JP5588468B2 - Switch device - Google Patents

Description

  The present invention relates to data communication technology, and more particularly to a switch device that relays Ethernet (registered trademark) frames.

  When confirming communication between bases in a communication network, it is common to check signal communication between bases by Ping using a PC, router, or the like that can execute layer 3 processing. However, layer 3 ping cannot confirm signal communication between terminals having IP addresses, and layer 2 processing that constitutes a layer 2 network cannot execute layer 3 processing. For this reason, it may be difficult to identify the fault occurrence section in the communication network when the communication confirmation by Ping cannot be performed, and even if the communication confirmation by Ping can be performed, it may not be sufficient to identify the fault occurrence section.

  Therefore, in order to confirm signal communication on the Ethernet, an operation / management / maintenance function called Ethernet OAM (operations, administration, maintenance) is being introduced. In Ethernet OAM, CC (continuous connectivity check) mechanism that constantly monitors the communication by sending a monitoring frame, and LB (LoopBack) and LT (LinkTrace) that can check the communication point-to-point with a remote base ) Has a mechanism that can isolate faulty sections.

JP 2009-71619 A

  Ethernet OAM has a concept of a management hierarchy called a domain, and an Ethernet OAM frame in which a value indicating a high domain level (in other words, a high management level) is set is assumed to be used by end users between remote sites. doing. On the other hand, it is assumed that an Ethernet OAM frame in which a value indicating a low domain level (in other words, a low management level) is set is used within a closed range within a communication carrier.

  Specifically, IEEE 802.1ag or ITU-TY. 1731 defines a management level of 0 to 7. Among these, management level values 0 to 2 are assigned to communication carriers, 3 and 4 are assigned to the entire communication carrier network, and 5 to 7 are assigned to users. According to the above rules, the management level value of the own device that is the Ethernet OAM transfer condition is set in the switch device, and the management level value set in the received Ethernet OAM frame is equal to or less than the management level value of the own device. In some cases, it is stipulated that the received Ethernet OAM be discarded.

  By the way, an Ethernet VPN (Virtual Private Network) service such as a wide area Ethernet service provided by a telecommunications carrier sells that an end user can send and receive any Ethernet frame between two remote locations via a telecommunications carrier network. Yes. However, in the conventional Ethernet VPN service, depending on the management level value of the Ethernet OAM frame transmitted by the end user, it may be discarded in the communication carrier network. The present inventor considered that this is a major disadvantage in the Ethernet VPN service that calls for protocol-free and there is room for improvement.

  The present invention has been made on the basis of recognition of the above problems of the present inventor, and a main object thereof is to provide a technique for suppressing a decrease in user convenience in transmission of an Ethernet OAM frame in a telecommunications carrier network. It is to be.

  In order to solve the above-described problem, a switch device according to an aspect of the present invention is a switch device for a carrier network, and includes a receiving unit that receives an Ethernet (registered trademark) OAM frame, and an Ethernet OAM received by the receiving unit. When the option TLV data of a predetermined value is not set in the frame, the determination unit determines that the frame is an Ethernet OAM frame transmitted from the user device, and the Ethernet OAM received by the reception unit When it is determined that the frame is an Ethernet OAM frame transmitted from a user device, a transfer unit that transfers the frame to an external device regardless of a level value indicating a management level set in the frame; Is provided.

  Another embodiment of the present invention is also a switch device. This device is a switch device that is arranged in a telecommunications carrier network and is adjacent to a user's device, and includes a receiving unit that receives an Ethernet OAM frame from the user's device, and an Ethernet OAM frame received by the receiving unit. A setting unit for setting the level value stored in the management level field as data of option TLV, and rewriting the level value of the field to a value indicating the management level that is transparently transferred in the communication carrier network; A transfer unit that transfers the Ethernet OAM frame with the rewritten level value to another switch device of the communication carrier network.

  Yet another embodiment of the present invention is also a switch device. This device is a switch device that is arranged in a carrier network and is adjacent to a user's device. The receiving unit receives an Ethernet OAM frame, and the Ethernet OAM frame received by the receiving unit is transferred to the user's device. If the frame is a power frame, the setting unit that rewrites the level value stored in the management level field of the frame to the level value set in the option TLV, and the Ethernet OAM frame in which the setting unit has rewritten the level value A transfer unit for transferring to the apparatus.

  Yet another embodiment of the present invention is also a switch device. This device is a switching device for a carrier network, and receives a frame according to a receiving unit that receives an Ethernet OAM frame and a level value indicating a management level set in the Ethernet OAM frame received by the receiving unit. When the transfer unit to be transferred to the external device or discarded and the level value set in the Ethernet OAM frame received by the reception unit is a value indicating a management level to be transparently transferred in the communication carrier network, the frame And a recording unit that records information on the transmission source in a predetermined storage area. The transfer unit transfers the Ethernet OAM frame in which the transmission source information recorded in the storage area is set to the external device regardless of the level value set in the frame.

  Note that any combination of the above-described constituent elements and the expression of the present invention converted between an apparatus, a method, a system, a program, a recording medium storing the program, and the like are also effective as an aspect of the present invention.

  ADVANTAGE OF THE INVENTION According to this invention, the fall of a user's convenience can be suppressed in transmission of the Ethernet OAM frame in a communication carrier network.

It is a figure which shows the structure of the communication system of embodiment. It is a block diagram which shows the function structure of the carrier L2 switch of 1st Embodiment. It is a figure which shows the structure of the CCM frame prescribed | regulated by IEEE802.1ag draft8.1. It is a flowchart which shows operation | movement of a carrier L2 switch. It is a block diagram which shows the function structure of the carrier L2 switch of 2nd Embodiment. It is a flowchart which shows operation | movement of a carrier L2 switch. It is a block diagram which shows the function structure of the carrier L2 switch of 3rd Embodiment. It is a figure which shows the example of data stored in an address information table. It is a figure which shows the example of data stored in a transmission condition table. It is a flowchart which shows operation | movement of a carrier L2 switch.

  FIG. 1 shows a configuration of a communication system according to an embodiment. In the communication system 100, an Ethernet frame is transmitted and received between the end user base 20 and the end user base 30 via the communication carrier network 10. The end user base is a network constructed and owned by the end user. In the end user base 20, a user L2 switch 22, which is a layer 2 switch that transmits an Ethernet frame to the communication carrier network 10 and receives an Ethernet frame from the communication carrier network 10, is installed. Similarly, a user L2 switch 32 that is a layer 2 switch is installed at the end user base 30.

  The carrier network 10 is a layer 2 network that provides an Ethernet VPN service to end users. The carrier network 10 includes a plurality of layer 2 switches, and specifically includes a carrier L2 switch 12a, a carrier L2 switch 12b, a carrier L2 switch 12c, and a carrier L2 switch 12d, which are collectively referred to as a carrier L2 switch 12. The communication carrier network 10 also transmits an Ethernet frame including user data as a main signal transmitted from the end user base. In the following, the transmission process of the Ethernet OAM frame transmitted from the end user base will be described in detail. To do.

  As shown in FIG. 1, IEEE802.1ag or ITU-TY. In 1731, management level values 0 to 2 are assigned to Ethernet OAM frames transmitted and received between adjacent carrier L2 switches 12. Management level values 3 and 4 are assigned to Ethernet OAM frames transmitted and received across the entire carrier network, in other words, transmitted and received between non-adjacent carrier L2 switches 12. Management level values 5 to 7 are assigned to Ethernet OAM frames transmitted and received between the end user base 20 and the end user base 30.

  Therefore, in the conventional carrier network 10, for example, when an Ethernet OAM frame addressed to the user L2 switch 32 is transmitted from the user L2 switch 22 with the management level value set to “4” or less, the Ethernet OAM The frame was discarded by the carrier L2 switch 12a and was not transmitted to the user L2 switch 32. This limits the user's free device monitoring and network monitoring, which may reduce user convenience.

  Therefore, in the embodiment, the Ethernet OAM frame transmitted from one end user base to the other end user base is transmitted transparently without being discarded in the communication carrier network 10 regardless of the management level value of the frame. A technique for transmitting is proposed. The configuration of the communication system 100 in FIG. 1 is common to the first to third embodiments.

(First embodiment)
FIG. 2 is a block diagram illustrating a functional configuration of the carrier L2 switch according to the first embodiment. The carrier L2 switch 12 includes a frame receiving unit 40, a frame sending unit 42, a monitoring processing unit 44, and a transfer processing unit 48. The configuration shown in FIG. 2 is common to the carrier L2 switch 12a to the carrier L2 switch 12d.

  Each block shown in the block diagram of the present specification can be realized in terms of hardware by elements and mechanical devices such as a CPU and a memory of a computer, and in terms of software, it can be realized by a computer program or the like. Then, the functional block realized by those cooperation is drawn. Therefore, those skilled in the art will understand that these functional blocks can be realized in various forms by a combination of hardware and software.

  The frame receiving unit 40 and the frame sending unit 42 include a plurality of communication ports connected to the transmission path of the communication carrier network 10. The frame receiving unit 40 receives the Ethernet OAM frame transmitted from the user L2 switch 22, the user L2 switch 32, and another carrier L2 switch 12. The frame transmission unit 42 transmits an Ethernet OAM frame to the user L2 switch 22, the user L2 switch 32, and the other carrier L2 switch 12.

  In the first embodiment, a CC message (hereinafter also referred to as “CCM frame”) is shown as an example of an Ethernet OAM frame. However, the present invention is not limited to this, and it goes without saying that the same processing can be performed for other types of Ethernet OAM frames such as LB messages (hereinafter also referred to as “LBM frames”) and LT messages. The same applies to a second embodiment described later.

  FIG. 3 shows the structure of the CCM frame, where the first line shows the number of bytes and the second line shows the number of bits. MDLEVEL 110 in the figure is a data field in which the management value level of the frame is set. The option TLV 112 is an area called “Organization Specific TLV”, and is a data field that can be freely used by a vendor of a layer 2 switch or a communication carrier. Specifically, this is an area specified by the last “TLV Type” from the “TLV Type” after the 119th byte in the CCM frame of FIG. Normally, in the CCM frame transmitted from the user L2 switch 22 and the user L2 switch 32 to the communication carrier network 10, the option TLV 112 is not set, and this data field itself is not included.

  Returning to FIG. 2, the transfer processing unit 48 executes Ethernet frame transfer processing. The transfer processing unit 48 includes a determination unit 50, a frame discard unit 52, and a switch unit 54.

  The determination unit 50 refers to the Ethernet OAM frame received by the frame reception unit 40 and determines whether the frame is a frame transmitted from the end user side, that is, the user L2 switch 22 or the user L2 switch 32. Specifically, the determination unit 50 confirms whether the option TLV 112 is included in the CCM frame received by the frame reception unit 40. If it is included, it is further confirmed whether or not a predetermined value (hereinafter also referred to as “carrier specified value”) indicating that the frame is a monitoring frame in the communication carrier network 10 is set in the option TLV 112. To do.

  As an example of the carrier specified value, the value of “TLV Type” is 31, the value of “TLV Length” is a predetermined value indicating the total length of the option TLV, “OUI” is all 1, the value of “Subtype” is 1, and “Value” May be all 1.

  When the option TLV 112 indicating the carrier specified value is set in the CCM frame, the determination unit 50 determines that the CCM frame is a monitoring frame in the communication carrier network 10 (hereinafter also referred to as “carrier CCM frame”). To do. The carrier CCM frame can be said to be a CCM frame transmitted by another carrier L2 switch 12. On the other hand, when the option TLV 112 is not set in the CCM frame or the value of the option TLV 112 does not match the carrier specified value, the CCM frame is also referred to as a monitoring frame (hereinafter referred to as “user CCM frame”) transmitted from the end user side. It is determined. The user CCM frame can be said to be a CCM frame transmitted by the user L2 switch 22 or the user L2 switch 32.

  The frame discard unit 52 refers to the management level value set in the MDLEVEL 110 of the carrier CCM frame. The management level value is a value indicating the domain level of the own device. In other words, the management level value preset in the own device as a reference for permitting passage of the CCM frame (hereinafter also referred to as “transmission reference value”). In the following cases, the carrier CCM frame is discarded. The discarded carrier CCM frame is not output to the frame sending unit 42 and is therefore not sent to the external device.

  For the user CCM frame, the frame discard unit 52 does not depend on the management level value set in the frame, in other words, regardless of the magnitude relationship between the management level value set in the frame and the transmission reference value of the own device. Not subject to disposal. Therefore, the user CCM frame is output to the frame sending unit 42 regardless of the management level value, and is sent to the external device.

  The switch unit 54 determines an output port to which the CCM frame is to be transmitted according to “DA_MAC (destination MAC address)” of the CCM frame, and passes the CCM frame to the frame transmission unit 42 together with information indicating the output port. Thereafter, the frame sending unit 42 sends the CCM frame from the communication port determined by the switch unit 54 as the output port.

  The transfer processing unit 48 (switch unit 54) refers to “DA_MAC (destination MAC address)”, “MA Name”, “MEP ID”, etc. of the CCM frame, and determines whether or not the CCM frame is addressed to the own device. Determine. When the CCM frame is destined for the own apparatus, the transfer processing unit 48 passes the CCM frame to the monitoring processing unit 44.

  The monitoring processing unit 44 refers to the CCM frame delivered from the transfer processing unit 48 and confirms the communication state and connection state with the other carrier L2 switch 12. And according to the communication state with the other carrier L2 switch 12, predetermined | prescribed maintenance processing, such as notification of an alert and recording to a log, is performed. When the received frame is an LBM frame, processing for transmitting a reply frame to the transmission source device may be executed.

  The monitoring processing unit 44 includes a carrier frame setting unit 46. The carrier frame setting unit 46 sets a carrier CCM frame periodically (for example, every 60 seconds elapses), passes the frame to the frame sending unit 42, and outputs the frame to the external device. The carrier frame setting unit 46 sets a predetermined management level value in the MDLEVEL 110 of the carrier CCM frame. Also, a field of option TLV 112 is provided in the carrier CCM frame, and a carrier specified value is set in the field.

  The operation of the carrier L2 switch 12 having the above configuration will be described below. FIG. 4 is a flowchart showing the operation of the carrier L2 switch 12. The operation shown in FIG. 4 is common to the carrier L2 switch 12a to the carrier L2 switch 12d. Although not shown in FIG. 4, the carrier L2 switch 12 in the carrier network 10 periodically transmits a carrier CCM frame including the option TLV 112 in which the carrier specified value is set to the other carrier L2 switch 12. The connectivity check process is executed on a regular basis.

  When the frame receiving unit 40 receives the CCM frame (Y in S10), the determination unit 50 confirms the option TLV 112 of the received frame (S12). When the option TLV 112 indicating the carrier specified value is not set, it is determined that the received frame is a user CCM frame. When the received frame is a user CCM frame (Y in S14), the transfer processing unit 48 outputs the user CCM frame from the communication port corresponding to the destination MAC address regardless of the management level value set in the frame. (S16).

  If the received frame is a carrier CCM frame (N in S14) and the management level value set in the frame exceeds the transmission reference value (Y in S18), the transfer processing unit 48 sends the carrier CCM frame to the destination The data is output from the communication port corresponding to the MAC address (S16). When the management level value set in the frame is equal to or less than the transmission reference value (N in S18), the carrier CCM frame is discarded (S20). If the frame receiving unit 40 has not received a CCM frame (N in S10), the subsequent steps are skipped and the flow of FIG.

The carrier L2 switch 12 according to the first embodiment has been described above.
In the conventional layer 2 VPN service, IEEE802.1ag, ITUY. Due to the restriction of 1731, the end user cannot send an Ethernet OAM frame having an arbitrary level value to a remote base device via the carrier network. Therefore, depending on the network scale of the end user, the level value of 5 to 7 assigned in the above standard may be insufficient. For example, it may be difficult to hierarchically manage a large number of communication devices.

  In the carrier L2 switch 12 of the first embodiment, a special bit string (carrier specified value) indicating a carrier CCM frame is set as the data of the option TLV of the CCM frame used in the communication carrier. Thereby, the management level can be determined only for the carrier CCM frame by distinguishing the carrier CCM frame from the user CCM frame. Further, for a user CCM frame having no special bit string in the option TLV, it is possible to perform transparent transfer by skipping the management level determination.

  According to the carrier L2 switch 12 of the first embodiment, it is possible to allow an end user to use an Ethernet OAM frame having an arbitrary management level value, and to provide a service that eliminates the Ethernet OAM restrictions defined by the above standards. it can. The end user can perform device monitoring and network monitoring with an Ethernet OAM frame in which an arbitrary management level is set, and can improve the usability of the end user in the Ethernet VPN service. For example, the end user can freely perform hierarchical operation monitoring at the layer 2 level.

(Second Embodiment)
FIG. 5 is a block diagram illustrating a functional configuration of the carrier L2 switch according to the second embodiment. The carrier L2 switch 12 having a characteristic configuration in the second embodiment is a layer 2 switch located at the end of the communication carrier network 10. In other words, it is a layer 2 switch installed at the boundary between the end user network and the carrier network 10, and is a layer 2 switch directly connected to the end user network device. Specifically, a carrier L2 switch 12a adjacent to the user L2 switch 22 and a carrier L2 switch 12d adjacent to the user L2 switch 32 in FIG.

  In the carrier network 10 of the second embodiment, the carrier L2 switch 12b and the carrier L2 switch 12c in FIG. 1 that are not adjacent to the user apparatus may be general layer 2 switches. That is, the carrier L2 switch 12b and the carrier L2 switch 12c may discard or transfer the frame according to the management level value set in the Ethernet OAM frame.

  The transfer processing unit 48 of the carrier L2 switch 12a further includes a user frame setting unit 56. FIG. 5 shows the configuration of the carrier L2 switch 12a, but the configuration of the carrier L2 switch 12d is the same. However, the difference is that the opposing devices of the frame receiving unit 40 and the frame sending unit 42 are the carrier L2 switch 12c and the user L2 switch 32. In FIG. 5, the same reference numerals are given to the functional blocks that are the same as or correspond to the functional blocks of the carrier L2 switch 12 of the first embodiment. In the following, overlapping description will be omitted as appropriate, and differences will be mainly described.

  The frame reception unit 40 records information indicating the reception port of the Ethernet frame in an in-device header that is a header added to the frame in the device. The switch unit 54 records information indicating the output port of the Ethernet frame in the in-device header.

  The determination unit 50 determines whether the CCM frame to be transferred is a frame transmitted from the user apparatus (that is, the user L2 switch 22) (hereinafter, also referred to as “inflow CCM frame”) or a frame to be transmitted to the user apparatus (hereinafter, “ It is determined whether it is also called “outflow CCM frame”) or another frame (hereinafter also referred to as “intra-network CCM frame”).

  Specifically, the determination unit 50 refers to the in-device header of the CCM frame to be transferred. When the receiving port is a communication port that accepts an Ethernet frame transmitted from the user L2 switch 22, in other words, a communication port connected to the user L2 switch 22, the CCM frame to be transferred is determined as an inflow CCM frame. . When the output port is a communication port that outputs an Ethernet frame addressed to the user L2 switch 22, in other words, a communication port connected to the user L2 switch 22, the CCM frame to be transferred is determined as an outflow CCM frame. If these conditions are not met, it is determined as an in-network CCM frame.

  The user frame setting unit 56 saves the original management level value set in the MDLEVEL 110 of the incoming CCM frame to the option TLV 112. Specifically, an option TLV 112 field is added to the inflow CCM frame, and the management level value set in the MDLEVEL 110 of the frame is transferred to the option TLV 112 field. Then, the user frame setting unit 56 rewrites the original management level value set in the MDLEVEL 110 of the incoming CCM frame to the highest value “7”. Note that the value for rewriting the original management level value may be a value that is a target of transparent transfer in the carrier network 10 according to the Ethernet OAM standard, and may be “5” or “6”.

  Further, the user frame setting unit 56 returns the management level value from “7” to the original management level value in the outflow CCM frame. Specifically, the management level value is extracted from the field of the option TLV 112, and the management level value is overwritten and set in the MDLEVEL 110.

  The frame discard unit 52 discards the intra-network CCM frame when the management level value set in the MDLEVEL 110 of the intra-network CCM frame is equal to or less than the transmission reference value of the own apparatus. The inflow CCM frame and the outflow CCM frame are not subject to discarding regardless of the management level value.

  The operation of the carrier L2 switch 12a having the above configuration will be described below. FIG. 6 is a flowchart showing the operation of the carrier L2 switch 12a. The operation shown in FIG. 6 is common to the carrier L2 switch 12d. Although not shown in FIG. 6, the carrier L2 switch 12 in the carrier network 10 periodically transmits a CCM frame to another carrier L2 switch 12 to regularly execute a connectivity confirmation process. .

  When the frame receiving unit 40 receives the CCM frame (Y in S30) and the switch unit 54 determines the output port of the CCM frame, the determination unit 50 determines the type of the CCM frame. When the CCM frame is an inflow CCM frame from the user base network to the carrier network 10 (Y in S32), the user frame setting unit 56 saves the original management level value set in the MDLEVEL 110 to the option TLV 112. (S34). Then, “7” is set as a new management level value (S36). If the CCM frame is not an inflow CCM frame (N in S32), S34 and S36 are skipped.

  When the CCM frame is an outflow CCM frame from the carrier network 10 to the network of the user base (Y in S38), the user frame setting unit 56 writes back the original management level value stored in the option TLV 112 to the MDLEVEL 110. (S40). Then, the field of the option TLV 112 is deleted (S42). If the CCM frame is not an outflow CCM frame (N in S38), S40 and S42 are skipped. If the CCM frame is an inflow CCM frame or an outflow CCM frame, in other words, if it is not an in-network CCM frame (N in S43), the transfer processing unit 48 sends the CCM frame from the communication port corresponding to the destination MAC address. Output (S44).

  When the CCM frame is an intra-network CCM frame (Y in S43), the transfer processing unit 48 compares the management level value set in the frame with the transmission reference value. When the management level value set in the frame exceeds the transmission reference value (Y in S46), the transfer processing unit 48 outputs the intra-network CCM frame from the communication port corresponding to the destination MAC address (S44). If the management level value set in the frame is equal to or less than the transmission reference value (N in S46), the in-network CCM frame is discarded (S48). If the frame receiving unit 40 has not received the CCM frame (N in S30), the subsequent steps are skipped and the flow of FIG.

  For example, when transmitting the CCM frame sent from the user L2 switch 22 to the user L2 switch 32, the carrier L2 switch 12a executes S34, S36, and S44. The carrier L2 switch 12b and the carrier L2 switch 12c execute S46 and S44, and the carrier L2 switch 12d executes S40, S42, and S44.

The carrier L2 switch 12 according to the second embodiment has been described above.
The carrier L2 switch 12 according to the second embodiment also achieves the effects described in the first embodiment. That is, the Ethernet OAM frame transmitted by the user can be transparently transferred regardless of the management level value in the layer 2 switch of the communication carrier. Further, by applying the configuration of FIG. 4 to the carrier L2 switch 12a and the carrier L2 switch 12d located at the boundary with the user base network, the other layer 2 switches in the telecommunications carrier network 10 have a general configuration. Well, it can be easy to implement.

(Third embodiment)
An outline of the third embodiment will be described. In the communication system 100 according to the third embodiment, an end user first transmits an LBM frame at a management level 7 between user base networks to which CCM frames are to be transmitted and received. When transmitting the LBM frame, the carrier L2 switch 12 of the communication carrier network 10 records the source MAC address set in the frame in a table. Thereafter, the carrier L2 switch 12 that has received the CCM frame from one user base to the other user base checks whether or not the transmission source MAC address set in the CCM frame has been recorded in the table. If it has been recorded, the CCM frame is transparently transferred regardless of the management level value set in the CCM frame. As a result, the end user first passes the management level 7 LBM frame, and thereafter can perform device monitoring and network monitoring using the CCM frame set to an arbitrary management level.

  In the third embodiment, the LBM frame is transmitted bi-directionally between the user base networks to which the CCM frame is to be transmitted / received. Then, it is confirmed whether the combination of the destination MAC address and the source MAC address recorded in each LBM frame is consistent. As a result, an exceptionally transparent transmission of the CCM frame can be provided strictly in accordance with the intention of the end user.

  FIG. 7 is a block diagram illustrating a functional configuration of the carrier L2 switch according to the third embodiment. The configuration shown in the figure is common to the carrier L2 switch 12a to the carrier L2 switch 12d. In FIG. 7, the same reference numerals are assigned to the functional blocks that are the same as or correspond to the functional blocks of the carrier L2 switch 12 of the first embodiment. In the following, overlapping description will be omitted as appropriate, and differences will be mainly described.

  The carrier L2 switch 12 further includes an address information recording unit 58, an address information table 60, a matching unit 62, and a transmission condition table 64. The transfer processing unit 48 includes a frame discard unit 52 and a switch unit 54.

  The address information table 60 is a storage area that holds a combination of a destination MAC address and a source MAC address set in an LBM frame having a management level value of 7. FIG. 8 shows an example of data stored in the address information table 60. Since the LBM frame is unicast, the “destination MAC” field and “source MAC” field indicate the destination MAC address and the source MAC address set in the LBM frame, and the layer 2 of the user base network. The MAC address (unicast address) of the switch is stored. Record No. 1 in FIG. 8 is recorded when the LBM frame is transmitted from the user L2 switch 22 to the user L2 switch 32. Record No. 2 is recorded when the LBM frame is transmitted from the user L2 switch 32 to the user L2 switch 22. It is recorded.

  Returning to FIG. 7, the transparency condition table 64 holds the conditions of the CCM frame to be transparently transferred regardless of the management value level. FIG. 9 shows an example of data stored in the transmission condition table 64. The “source MAC” column stores the source MAC address set in the CCM frame to be transparently transferred. Information indicating that transparent transfer is performed is stored in the “filter condition” column.

  Returning to FIG. 7, the frame discarding unit 52 refers to the transmission condition table 64 and determines whether or not the CCM frame received by the frame reception unit 40 is a frame to be transparently transferred. Specifically, it is determined whether or not the source MAC address set in the CCM frame matches the source MAC address of the transparent transfer target stored in the transparent condition table 64.

  If they match, it is determined that the CCM frame is a transparent transfer target, regardless of the management level value, and is not subject to discarding, and is transferred to an external device. If they do not match, the management level value of the CCM frame is compared with the transmission reference value of its own device, assuming that the CCM frame is not subject to transparent transfer. If the management level value of the CCM frame exceeds the transmission reference value, it is excluded from discarding and transferred to an external device. On the other hand, if the management level value of the CCM frame is equal to or less than the transmission reference value, the CCM frame is discarded.

  When the frame receiving unit 40 receives an LBM frame having a management level value of 7, the address information recording unit 58 records the destination MAC address and the transmission source MAC address set in the LBM frame in the address information table 60.

  The collation unit 62 determines whether there are two records (hereinafter also referred to as “symmetric records”) in which the combination of the destination MAC address and the source MAC address is symmetric in the address information table 60. Specifically, in the first record, the destination MAC address is “MAC_α” and the source MAC address is “MAC_β”, and in the second record, the destination MAC address is “MAC_β” and the source MAC address is “MAC_α”. The first record and the second record are specified as symmetrical records. In the example of FIG. 8, record No1 and record No2 are specified as symmetrical records.

  When the symmetric record is specified in the address information table 60, the matching unit 62 records the transmission source MAC address of each symmetric record in the transmission condition table 64 in association with the filter operation “transmission”. Thereafter, the transfer processing unit 48 transparently transfers the CCM frame in which the transmission source MAC address of the symmetric record is set regardless of the management level value.

  The operation of the carrier L2 switch 12 having the above configuration will be described. As a premise, the user L2 switch 22 first transmits an LBM frame having a management level value 7 to the user L2 switch 32, and then transmits a CCM frame having an arbitrary management level value. The same applies to the user L2 switch 32. First, an LBM frame having a management level value of 7 is transmitted to the user L2 switch 22, and then a CCM frame having an arbitrary management level value is transmitted.

  FIG. 10 is a flowchart showing the operation of the carrier L2 switch 12. The operation shown in FIG. 10 is common to the carrier L2 switch 12a to the carrier L2 switch 12d. Although not shown in FIG. 10, the carrier L2 switch 12 in the carrier network 10 periodically transmits a CCM frame to another carrier L2 switch 12 to regularly execute a connectivity confirmation process. .

  When the frame receiving unit 40 receives the LBM frame set to the management level value “7” (Y in S50), the address information recording unit 58 uses the destination MAC address and source MAC address set to the LBM frame as address information. It records on the table 60 (S52). The collation unit 62 detects a symmetric record in the address information table 60. If there is a symmetric record in the address information table 60 (Y in S54), the source MAC address set in the symmetric record is recorded in the transparency condition table 64 (S56). If a symmetric record in the address information table 60 has not been detected (N in S54), S56 is skipped, and if an LBM frame set to the management level value “7” has not been received (N in S50), S52˜ S56 is skipped.

  When the frame receiving unit 40 receives the CCM frame (Y in S58), the transfer processing unit 48 matches the transmission source MAC address of the CCM frame with the transmission source MAC address stored as the transparent transfer target in the transparent condition table 64. Determine whether. When the transmission source MAC address of the CCM frame is a transparent transfer target (Y in S60), the transfer processing unit 48 transfers the CCM frame to the external device regardless of the management level value set in the CCM frame (S62). .

  When the source MAC address of the CCM frame is not a transparent transfer target (N in S60), the transfer processing unit 48 compares the management level value set in the frame with the transparent reference value. When the management level value set in the frame exceeds the transmission reference value (Y in S64), the transfer processing unit 48 outputs the CCM frame from the communication port corresponding to the destination MAC address (S62). When the management level value set in the frame is equal to or smaller than the transmission reference value (N in S64), the CCM frame is discarded (S66). If a CCM frame has not been received (N in S58), the subsequent steps are skipped and the flow of FIG.

The carrier L2 switch 12 according to the third embodiment has been described above.
The carrier L2 switch 12 of the third embodiment also provides the effects described in the first embodiment. That is, the Ethernet OAM frame transmitted by the user can be transparently transferred regardless of the management level value. Specifically, an Ethernet OAM frame with a management level value “7” output from the user apparatus is transmitted in advance in the layer 2 switch of the communication carrier, and the transmission source MAC address of the user apparatus is learned in advance. Thereby, the Ethernet OAM frame of an arbitrary management level output from the user device can be transmitted to the destination user device without being discarded in the communication carrier network 10.

  In the third embodiment, in order to set the transmission condition of the CCM frame, the end user needs to once transmit and receive the LBM frame having the management level value “7” between the bases via the communication carrier network 10. is there. Unlike a CCM frame for regular monitoring, the LBM frame is a unicast frame that is generally used for the purpose of isolating a faulty section when a fault occurs. Therefore, it is preferable to use the LBM frame having the management level value “7” as an explicit statement of the end user's intention to set the transparent condition of the CCM frame.

  In the third embodiment, LBM frames are transmitted from both user apparatuses that transmit and receive CCM frames, and the learning results of the LBM frames are matched (that is, the combination of the destination MAC address and the source MAC address is symmetrical). Set the transmission condition. The setting of the transmission condition is an exception and requires strictness because it eliminates the restrictions on the standard regarding the management level. In the third embodiment, it is possible to avoid setting the transmission condition against the end user's intention by transmitting the LBM frame from both user apparatuses that transmit and receive the CCM frame.

  In the third embodiment, the Ethernet OAM frame to be transparently transferred is a CCM frame. However, another Ethernet OAM frame such as an LBM frame or an LTM frame may be used. Further, the management level value of the LBM frame for setting the transparent condition may be equal to or greater than the value that is subject to transparent transfer in the communication carrier network 10 in accordance with the Ethernet OAM standard. For example, the condition is that 5 or more LBM frames are received. The transmission conditions may be set as follows.

  The present invention has been described based on the first to third embodiments. It is understood by those skilled in the art that these embodiments are exemplifications, and that various modifications can be made to combinations of the respective constituent elements and processing processes, and such modifications are also within the scope of the present invention. By the way.

  Any combination of the above-described first to third embodiments and modifications is also useful as an embodiment of the present invention. The new embodiment generated by the combination has the effects of the combined embodiment and the modified examples. In addition, it should be understood by those skilled in the art that the functions to be fulfilled by the constituent elements described in the claims are realized by the individual constituent elements shown in the embodiments and the modified examples or by their cooperation. .

  10 carrier network, 12 carrier L2 switch, 48 transfer processing unit, 50 determination unit, 52 frame discard unit, 54 switch unit, 56 user frame setting unit, 58 address information recording unit, 60 address information table, 62 verification unit, 64 Transmission condition table, 100 communication system, 110 MDLEVEL, 112 optional TLV.

Claims (5)

A switch device for a carrier network,
A receiving unit for receiving an Ethernet (registered trademark) OAM frame;
A determination unit that determines that the frame is an Ethernet OAM frame transmitted from a user apparatus when data of an option TLV having a predetermined value is not set in the Ethernet OAM frame received by the reception unit; ,
When it is determined that the Ethernet OAM frame received by the receiving unit is an Ethernet OAM frame transmitted from the user's device, the frame is externally transmitted regardless of the level value indicating the management level set in the frame. A transfer unit for transferring to the device;
A switch device comprising: A switch device arranged in a telecommunications carrier network and adjacent to a user device,
A receiver for receiving an Ethernet OAM frame from the user device;
For the Ethernet OAM frame received by the receiving unit, the level value stored in the management level field of the frame is set as option TLV data, and the level value of the field is transparently transferred in the carrier network. A setting unit for rewriting the value indicating the management level;
A transfer unit configured to transfer the Ethernet OAM frame in which the setting unit has rewritten the level value to another switch device of the carrier network;
A switch device comprising: A switch device arranged in a telecommunications carrier network and adjacent to a user device,
A receiver for receiving an Ethernet OAM frame;
When the Ethernet OAM frame received by the receiving unit is a frame to be transferred to the user device, the level value stored in the management level field of the frame is rewritten to the level value set in the option TLV. A setting section;
A transfer unit that transfers the Ethernet OAM frame whose level value is rewritten by the setting unit to the user device;
A switch device comprising: A switch device for a carrier network,
A receiver for receiving an Ethernet OAM frame;
A transfer unit that transfers the frame to an external device or discards the frame according to a level value indicating a management level set in the Ethernet OAM frame received by the receiving unit;
When the level value set in the Ethernet OAM frame received by the receiving unit is a value indicating a management level that is transparently transferred by the carrier network, information on the transmission source of the frame is recorded in a predetermined storage area. Recording section to
With
The switch unit transfers the Ethernet OAM frame set with the transmission source information recorded in the storage area to an external device regardless of the level value set in the frame. When the level value set in the first Ethernet OAM is a value indicating a management level that is transparently transferred in the carrier network, the recording unit stores the destination information and the transmission source information in the frame. If the level value recorded in the storage area 1 and set in the second Ethernet OAM is a value indicating the management level that is transparently transferred in the carrier network, the destination information of the frame and the transmission source Record the information in the second storage area,
In the transfer unit, the transmission source information recorded in the first storage area matches the destination information recorded in the second storage area, and the transfer information is recorded in the first storage area. When the destination information and the transmission source information recorded in the second storage area match, the Ethernet OAM frame in which the transmission source information recorded in the first storage area is set The switch device according to claim 4, wherein the switch device transfers the data to an external device regardless of the level value set in (5).

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