JP2005184083A - Transmission system and transmission apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a transmission system and a transmission apparatus capable of reducing time and effort required for setting work for the operation of a network, thereby realizing improvement of operating convenience. <P>SOLUTION: A unique bit sequence is inserted into J0 bite of an SDH frame to be sent from a transmission port in an each transmission apparatus 100, and each transmission apparatus 100 detects the bit sequence of J0 bite included in the received SDH frame. Then, a monitoring apparatus 200 is notified of both the inserted bit sequence and detected bit sequence of JO bite. By doing this, the monitoring apparatus 200 recognizes the connection relation for each path in each transmission apparatus 100, and generates network configuration information on the basis of a result thereof. The monitoring apparatus 200 transmits the network configuration information to each transmission apparatus 100 to allow a network configuration storage section 7 to store the information. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a transmission system that transmits digital data in accordance with a standard such as SDH (Synchronous Digital Hierarchy) or SONET (Synchronous Optical NETwork), and a transmission apparatus used in the transmission system. In particular, the present invention relates to an improvement in a method for managing a transmission system that forms a ring network.

  The SDH transmission system constituting the ring network has a redundant switching function (MS-Shared Protection Ring: hereinafter referred to as Ring APS) using K bytes defined in SOH (Section Over Head) of the transmission frame. In order to realize Ring APS, various information such as the number of nodes in the ring network, the connection relationship between the nodes, and the network topology (hereinafter collectively referred to as network configuration information) are set in advance in each of a plurality of transmission apparatuses. There is a need. Each transmission device stores the set network configuration information, and redundant switching is realized by autonomously performing distributed processing based on this information.

  In addition to K bytes, SOH defines information called J0 bytes. The J0 byte is control information used for detecting erroneous connection of an optical fiber cable used as a transmission line. By determining the match / mismatch between the transmission J0 byte transmitted from the transmission side of the transmission frame and the reception J0 byte received at the reception side, erroneous connection of the optical fiber in the section sandwiched between these transmission devices It can be detected.

  By the way, in the existing system, the network configuration information and the transmission / reception J0 byte are both set manually by the operator. Since any setting operation must be performed for each transmission apparatus, the operator's trouble at the initial setup of the system or at the time of restarting the system is very complicated, and there is a high possibility of mistakes. It has also been pointed out that the transmission system cannot be fully operated until such work is completed, and therefore the start of operation tends to be delayed.

  Further, in recent years, a plurality of VPNs (Virtual Private Networks) are formed in a ring network using a transmission device or a cross-connect device that can accommodate a plurality of lines. In such a system, one transmission apparatus is often operated as a node across a plurality of VPNs. Accordingly, it is necessary to set the network configuration information and each J0 byte for each VPN, and the operator's effort, the possibility of mistakes, the time required for network operation, etc. are doubled.

Related techniques are disclosed in Patent Documents 1 to 3 below. Patent Document 1 discloses various management information defined in SOH. Patent Document 2 discloses details regarding a section trace function using the J0 byte. Patent Document 3 discloses a wavelength division multiplexing optical transmission system in which wavelength connection can be confirmed by writing a wavelength ID in SOH.
JP 2001-7829 A (paragraph number [0016], FIG. 4) JP 2000-41024 (paragraph numbers [0012] to [0014], FIG. 4) JP 2000-183853 A (paragraph numbers [0026] to [0030], FIG. 1)

  As described above, in the existing transmission system, operations such as setting of network configuration information and setting of J0 byte are performed manually by the operator. For this reason, there is a problem that the labor of the operator is large at the time of initial setup of the system or at the time of restarting the system. Accompanying this, there is a risk of work mistakes and a problem that it takes a long time to operate the system.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a transmission system and a transmission apparatus that can reduce the labor required for setting operations for network operation, thereby improving the convenience of operation. is there.

  In order to achieve the above object, according to one aspect of the present invention, a transmission signal frame having an overhead area (for example, SOH) (for example, an SDH frame such as STM-4, 16) is multiplexed in a hierarchical multiplexing unit. In a transmission system comprising a plurality of transmission devices (for example, the transmission device 100) that transmit data and a host device (for example, the monitoring device 200) that manages a communication network formed by the plurality of transmission devices, the plurality of transmissions Each of the devices inserts unique information for each multiplexing unit (for example, transmission path or section) into a predetermined position (for example, J0 byte) in an overhead area of a transmission signal frame to be transmitted (for example, J0 signal insertion) Unit 1) and detection means for detecting information on the predetermined position in the overhead region of the received transmission signal frame ( For example, the J0 signal detection unit 2) and notification means (for example, the J0 signal insertion unit 1 and the J0 signal detection unit) for notifying the higher-level device of the unique information inserted by the insertion unit and the detection information detected by the detection unit 2), and the higher-level device recognizes a connection relationship for each of the multiplexing units of the plurality of transmission devices based on the unique information and detection information notified by the notification unit. For example, the network configuration recognition unit 8) notifies each of the plurality of transmission devices of network configuration information obtained from the recognition result of the recognition means, and sets the necessary information for operation of the communication network to the plurality of transmission devices. The transmission system is provided with setting means (for example, network configuration setting unit 10) to be set in each of the above.

  By taking such means, for example, taking SDH as an example, a unique bit string is inserted into the J0 byte for each section, that is, a unique bit string in all transmission devices and accommodated lines. The bit string of J0 byte is detected in each transmission device. Then, the bit string inserted in the J0 byte and the detected bit string are notified from each transmission device to the host device. As a result, the host device can recognize the connection relationship for each section of each transmission device, and can uniquely determine it. Thereby, the network configuration information can be obtained in the host device, and this network configuration information is set in each transmission device. That is, network configuration information is automatically generated and set in each transmission device. Therefore, it is possible to reduce the work involved by the operator, prevent mistakes, save time, and shorten the time until the system operation is started.

  According to the present invention, it is possible to reduce the time and effort required for setting operations for network operation, thereby providing a transmission system and a transmission apparatus that improve the convenience of operation.

  FIG. 1 is a functional block diagram showing an embodiment of a transmission apparatus 100 and a monitoring apparatus 200 used in the transmission system according to the present invention. In the present embodiment, a transmission system is assumed that is compliant with SDH and includes an APS described in the ITU-T recommendation G series. In FIG. 1, a transmission device 100 is connected to another transmission device (not shown) via a transmission line F in a ring shape to form a ring network. The transmission path F transmits an SDH frame in which a plurality of paths are time-division multiplexed. Each path corresponds to a multiplexing unit. The monitoring device 200 is connected to one of the transmission devices 100 via an OAM (Operation and Maintenance) line and manages the ring network. Such a system is used for an optical submarine cable system connecting continents.

  In FIG. 1, a transmission apparatus 100 includes a J0 signal insertion unit 1, a transmission path failure detection unit 2, a J0 signal detection unit 3, an expected value storage unit 4, a comparison unit 5, an alarm notification unit 6, and a network. A configuration storage unit 7, a display control unit 11, and a display unit 12 are provided.

  The J0 signal insertion unit 1 inserts a unique bit string for each path into the J0 byte in the SOH of the SDH frame sent to the transmission path F. This bit string is a unique value in all transmission devices and all sections in the system. This bit string is notified to the monitoring device 200. Since the J0 byte is an 8-bit sequence, 256 types of information can be distinguished.

  The transmission path failure detection unit 2 monitors the SDH frame received via the transmission path F and detects the presence or absence of a failure such as LOS (Loss of Signal) or LOF (Loss of Frame) in the transmission path F. When a failure is detected, this is notified to the alarm notification unit 6. The J0 signal detection unit 3 detects the bit string of the J0 byte in the SOH of the SDH frame received via the transmission path F. As a result, the bit string inserted by the adjacent transmission device via the section is detected. The detected bit string is also notified to the monitoring apparatus 200.

  However, in the state where the transmission path failure is detected by the transmission path failure detection unit 2, the reliability of the detected bit string is lost. Therefore, in such a state, the J0 signal detection unit 3 holds the immediately preceding bit string among the J0 bytes that sequentially arrive for each transmission frame.

  The expected value storage unit 4 stores the expected value of the J0 byte notified from the monitoring device 200 in a semiconductor memory or the like. The expected value of the J0 byte is a bit string that is expected to be detected by the J0 signal detection unit 3 as a result of the network configuration information. The comparison unit 5 compares the bit string stored in the expected value storage unit 4 with the bit string detected by the J0 signal detection unit 3. If both bit strings are different, the comparison unit 5 notifies the alarm notification unit 6 to that effect.

  More specifically, the comparison unit 5 performs the comparison process between the bit string and the expected value only when a change occurs in the bit string of the J0 byte output from the J0 signal detection unit 3. However, in a state where nothing is set in the J0 signal expected value storage unit, the comparison unit 5 does not execute the comparison process.

  When the comparison unit 5 notifies that the bit string detected by the J0 signal detection unit 3 is not an expected value, the alarm notification unit 6 notifies the monitoring device 200 as an alarm. The network configuration storage unit 7 stores the network configuration information notified from the monitoring device 200 in a semiconductor memory or the like. The display control unit 11 reads the network configuration information from the network configuration storage unit 7 and visually displays a network configuration diagram reflecting the network configuration information on the display unit 12.

  In FIG. 1, the monitoring apparatus 200 includes a network configuration recognition unit 8, an expected value setting unit 9, and a network configuration setting unit 10. The network configuration recognition unit 8 acquires a transmission bit string and a reception bit string of the J0 byte for each transmission device based on information notified from the J0 signal insertion unit 1 and the J0 signal detection unit 3 of each transmission device. Since the transmission bit string of the J0 byte transmitted from each transmission device is unique, the network configuration recognition unit 8 can recognize the connection configuration of each transmission device in the ring network. That is, the network configuration recognition unit 8 recognizes the connection relationship for each line of each transmission apparatus 100 based on the transmission bit string and the reception bit string of the J0 byte received from each transmission apparatus 100.

  The expected value setting unit 9 obtains an expected value that is expected to be detected by the J0 signal detection unit 3 of each transmission device 100 as a result of the recognition result in the network configuration recognition unit 8, and an expected value storage unit of each transmission device 100. 4 is stored. That is, the expected value setting unit 9 sets an expected value in the expected value storage unit 4 before the system enters operation. The expected value to be set is a value detected by the J0 signal detection unit 3 at that time. If a fiber misconnection occurs after the setting is completed, a difference is generated between the received J0 signal and the expected value, whereby an alarm is notified from the transmission apparatus 100 to the monitoring apparatus 200.

  The network configuration setting unit 10 notifies each transmission device 100 of the network configuration information obtained from the recognition result in the network configuration recognition unit 8, and stores the setting information necessary for operating the ring network in the network configuration storage unit 7. Let The setting information includes the number of nodes in the ring network, the node ID of each transmission device 100, the topology of the ring network, and the like.

  The network configuration recognizing unit 8 sets the communication network state as a partial ring network when the received J0 signal is indefinite in any of the transmission apparatuses 100 (caused by cable disconnection or failure). recognize.

  Each functional block shown in FIG. 1 is regarded as a functional object of a program described in a dedicated language, for example. In addition, each transmission apparatus 100 includes a function object (not shown) for performing Ring APS. Each transmission apparatus 100 performs switching processing based on Ring APS based on the network configuration information set in the network configuration storage unit 7.

  1 shows a case where the number of lines accommodated in the transmission apparatus 100 is one, the present invention is not limited to this, and a plurality of lines can be accommodated. This corresponds to a state where a plurality of sub-networks are formed in the ring network. Each subnetwork is operated as a logical ring network. In this case, in each transmission apparatus 100, the J0 signal insertion unit 1, the transmission path failure detection unit 2, the J0 signal detection unit 3, the expected value storage unit 4, the comparison unit 5, and the network configuration storage unit 7 are provided for each line. Provided. Next, an example of a network configuration formed by the transmission apparatus 100 that can accommodate a plurality of lines will be described.

  FIG. 2 is a diagram illustrating an example of a network configuration using the transmission apparatus 100 of FIG. In FIG. 2, transmission apparatuses each having the configuration of FIG. 1 are connected in a ring shape. Each transmission device is referred to as a node A to a node D. Each of the nodes A to D includes four transmission / reception ports on the EAST side and the WEST side. On the EAST side and WEST side, the four ports are divided into two service systems and two protection systems. Such a network configuration is called 4-fiber MS SPRing (Multiplex Section Shared Protection Ring).

  In this type of network, a plurality of ring networks as logical sub-networks can be formed. Each ring network is formed by grouping a plurality of paths multiplexed in an SDH frame. In FIG. 2, four ring networks are shown, and each is distinguished as ring R1 to ring R4.

  The ring R1 is a ring network in which the nodes A to D are logically connected. The ring R2 is a ring network to which nodes other than the node C are connected. The ring R3 is a ring network to which nodes other than the node D are connected. The ring R4 is a ring network to which nodes other than the node A are connected. In FIG. 2, in each transmission apparatus, WEST port 1 and EAST port 1, WEST port 2 and EAST port 2, WEST port 3 and EAST port 3, and WEST port 4 and EAST port 4 are connected to each other. Indicates. A schematic diagram corresponding to FIG. 2 is displayed on the display unit 12 of FIG.

  FIG. 3 is a diagram illustrating an example of the J0 byte transmitted from each port in the network of FIG. In FIG. 3, although the J0 byte is simply shown as a two-digit number, it is originally a binary number represented by 8 bits. Each J0 byte has a unique value in all ports of all nodes.

  FIG. 4 is a diagram showing the J0 byte that should be received at the reception ports of the nodes A to D when the J0 byte shown in FIG. 3 is transmitted in the network having the configuration shown in FIG. That is, FIG. 4 shows the expected value of the J0 byte. From the opposite viewpoint, the monitoring apparatus 200 can recognize the network configuration in FIG. 2 by acquiring the information in FIGS. 3 and 4.

  FIG. 5 is a diagram showing an example of a partial network formed in the network having the configuration shown in FIG. In FIG. 5, a case is assumed where node A to node B and node C to node D are not connected due to the delay in laying the cable of ring R1. In such a state, as shown in FIG. 4, a J0 byte that is not received by the nodes A, C, and D is generated. Based on this, the network configuration recognition unit 8 of the monitoring apparatus 200 recognizes the ring R1a and the ring R1b as separate partial networks.

  When recognizing that a partial ring exists in the network, the network configuration recognition unit 8 generates network configuration information for operating the network including the partial ring and passes it to the network configuration setting unit 10. The network configuration setting unit 10 sets the network configuration information by transmitting it to each transmission device 100 and storing it in the network configuration storage unit 7. Thereby, the network can start operation including the partial ring.

  Then, when cable laying is completed and a full ring is formed, it is recommended to reset the network configuration information after temporarily stopping Ring APS. This makes it possible to flexibly cope with changes in the network configuration.

  As described above, in this embodiment, each transmission apparatus 100 inserts a unique bit string into the J0 byte of the SDH frame sent from the transmission port, and also transmits the J0 byte bit string included in the received SDH frame to each transmission apparatus. Detect at 100. Then, the monitoring apparatus 200 is notified of both the inserted J0 byte bit string and the detected bit string. As a result, the monitoring device 200 recognizes the connection relationship for each path of each transmission device 100 and generates network configuration information based on the result. The network configuration information is transmitted from the monitoring device 200 to each transmission device 100 and stored in the network configuration storage unit 7.

  As described above, network configuration information is automatically generated, and setting processing of network configuration information to each transmission device 100 is also automatically performed. As a result, information necessary for operating a function such as Ring APS can be set in each transmission apparatus without intervention of an operator's manual operation. As a result, the labor of the operator can be remarkably reduced, and the possibility of an operation error can be eliminated. Furthermore, it is possible to drastically shorten the period from cable laying to system operation. Furthermore, since the partial ring can be recognized in the monitoring apparatus 200, it is possible to further shorten the period required until the system is operated by using this individual ring. From these, it is possible to reduce the time and effort required for the setting operation for network operation, and it is possible to provide a transmission system and a transmission device that improve the convenience of operation.

  In addition, this invention is not limited to the said Example as it is. For example, in the above embodiment, SDH is taken as an example, but the present invention can be similarly applied to SONET. In the above embodiment, a unique value is written in the J0 byte. However, the J0 byte is not limited, and other areas such as D1 to D8 bytes may be used. In addition, more information can be distinguished by using not only one byte but also a plurality of bytes.

  Furthermore, the present invention can be embodied by modifying the components without departing from the scope of the invention in the implementation stage. Various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the above embodiments. For example, some components may be deleted from all the components shown in the embodiments.

The functional block diagram which shows embodiment of the transmission apparatus 100 used for the transmission system concerning this invention, and the monitoring apparatus 200. FIG. The figure which shows the example of a network structure using the transmission apparatus 100 of FIG. The figure which shows the example of the J0 byte transmitted from each port in the network of FIG. The figure which shows the J0 byte which should be received in the receiving port of node AD when the J0 byte shown in FIG. 3 is transmitted in the network of the structure shown in FIG. The figure which shows an example of the partial network formed in the network of the structure of FIG.

Explanation of symbols

  A to D: Node, R1 to R4: Ring network, R1a, R1b ... Partial ring, F ... Transmission path, 1 ... J0 signal insertion section, 2 ... Transmission path failure detection section, 3 ... J0 signal detection section, 4 ... Expectation Value storage unit, 5 ... comparison unit, 6 ... alarm notification unit, 7 ... network configuration storage unit, 8 ... network configuration recognition unit, 9 ... expected value setting unit, 10 ... network configuration setting unit, 11 ... display control unit, 12 ... Display unit, 100 ... Transmission device, 200 ... Monitoring device

Claims (8)

In a transmission system comprising a plurality of transmission devices that multiplex and transmit transmission signal frames having an overhead area in a hierarchical multiplexing unit, and a host device that manages a communication network formed by these plurality of transmission devices ,
Each of the plurality of transmission devices is
Inserting means for inserting unique information for each multiplexing unit at a predetermined position in an overhead region of a transmission signal frame to be transmitted;
Detecting means for detecting information of the predetermined position in an overhead region of a received transmission signal frame;
Notification means for notifying the higher-level device of the specific information inserted by the insertion means and the detection information detected by the detection means,
The host device is
Recognizing means for recognizing a connection relationship for each of the multiplexing units of the plurality of transmission devices based on the unique information and detection information notified by the notification means;
Setting means for notifying each of the plurality of transmission devices of network configuration information obtained from the result of recognition in the recognition means, and setting the setting information necessary for operation of the communication network in each of the plurality of transmission devices; A transmission system comprising: The higher-level device further includes an expected value setting unit that individually stores an expected value that is expected to be detected by the detection unit as a result of the recognition result in the recognition unit, in each of the plurality of transmission devices,
Each of the plurality of transmission devices is
A comparison means for comparing the detection information with the expected value;
2. The transmission system according to claim 1, further comprising report means for notifying the higher-level device when the detection information and the expected value do not match as a result of comparison by the comparison means. 2. The transmission system according to claim 1, wherein each of the plurality of transmission apparatuses includes a display unit that visually displays a network configuration diagram that reflects the network configuration information notified by the setting unit. The communication network is a ring network in which the plurality of transmission devices are connected in a ring shape via a transmission path,
And a protection function for relieving the transmission signal frame from a failure,
The transmission system according to claim 1, wherein the setting unit sets configuration information of the ring network in each of the plurality of transmission apparatuses. When a plurality of sub-networks corresponding to the multiplexing unit can be formed in the ring network,
The recognizing unit recognizes a subnetwork in which a ring connection between transmission devices is incomplete as a partial ring,
The transmission system according to claim 4, wherein the setting unit causes each of the plurality of transmission apparatuses to set setting information necessary for operating the partial ring. A transmission system compliant with SDH (Synchronous Digital Hierarchy),
The protection function is APS (Automatic Protection Switching) described in the ITU-T recommendation G series,
5. The transmission system according to claim 4, wherein the insertion unit inserts the unique information into a J0 byte in an SDH frame. In a transmission apparatus that is installed in a communication network and transmits a transmission signal frame having an overhead area by multiplexing in a hierarchical multiplexing unit,
Inserting means for inserting unique information for each multiplexing unit at a predetermined position in an overhead region of a transmission signal frame to be transmitted;
Detecting means for detecting information of the predetermined position in an overhead region of a received transmission signal frame;
A transmission apparatus comprising: notification means for notifying the higher-order apparatus of the communication network of the unique information inserted by the insertion means and the detection information detected by the detection means. Further, when network configuration information reflecting a connection relationship for each multiplexing unit with another transmission device is notified from the upper device based on the unique information and detection information notified to the upper device, 8. The transmission apparatus according to claim 7, further comprising display means for visually displaying a network configuration diagram reflecting the network configuration information.

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