives the switching completion message from the path start point communication device.

(11) Step F15:
The communication device stop processing unit 211 of the communication device to be stopped determines whether or not switching of all the autonomous distributed control paths requested in Step F13 is successful when the switching completion waiting timer times out.

(12) Step F16:
When all the requested autonomous distributed control paths have been successfully switched, the communication device stop processing unit 211 of the communication device to be stopped requests the notification processing unit 215 to transmit a communication device stop preparation success notification to the EMS. To do.

(13) Step F17:
The communication device stop processing unit 211 of the communication device to be stopped requests the notification processing unit 215 to fail the communication device stop preparation failure with respect to the EMS when all or part of the requested autonomous distributed control path switching fails. Send a notification.

(14) Step F03:
The EMS receives the communication device stop preparation success notification or the communication device stop preparation failure notification from the stop target autonomous distributed control compatible communication device.

(15) Step F04:
After the timeout of the communication device stop preparation result timer, the EMS notifies the maintenance person of the communication device stop preparation success or the communication device stop preparation failure through a screen display or the like.

(16) If all communication devices are successfully prepared for stopping, there will be no path through the autonomous decentralized control device accommodated in the station or rack to be stopped. Perform the work. When the communication device stop preparation fails, the maintenance person does not or does not perform the stop operation according to the network management policy.

[Effect of this embodiment]
The first effect is that when a station / rack that accommodates a plurality of communication devices is stopped, a large number of paths that have been set can be switched autonomously and distributed to continue the service. The reason is that the set paths are switched while avoiding all the communication devices accommodated in the station / rack to be stopped.

  The second effect is that the work of the maintenance person is greatly reduced when switching the set paths while avoiding all the communication devices accommodated in the station / rack to be stopped. The reason is that the maintenance person only needs to specify the communication device group ID of the communication device housed in the station or rack to be stopped with respect to the EMS.

  The third effect is that the load on the EMS CPU and memory can be reduced when switching the set path while avoiding all the communication devices accommodated in the station / rack to be stopped. . The reason is that the EMS only needs to send a communication device preparation request message to all communication devices having the communication device group ID to be stopped, and avoid all communication devices accommodated in the station / rack to be stopped. This is because a route search or the like is performed on the communication device side.

  The fourth effect is that it is possible to shorten the processing time until the station / rack accommodating a plurality of communication devices is stopped. The reason is that processing until the station / rack that accommodates a plurality of communication devices is stopped is distributed among EMS, communication devices having communication device group IDs to be stopped, and start communication devices of switching target paths, This is because the load on the CPU and memory of each device is reduced. Therefore, this embodiment is particularly effective when resources such as CPU and memory of each device are insufficient.

[Third embodiment]
In the second embodiment, the search for the switching destination route is performed by the communication device at the start point of each path, but in the present embodiment, this processing is performed by EMS.

  FIG. 7 shows a functional block diagram of the EMS used in this embodiment. The EMS according to the present embodiment is different from the EMS illustrated in FIG. 5 in that it further includes a routing processing unit 124.

  The routing processing unit 124 performs an EMS control process on a path search request specifying the ID of the communication device as the start point, the ID of the communication device as the end point, and the ID of the communication device group of the communication device to be avoided from the communication device at the start point of the path. When received through the unit 123, the path 123 has a function of searching for a route that avoids all communication devices having the communication device group ID to be stopped from the route from the start point communication device to the end point communication device. The routing processing unit 124 has a function of transmitting the searched route to the requesting communication device through the EMS control processing unit 123.

  Next, the operation of this embodiment will be described. Among the operations of the present embodiment, the operations other than the operation of Step F22 in FIG. 6 are the same as those of the second embodiment. In the present embodiment, the process corresponding to step F22 in FIG. 6 is executed as follows.

  The routing processing unit 212 of the starting communication device of the autonomous distributed control path sends an EMS search request for a route specifying the ID of the own communication device serving as the starting point, the ID of the communication device serving as the ending point, and the ID of the communication device group of the communication device to be avoided. Send to.

  The routing processing unit 124 of the EMS that has received this search request searches for a route that avoids all the communication devices having the communication device group ID to be stopped among the routes from the start point communication device to the end point communication device. A communication device having a communication device group ID is determined with reference to the communication device group information storage unit 111. Then, the routing processing unit 124 returns the searched route to the requesting communication device.

  The routing processing unit 212 of the start point communication apparatus notifies the path switching processing unit 214 of the route returned from the EMS for the processing after Step F22.

  By configuring as described above, the effect of reducing the processing load of the EMS is lost, but the search policy for the switching destination route can be unified. The reason is that the switching destination route is searched at one place in the EMS.

A1 to A3, B1 to B3, C1 to C3, S1, D1 ... Communication device 1 ... EMS
111 ... Communication device group information storage unit 112 ... Existing EMS information storage unit 121 ... Station building / rack stop processing unit 122 ... Existing EMS processing unit 123 ... EMS control processing units 201-207 ... Communication device 211 ... Communication device stop processing unit 212 ... routing processing unit 213 ... path management processing unit 214 ... path switching processing unit 215 ... notification processing unit 216 ... device control processing unit 221 ... communication device group information storage unit 222 ... path information storage unit 223 ... other various information storage units

Claims (8)

A path switching method in a network including a management unit and a plurality of communication devices, and having a storage unit that stores correspondence between an identifier of the communication device and an identifier of a communication group to which the communication device belongs,
The management device transmits a stop preparation request to the communication device to be stopped,
The communication device that has received the stop preparation request detects a path that passes through the communication device, and for each detected path, the communication device to which the communication device belongs belongs to the communication device at the start point of the path. Send a path switch request including the identifier,
The communication device that has received the path switching request corresponds to the communication group identifier that has the same start point and end point as the path and is included in the path switching request. And switching to a path that does not pass through the communication device having the identifier of the communication device stored in the storage unit. In the path switching, the communication device that has received the path switching request has the same start point and end point and is stored in the storage unit corresponding to the identifier of the communication group included in the path switching request. 2. The path switching method according to claim 1, wherein a path having a path that does not pass through a communication apparatus having an identifier of the communication apparatus is searched, and a path having the searched path is set as a switching destination path. In the path switching, the communication device that has received the path switching request has the same start point and end point and is stored in the storage unit corresponding to the identifier of the communication group included in the path switching request. 2. The path of the path that does not pass through the communication apparatus having the identifier of the communication apparatus is requested to the management apparatus, and the path having the path searched by the management apparatus is set as a switching destination path. The path switching method described in 1. 4. The path switching method according to claim 1, wherein the storage unit records the identifier of the same communication group in a plurality of communication devices accommodated in the same station. 4. The path switching method according to claim 1, wherein the storage unit records the identifier of the same communication group in a plurality of communication devices accommodated in the same rack. Consists of a management device and a plurality of communication devices,
The management device
A stop processing unit that transmits a stop preparation request to the communication device to be stopped;
The communication device
A storage unit that stores a correspondence between an identifier of the communication device and an identifier of a communication group to which the communication device belongs;
When the stop preparation request is received, a path passing through the own communication apparatus is detected, and for each detected path, an identifier of the communication group to which the own communication apparatus belongs is included for the communication apparatus at the start point of the path A communication device stop processing unit for transmitting a path switching request;
When the path switching request is received from another communication device, the path whose switching is requested by the path switching request has the same start point and end point as the path, and the identifier of the communication group included in the path switching request And a path switching processing unit that switches to a path that does not pass through the communication device having the identifier of the communication device stored in the storage unit. A communication device connected to a network,
A storage unit for storing a correspondence between an identifier of a communication device existing in the network and an identifier of a communication group to which the communication device belongs;
When a stop preparation request is received, a path that passes through the communication apparatus is detected, and for each detected path, a path that includes the identifier of the communication group to which the communication apparatus belongs to the communication apparatus that is the starting point of the path A communication device stop processing unit for transmitting a switching request;
When the path switching request is received from another communication apparatus, the path requested to be switched by the path switching request is set to the identifier of the communication group having the same start point and end point as the path and included in the path switching request. Correspondingly, a communication apparatus comprising: a path switching processing section that switches to a path that does not pass through a communication apparatus having an identifier of the communication apparatus stored in the storage section. A computer connected to a network and constituting a communication device having a storage unit that stores a correspondence between an identifier of a communication device existing in the network and an identifier of a communication group to which the communication device belongs;
When a stop preparation request is received, a path that passes through the communication apparatus is detected, and for each detected path, a path that includes the identifier of the communication group to which the communication apparatus belongs to the communication apparatus that is the starting point of the path A communication device stop processing unit for transmitting a switching request;
When the path switching request is received from another communication apparatus, the path requested to be switched by the path switching request is set to the identifier of the communication group having the same start point and end point as the path and included in the path switching request. Correspondingly, a program for causing a function to function as a path switching processing unit that switches to a path that does not pass through a communication device having an identifier of the communication device stored in the storage unit.

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