JP2011015062A - Relay equipment, relay method, and relay program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide relay equipment or the like which prevents a signal disconnection of a time until a topology database stabilizes and a signal deterioration, and reduces a time until a communication restoration.SOLUTION: Relay equipment 110 relaying a communication of a data frame in an RPR (resilient packet ring) network has: a fault route determining portion 271 determining whether or not a data frame transmitted is a data frame through a fault occurrence point based on fault information when a fault occurs in the network; and a transmission method setting portion 273 setting to a multicast transmission a transmission method of a fault route data frame with respect to the fault route data frame determined to be a data frame through the fault occurrence point.

Description

  The present invention relates to a relay device in an RPR (resilient packet ring) network.

  RPR, which combines SONET / SDH (Synchronous Optical NETwork / Synchronous Digital Hierarchy) reliability, quality, management functions and efficient packet network communication functions, has been standardized as IEEE 802.17, and is the backbone of the next generation network. It is attracting attention as a construction technology.

The RPR network has a standardized protection function called “Steer” that prevents the communication of data frames from being interrupted by using a double ring configuration when a failure occurs. When a failure occurs, the relay device serving as an edge broadcasts a control frame to prompt each relay device to change the topology database. Each relay apparatus that has received the control frame updates the topology database and switches the transmission direction of the data frame to the transmission direction using a ringlet in which no failure has occurred.
Techniques such as a failure recovery method related to recovery when a failure occurs in an RPR network are disclosed (for example, see Patent Document 1).

International Publication No. 2006/104285

However, in the case of the “Steer” function, ringlet switching is not performed until the topology database of all the relay devices is stabilized. Therefore, the state of signal interruption and signal degradation continues during that time, and it takes time to recover. There is a problem that it will be applied.
In addition, the disclosed technology such as the failure recovery method has a problem that it is not possible to prevent signal interruption and signal degradation during the time until the topology database is stabilized.

  Therefore, a relay device or the like is provided that prevents signal interruption and signal deterioration in the time until the topology database is stabilized, and shortens the time until communication restoration.

  The relay apparatus disclosed in the present application is a relay apparatus that relays data frame communication in an RPR network that is a ring network connected by a double ring. When a failure occurs in the network, a data frame that passes through the location of the failure is determined. For the data frame passing through the location of failure, the transmission method is set to multicast transmission.

  In this way, for data frames that pass through the location of failure, the effect of being able to reduce the time until the topology database is stabilized and shorten the time until communication is restored by using multicast transmission as the transmission method. Play.

It is a block diagram of an RPR ring network. It is a functional block diagram of a relay apparatus. It is a figure which shows the data format in the relay apparatus which concerns on 1st Embodiment. It is a figure which shows an example of the table structure of a topology database. It is a hardware block diagram of the relay apparatus which concerns on 1st Embodiment. It is a functional block diagram of the relay apparatus which concerns on 1st Embodiment. It is a flowchart which shows operation | movement of RPR MAC in the relay apparatus which concerns on 1st Embodiment. It is a flowchart which shows the process of priority control in the relay apparatus which concerns on 1st Embodiment.

  Embodiments of the present invention will be described below. The present invention can be implemented in many different forms. Therefore, the present invention should not be construed based only on the description of this embodiment. Also, the same reference numerals are given to the same elements throughout the present embodiment.

  In the following embodiments, the apparatus will be mainly described. However, as is apparent to those skilled in the art, the present invention can also be implemented as a method and a program for operating a computer. In addition, the present invention can be implemented in hardware, software, or hardware and software embodiments. The program can be recorded on any computer-readable medium such as a hard disk, CD-ROM, DVD-ROM, optical storage device, or magnetic storage device. Furthermore, the program can be recorded on another computer via a network.

(First embodiment of the present invention)
The relay device according to the present embodiment will be described with reference to FIGS. First, the “Steer” function that the RPR has as a standard will be described. FIG. 1 is a configuration diagram of an RPR ring network. The RPR network 100 is a ring network in which a maximum of 255 relay devices 110 (110-1 to 110-n: n ≦ 255) are connected by a double ring. In FIG. 1, the clockwise direction is the ringlet 0 and the counterclockwise direction is the ringlet 1. In normal data frame communication, a route ringlet having a small number of relay devices 110 to be relayed is selected and transmitted. In the case of FIG. 1, for the communication between the terminal A connected to the relay device 110-1 and the terminal C connected to the relay device 110-3, the clockwise ringlet 0 with a small number of relay devices 110 to be relayed is used. Selected. For communication between the terminal A connected to the relay device 110-1 and the terminal B connected to the relay device 110-5, the counterclockwise ringlet 1 having a small number of relay devices 110 to be relayed is selected.

  One ringlet is selected when the data frame is set to unicast (a setting for transmitting a data frame by designating a single partner). In the case of multicast setting (setting for transmitting a data frame by designating a plurality of partners), the bidirectional of ringlet 0 and ringlet 1 is selected, and the data frame is transmitted bidirectionally.

  Next, the configuration of the relay device 110 will be described. FIG. 2 is a functional block diagram of the relay apparatus. A PHY (Physical layer) 201 and a MAC (Media Access Control) 202 terminate each layer of a data frame input from a terminal side (hereinafter referred to as an Ethernet side).

  Here, the format of the data frame will be described. FIG. 3 is a diagram illustrating a data format in the relay device according to the present embodiment. FIG. 3A shows a data frame format when the layer is terminated by the PHY 201 and the MAC 202. It has DA (Destination Address: destination address), SA (Source Address: source address), pay load (transmission data), and FCS (frame check sequence).

  Returning to FIG. 2, the RPR Enhance Bridge 210 includes a learning MAC address table 211 and learns the MAC addresses of the terminals connected to each relay apparatus 110. This learning MAC address table 211 has the RPR MAC address of each relay device 110 on the ring and the MAC address information of the terminal connected to each relay device 110, and which terminal is connected to which relay device 110. Have been learning.

  The first RPR header addition / deletion unit 212 searches the learning MAC address table 211 for the DA of the data frame input from the Ethernet side. Then, RPR MAC DA (destination relay device address) is allocated and added to DA of the data frame. Also, a flooding indication (2-bit information, hereinafter referred to as fi) is set to set unicast transmission or multicast transmission. The header added here is deleted when the data frame is output to the Ethernet side.

The data format at this time is shown in FIG. From FIG. 3A, ttl base (initial value of ttl (Time To Live)), expanded control (1 byte information, field containing fi), and HEC (header error check) are added. Yes.
Returning to FIG. 2, the RPR MAC 220 includes a second RPR header addition / deletion unit 221, a priority control unit 230, an acquisition determination unit 222, and a multicast function unit 223.

  The second RPR header addition / deletion unit 221 adds, to the data frame input from the Ethernet side, a ringlet based on the topology database (details will be described later) and the RPR MAC DA, ttl value (maximum hop count) Yes, every time it passes through the relay device, 1 is subtracted) and added. Further, any service class of class A, class B, or class C is added. The service class is used in the processing of the priority control unit 230, which will be described later, and has a priority order of class A> class B> class C. The data frame input from the Ethernet side is stored in the memory 2 in order to send the data frame with a lower priority than the data frame input from the other relay apparatus 110. The header added here is deleted when the data frame is output to the Ethernet side.

  Here, the topology database will be described. FIG. 4 is a diagram illustrating an example of a table configuration of the topology database. The topology database is a database constructed so that each relay apparatus shares ring topology information. The information to be constructed is defined by IEEE 802.17.

  In the upper table, information such as the number of relay devices 110 on the ring, the state of the ring, and the MAC address of the own relay device 110 is constructed. Also, information (information such as protection, edge, MAC address, etc.) related to the other relay device 110 adjacent to the own relay device 110, information related to their checksum, and the like are constructed. In the lower table, for each relay device 110 on the ring, information about the relay device 110 is constructed.

  The construction of the topology database is performed by transmitting and receiving control frames. Each relay apparatus 110 broadcasts a control frame to a bidirectional ringlet. The control frame includes information of the transmission source relay device 110, and each relay device 110 that has received the control frame updates the contents of the topology database related to the transmission source relay device 110.

  Also, each relay device 110 transmits and receives control frames between adjacent relay devices 110, and whether the checksum calculated based on the information in the topology database matches the checksum calculated by the adjacent relay device 110. Determine. If the checksums are different, it is determined that the adjacent relay device 110 has been deleted from the ring, and the topology database is updated. The second RPR header addition / deletion unit 221 determines the ringlet and ttl value based on the topology database information thus constructed and the RPR MAC DA.

  The data format after processing by the second RPR header addition / deletion unit 221 is shown in FIG. From FIG. 3B, ttl and base control (a field of 1-byte information and including a service class (2 bits)) are newly added.

  Returning to FIG. 2, the priority control unit 230 performs priority control of data frame transmission. The scheduler performs write control so that data frames are distributed to queues for each service class in the memory 1 and the memory 2. In addition, read control is performed so that a transmission right is given from a queue having a high priority. Here, the transmission priority of the data frame stored in the memory 1 is high, and the transmission priority of the data frame stored in the memory 2 is set low.

  The take-in determination unit 222 compares the RPR MAC DA of the data frame transmitted from the other relay device 110 with the RPR MAC address of the own relay device 110. If the addresses match, in order to output the data frame to the Ethernet side, the data frame is output to the second RPR header addition / deletion unit 221 and the header part is deleted. If the addresses do not match, the data frame is stored in the memory 1 to be sent to the other relay apparatus 110 with a higher priority than the data frame input from the Ethernet side.

  The multicast function unit 223 refers to the extended control fi, performs multicast transmission processing on the data frame having the multicast setting, passes through the data frame having unicast setting without performing anything, and performs the unicast transmission processing.

The GFP framer 240 encapsulates the data frame by GFP (generic framing procedure). The data format at this time is shown in FIG. A GFP header (GFP header) and FCS are newly added.
The details of the data format (particularly multicast identifier) in FIG. 3D will be described later.

The SONET framer 250 maps the data frame to the SONET frame. The data format at this time is shown in FIG. The data frame is mapped to the SONET frame, and an overhead (SONET overhead) is added.
The OPT 260 is an optical module and converts electrical signals and optical signals to each other.
The control CPU 280 performs processing such as construction of a topology database and transmission / reception of control frames.

  Next, the flow of the data frame will be described. In FIG. 2, a data frame input from the Ethernet side is terminated at each layer by PHY 201 and MAC 202 (FIG. 3A) and input to RPR Enhance Bridge 210. The RPR header is added by the first RPR header addition / deletion unit 212 and the second RPR header addition / deletion unit 221 (FIGS. 3B and 3C) and input to the memory 2 of the priority control unit 230. The

  The priority control unit 230 is an example of priority order control means, and priority control is performed. Here, the priority of the data frame (stored in the memory 1) input from the capture determination unit 222 and relayed to the other relay device 110 is increased, and the data frame (stored in the memory 2) input from the Ethernet side is increased. Read control is performed to lower the priority. The data frame stored in the queue with the higher priority is output to the multicast function unit 223.

  A data frame having a multicast setting is multicast transmitted (transmitted to both ringlets), and a data frame having a unicast setting is passed through and transmitted only to one ringlet. The data frame output from the multicast function unit 223 is GFP encapsulated by the GFP framer 240 (FIG. 3 (E)) and mapped to the SONET framer by the SONET framer 250 (FIG. 3 (F)). Is output.

  In the data frame input from the RPR network side, the respective headers are deleted by the SONET framer 250 and the GFP framer 240 and input to the capture determination unit 222. The data frame addressed to the other relay apparatus 110 is stored in the memory 1. Thereafter, the data is output from the memory 1 to the RPR network by the same processing as described above. The header of the data frame addressed to the own relay apparatus 110 is deleted by each processing unit, and the data frame is output to the terminal on the Ethernet side.

  When an abnormality such as a failure occurs on the RPR network 100, the relay device 110 serving as an edge first detects the abnormality by a self-ring alarm or the like. The relay device 110 serving as an edge that detects an abnormality broadcasts a control frame to prompt each relay device 110 to update the topology database.

  In order for the topology database to be stable, each relay apparatus 110 receives a control frame, and the protection state of the topology database needs to be updated. Further, it is necessary to confirm that the checksum between the adjacent relay apparatuses 110 is the same as the checksum of the topology database held by the own relay apparatus 110.

  The checksum is confirmed between all adjacent relay apparatuses 110, and the same checksum is shared by all the relay apparatuses 110, so that the topology database is stabilized. The exchange between the adjacent relay apparatuses 110 generally requires about 50 ms. When up to 255 relay devices 110 are connected, signal interruption and signal degradation of about 50 ms × 255 = 12 s occur.

  When the topology database is stabilized, the transmission path of the data frame is switched from the ringlet that passes through the failure occurrence location to the ringlet that does not pass through the failure occurrence location. This protection operation is the “Steer” function.

  With this “Steer” function, the current state is maintained from the occurrence of a failure until the topology database in all the relay apparatuses 110 on the ring is stabilized, and data frames are continuously transmitted to the ringlet via the failure occurrence location. . Therefore, the signal interruption and signal deterioration as described above will continue.

  Therefore, in the relay apparatus according to the present embodiment, the data frame transmission method is changed from unicast transmission to multicast transmission when the occurrence of the failure is recognized in order to shorten the time of such signal interruption and signal degradation. Implement a mechanism to do.

  In addition, when a data frame is multicast transmitted, there is a possibility that the line load of the normal ringlet that has not failed is increased. Therefore, in the relay apparatus according to the present embodiment, control is performed to set the communication priority lower for the data frame passing through the location where the failure has occurred.

  FIG. 5 is a hardware configuration diagram of the relay device according to the present embodiment. The relay device 110 includes a CPU 510, a RAM 520, a ROM 530, a hard disk (referred to as HD) 540, a communication I / F 550, and an input / output I / F 560. Various programs (for example, a relay program, etc.) are stored in the ROM 530 and the HD 540, read out to the RAM 520 as necessary, and executed by the CPU 510. The communication I / F 550 is an interface for performing communication. The input / output I / F 560 is an interface for receiving input from an input device and outputting data. The input / output I / F 560 can be connected to a drive corresponding to a removable disk such as a magneto-optical disk, a floppy disk (registered trademark), a CD-R, or a DVD-R, if necessary.

  FIG. 6 is a functional block diagram of the relay device according to the present embodiment. A difference from the functional block diagram of the relay apparatus shown in FIG. 2 is that the RPR MAC 220 includes a data frame control unit 270. Further, the priority control unit 230 includes a first multicast frame identifier determination unit 231 and a second multicast frame identifier determination unit 232, and a memory 3 is newly added.

  The data frame control unit 270 includes a failure route determination unit 271 as an example of a failure route determination unit, and a transmission method setting unit 272 as an example of a transmission method setting unit. In addition, a multicast identifier adding unit 273 as an example of an identifier adding unit and a multicast identifier deleting unit 274 as an example of an identifier deleting unit are provided.

  The data frame control unit 270 receives and holds failure information from the SONET framer 250 and the control CPU 280. For the relay device 110 that becomes an edge when a failure occurs, the LOS (Loss Of Signal) or SF (Signal Failure) is detected from the SONET framer 250, and the failure information is transmitted to the data frame control unit 270. For the relay device 110 that is not an edge when a failure occurs, the control CPU 280 recognizes the failure information from the control frame transmitted from the relay device 110 that detected the failure, and the failure information is transmitted to the data frame control unit 270. The transmitted failure information is held by the data frame control unit 270.

  The failure route determination unit 271 determines the data frame to be unicast transmitted via the failure location from the stored failure information, topology database information, extended control fi in the RPR header, and RPR MAC DA information. To do.

  The transmission method setting unit 272 replaces fi with the multicast setting for the data frame that is determined by the failure determination unit 271 to be a data frame that is unicast transmitted via the failure location (referred to as a failure-routed data frame). .

  The multicast identifier adding unit 273 adds a multicast identifier (1 byte) having a multicast identification bit (1 bit) and a reserve (7 bits) to the RPR header. A data frame via a failure is added as multicast identification bit = “1”. For data frames other than the data frame via failure (data frame originally set by multicast and data frame set by unicast that does not go through the location where the failure occurred, and is a normal data frame), multicast identification bit = “0” ".

The format of the data frame when the multicast identifier is added to the RPR header by the processing of the multicast identifier adding unit 273 is shown in FIG. A multicast identifier (1 byte) is newly added from FIG. As described above, the multicast identifier has a multicast identification bit (1 bit) and a reserve (7 bits). The reserve is a reserved area for function expansion or the like later, and need not be provided.
The multicast identifier deletion unit 274 deletes the multicast identifier when outputting the data frame to the Ethernet (registered trademark) side.

  The first multicast frame identifier determination unit 231 refers to the multicast identifier of the data frame input from the capture determination unit 222. When the multicast identification bit is “1”, the data frame is output to the newly added memory 3. When the multicast identification bit is “0”, the data frame is output to the memory 1.

  The second multicast frame identifier determination unit 232 refers to the multicast identifier of the data frame input from the data frame control unit 270. When the multicast identification bit is “1”, the data frame is output to the newly added memory 3. When the multicast identification bit is “0”, the data frame is output to the memory 2.

  In the priority control unit 230, the scheduler performs read control of the data frames stored in each memory in the priority order of memory 1> memory 2> memory 3. That is, the priority of sending the data frame via the failure is controlled to the lowest priority.

  Next, a data frame flow in the relay apparatus according to the present embodiment will be described. The data frame input from the Ethernet side is processed in the same manner as in FIG. 2 up to the second RPR header addition / deletion unit 221. The RPR header is added by the second RPR header addition / deletion unit 221 and input to the data frame control unit 270.

  For the data frame via failure, fi is replaced with the multicast setting, and the multicast identifier is added with the multicast identification bit = “1”. For a normal data frame, a multicast identifier is added with multicast identification bit = “0”.

  The priority order is controlled based on the added multicast identifier. The priority order is similarly controlled for the data frame input from the capture determination unit 222. Details of the process for controlling the priority will be described later.

  When the priority is controlled, the data frame is output to the multicast function unit 223, and the data frame is output to the RPR network according to the transmission method set to fi.

  Next, the operation of the RPR MAC 220 will be described. FIG. 7 is a flowchart showing the operation of the RPR MAC in the relay device according to the present embodiment. First, the second RPR header addition / deletion unit 221 adds an RPR header to the data frame received from the Ethernet side, and outputs it to the data frame control unit 270 (step S71). The failure route determination unit 271 determines whether or not the failure-routed data frame passes through the failure point (step S72). If it is not a data frame via failure, the multicast identifier adding unit 273 adds the multicast identifier as multicast identification bit = “0” (step S76).

  If it is a data frame via failure, the failure determination unit 271 refers to fi and determines whether or not the unicast setting is set (step S73). If it is not unicast setting, the multicast identifier adding unit 273 adds the multicast identifier as multicast identification bit = “0” (step S76).

  If it is unicast setting, the transmission method setting unit 272 replaces fi with the multicast setting (step S74), and the multicast identifier adding unit 273 adds the multicast identifier as multicast identification bit = “1” (step S75). . When the multicast identifier is added, the priority control unit 230 performs priority control (step S77).

  Here, the priority control process will be described in detail. FIG. 8 is a flowchart showing the priority control process in the relay device according to the present embodiment. Here, it is assumed that the service class is divided into class A, class B, and class C, and the priority order of transmission is class A> class B> class C. The priority control process will be described separately for a data frame input from the Ethernet side and a data frame input from the RPR network side.

  For a data frame input from the Ethernet side, first, the second multicast frame identifier determination unit 232 determines a multicast identification bit (step S801). If the multicast identification bit is “1”, the service class is determined in step S802. If the service class is class A, the data frame is stored in the class A + multicast identifier queue in the memory 3 (step S805). If the service class is class B, the data frame is stored in the class B + multicast identifier queue in the memory 3 (step S804). If the service class is class C, the data frame is stored in the class C + multicast identifier queue of the memory 3 (step S803).

  If the multicast identification bit is “0” in step S801, the service class is determined in step S806. If the service class is class A, the data frame is stored in the class A queue of the memory 2 (step S809). If the service class is class B, the data frame is stored in the class B queue of the memory 2 (step S808). If the service class is class C, the data frame is stored in the class C queue of the memory 2 (step S807).

  For the data frame input from the RPR network side, first, the first multicast frame identifier determination unit 231 determines the multicast identification bit (step S810). When the multicast identification bit is “1”, the service class is determined in step S 802 as in the case of the data frame input from the Ethernet side, and the data frame is stored in each queue of the memory 3.

If the multicast identification bit is “0” in step S810, the service class is determined in step S811. If the service class is class A, the data frame is stored in the class A queue of the memory 1 (step S814). If the service class is class B, the data frame is stored in the class B queue of the memory 1 (step S813). If the service class is class C, the data frame is stored in the class C queue of the memory 1 (step S812).
In this way, the priority order can be controlled by distinguishing and storing the data frame through failure and the normal data frame.

  Returning to FIG. 7, when priority control is performed in step S77, the multicast function unit 223 determines whether or not fi is a multicast setting (step 78). If it is multicast setting, the data frame is subjected to multicast transmission processing (step S79), and if it is unicast, the data frame is subjected to unicast transmission processing (step 80), and the processing is terminated.

  As shown in FIG. 6, each memory of the priority control unit 230 may be an independent device, or one memory is virtually divided and processed as memory 1 to memory 3 in FIG. May be.

  The multicast identifier adding unit 273, the multicast identifier deleting unit 274, the first multicast frame identifier determining unit 231, the second multicast frame identifier determining unit 232, and the memory 3 may be omitted. In that case, the process of setting the priority order of the data frame via the failure to the lowest order may not be performed.

  As described above, with respect to the data frame via a failure, the transmission method is set to multicast transmission, so that the time until the topology database is stabilized can be reduced, and the time until communication restoration can be shortened.

  In addition, by setting the priority of the data frame via a failure lower than the priority of the normal data frame, it is possible to prevent a line overload state caused by a communication amount that increases due to the occurrence of the failure. .

  Furthermore, the memory of the data frame passing through the own relay device, the data frame transmitted from the terminal of the own relay device, and the data frame via the fault is divided, so that priority control can be performed efficiently and accurately. Play.

  Furthermore, by adding or deleting an identifier for determining whether or not the data frame is through a failure, the type of the data frame can be easily determined and the processing can be performed efficiently.

  Although the relay device has been described according to each of the above embodiments, the technical scope of the relay device disclosed in the present application is not limited to the scope described in the embodiment, and various modifications or improvements are added to each of the embodiments. Is possible. And embodiment which added such a change or improvement is also contained in the technical scope of this application. This is apparent from the claims and the means for solving the problems.

  (Supplementary Note 1) In the relay device that is connected in an RPR (resilient packet ring) network that is a dual ring network in which a plurality of relay devices are connected by a double path, and relays data frame communication, Frame identifier adding means for recognizing occurrence of a failure in the network and adding a frame identifier used for identification for multicast transmission of the data frame to the data frame passing through the location of the failure based on failure information relating to the failure that has occurred And storing means for storing the data frames with the frame identifier added according to the priority order to be transmitted based on the frame identifier, and prioritizing transmission of the data frames stored in the storage means to the network Send in order from the data frame stored in the high-order category Priority control means, and multicast transmission means for sending the data frame in which the frame identifier added to the data frame output from the priority control means indicates multicast transmission to the two-way path of the double path, A relay device provided.

  (Supplementary Note 2) Frame identifier determination means for determining whether or not a frame identifier added to a data frame received from the double path is a frame identifier indicating multicast transmission, and the frame identifier determination means The priority control means for storing a data frame whose identifier is determined not to indicate multicast transmission in a section of the storage means having a higher transmission order than the data frame determined to indicate multicast transmission; The relay device according to Supplementary Note 1, wherein:

100 RPR network 110 Relay device 201 PHY
202 MAC
210 RPR Enhancement bridge
211 Learning MAC address table 212 First RPR header addition / deletion unit 220 RPR MAC
221 Second RPR header addition / deletion unit 222 Capture determination unit 223 Multicast function unit 230 Priority control unit 231 First multicast frame identifier determination unit 232 Second multicast frame identifier determination unit 240 GFP framer 250 SONET framer 260 OPT module 270 Data frame control unit 271 Failure determination unit 272 Transmission method setting unit 273 Multicast identifier adding unit 274 Multicast identifier deleting unit 280 CPU for control
510 CPU
520 RAM
530 ROM
540 HD
550 Communication I / F
560 I / O I / F

Claims (7)

In the relay device that is connected in an RPR (resilient packet ring) network, which is a double ring network in which a plurality of relay devices are connected by a double path, and relays data frame communication,
When recognizing the occurrence of a failure in the network, it is determined whether or not the data frame sent to the network is a data frame that passes through the location where the failure has occurred, based on failure information relating to the failure that has occurred. A failure determination means;
A relay apparatus comprising: a transmission method setting unit configured to set a transmission method of a data frame via a failure to multicast transmission for a data frame via a failure that is determined to be a data frame via the failure occurrence point by the failure passage determination unit. The relay device according to claim 1,
A priority order control means for controlling the priority order of data frames sent to the network;
The relay apparatus in which the priority control means sets the priority of the data frame passing through the failure lower than the priority of the normal data frame not passing through the failed portion. The relay device according to claim 2,
Storing means for storing the data frame;
A first block for storing a normal data frame addressed to a terminal connected to another relay device via the own relay device; the storage means addressing a terminal connected to the other relay device from the terminal connected to the own relay device; A relay device that is divided into a second block that stores normal data frames and a third block that stores the failure-caused data frames. The relay device according to claim 3,
The priority order setting means has a priority order in the order of a normal data frame stored in the first block, a normal data frame stored in the second block, and a data frame through failure stored in the third block. A relay device that sets a high value. The relay device according to any one of claims 1 to 4,
Identifier adding means for adding an identifier for determining whether or not the data frame is a data frame via a failure;
An identifier deleting means for deleting the identifier added by the identifier adding means,
When the data frame is sent from the own relay device to the network, the identifier adding means adds an identifier, and when the data frame is sent from the own relay device to a terminal connected to the own relay device, A relay device in which the identifier deleting unit deletes the identifier. In a relay method for relaying data frame communication in an RPR (resilient packet ring) network, which is a ring network connected by a double ring,
When a failure occurs in the network, it is determined whether the data frame transmitted to the network is a data frame that passes through the failure occurrence location where the failure has occurred, based on failure information relating to the failure that has occurred. The failure determination step,
A relay method including a transmission method setting step of setting the transmission method of the data frame via a failure to multicast transmission for the data frame via the failure determined to be a data frame via the failure occurrence location in the failure passage determination step. In a relay program that causes a computer to function to relay data frame communication in a RPR (resilient packet ring) network, which is a ring network connected by double rings,
When a failure occurs in the network, it is determined whether the data frame transmitted to the network is a data frame that passes through the failure occurrence location where the failure has occurred, based on failure information relating to the failure that has occurred. Means for determining whether or not a failure has occurred,
Relay that causes the computer to function as a transmission method setting unit that sets the transmission method of the data frame via failure to multicast transmission for the data frame via failure determined by the failure determination unit as a data frame that passes through the location where the failure has occurred program.

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