JP2015188126A - Communication device and communication system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To promptly recover a line disconnection caused when a setting change in a communication standard is performed.SOLUTION: A communication device 10 includes: a communication processing section 12 setting one of the OTU 2 standard and the OTU 2e standard and sending/receiving a frame according to a set communication standard; an alarm generating section 18 generating an LOF alarm when desynchronization in a frame occurs in the communication processing section 12; an alarm detection section 16 outputting a switching request when the LOF alarm is detected; and a setting switching section 14, when receiving the switching request, switching one communication standard set in the communication processing section 12 at that time to the other communication standard.

Description

  The present invention relates to a communication device and a communication system, and more particularly to a communication device and a communication system capable of switching communication standards.

  ITU-T (International Telecommunication Union Telecommunication Standardization Sector) Recommendation G. Some optical long-distance transfer standards of 709 (OTN: Optical Transport Network) have a plurality of standards at the same data transfer rate. It is a standard G.10 standard for transferring 10 GbE (10 Gigabit Ethernet (registered trademark)). 709 standard OTU2 and G.709. It is OTU2e of the sup43 standard.

  The OTN standard regards transfer data (Ethernet (registered trademark) or SDH / SONET data) as a byte sequence, adds a delimiter overhead and FEC (Forward Error Correction) error correction code block for each fixed-length frame, and repeats optical amplification Is a protocol that realizes long-distance transmission repeatedly.

  In OTU2, for example, when transferring 10 GbE data with a frequency of 10.3125 Gb / s, the data is not sent as it is, but is transferred on an OTN frame after processing such as interframe idle compression. The frequency of the OTU2 frame is 10.7 Gb / s.

  In the OTU2e, when transferring 10 GbE data, all the frames including the Ether frame and the idle frame are regarded as byte strings, and transferred on the OTN frame as they are. Therefore, the frequency of the OTU2e frame is higher than that of the OTU2 frame and is 11.1 Gb / s.

JP 2009-159062 A

  FIGS. 1A and 1B are diagrams for explaining the problem of the present invention. 1A and 1B, the first communication device 100 located at its own station is connected to the second communication device 102 located at the opposite station via an optical fiber 104. The first communication device 100 and the second communication device 102 correspond to both the OTU2 and OTU2e standards on the same hardware, and are configured to be able to switch the standards used by software.

  In FIG. 1A, both the first communication device 100 and the second communication device 102 are set to OTU2. In this case, the first communication device 100 and the second communication device 102 can normally communicate. The 10 GbE data input from the client side to the first communication device 100 is added with a header (HDR) and an error correction code block (FEC) by the first communication device 100 to form an OTU2 frame, and is transferred to the second communication device 102. The The OTU2 frame is terminated at the second communication apparatus 102 to become 10 GbE data, and is output to the client side.

  In FIG. 1B, the first communication device 100 is set to OTU2, and the second communication device 102 is set to OTU2e. In this case, the first communication device 100 and the second communication device 102 cannot communicate with each other because the used frequencies are different. That is, the 10.7 Gbps OTU2 frame transmitted from the first communication device 100 cannot be received by the second communication device 102 configured to receive the 11.1 Gbps OTU2e frame. In the second communication device 102, since the frame is not visible, a LOF (loss of frame) alarm is generated. Similarly, the 11.1 Gbps OTU2e frame transmitted from the second communication apparatus 102 cannot be received by the first communication apparatus 100 set to receive the 10.7 Gbps OTU2 frame. In the first communication device 100, the LOF alarm is generated because the frame becomes invisible.

  When changing the setting of the communication standard in the first communication device 100 and the second communication device 102, the connection is lost unless both the first communication device 100 and the second communication device 102 are changed. For example, as shown in FIG. 1A, when both the first communication device 100 of the own station and the second communication device 102 of the opposite station are both set to OTU2 and the line is connected, only the first communication device 100 of the own station Is switched to OTU2e, the second communication device 102 of the opposite station remains OTU2, so the line between the first communication device 100 and the second communication device 102 is disconnected, and a LOF alarm is generated in both devices.

  When the control of the first communication device 100 and the second communication device 102 is performed by an out-band method (a method in which both the own station and the opposite station perform monitoring control independently), the first communication device 100 of the own station is directly operated. Thus, it is necessary to change the setting of the communication standard, and further, remotely change the second communication device 102 of the opposite station. Therefore, the line disconnection state continues until the setting change of both communication apparatuses is completed.

  Further, the control of the first communication device 100 and the second communication device 102 is performed in an in-band method (a method in which the setting / control frame of the opposite station is superimposed on the main line connected by the own station / opposing station to perform monitoring control). If this is done, a procedure is required to change the communication standard setting. That is, when the in-band method is adopted, the setting must be changed from the opposite station, and then the setting of the own station must be changed. If the setting of the own station is erroneously changed first, the second communication apparatus 102 cannot be accessed from the first communication apparatus 100 of the own station via the in-band to the second communication apparatus 102 of the opposite station. This is because it cannot be changed. Even in this in-band method, the line disconnection state continues until the setting change of both communication apparatuses is completed.

  Regardless of the form of the control line (out-band / in-band), it is desirable for the line provider to quickly recover even if a line break occurs and provide a longer service duration.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a communication apparatus and a communication system that can quickly recover from a line break that occurs when a communication standard setting is changed.

  In order to solve the above-described problem, a communication apparatus according to an aspect of the present invention sets either a first communication standard or a second communication standard different from the first communication standard, and transmits a frame according to the set communication standard. A communication processing unit that performs transmission / reception, an alarm generation unit that generates an alarm when out of frame synchronization occurs in the communication processing unit, an alarm detection unit that outputs a switching request when an alarm is detected, and a switching request And a setting switching unit that switches one communication standard set in the communication processing unit to the other communication standard at that time.

  Another aspect of the present invention is a communication system. This system includes the first and second communication apparatuses described above, and a transmission path that connects the first communication apparatus and the second communication apparatus.

  It should be noted that any combination of the above-described constituent elements and a representation of the present invention converted between an apparatus, a method, a system, a program, a recording medium storing the program, etc. are also effective as an aspect of the present invention.

  According to the present invention, it is possible to provide a communication apparatus and a communication system that can quickly recover from a line break that occurs when a communication standard setting is changed.

FIGS. 1A and 1B are diagrams for explaining the problem of the present invention. It is a figure for demonstrating the communication apparatus which concerns on this embodiment. It is a flowchart for demonstrating operation | movement of the communication apparatus which concerns on embodiment of this invention. It is a figure for demonstrating the specific example of operation | movement of the communication apparatus which concerns on this embodiment. It is a sequence diagram for demonstrating the specific example of operation | movement of the communication apparatus which concerns on this embodiment.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the accompanying drawings. Note that the same reference numerals denote the same or corresponding parts throughout the drawings.

  FIG. 2 is a diagram for explaining the communication device 10 according to the present embodiment. The communication device 10 shown in FIG. 2 is an interface board that is inserted into a shelf in a station building. This interface board has a function of converting a 10 GbE frame input from the client side into an OTN frame and outputting it to the optical network side, and terminating the OTN frame input from the network side and outputting it to the client side.

  As illustrated in FIG. 2, the communication device 10 includes a communication processing unit 12, a setting switching unit 14, an alarm detection unit 16, an alarm generation unit 18, a monitoring unit 20, and a setting control unit 22. The communication device 10 is monitored and controlled by a terminal 24 such as a personal computer.

  The communication processing unit 12 has a function of converting a 10 GbE frame into an OTN frame and transferring it. That is, the communication processing unit 12 regards the 10 GbE frame input from the client side as a byte sequence, generates an OTN frame by adding a delimiter overhead and an FEC error correction code block for each fixed-length frame, and sends the OTN frame to the optical network side. To do.

  Further, the communication processing unit 12 has a function of terminating the OTN frame and reproducing the 10 GbE frame. That is, after confirming the normality of a plurality of OTN frames received from the optical network side, the communication processing unit 12 combines these frames to reproduce the original 10 GbE frame and sends it to the client side.

  In the present embodiment, the communication processing unit 12 can communicate according to one of two different communication standards, the OTU2 standard and the OTU2e standard. OTU2 and OTU2e are mounted on the same hardware, and one of them is set as a use standard by an instruction from the outside.

  OTU2 is a standard defined in ITU-T G.709. In OTU2, when 10.3125 Gb / s 10 GbE data is transferred, an overhead and an error correction code block are added after processing such as interframe idle compression. The frequency of the OTU2 frame is 10.7 Gb / s.

  OTU2e is a G.I. This is a standard defined in sup43. In OTU2e, when transferring 10 GbE data, an overhead and an error correction code block are added as they are. Therefore, the frequency of the OTU2e frame is higher than that of the OTU2 frame and is 11.1 Gb / s.

  The monitoring unit 20 has a function of monitoring the operation state of the communication processing unit 12. The monitoring unit 20 outputs monitoring information to the terminal 24.

  Based on an instruction from the terminal 24, the setting control unit 22 sets the communication standard of the communication processing unit 12 of the own device (own station) to one of OTU2 and OTU2e. Moreover, the setting control part 22 can switch the communication standard of the communication apparatus arrange | positioned at the opposite station by in-band communication. That is, when the terminal 24 is instructed to switch the communication standard in the communication device of the opposite station, the setting control unit 22 superimposes the switching instruction frame on the main line connected between the own station and the opposite station, To send. Upon receiving this switching instruction frame, the opposite station setting control unit 22 switches the communication standard of the opposite station. That is, if the standard set when the switching instruction frame is received by in-band communication is OTU2, the setting is switched to OTU2e. On the other hand, if the standard set when the switching instruction frame is received by in-band communication is OTU2e, the setting is switched to OTU2.

  The alarm generation unit 18 generates a LOF alarm when the communication processing unit 12 loses frame synchronization. The alarm generation unit 18 outputs a LOF alarm to the alarm detection unit 16 and the terminal 24. The alarm generation unit 18 generates a LOF alarm when a frame synchronization pattern mismatch is detected for 3 ms continuously.

  The alarm detection unit 16 detects the occurrence of a LOF alarm in the alarm generation unit 18. The alarm detection unit 16 outputs a switching request to the setting switching unit 14 when the LOF alarm is generated for a predetermined protection time. The alarm detection unit 16 has a normal processing mode (operation mode) and a state transition mode (latch mode). When the setting switching unit 14 that is a lower block is operating (that is, during setting switching), the alarm detection unit 16 does not operate as a latch mode. On the other hand, when the setting switching unit 14 is in another state (that is, setting switching is not being performed), the alarm detection unit 16 performs the normal operation (that is, detection of LOF alarm and switching request) as the normal processing mode.

  When the setting switching unit 14 receives a switching request from the alarm detection unit 16, the setting switching unit 14 switches one communication standard set in the communication processing unit 12 to the other communication standard. That is, if the standard set in the communication processing unit 12 when the switching request is received from the alarm detection unit 16 is OTU2, the setting is switched to OTU2e. On the other hand, if the standard set in the communication processing unit 12 when the switching request is received from the alarm detection unit 16 is OTU2e, the setting is switched to OTU2. The setting switching unit 14 reports the setting switching state to the alarm detection unit 16 that is the upper block. That is, the setting switching unit 14 notifies the alarm detection unit 16 of “setting switching” during setting switching of the communication processing unit 12, and notifies “not operating” otherwise.

  FIG. 3 is a flowchart for explaining the operation of the communication apparatus 10 according to the embodiment of the present invention.

  It is assumed that the communication device 10 is in operation with a communication device arranged at the opposite station. First, the alarm detection unit 16 detects whether or not the LOF alarm has occurred in the alarm generation unit 18 (S10). When the LOF alarm is not detected, the process returns to S10 (N of S10).

  On the other hand, when the LOF alarm is detected (Y of S10), the alarm detector 16 determines whether or not the LOF alarm is generated for a predetermined protection time (S12). When the LOF alarm is not generated for a predetermined protection time, the process returns to S10 (N in S12).

  On the other hand, when the LOF alarm is generated for a predetermined protection time (Y in S12), a switching request is output to the setting switching unit 14. Upon receiving the switching request, the setting switching unit 14 determines whether or not the current line setting is OTU2 (S14).

  When the current line is OTU2e (N in S14), the setting switching unit 14 switches the line setting of the communication processing unit 12 to OTU2 (S16). On the other hand, when the current line is OTU2 (Y in S14), the setting switching unit 14 switches the line setting of the communication processing unit 12 to OTU2e (S18).

  Thereafter, the operation flow is temporarily terminated after a predetermined protection time has elapsed, and the next operation flow (ie, S10) is started again.

  FIG. 4 is a diagram for explaining a specific example of the operation of the communication apparatus 10 according to the present embodiment. FIG. 5 is a sequence diagram for explaining a specific example of the operation of the communication apparatus 10 according to the present embodiment. In FIG. 4, the first communication device 10a disposed in the own station, the second communication device 10b disposed in the opposite station, and the optical transmission line 26 (which connects the first communication device 10a and the second communication device 10b) ( A communication system 40 including an optical fiber) and a terminal 24 that controls each device of the communication system 40 is disclosed.

  In the communication system 40, the terminal 24 is arranged in its own station and directly controls the first communication device 10a. Further, the terminal 24 controls the second communication device 10b of the opposite station by in-band communication.

  Here, it is assumed that both the first communication device 10a of the own station and the second communication device 10b of the opposite station are set to OTU2. Here, when a setting switching instruction is issued from the terminal 24 to the first communication device 10a of the local station, the setting control unit 22 of the first communication device 10a switches the set OTU2 to the OTU2e. At this time, since the first communication device 10a becomes OTU2e and the second communication device 10b becomes OTU2, frame synchronization loss occurs in both stations, and the line between the own station and the opposite station is disconnected. At this time, the LOF alarm is generated in the alarm generators 18 of both stations.

  At this time, the alarm detection unit 16 of the first communication device 10a is in the latch mode because the setting switching unit 14 of the own device is operating, and does not operate. On the other hand, the alarm detection unit 16 of the second communication device 10b outputs a switching request to the setting switching unit 14 of the own device when the LOF alarm is continuously generated for a predetermined protection time. As described above, in the present embodiment, a protection time is provided instead of immediately issuing a switching request when a LOF alarm is generated. As a result, it is possible to prevent a situation in which a switching request is issued each time a LOF alarm occurs and the setting of the standard is switched. On the other hand, if the LOF alarm does not occur for a predetermined protection time, the process returns to the normal process (no switching request is issued).

  The setting switching unit 14 of the second communication device 10b that has received the switching request from the setting switching unit 14 switches the setting from OTU2 to OTU2e. As a result, the setting of the first communication device 10a and the setting of the second communication device 10b become the same OTU2e, so that the frame synchronization is established, the line between the own station and the opposite station is restored, and the LOF alarm is restored. To do.

  When the LOF alarm recovers, the alarm detection unit 16 of the second communication device 10b completes the setting switching after the protection time has elapsed. That is, the alarm detection unit 16 of the second communication device 10b does not issue a switching request even if the LOF alarm is detected within the protection time after the LOF alarm is recovered. Immediately after the LOF alarm is recovered, communication is not stable, and there is a possibility that the LOF alarm will occur. By providing the protection time in this way, a switching request is issued each time the LOF alarm occurs, The situation where the setting is switched can be prevented.

  The configuration and operation of the communication device 10 according to the present embodiment have been described above. According to the present embodiment, the communication standard of the second communication device 10b of the opposite station is automatically set to the first communication using the LOF alarm that is always generated when the communication standard setting of the first communication device 10a of the own station is changed as a trigger. It is possible to switch to the same communication standard as the device 10a. When changing the setting of the communication standard, it is only necessary to switch the standard of the first communication device 10a of the local station, and the setting switching work of the second communication device 10b of the opposite station is not required. it can. Further, since the double setting switching work is not required, the operator's work efficiency can be improved.

  In addition, as described above, in a communication device adopting the conventional in-band method, when changing the setting of the communication standard, the setting must be changed from the opposite station, and then the setting of the own station must be changed thereafter. However, according to the communication apparatus 10 according to the present embodiment, there is no need to follow such a procedure for changing the setting. That is, if the standard of one communication device of the own station or the opposite station is switched, the standard of the other communication device is automatically switched and the line is restored. Therefore, the communication apparatus 10 according to the present embodiment is advantageous in improving the operator's work efficiency from this viewpoint.

  The present invention has been described based on the embodiments. This embodiment is an exemplification, and it will be understood by those skilled in the art that various modifications are possible depending on the combination of each component and each processing process, and such modifications are within the scope of the present invention. is there.

  DESCRIPTION OF SYMBOLS 10 Communication apparatus, 10a 1st communication apparatus, 10b 2nd communication apparatus, 12 Communication processing part, 14 Setting switching part, 16 Alarm detection part, 18 Alarm generation part, 20 Monitoring part, 22 Setting control part, 24 Terminal, 26 Light 40, communication system, 100 first communication device, 102 second communication device.

Claims (5)

A communication processing unit configured to set one of a first communication standard and a second communication standard different from the first communication standard, and to transmit and receive a frame according to the set communication standard;
An alarm generating unit for generating an alarm when out-of-frame synchronization occurs in the communication processing unit;
An alarm detector that outputs a switching request when the occurrence of the alarm is detected;
When the switching request is received, a setting switching unit that switches one communication standard set in the communication processing unit to the other communication standard at that time,
A communication apparatus comprising:   The communication device according to claim 1, wherein the alarm detection unit outputs the switching request when the alarm is generated for a predetermined protection time.   The communication apparatus according to claim 1 or 2, wherein the setting of the communication standard in the communication processing unit can be switched by in-band communication. The first communication standard is an OTU2 standard defined in ITU-T G.709.
The second communication standard is ITU-T G.264. The communication apparatus according to claim 1, wherein the communication apparatus is an OTU2e standard defined in sup43. The first and second communication devices according to any one of claims 1 to 4,
A transmission line connecting the first communication device and the second communication device;
A communication system comprising:

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