JP2010098520A - Continuity confirmation method, continuity confirmation program, communication device, and continuity confirmation system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide techniques for confirming continuity of an optical path on an optical network at a high speed and for lightening the processing load on a switch device and making the device compact. <P>SOLUTION: A start-point node 2a transmits a signaling message for securing a band resource for the end point of the optical path in the form of an optical signal (S3), and an end-point node 2c determines whether continuity of the band resource for the end point is normal based upon a reception state of the signaling message (S4), and transmits a signaling message to the start-point node 2a in the form of an optical signal (S5) when determining that the continuity is normal. The start-point node 2a determines whether continuity of a band resource for the start point in a continuity test section is normal (S6) based upon a reception state of the signaling message transmitted from the end-point node 2c, and transmits notice of normal continuity confirmation showing that the continuity is normal to the end-point node 2c (S7) when determining that the continuity is normal. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an optical path continuity test technique used for communication between nodes of an optical network.

  In recent years, the network has been remarkably increased in speed and capacity, and the limit of electrical processing is approaching. Instead, all-optical networks that perform everything from signal transmission to transmission and reception as light are drawing attention as next-generation networks. By transmitting optical signals (optical signals) directly to the end without converting them to electrical signals, ultra-high-speed and large-capacity transmission such as 40 Gbit / s and 100 Gbit / s can be realized, and power consumption can be reduced. Is possible. In addition, there is a feature of transparency indicating that signals having different modulation schemes can be mixed and signals having different signal speeds can be mixed.

  In such an optical network, there is a switch device having a function of switching the route of the optical path. Thanks to these switching devices, the optical signal can be switched in the direction to be transferred as it is. There are various types of optical switches such as MEMS (Micro Electric Mechanica 1 Switch) and TO switch (Thermo-Optics Switch).

  An optical switch is a passive device that switches a signal coming from an input port to an appropriate output port and forwards it to the next device, so it is difficult to detect its own failure or abnormality during signal transmission. . Therefore, before setting an optical path and transmitting an optical signal, it is necessary to conduct a continuity test for confirming whether the optical path passing through the switch device is normally set.

  Further, as an optical network becomes widespread, an optical path setting method based on GMPLS (Generalized Multi Protocol 1 Labe1 Switching) technology has been permeated. By using this GMPLS technology, an optical path can be set automatically and at high speed, so that an on-demand service for setting an optical path of a necessary band for a necessary time only when necessary can be easily realized.

  Conventionally, for example, as shown in FIG. 15 and FIG. 16, a continuity test procedure that can use a signaling protocol such as GMPLS is known as a setup procedure for establishing an optical path (see Patent Document 1). . Here, for the sake of simplicity, only a path start node, a path end node, and an intermediate node thereof are shown, and a simple process flow until a continuity is confirmed without a failure is shown. In the following, the direction in which an optical signal is transmitted from the path activation node to the path termination node is referred to as the downstream direction, and the opposite direction is referred to as the upstream direction. The processing shown in FIG. 15 is to confirm the normality of the optical path by continuously conducting a continuity test after the signaling for setting the optical path is completed.

  Specifically, when the path activation node issues an optical path setting notification (Path: S201), the optical path setting notification (Path) is transferred to the path termination node via the intermediate node. The path termination node sets the switch route so that an optical path is formed according to the optical path setting notification (Path) (S202), and sends a resource reservation notification (Resv: S203) via the intermediate node. Reply to the start node. After completing the setting of the optical path (S204), the path activation node transmits an instruction (inspection notification) to perform a normality inspection (continuity test) to the path termination node (S205), and the monitoring light for that purpose The signal is transmitted to the path termination node (S206). The path termination node determines whether or not the monitoring light signal is normally detected, and if it is normally detected (S207: OK / NG determination → OK), transmits a normal notification to the path activation node. (S208). The path activation node ends transmission of the monitoring light signal (S209), and transmits a normality inspection end notification to the path termination node (S210). As a result, in the downstream continuity test, only the path termination node among all the nodes constituting the set path performs the determination (conductivity confirmation) to confirm the normality of the continuity, and the downstream direction continuity test is performed. The continuity test can be terminated. Note that the continuity test is performed in the same way in the upstream direction.

Further, the processing shown in FIG. 16 is performed to confirm the normality of the optical path by performing signaling for setting the optical path and the continuity test in parallel. Specifically, the path activation node transmits an optical path setting notification (Path) (S221), and sets the switch path. When the intermediate node receives the optical path setting notification (Path), the intermediate node transfers it to the path termination node, and sets the switch path of its own node (S222). Furthermore, a monitoring light signal is transmitted toward the path activation node (S223), and an inspection notification is transmitted (S224). If the path activation node has detected the monitoring light signal normally (S225: OK / NG determination → OK), it transmits a normal notification to the intermediate node (S226). When receiving the normal notification, the intermediate node stops the monitoring light signal (S227). The same process is performed for each link constituting the path. That is, following S221, when the path termination node receives the optical path setting notification (Path) via the intermediate node, the intermediate node and the path activation node (S222 to S227) and the intermediate node A continuity test is carried out (S228 to S233). If the path termination node is normal as a result of the continuity test, the path termination node transmits a normality notification to the path activation node (S234). The path activation node transmits a normality check completion notification to the path termination node (S235). This completes the upstream continuity test. In the downstream direction, a continuity test is performed by the same process.
Japanese Patent No. 3938315 (FIGS. 4 and 11)

  However, in the conventional continuity confirmation method as shown in FIG. 15, the continuity test is started after all the signaling for setting the optical path is completed, so that the optical path setting time including the continuity confirmation becomes long. There is.

  In the conventional continuity check method shown in FIG. 16, for example, in the continuity test in the upstream direction, all nodes except for the path termination node of the set path need to check continuity. The determination time is longer than that in the case of determination, and as a result, the optical path setting time including conduction confirmation is increased.

  As described above, when the optical path setting time becomes long, the following problem occurs. For example, for an application that requires an optical path setup time on the order of seconds in an on-demand service using an optical path setup method based on the GMPLS technology, an increase in the optical path setup time leads to a delay in service start by the application. , Fatal. Therefore, there is a need for a method for confirming conduction at high speed when setting an optical path.

  Further, when setting a path, there is the following two problems when trying to conduct a continuity test in addition to signaling. First, there is a problem that the processing load of a communication device having a switch function increases. Secondly, at the same time, such a communication device has not only a device configuration for signaling processing but also a device configuration for continuity test, so that the number of parts increases and the communication device becomes enormous. There is also.

  The first problem, that is, when the processing load of a communication device having a switch function increases, the probability that a failure occurs in this communication device may increase accordingly. In addition, the second problem, that is, when a communication device having a switch function is enlarged, a limited space reserved for the switch device is occupied to install the enlarged communication device. There will be less space for the device.

  Therefore, the present invention provides a technique that solves the above-described problems, enables high-speed confirmation of optical path continuity in an optical network, and enables reduction in processing load and miniaturization of the switch device. The purpose is to do.

  In order to solve the above-described problem, the continuity confirmation method according to claim 1 is a communication device that transfers data of wavelength and TDM (time division multiplexing) by switching a path of an optical path by an optical switch of a switching unit; A signal transmission / reception device having a function of transferring a packet by passing the data to the communication device; and a data link connected between a plurality of nodes each indicating the communication device and the signal transmission / reception device to transmit an optical signal; And a control link that is connected between the nodes and transmits a control signal, and is generated by light sources in both nodes between two communication devices that indicate a start point node and an end point node of the optical path that is a continuity test target section. A conduction confirmation method in a conduction confirmation system for conducting conduction confirmation of the optical path by transmitting an optical signal, wherein the start node is A step of transmitting a signaling message for securing a bandwidth resource for the end point of the continuity test target section as an optical signal, and the end point node sets the bandwidth resource for the end point based on the reception status of the signaling message. A step of performing continuity confirmation for the end point by determining whether or not continuity is normal, and signaling to the start point node when it is determined that continuity of the band resource for the end point is normal Transmitting the message as an optical signal, and the start node is normal in the continuity of the band resource toward the start point of the continuity test target section based on the reception status of the signaling message transmitted from the end node. Determining whether or not the continuity is confirmed toward the start point, and When it is determined that the continuity is normal in the continuity check in the point direction, a step of transmitting a normality confirmation notification indicating the fact to the end node is executed.

  According to this procedure, in the conduction confirmation method of the conduction confirmation system, the establishment of the optical path and the conduction test of the established optical path are performed in parallel. In this case, first, a signaling message for ensuring that the start point node has a band toward the end point is transmitted as an optical signal. At this time, a signaling message, which is a control signal for securing a band for the end point, is transmitted through the data link for optical signals. That is, it is possible to simultaneously secure a band for the end point and transmit the test optical signal in the end point direction. As a result, the end point node that has received the signaling message for securing the band for the end point can quickly execute the continuity confirmation for the end point. Then, in the reverse direction, the end point node transmits a signaling message for ensuring a band toward the start point as an optical signal. Thereby, similarly, the starting point node can quickly execute the conduction confirmation toward the starting point. Therefore, it is possible to confirm the normality of the optical path at high speed as compared with the case where the control signal for securing the band and the optical signal for continuity test are transmitted separately. Furthermore, it is possible to reduce the processing load on the start node and the end node.

  Further, in order to solve the above-described problem, the continuity confirmation method according to claim 2 includes a communication device that transfers wavelength and TDM data by switching a path of an optical path by an optical switch of a switching unit, and the communication device. A signal transmission / reception device having a function of transferring a packet by passing the data to a data link; a data link connected between a plurality of nodes each indicating the communication device and the signal transmission / reception device; A communication link that is connected in between and transmits a control signal between the two communication devices indicating one node on the start point side and the other node on the end point side of the continuity test target section in which the optical path is divided for each link Continuity confirmation method in a continuity confirmation system for confirming continuity of the optical path for each link by transmitting an optical signal generated by a light source in both nodes Then, from the start node to the end node of the optical path, a set of two continuous communication devices is sequentially subjected to continuity check processing for each continuity test target section formed by shifting the combination one by one. And in the continuity check process, one node on the start point side of the continuity test target section transmits a signaling message as an optical signal for securing a band resource for the other node of the continuity test target section. And the other node determines whether or not the continuity of the band resource for the own node is normal based on the reception status of the signaling message, thereby confirming the continuity from the one node to the other node. And the next continuity test target section when it is determined that the continuity of the band resource for the local node is normal. And performing a step of transmitting a signaling message as an optical signal toward the opposite node of the continuity test target section, and when determining that the continuity is normal in the continuity confirmation for the end node, A set of two communication devices continuous from the end node to the start point node sequentially performs the continuity check process for each of the continuity test target sections formed by shifting the combination one by one, and the start point node However, when it is determined that the continuity is normal in the continuity confirmation for the own node, it is determined that the continuity of the bidirectional band resource of the optical path is normal.

  According to this procedure, in the continuity confirmation method of the continuity confirmation system, when performing the establishment of the optical path and the continuity test of the established optical path in parallel, the control signal for securing the bandwidth is used for the continuity test. Since it is transmitted as an optical signal, it is possible to check the normality of the optical path at high speed. In addition, since the continuity check process is sequentially performed for each continuity test target section in which the optical path is divided for each link, it is possible to identify the cause of the continuity failure and to grasp the continuity failure in a short time. Furthermore, the processing load on each communication device can be reduced.

  Further, in order to solve the above-described problem, the continuity confirmation method according to claim 3 includes a communication device that transfers wavelength and TDM data by switching a path of an optical path by an optical switch of a switching unit, and the communication device. A signal transmission / reception device having a function of transferring a packet by passing the data to a data link; a data link connected between a plurality of nodes each indicating the communication device and the signal transmission / reception device; A communication link that is connected in between and transmits a control signal between the two communication devices indicating one node on the start point side and the other node on the end point side of the continuity test target section in which the optical path is divided for each link Continuity confirmation method in a continuity confirmation system for confirming continuity of the optical path for each link by transmitting an optical signal generated by a light source in both nodes Then, from the start node to the end node of the optical path, a set of two continuous communication devices is sequentially subjected to continuity check processing for each continuity test target section formed by shifting the combination one by one. In the continuity check process, one of the nodes on the start point side of the continuity test target section performs a step of transmitting a signaling message as an optical signal for securing a band resource toward the end point of the continuity test target section. The other node on the end point side of the continuity test target section confirms whether or not the continuity of the band resource for the end point is normal based on the reception status of the signaling message, thereby confirming the continuity for the end point direction. And when it is determined that the continuity of the band resource toward the end point is normal, the Transmitting a nulling message as an optical signal, and the one node performs continuity of a band resource toward the start point of the continuity test target section based on a reception status of a signaling message transmitted from the other node. By determining whether the continuity is normal by determining whether the continuity is normal for the starting point, and when determining that the continuity is normal in the continuity confirmation for the starting point, a normality confirmation notification indicating that is provided. Transmitting to the other node, and when the end node receives the normality confirmation notification, determining that the continuity of the bidirectional band resource of the optical path is normal Features.

  According to this procedure, in the continuity confirmation method of the continuity confirmation system, when performing the establishment of the optical path and the continuity test of the established optical path in parallel, the control signal for securing the bandwidth is used for the continuity test. Since it is transmitted as an optical signal, it is possible to check the normality of the optical path at high speed. In addition, since the continuity check process is sequentially performed for each continuity test target section in which the optical path is divided for each link, it is possible to identify the cause of the continuity failure and to grasp the continuity failure in a short time. Furthermore, the processing load on each communication device can be reduced.

  The continuity check method according to claim 4 is the continuity check method according to claim 1 or claim 3, wherein when the start node determines that continuity is normal in the continuity check, the switching unit Further executing the step of setting the setting of the optical switch for data input / output for transferring the data, and the normality confirmation notification transmitted from the node opposite to the continuity test target section by the end point node The step of setting the optical switch of the switching unit for data input / output for transferring the data is further executed, triggered by the arrival of.

  According to such a procedure, since a dedicated notification message for changing the setting of the optical switch of the switching unit of the communication device is not necessary, the load on the communication device for receiving the message is reduced. Further, the communication apparatus can quickly shift from the process for confirming the success of the continuity test to the process for transferring data delivered from the signal transmitting / receiving apparatus.

  Further, the continuity check method according to claim 5 is the continuity check method according to claim 2, wherein when the start point node and the end point node determine that continuity is normal in the continuity check for the own node, The step of setting the optical switch of the switching unit for data input / output for transferring the data is further performed.

  According to such a procedure, since a dedicated notification message for changing the setting of the optical switch of the switching unit of the communication device is not necessary, the load on the communication device for receiving the message is reduced. Further, the communication apparatus can quickly shift from the process for confirming the success of the continuity test to the process for transferring data delivered from the signal transmitting / receiving apparatus.

  The continuity check method according to claim 6 is the continuity check method according to any one of claims 1 to 5, wherein a node that performs the continuity check is a band resource of the continuity test target section. When it is determined that the continuity is not normal, an unconfirmed normality notification indicating that is transmitted to a node facing the continuity test target section.

  According to such a procedure, in the continuity test target section, the node opposite to the end point node that is determined to be not normal is quickly recognized that the continuity is not normal, and the next step is to set a normal optical path. It is possible to move to the process in a short time.

  The continuity check method according to claim 7 is the continuity check method according to any one of claims 1 to 6, wherein a node that executes the continuity check faces the continuity test target section. When the strength of the signaling message received from the node is equal to or lower than a predetermined threshold, it is determined that the continuity of the band resource in the continuity test target section is not normal.

  According to this procedure, in the continuity test target section, the node receiving the normality unconfirmed notification recognizes that the quality of the transmitted optical signal is not good, and performs the next process for setting a normal optical path. It is possible to move in a short time.

  The continuity check method according to claim 8 is the continuity check method according to any one of claims 1 to 7, wherein a node that executes the continuity check faces the continuity test target section. When the signaling message transmitted from the node does not arrive even after a predetermined time has elapsed, it is determined that the continuity of the band resource in the continuity test target section is not normal.

  According to such a procedure, in a continuity test target section, a node that performs continuity confirmation reliably grasps that continuity has failed when a signaling message to be received does not arrive even after a predetermined time has elapsed. It is possible. Thereby, it is possible to move to the next process for setting a normal optical path in a short time.

  The continuity confirmation method according to claim 9 is the continuity confirmation method according to any one of claims 1 to 8, wherein a start node of the optical path and an end node of the optical path are: After determining that the continuity of the band resource of the optical path that is both the continuity test target section is normal, one node sends a BER measurement signal for measuring the BER (bit error rate) to the other node. A BER that executes a series of processes in which the other node receives the BER measurement signal and performs a step of measuring a BER from the received BER measurement signal in both directions of the optical path. A measurement process is performed.

  According to such a configuration, the continuity confirmation system performs not only the establishment of the optical path and its continuity test but also the BER measurement process, so that the quality of the signal transmitted through the established optical path can be measured. . Therefore, an optical path that does not satisfy a predetermined signal quality requirement is not used, and an optical path that satisfies the signal quality requirement can be provided to the user.

  Further, the continuity check method according to claim 10 is the continuity check method according to claim 9, wherein one of the nodes on the start point side of the continuity test target section performs the normal operation before the BER measurement process. As a sex confirmation notification, a message indicating that the BER measurement process is performed between both end points of the optical path following the continuity test of the continuity test target section is transmitted to the other node on the end point side of the continuity test target section, The start node of the optical path and the end node of the optical path switch the setting of the optical switch of the switching unit from the setting for continuity test to the setting for BER measurement before the BER measurement process, and the BER measurement process Thereafter, the setting of the optical switch of the switching unit is switched from the setting for BER measurement to the setting for data input / output for transferring the data.

  According to such a procedure, the end-point node of the optical path receives a message indicating that the BER measurement process is performed as a message indicating that the continuity is normal, and therefore performs extra processing associated with performing the BER measurement process. In addition, the continuity test process can be followed by the BER measurement process. Therefore, it becomes possible to start BER measurement in a short time from the end of the continuity test. Further, it is possible to shift from the end of the BER measurement to a process for transferring data in a short time.

  A continuity check program according to claim 11 is a communication device that functions as the continuity check method according to any one of claims 1 to 10 as one node on a start point side of the continuity test target section. This is a program for causing a computer to execute. By being configured in this way, a computer in which this program is installed can realize each function based on this program.

  A continuity check program according to claim 12 is a communication device that functions as the other node on the end point side of the continuity test target section according to any one of claims 1 to 10. This is a program for causing a computer to execute. By being configured in this way, a computer in which this program is installed can realize each function based on this program.

  The communication device according to claim 13 has a communication device that transfers wavelength and TDM data by switching a route of an optical path, and a function of transferring a packet by passing the data to the communication device. A signal transmission / reception device, a data link connected between a plurality of nodes respectively indicating the communication device and the signal transmission / reception device and transmitting an optical signal, and a control link connected between the nodes and transmitting a control signal. As the start point node in a continuity confirmation system for confirming the continuity of the optical path by transmitting an optical signal generated by a light source in both nodes between two communication devices indicating the start point node and the end point node of the optical path A functioning communication device comprising: a switching unit having an optical switch for switching a path of the optical path; and a band redirection toward an end point of the optical path. A signaling message for securing the source is transmitted as an optical signal, and whether or not conduction of band resources toward the start point of the optical path is normal based on a reception status of the signaling message transmitted as an optical signal from the end node If it is determined that the continuity is normal in the continuity confirmation for the starting point and the signaling message transmission / reception means for performing the continuity confirmation for the start point by determining whether or not the normality confirmation notification indicating that is the above Signaling message control means for transmitting to the end point node, and when it is determined that the continuity is normal in the continuity confirmation, an optical switch of the switching unit is provided so that the data passed from the signal transmitting / receiving device can be input / output Switching control means for controlling.

  According to such a configuration, the communication device transmits a signaling message for ensuring a bandwidth toward the end point of the optical path as an optical signal, so the time until the normality of conduction at the end node is confirmed is ensured. Therefore, the control signal and the optical signal for continuity test can be shortened as compared with the case where the signal is transmitted separately. In addition, since the communication device confirms the normality of conduction toward the start point of the optical path according to the reception status of the signaling message for ensuring the bandwidth toward the start point of the optical path, the time until confirmation of the normality of conduction is longer than before. Can also be shortened. Furthermore, the processing load of the communication device can be reduced, and the size can be reduced.

  The communication device according to claim 14 has a communication device that transfers wavelength and TDM data by switching a route of an optical path, and a function of transferring a packet by passing the data to the communication device. A signal transmission / reception device, a data link connected between a plurality of nodes respectively indicating the communication device and the signal transmission / reception device and transmitting an optical signal, and a control link connected between the nodes and transmitting a control signal. As an end point node in a continuity confirmation system for confirming continuity of the optical path by transmitting an optical signal generated by a light source in both nodes between two communication devices indicating a start point node and an end point node of the optical path A functioning communication device comprising: a switching unit having an optical switch for switching a path of the optical path; and an optical signal from the start node. The continuity confirmation for the end point is performed by determining whether the continuity of the band resource for the end point is normal based on the reception status of the signaling message to be transmitted. When it is determined that the signal is normal, the signaling message transmitting / receiving means for transmitting a signaling message as an optical signal toward the start point node, and the continuity in the continuity check for the start point transmitted from the start point node is normal. Signaling message control means for receiving a normality confirmation notification indicating that it has been determined, and an optical switch of the switching unit so that the data delivered from the signal transmitting / receiving device can be input and output when the normality confirmation notification is received And switching control means for controlling the operation.

  According to such a configuration, the communication apparatus receives a signaling message for ensuring a band toward the end point of the optical path as an optical signal. Therefore, the control signal for securing the band and the optical signal for continuity test are separately provided. Compared with the case of receiving the signal, the time required to confirm the normality of conduction can be shortened. In addition, since the communication device transmits a signaling message for ensuring the bandwidth toward the start point of the optical path as an optical signal, it is possible to shorten the time until confirmation of normality of conduction at the start point node compared to the conventional case. It is. Furthermore, the processing load of the communication device can be reduced, and the size can be reduced.

  The continuity confirmation system according to claim 15 is a communication device that transfers wavelength and TDM data by switching a path of an optical path, and a function that transfers packets by passing the data to the communication device. A signal transmission / reception device, a data link connected between a plurality of nodes each indicating the communication device and the signal transmission / reception device, and transmitting a control signal connected between the nodes, A continuity confirmation system for confirming the continuity of the optical path by transmitting an optical signal generated by a light source in both nodes between two communication devices indicating a start node and an end node of the optical path, A communication device according to claim 13 is provided as the start point node, and a communication device according to claim 14 is provided as the end point node. To.

  According to such a configuration, the start point node and the end point node of the optical path respectively transmit a signaling message for securing the bandwidth of the optical path as an optical signal, so that the control signal for securing the bandwidth and the light for continuity test are transmitted. Compared with the case where the signals are transmitted separately, it is possible to check the normality of the optical path at high speed. Furthermore, the processing load of the apparatus can be reduced in the entire system, and the apparatus can be downsized.

  According to the present invention, optical path continuity can be confirmed at high speed in an optical network, the processing load of the switch device can be reduced, and the device can be downsized.

  The best mode for carrying out the continuity confirmation system and communication device of the present invention (hereinafter referred to as “embodiment”) will be described in detail below with reference to the drawings.

(First embodiment)
[Overview of continuity check system]
FIG. 1 is an explanatory diagram showing an outline of a continuity confirmation system according to an embodiment of the present invention, where (a) shows an example of the overall configuration and (b) shows an example of a set path. As shown in FIG. 1A, the continuity confirmation system 1 includes a communication device 2 (2a, 2b, 2c, 2d) and a signal transmission / reception device 3 (3a, 3b, 3c) as a plurality of nodes connected by links. ). This network NW is operated by, for example, a communication carrier (carrier). In FIG. 1, the number of nodes is not particularly limited.

The communication apparatus 2 transfers data of wavelength and TDM (time division multiplexing) by switching a path of an optical path (hereinafter also simply referred to as a path). For example, a layer capable of establishing an optical path 1 device and an optical cross connect (OXC) device having a switching function.
The signal transmitting / receiving device 3 has a function of transferring a packet by passing data to the communication device 2, and is, for example, a router device.

  As shown in FIG. 1B, a data link 5 that transmits an optical signal and a control link 6 that transmits a control signal are connected between the nodes of the network NW. In the following description, one optical path having the communication device 2a shown in FIG. 1B as a start node, the communication device 2b as a relay node, and the communication device 2c as an end node will be described as an example.

  The continuity confirmation system 1 transmits a signaling message exchanged between the two communication devices (2a, 2c) indicating the start and end nodes of the optical path as an optical signal (test light) generated by the light sources in both nodes. By doing so, the conduction of the optical path is confirmed. When the optical path is normally established, data (optical signal) is transmitted between the signal transmitting / receiving apparatuses 3 that can transmit and receive the optical signal (data). The number of data links 5 can be set to an arbitrary number.

In this embodiment, the continuity confirmation system 1 is further provided with a control server (control device) 4 as shown in FIG.
The control server 4 controls each node of the network NW. The control server 4 and each node of the network NW can exchange control signals bidirectionally via the control link 6. The control server 4 has a function of accepting an optical path setting request from the outside of the continuity confirmation system 1, and when an optical path setting request is received, performs a route calculation to establish an appropriate path for the request. Then, a path establishment request (path setting request) is made to the communication device 2 or the like.

  In the present embodiment, the communication device 2 that has received the path setting request performs a test for continuity confirmation in parallel with establishing a path by flowing path establishment signaling between the communication devices 2. did. Further, RSVP (ReSerVation Protocol 1) is assumed as a signaling protocol exchanged between nodes, and RSVP is exchanged through a line (data link 5) through which an optical signal actually flows. Further, the communication device 2 that has received the RSVP Path Message executes a cross-connect setting for downstream (downstream direction) at the minimum. In the present embodiment, the cross-connect setting for upstream (upstream direction) is performed when an RSVP Resv Message that is a response to the RSVP Path Message is received. Note that when receiving the RSVP Path Message, the cross-connect setting for downstream (downstream direction) and upstream (upstream direction) may be performed simultaneously.

[Configuration of communication device]
FIG. 2 is a functional block diagram showing an example of the configuration of the communication apparatus according to the embodiment of the present invention.
The communication device 2 includes, for example, an arithmetic device such as a CPU (Central Processing Unit), a storage device such as a memory and a hard disk, a NIC (Network Interface Card) for communicating via a link, and an optical via a link. It comprises an interface for transmitting and receiving signals and control signals, a program, a light source for irradiating an optical signal (test light), and a receiver (light receiving means) for receiving the test light. This communication device 2 is realized by the hardware device and software cooperating to control the hardware resources described above by a program. As shown in FIG. 2, the input / output unit 10, the switching unit 20, , A storage unit 30, a control unit 40, and a signaling message transmission / reception unit 50.

  In the following description, it is assumed that the communication device 2 that functions as a start point node and an end point node has all the configurations shown in FIG. 2, and the communication device 2 that functions as a relay node does not include the signaling message transmission / reception unit 50. In addition, functions unique to the start point node and the end point node will be described, but it is needless to say that both functions may be provided. That is, the communication device 2 described as the start point node may be configured to function as the end point node depending on the case.

  The input / output unit 10 includes an interface (input interface) when an optical signal passing through the communication device 2 is input and an interface (output interface) when it is output. The input / output unit 10 inputs an optical signal (data, test optical signal) input from the outside to the input interface to the switching unit 20 and is appropriately switched by the switching unit 20, and then the optical signal from the output interface. (Data, test optical signal) is output to the outside.

The input / output unit 10 includes a server port 11 as an interface capable of communicating with the control server 4. The input / output unit 10 includes a path establishment port 12a and a data input / output port 13a as input interfaces, and a path establishment port 12b and a data input / output port 13b as output interfaces. Yes.
The path establishment ports 12a and 12b are interfaces for exchanging a signaling message (test light) transmitted as an optical signal when the path is established.
The data input / output ports 13a and 13b are interfaces used for transferring data (optical signals) as packets after the continuity test. The number of these ports can be set arbitrarily.

The server port 11 is connected with a cable (communication line) as a control link 6 constituting a management plane.
A cable (communication line) as a control link 6 for a control plane (C-plane) is connected to an interface for exchanging control signals.
An optical fiber cable as a data link 5 for a data plane (D-plane) is connected to an interface for exchanging optical signals (test light, data).

  The switching unit 20 includes an optical switch (hereinafter referred to as a switch SW) that switches the path of the optical path, and switches an optical signal that has arrived at the input interface of the input / output unit 10 to an appropriate output interface. When the switching unit 20 switches the switch SW under the control of the control unit 40, for example, the connection in the communication device 2 is switched from the path establishment port 12a side to the data input / output port 13a side and connected to the input interface. The external link connection destination is switched. The switching unit 20 is configured by, for example, a MEMS or a TO switch.

  The storage unit 30 stores a program that realizes each function of the communication device 2 and various types of data (for example, information such as interface information 31 and optical path information 32) that the control unit 40 refers to. The storage unit 30 is realized by a storage device such as a random access memory (RAM), a flash memory, and a hard disk drive (HDD).

FIG. 3 is a diagram illustrating an example of interface information stored in the communication apparatus illustrated in FIG.
The interface information 31 includes an ID (interface ID), an address, an ID of the opposite node (adjacent node) (opposite node ID), and an address of the interface of the opposite node (opposite node IF address) for the input interface and the output interface. ), Information such as wavelength. The address represents, for example, an IP address. The wavelength represents the wavelength supported by each interface. These information shall be set manually or collected by protocol. The interface information 31 is referred to when the control unit 40 controls the switching unit 20. Note that the communication device 2 rewrites the interface information 31 to the latest information periodically or before starting the continuity confirmation process.

  FIG. 4 is a diagram illustrating an example of optical path information stored in the communication apparatus illustrated in FIG. The optical path information 32 includes an optical path ID (path ID), an input interface ID, an output interface ID, a path state, and the like. The optical path information 32 is referred to when the control unit 40 manages the optical path.

  The control unit 40 can be connected to the input / output interface of the input / output unit 10 via the switching unit 20, and has a function of communicating with other nodes and the control server 4. As shown in FIG. 2, the switching control unit 41 and the signaling message control unit 42 are provided as functions realized by executing a predetermined program stored in.

  The switching control unit 41 controls the switch for causing the switching unit 20 to switch the optical signal from the input interface to an appropriate output interface. The switching control means 41 has a function of switching an optical signal (data) transferred as a packet and a function of switching a test optical signal. Which output interface the switching control unit 41 should switch to is determined by referring to the information in the storage unit 30. It is also possible to make a determination by setting from the outside of the communication device 2.

When the switching control means 41 functions as a starting point node, the switching control unit 41 can input / output data transferred from the signal transmitting / receiving device 3 when it is determined that the continuity is normal in the continuity confirmation in the signaling message transmitting / receiving unit 50. 20 switches SW are controlled.
When the switching control unit 41 functions as an end node, when the normality confirmation notification is received from the start node, the switching control unit 41 controls the switch SW of the switching unit 20 so that the data transferred from the signal transmitting / receiving device 3 can be input / output. To do.

  The signaling message control means 42 carries out processing of signaling messages for path establishment and continuity confirmation. The signaling message control means 42 processes a message input from the outside via the signaling message transmission / reception unit 50, the switching unit 20 and the input / output unit 10, and sends the processed message to the outside via the signaling message transmission / reception unit 50 or the like. Or output.

When the signaling message control unit 42 functions as a start point node and determines that the continuity is normal in the continuity check toward the start point, the signaling message control unit 42 transmits a normality confirmation notification indicating that to the end point node.
When the signaling message control unit 42 functions as an end point node, the signaling message control unit 42 receives a normality confirmation notification transmitted from the start point node and indicating that continuity is determined to be normal in the continuity confirmation toward the start point.

  The signaling message transmission / reception unit (signaling message transmission / reception means) 50 can be connected to the input / output interface of the input / output unit 10 via the switching unit 20 and has a function of communicating with other nodes and the control server 4. Although not shown, the light source for irradiating the optical signal (test light), the receiver (light receiving means) for receiving the test light, and the intensity of the test light by the signal output from this receiver And a processing unit for executing a process of performing continuity confirmation.

  The processing unit (not shown) of the signaling message transmission / reception unit 50 is realized by a CPU or the like executing a predetermined program stored in the storage unit 30. When the signaling message control unit 42 sets the optical path, the optical path is set. In order to confirm the normality of the light, control for transmitting an optical signal (test light) to the opposite node and control for confirming the normality of conduction by receiving the test light from the opposite node are performed.

  When the signaling message transmission / reception unit 50 functions as a start point node, the signaling message transmission unit 50 transmits a signaling message for securing a band resource for the end point of the optical path as an optical signal, and the reception status of the signaling message transmitted as an optical signal from the end point node On the basis of the above, it is determined whether or not the conduction of the band resource toward the start point of the optical path is normal, thereby confirming the conduction toward the start point.

  When the signaling message transmission / reception unit 50 functions as an end point node, the signaling message transmission / reception unit 50 determines whether or not the continuity of the band resource toward the end point is normal based on the reception state of the signaling message transmitted as an optical signal from the start point node. When the continuity confirmation for the end point is executed and it is determined that the continuity of the band resource for the end point is normal, a signaling message is transmitted as an optical signal toward the start point node.

  In the present embodiment, the signaling message transmitting / receiving unit 50 determines that conduction is normally performed (conduction OK) when the intensity (power) of the received test light is equal to or greater than a predetermined threshold. Further, the signaling message transmission / reception unit 50 is not normally connected when the test light transmitted from the node facing the optical path does not arrive even after a predetermined time has elapsed (conduction NG). Is determined. The signaling message transmitting / receiving unit 50 determines that the continuity is not normal even when the test light is received and the power of the test light is smaller than a predetermined threshold value.

[Control server configuration]
FIG. 5 is a block diagram showing an example of the configuration of the control server shown in FIG. As illustrated in FIG. 5, the control server 4 includes an input / output unit 60, a transmission / reception unit 70, a storage unit 80, and a control unit 90. The input / output unit 60 is an input / output interface that can communicate with each node of the network NW (see FIG. 1). The transmission / reception unit 70 is a communication device that exchanges control signals such as various messages with each node of the network NW (see FIG. 1). Further, the transmission / reception unit 70 receives a request for establishing a path (for example, path A) (an optical path setting request) from an external device or the like of the continuity confirmation system 1 via the input / output unit 60. This path establishment request includes information necessary for path establishment, such as the end point of path A and the bandwidth required for path A.

  The storage unit 80 is realized by a storage device such as a RAM or an HDD, and a program for realizing each function of the control server 4 and various data (for example, interface information 81, optical path information 82, etc.) referred to by the control unit 90. Information). The interface information 81 and the optical path information 82 stored in the storage unit 80 are, for example, information obtained by accumulating individual node information exemplified in FIGS. 3 and 4 for each node.

  As shown in FIG. 5, the control unit 90 includes a route calculation unit 91 and a node control unit 92 as functions realized by a CPU or the like executing a predetermined program stored in the storage unit 30. Yes. The route calculation unit 91 uses the optical path setting request received by the transmission / reception unit 70 as a trigger, performs route calculation to establish an appropriate path for the request, and outputs the calculated route to the node control unit 92.

The node control unit 92 gives a path establishment instruction to a node such as the communication apparatus 2 so as to establish a path along the route calculated by the route calculation unit 91. This path establishment instruction includes the node address of the node through which the path (for example, path A) requested by the path establishment request (optical path setting request) passes, the bandwidth of the path A, and the like.
In addition, the node control unit 92 accepts success / failure of the continuity test from each node, and when the NG is accepted, instructs the route calculation unit 91 to recalculate the route.

  In this embodiment, the node control unit 92 transmits a path establishment instruction as an instruction to secure bandwidth resources of the optical path by exchanging a signaling protocol between the start point node and the end point node according to the operation of the operator of the control server 4. Send.

[Operation of continuity check system]
Next, with reference to FIG. 6 to FIG. 8 (refer to FIG. 1, FIG. 2 and FIG. 5 as appropriate), the continuity confirmation processing procedure of the continuity confirmation system 1 will be described. FIG. 6 is a sequence diagram showing the flow of processing when the normality of conduction is confirmed in both directions, and FIGS. 7 and 8 are the flow of processing when the normality of conduction of either one cannot be confirmed. FIG.

[Flow of processing when normality of conduction is confirmed in both directions]
First, with reference to FIG. 6, the flow of processing when normality of conduction in both directions has been confirmed will be described in detail. In advance, the start point node 2a and the end point node 2c set the switch SW of the switching unit 20 for the continuity test. First, when the control server 4 receives a request for establishing a path (referred to as path A) shown in FIG. 1B, for example, from an external device of the continuity confirmation system 1 via the input / output unit 60, the control server 4 Is used as a trigger to calculate the path A (step S1), and a path establishment instruction is issued via the control link 6 to the start node (communication device) 2a of the path A (step S2).

  The source node 2a that has received the path establishment instruction from the control server 4 performs a path establishment process by transmitting a signaling protocol message by the signaling message control means 42 of the control unit 40. The start node 2a transmits, for example, an RSVP Path Message (test light) of a signaling protocol from the data link 5 to the end node (communication device) 2c via the relay node (communication device) 2b. By using the RSVP Path Message (test light), a band resource for the path A is secured from the end node 2c toward the start node 2a (upstream direction) (step S3). Further, in parallel with the process of transmitting the RSVP Path Message (test light), the start node 2a receives the path A information received as a path establishment instruction from the control server 4 in the interface information 31 and the optical path information 32 of the storage unit 30. To store.

  On the other hand, when the RSVP Path Message (test light) transmitted from the start point node 2a reaches the end point node 2c, the end point node 2c determines whether the downstream continuity is normally performed by the signaling message transmitting / receiving unit 50. (Step S4). If the end node 2c determines that the continuity is normal (step S4: OK), the RSVP Resv Message (test light) is relayed from the data link 5 toward the start point node 2a (in the upstream direction) to confirm the continuity. It transmits via the node (communication device) 2b (step S5). This RSVP Resv Message is transmitted as a normality confirmation notification in the downstream direction.

  The source node 2a that has received the RSVP Resv message from the end node 2c recognizes that the downstream normality has been confirmed, and whether or not the upstream continuity has been normally performed by the signaling message transmission / reception unit 50. Is determined (step S6). When the start point node 2a determines that the continuity is normally performed (step S6: OK), the signaling message transmitting / receiving unit 50 transmits a signaling message (normality confirmation notification) for notifying the normality to the end point node 2c. (Step S7). An example of this message is an RSVP Resvconf message. The start node 2a transmits an RSVP Resvconf message via the control link 6. Then, the source node 2a that has transmitted the signaling message notifying normality of conduction sets the switch port as a data input / output port, and prepares for reception of an actual optical signal (step S8). On the other hand, the end node 2c that has received the signaling message (RSVP Resvconf message) for notifying the normality in the upstream direction from the start point node 2a recognizes that the normality in the upstream direction has been confirmed, and the switching control means 41 The switch SW of the switching unit 20 is switched to the data input / output setting (step S9) to prepare for receiving an actual optical signal (data).

  In addition, following step S8, the start node 2a uses the signaling message control means 42 of the control unit 40 to indicate that the continuity confirmation (communication confirmation) is normal (conduction normality) and the switch setting completion. (Conduction OK notification) is transmitted to the control server 4 via the control link 6 (step S10). Similarly, the end node 2c notifies the control server 4 of the completion of the switch setting (step S11). As a result, data (optical signal) is transmitted from the start node 2a to the end node 2c (step S12).

[Flow of processing when the start node cannot confirm the normality of continuity]
Next, with reference to FIG. 7, the flow of processing when the starting point node cannot confirm the normality of conduction will be described. The same processes as those in FIG. 6 are denoted by the same reference numerals, and redundant description will be omitted, and will be simplified as appropriate. Each process of step S1-step S5 shown in FIG. 7 is the same. However, in step S5, it is assumed that the RSVP Resv message transmitted by the end point node 2c has not arrived at the start point node 2a for some reason (step S21: disruption). In this case, the start point node 2a determines that the continuity is not normally performed by the signaling message transmission / reception unit 50 (step S22: OK / NG determination → NG). Even if the test light is received and the power of the test light is smaller than a predetermined threshold value, the start point node 2a determines that the conduction is not normal.

  Then, the source node 2a transmits, to the control server 4, a message (notification of continuity NG) notifying that the normality of continuity has not been confirmed by the signaling message transmission / reception unit 50 (step S23). Thereby, the control server 4 performs recalculation to search for another route for the path A (step S24), and returns to step S2.

  Then, the start point node 2a transmits an RSVP path release message (notice of normality confirmation) from the control link 6 to the end point node 2c via the relay node 2b (step S25). This RSVP path release message is a message indicating that the continuity of the band resources of the optical path is not normal. With this message, it is possible to release the bandwidth resource for path A that has already been secured by the signaling protocol. Then, the end node 2c that has received the path release message recognizes that the normality of conduction has not been confirmed (conduction NG) (step S26), and the control unit 40 releases the bandwidth resource for path A. RSVP path release message is transmitted to (step S27).

[Processing flow when the destination node cannot confirm the normality of continuity]
Next, with reference to FIG. 8, the flow of processing when the end point node cannot confirm the normality of conduction will be described. The same processes as those in FIG. 6 are denoted by the same reference numerals, and redundant description will be omitted, and will be simplified as appropriate. Each process of step S1-step S3 shown in FIG. 8 is the same. However, in step S3, it is assumed that the test light transmitted from the start point node 2a has not reached the end point node 2c for some reason (step S31: disruption). In this case, the RSVP Path Message (test light) transmitted from the start point node 2a does not return an RSVP Resv Message (path establishment response) from the end point node 2c even if a predetermined time has elapsed since the start of transmission. With this as a trigger, the signaling message transmission / reception unit 50 determines that the continuity has not been normally performed (step S32: OK / NG determination → NG). Then, the start node 2a terminates the transmission of the test light directed toward the end node 2c (downstream) by the continuity confirmation unit 50, and notifies that the normality of continuity cannot be confirmed by the signaling message control means 42. Message (conduction NG notification) to be transmitted to the control server 4 (step S33).

  Since the subsequent processes in steps S34 to S37 are processes in which the start point and the end point are replaced with respect to the processes in step S24 to step S27 in FIG. Even if the end node 2c receives the test light transmitted by the start point node 2a in step S3, if the test light power is smaller than a predetermined threshold, step S32 (NG determination) and The end node 2c performs the process of step S33.

  According to the first embodiment, since the start point node 2a and the end point node 2c of the optical path each transmit a signaling message for securing the bandwidth of the optical path as an optical signal, the signaling message for securing the bandwidth is connected to the signaling message. Compared with the case where the test optical signal is transmitted separately, it is possible to confirm the normality of the optical path at high speed. Furthermore, the entire continuity confirmation system 1 can reduce the processing load of the communication device 2, and the communication device 2 can be downsized.

  Further, when the continuity is not normal, the communication device 2 quickly establishes a recalculated path by notifying the control server 4 and when the two-way continuity is normal, the communication device 2 sets the switch SW. Since it is set for data input / output, it is possible to quickly shift from the continuity test process to the process for transferring data.

(Second Embodiment)
FIG. 9 is a block diagram showing an example of the configuration of a communication apparatus according to another embodiment of the present invention.
The continuity system of the second embodiment is the same as that of the communication system 2A shown in FIG. 9 except that the BER measurement function unit 100 is provided and the input / output unit 10 is further provided with BER measurement ports 14a and 14b. This is the same as in the first embodiment. In the following, functions and operations different from those of the first embodiment will be described, description of the same configuration as that of the first embodiment and drawings will be omitted, and the same reference numerals will be given to the same configuration.

  In the second embodiment, it is assumed that the communication device 2 </ b> A that functions as the start point node and the end point node includes the BER measurement function unit 100. Further, the BER measurement function unit 100 has a function as a measurement side and a function as a measured side, which will be described individually, but are assumed to have both functions.

  The BER measurement function unit 100 can be connected to the input / output interface of the input / output unit 10 via the switching unit 20, and although not shown, a light source for emitting a BER measurement signal, and a BER measurement signal A receiver (light receiving means) for receiving and a BER measuring device are provided. The BER measurement signal is also used as a test light (test optical signal) generated from a light source (not shown) of the signaling message transmission / reception unit 50, and a signaling message transmission / reception is performed as a receiver (light receiving means) for receiving the BER measurement signal. The receiver 50 (light receiving means) (not shown) of the unit 50 may be used.

  As a measurement-side function, the BER measurement function unit 100 transmits a BER measurement signal for measuring a BER (bit error rate) from the data link 5 to the other end node. The node on the BER measurement side sets the switching unit 20 for BER by the switching control means 41 before actually transmitting the BER measurement signal. For example, the end point node 2c setting the switching unit 20 for BER means setting the BER measurement signal output from the BER measurement function unit 100 of the end point node 2c to be transmitted toward the start point node 2a. To do. As a result, a BER measurement signal is transmitted via the BER measurement port 14b of the output interface. In the second embodiment, when the BER measurement function unit 100 of the end point node 2c receives a message indicating that the BER measurement process is performed between the both end points of the optical path from the start point node 2a, the switching unit 20 is changed. Set for BER.

  The BER measurement function unit 100 receives a BER measurement signal from the other end point node via the BER measurement port 14a as a function on the measured side, and measures the BER from the received BER measurement signal. Before actually receiving the BER measurement signal, the node on the BER measurement side prepares to receive the BER measurement signal via the BER measurement port 14a of the input interface. The BER measurement function unit 100 outputs the BER measurement result to a processing unit (not shown) of the signaling message transmission / reception unit 50. This processing unit (not shown) determines whether or not the measured BER is within the range of values to be satisfied (required conditions) (OK / NG determination), and whether or not the conditions are satisfied (OK notification or NG notification). ) To the control server 4.

  In the second embodiment, the value instructed by the user at the time of request for establishing a path is used as the BER value to be satisfied. Therefore, the value designated by the user is notified from the control server 4 to the endpoint node as a BER measurement preparation instruction along with the path establishment instruction each time. In this case, the BER measurement preparation instruction includes a BER value to be satisfied, a measurement time, a BER measurement signal type, and the like. Note that the BER value to be satisfied is not limited to this, and can be determined in advance on the continuity confirmation system side. In this case, the BER value to be satisfied can be set in advance at the node at the end point.

[Operation of continuity check system]
Next, with reference to FIGS. 10 to 12 (refer to FIGS. 1, 5, 6 and 9 as appropriate), an operation procedure in the continuity confirmation system according to the second embodiment for performing BER measurement as well as continuity confirmation when a path is established will be described. To do. FIG. 10 is a sequence diagram showing the flow of processing when the BER conditions are satisfied in both directions, FIG. 11 is a sequence diagram showing details of the BER processing, and FIG. 12 shows either BER. It is a sequence diagram which shows the flow of a process when these conditions cannot be satisfied.

[Flow of processing when BER conditions are satisfied in both directions]
First, with reference to FIG. 10, the flow of processing when the BER condition is satisfied in both directions will be described. The same processes as those in FIG. 6 are denoted by the same reference numerals, and redundant description will be omitted, and will be simplified as appropriate. As a premise of step S1, it is assumed that the control server 4 receives a request for measuring a BER in order to transmit a signal in a good quality state at the same time as a request for establishing a path A. Thereby, the control server 4 issues a BER measurement preparation instruction together with the path establishment instruction to the start point node 2a after the route calculation (step S1) (step S2a). Henceforth, each process of step S3-step S6 shown in FIG. 10 is the same as that of FIG. Subsequent to step S6, the start point node 2a transmits a message (BER measurement notification message) for notifying that BER measurement is performed (step S41). This message also has a meaning of a message (FIG. 6: step S7) for notifying that conduction is normal. The BER measurement notification message is not limited to a signaling protocol message, but may be a message of another protocol.

  And each process of step S42-step S44 following step S41 is the same as each process of step S8-step S10 shown in FIG. However, in steps S42 and S44, the switch SW is not set for data input / output, but is set for BER. Next, the end node 2c transmits a message (BER measurement notification reception message) indicating that the BER measurement notification has been received to the start node 2a (step S45).

  And after the bidirectional | two-way conduction | electrical_connection confirmation of the path | pass to establish is successful by the process to step S45, the starting point node 2a prepares for performing the BER measurement process (step S46a) of step S46. In addition, the end node 2c prepares for performing the BER measurement process (step S46b) in step S46.

  Reference is now made to FIG. In the BER measurement process, first, in the BER measurement from the start node 2a to the end node 2c (downstream direction), in step S46a, the end node 2c receives the BER measurement notification message (step S41) and actually measures the BER. Suppose you are ready to do. Then, the start point node 2a prepares to output a signal for BER measurement, and outputs a signal for BER measurement when ready (step S51).

  The end node 2c that has received the signal for BER measurement from the start point node 2a measures the BER, determines whether or not the measured BER satisfies the required conditions (step S52: OK / NG determination), and determines The result is notified to the control server 4 as a BER determination notification (OK notification or NG notification) (step S53), and the measurement in the downstream direction is terminated (step S54).

  The control server 4 that has received the BER determination notification (OK notification or NG notification) from the end node 2c issues an instruction to end the signal output for BER measurement to the start point node 2a (step S55). The start point node 2a that has received the instruction ends the signal output for BER measurement (step S56).

  When the start point node 2a and the end point node 2c complete the BER measurement in the direction from the start point node 2a to the end point node 2c (step S46a), the start point node 2a and the end point node 2c perform reverse (upstream) BER measurement (step S46b). A series of processing (step S61 to step S66) indicating step S46b corresponds to processing in which the role of the start node 2a and the role of the end node 2c are interchanged in step S46a, and thus description thereof is omitted.

  Then, as shown in FIG. 10, when the control server 4 receives an OK notification from the end node 2c (step S71) and also receives an OK notification from the start point node 2a (step S72), the BER is set in both directions. Will be satisfied. In this case, the control server 4 issues an instruction (path switching instruction) to set the switch SW of the switching unit 20 for data input / output to the start node 2a and the end node 2c (step S73). Then, the start point node 2a and the end point node 2c that have received the instruction (path switching instruction) respectively set the switch SW of the switching unit 20 for data input / output by the control unit 40 (steps S74 and S75). As a result, data (optical signal) is transmitted from the start point node 2a to the end point node 2c (step S76).

  On the other hand, when the BER does not satisfy the required condition even in one direction, for example, when the end node 2c transmits an NG notification to the control server 4 as shown in FIG. 12 (step S81), the control server 4 Is recalculated in order to find (step S82). At this time, the node (end point node 2c) determined not to satisfy the BER transmits an RSVP path release message toward the other end point node (start point node 2a) (step S83).

  In the second embodiment, not only the establishment of the optical path and its continuity test but also the BER measurement process is performed, so that the quality of the signal transmitted through the established optical path can be measured. In addition, when a predetermined signal quality requirement is not satisfied, a recalculated path is established by promptly notifying the control server 4, bidirectional conduction is normal, and signal quality Since the switch SW is set for data input / output when the required conditions are satisfied, it is possible to provide the user with an optical path that satisfies the signal quality requirements.

(Third embodiment)
The third embodiment differs from the first and second embodiments in that the communication device 2 that functions as a relay node also includes a signaling message transmission / reception unit 50. Therefore, the same configuration and the same operation are denoted by the same reference numerals, and the drawings and description are omitted as appropriate. FIG. 13 is a flowchart showing a flow of processing corresponding to success or failure of the continuity test in the continuity confirmation system according to another embodiment of the present invention. The same processes as those in FIG. 6 are denoted by the same reference numerals, and redundant description will be omitted, and will be simplified as appropriate.

  First, when receiving a request for establishing a path (for example, path A), the control server 4 calculates a path of the path A (step S91), and issues a path establishment instruction to the start node 2a of the path A (step S92). ). The start node 2a transmits, for example, an RSVP Path Message (test light) of a signaling protocol from the data link 5 to the relay node 2b (step S93a). The relay node 2b determines whether or not conduction in the downstream direction is normally performed (step S94a).

  If it is determined in step S94 that the relay node 2b is not normal, the relay node 2b sends an RSVP path release message from the control link 6 to the start node 2a that is the opposite node of the link (continuity test target section) on which the continuity test is performed. (Normal unconfirmed notification) is transmitted (step S94: NG).

  On the other hand, if it is determined in step S94 that the relay node 2b is normal, the relay node 2b sends the received RSVP Path Message (test light) from the data link 5 to the end point node 2c that is the opposite node in the next continuity test target section. ) Is transferred (step S94: OK). In this case, the same processing is performed in the next continuity test target section. However, in this example, since there is one relay node 2b and the next continuity test target section is the last continuity test target section in the downstream direction, special processing is performed. First, the end point node 2c determines whether or not conduction in the downstream direction is normally performed as usual (step S95a).

  If it is determined in step S95 that the node is not normal, the end point node 2c sends an RSVP path release message from the control link 6 to the relay node 2b that is the opposite node of the link (continuity test target section) on which the continuity test was performed. (Normality unconfirmed notification) is transmitted (step S95: NG). This RSVP path release message is transferred to the start node 2a. In this case, the start point node 2a transmits a conduction NG notification to the control server 4 (step S96a). Thereby, the control server 4 recalculates the route.

  On the other hand, if it is determined in step S95 that the node is normal, the end node 2c switches the port of the switch SW of the switching unit 20 to the data input / output setting (step S97a), and accepts the actual optical signal (data). Prepare. Then, the end point node 2c transmits to the control server 4 a continuity OK notification indicating that the continuity is normal and a SW setting completion notification indicating completion of the switch setting (step S98a).

  Since the above-described steps S93a to S98a are continuity tests in the downstream direction of the optical path (path A), the same processing is subsequently performed in the upstream direction (steps S93b to S98b). This is because the end point node 2c transmits an RSVP Resv Message (test light) from the data link 5 toward the start point node 2a (upstream) in accordance with the received RSVP Path Message (test light). ) By starting the process of transmitting via 2b, it can be performed in the same way as in the downstream direction. Therefore, the description of the upstream continuity test is omitted. Finally, if the start-point node 2a determines that the continuity is normal in the continuity confirmation toward the own node (upstream direction), the start-point node 2a determines that the continuity of the bidirectional band resource of the optical path is normal. The bi-directional continuity test ends. As a result, data (optical signal) is transmitted from the start node 2a to the end node 2c (step S99). As another method for starting the upstream continuity test, the end point node 2c can wait for an instruction from the control server 4 and transmit an RSVP Resv Message (test light).

  In the third embodiment, light generated by light sources in both nodes between two communication devices indicating one node on the start point side and the other node on the end point side of the continuity test target section in which the optical path is divided for each link. By transmitting a signal, the continuity of the optical path is confirmed for each link. Then, as illustrated in FIG. 13, continuity confirmation is performed for each continuity test target section formed by shifting a pair of two continuous communication devices one by one from the start node 2a to the end node 2c of the optical path. Processing is performed sequentially. Here, there may be a plurality of relay nodes 2b. In the first and second embodiments, the continuity test target section is the entire optical path.

  According to the third embodiment, the conduction normality of the optical path can be confirmed at high speed, the processing load of each communication device can be reduced, and the conduction test target section in which the optical path is divided for each link. Since the conduction confirmation process is sequentially performed every time, it is possible to identify the cause of the conduction failure and to grasp the conduction failure in a short time.

(Fourth embodiment)
In the fourth embodiment, the relay node also includes the signaling message transmission / reception unit 50 and performs a continuity test for each link, which is a modification of the third embodiment. Therefore, the same configuration and the same operation are denoted by the same reference numerals, and the drawings and description are omitted as appropriate. FIG. 14 is a flowchart showing a flow of processing until continuity is confirmed by a continuity confirmation system according to still another embodiment of the present invention. The same processes as those in FIG. 6 are denoted by the same reference numerals, and redundant description will be omitted, and will be simplified as appropriate.

  Each process of step S1-step S8, S10 shown in FIG. 14 is the same. However, the relay node 2b performs the same process before the end node 2c determines whether or not conduction is normally performed by the Path Message. That is, in step S3, when the relay node 2b receives the RSVP Path Message in the first link processing, the received Path Message is transferred to the end point node 2c (Step S101), and whether or not conduction has been normally performed. If the continuity is normal (step S4: OK), an RSVP Resv Message (test light) is transmitted toward the start node 2a (step S5). Then, the start node 2a that has received the RSVP Resv message from the relay node 2b determines whether or not the continuity is normally performed (step S6). A message is transmitted to the relay node 2b (step S7), and the setting of the switch SW is switched (step S8).

  In the processing of the next link, the end node 2c receives the Path Message transferred in step S101, and performs continuity confirmation processing between the relay node 2b and the end node 2c (steps S101 to S105). These series of processes are the same as the continuity confirmation process (steps S3 to S7) performed between the start node 2a and the relay node 2b. When receiving the normality confirmation notification (RSVP Resvconf message) (step S105), the end node 2c determines that the continuity of the bidirectional band resource of the optical path is normal. When the conduction is normally performed as described above, the end point node 2c switches the setting of the switch SW (step S106), and a message indicating that (conduction OK notification, SW setting completion notification) is sent to the control server 4. Transmit (step S107). As a result, data (optical signal) is transmitted from the start node 2a to the end node 2c (step S108).

  According to the fourth embodiment, the conduction normality of the optical path can be confirmed at high speed, the processing load of each communication device can be reduced, and the continuity test target section in which the optical path is divided for each link. Since the conduction confirmation process is sequentially performed every time, it is possible to identify the cause of the conduction failure and to grasp the conduction failure in a short time.

  As mentioned above, although each embodiment of this invention was described, this invention is not limited to these, It can implement in the range which does not change the meaning. For example, in the second embodiment, it has been described that the BER measurement is performed after the continuity test. However, the continuity test can also be performed in combination with the BER measurement.

  In this case, although not shown in the figure, as in the process shown in FIG. 10, the RSVP Path Message (test) is used as the BER measurement signal in the step (S3) in which the start node 2a transmits the RSVP Path Message (test light). Light). Then, in the step (S4) in which the end point node 2c executes continuity confirmation, the RSVP Path Message (test light) transmitted from the start point node 2a is received, and the continuity of the band resource toward the end point of the optical path is normal. At the step (S5) of determining whether or not there is, measuring the BER from the received RSVP Path Message (test light), and further transmitting the RSVP Path Message (test light), RSVP Resv Send a message (test light). Subsequently, in the step (S6) in which the start point node 2a performs continuity confirmation, the RSVP Resv Message (test light) transmitted from the end point node 2c is received, and the continuity of the band resource toward the start point of the optical path is normal. And BER may be measured from the received RSVP Resv Message (test light). Here, for the setting of the switch SW, the setting for the continuity test also serves as the setting for the BER. Thereby, it is possible to complete | finish in a short time rather than the case where a continuity test and a BER measurement are implemented separately. Therefore, it is possible to quickly provide the user with an optical path that satisfies the signal quality requirements.

  In addition, one node on the start point side of the continuity test target section is the above-described switching control unit 41, signaling message control unit 42, and signaling message transmission / reception unit. It can be realized by operating with a program that functions as 50 processing units (not shown). This program can also be written and distributed on a recording medium such as a CD-ROM.

  Similarly, the other node on the end point side of the continuity test target section transmits the layer 1 device or the optical cross-connect device computer on the end side of the optical path to the switching control means 41, signaling message control means 42, and signaling message transmission / reception described above. It can be realized by operating with a program that functions as a processing unit (not shown) of the unit 50. This program can also be written and distributed on a recording medium such as a CD-ROM.

  These programs may be transmitted from a computer system storing the program in a storage device or the like to another computer system via a transmission medium or by a transmission wave in the transmission medium. Here, the “transmission medium” for transmitting the program refers to a medium having a function of transmitting information such as a network such as the Internet or a communication line such as a telephone line. These programs may be for realizing a part of the above-described processing. Furthermore, what can implement | achieve the above-mentioned process in combination with the program already recorded on another apparatus, what is called a difference file (difference program) may be sufficient.

It is explanatory drawing which shows the outline | summary of the conduction | electrical_connection confirmation system which concerns on embodiment of this invention, Comprising: (a) has shown an example of the whole structure, (b) has shown an example of the path | pass set, respectively. It is a functional block diagram which shows an example of a structure of the communication apparatus which concerns on embodiment of this invention. It is a figure which shows an example of the interface information which the communication apparatus shown in FIG. 2 memorize | stores. It is a figure which shows an example of the optical path information which the communication apparatus shown in FIG. 2 memorize | stores. It is a block diagram which shows an example of a structure of the control server shown in FIG. It is a sequence diagram which shows the flow of a process until confirming continuity with the continuity confirmation system which concerns on embodiment of this invention. It is a sequence diagram which shows the flow of a process when upstream conduction | electrical_connection is not confirmed with the conduction | electrical_connection confirmation system which concerns on embodiment of this invention. It is a sequence diagram which shows the flow of a process when downstream conduction | electrical_connection is not confirmed by the conduction confirmation system which concerns on embodiment of this invention. It is a block diagram which shows an example of a structure of the communication apparatus which concerns on other embodiment of this invention. It is a sequence diagram which shows the flow of a process until confirming conduction | electrical_connection of a high quality optical signal with the conduction confirmation system which concerns on other embodiment of this invention. It is a sequence diagram which shows the flow of the BER measurement process shown in FIG. It is a sequence diagram which shows the flow of a process when the conduction | electrical_connection of a high quality optical signal is not confirmed with the conduction | electrical_connection confirmation system which concerns on other embodiment of this invention. It is a flowchart which shows the flow of the process corresponding to the success or failure of a continuity test in the continuity confirmation system which concerns on other embodiment of this invention. It is a flowchart which shows the flow of a process until confirming continuity with the continuity confirmation system which concerns on further another embodiment of this invention. It is a sequence diagram which shows the flow of a process until it confirms continuity with the conventional continuity confirmation method. It is a sequence diagram which shows the flow of a process until it confirms continuity with the other conventional continuity confirmation method.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Continuity confirmation system 2 (2a, 2b, 2c), 2A Communication apparatus 3 (3a, 3b, 3c) Signal transmission / reception apparatus 4 Control server (control apparatus)
5 Data link 6 Control link 10 Input / output unit 11 Server port 12a, 12b Path establishment port 13a, 13b Data input / output port 14a, 14b BER measurement port 20 Switching unit 30 Storage unit 31 Interface information 32 Optical path information 40 Control unit 41 Switching control unit 42 Signaling message control unit 50 Signaling message transmission / reception unit (signaling message transmission / reception unit)
60 I / O unit 70 Transmission / reception unit 80 Storage unit 81 Interface information 82 Optical path information 90 Control unit 91 Route calculation unit 92 Node control unit 100 BER measurement function unit NW network

Claims (15)

A communication device that transfers data of wavelength and TDM (time division multiplexing) by switching the optical path route by the optical switch of the switching unit, and a function of transferring packets by passing the data to the communication device A signal transmission / reception device; a data link connected between a plurality of nodes each representing the communication device and the signal transmission / reception device; and a control link connected between the nodes and transmitting a control signal. A continuity confirmation system for confirming the continuity of the optical path by transmitting an optical signal generated by the light source in both nodes between the two communication devices indicating the start point node and the end point node of the optical path, which is a continuity test target section. A conduction confirmation method in
The starting node is
Performing a step of transmitting a signaling message as an optical signal for securing a band resource for an end point of the continuity test target section;
The end node is
Performing continuity confirmation for the end point by determining whether continuity of the band resource for the end point is normal based on the reception status of the signaling message;
When it is determined that the continuity of the band resource for the end point is normal, a step of transmitting a signaling message as an optical signal toward the start point node is performed.
The starting node is
The continuity check for the start point is performed by determining whether or not the continuity of the band resource for the start point of the continuity test target section is normal based on the reception status of the signaling message transmitted from the end node. Steps,
And a step of transmitting a normality confirmation notification to that effect to the end node when it is determined that conduction is normal in the conduction confirmation toward the start point. A communication device that transfers the wavelength and TDM data by switching the path of the optical path by the optical switch of the switching unit; and a signal transmission and reception device that has a function of transferring the packet by passing the data to the communication device; A data link connected between a plurality of nodes respectively indicating the communication device and the signal transmitting / receiving device and transmitting an optical signal; and a control link connected between the nodes and transmitting a control signal; By transmitting an optical signal generated by the light source in both nodes between the two communication devices indicating one node on the start point side and the other node on the end point side of the continuity test target section divided for each link, A continuity confirmation method in a continuity confirmation system for confirming continuity of an optical path,
From the start node to the end node of the optical path, a set of two continuous communication devices sequentially performs a continuity check process for each continuity test target section formed by shifting the combination one by one,
In the conduction confirmation process,
One node on the start point side of the continuity test target section is
Performing a step of transmitting a signaling message as an optical signal for securing a band resource for the other node of the continuity test target section;
The other node is
Performing continuity confirmation for the other node from the one node by determining whether the continuity of the band resource for the own node is normal based on the reception status of the signaling message;
When it is determined that the continuity of the band resource for the own node is normal, the step of transmitting a signaling message as an optical signal to the node opposite to the continuity test target section is executed in the next continuity test target section And
When it is determined that the end node is normal in the continuity check for its own node, the set of two communication devices that continue from the end node to the start node is shifted by one by one. The continuity check process is sequentially performed for each continuity test target section to be formed,
The continuity check method characterized in that, when it is determined that continuity is normal in the continuity check directed to its own node, the start node determines that continuity of the bidirectional band resource of the optical path is normal. A communication device that transfers the wavelength and TDM data by switching the path of the optical path by the optical switch of the switching unit; and a signal transmission and reception device that has a function of transferring the packet by passing the data to the communication device; A data link connected between a plurality of nodes respectively indicating the communication device and the signal transmitting / receiving device and transmitting an optical signal; and a control link connected between the nodes and transmitting a control signal; By transmitting an optical signal generated by the light source in both nodes between the two communication devices indicating one node on the start point side and the other node on the end point side of the continuity test target section divided for each link, A continuity confirmation method in a continuity confirmation system for confirming continuity of an optical path,
From the start node to the end node of the optical path, a set of two continuous communication devices sequentially performs a continuity check process for each continuity test target section formed by shifting the combination one by one,
In the conduction confirmation process,
One node on the start point side of the continuity test target section is
Performing a step of transmitting a signaling message as an optical signal for securing a band resource for an end point of the continuity test target section;
The other node on the end point side of the continuity test target section is
Performing continuity confirmation for the end point by determining whether continuity of the band resource for the end point is normal based on the reception status of the signaling message;
When it is determined that the continuity of the band resource for the end point is normal, a signaling message is transmitted to the one node as an optical signal, and
The one node is
Based on the reception status of the signaling message transmitted from the other node, the continuity check for the start point is performed by determining whether or not the continuity of the band resource for the start point of the continuity test target section is normal. And steps to
When it is determined that conduction is normal in the conduction check toward the start point, a normality confirmation notification indicating that is transmitted to the other node, and
The end node is
When the normality confirmation notification is received, it is determined that the continuity of the bidirectional band resource of the optical path is normal. If the start node determines that continuity is normal in the continuity check, further executes a step of setting the setting of the optical switch of the switching unit for data input / output for transferring the data,
The end node is
The optical switch setting of the switching unit is set for data input / output for transferring the data, triggered by the arrival of the normality confirmation notification transmitted from the opposite node of the continuity test target section. The continuity confirmation method according to claim 1, wherein the step is further executed.   A step of setting the setting of the optical switch of the switching unit for data input / output for transferring the data when the start point node and the end point node determine that the continuity is normal in the continuity check directed to the own node; The continuity confirmation method according to claim 2, further comprising:   When the node that performs the continuity check determines that the continuity of the band resource in the continuity test target section is not normal, a normality unconfirmed notification indicating that is transmitted to the opposite node in the continuity test target section. The conduction confirmation method according to any one of claims 1 to 5, wherein:   When the node that performs the continuity check has a signaling message strength received from a node opposite to the continuity test target section that is equal to or lower than a predetermined threshold, the continuity test of the band resource in the continuity test target section is performed. The continuity confirmation method according to any one of claims 1 to 6, wherein it is determined that the state is not normal.   When the node that performs the continuity check does not arrive after the signaling message transmitted from the opposite node of the continuity test target section has elapsed in advance, the continuity test target section The continuity check method according to any one of claims 1 to 7, wherein it is determined that the continuity of the band resource is not normal. The optical path start point node and the optical path end point node are:
After determining that the continuity of the band resource of the optical path that is both the continuity test target section is normal, one node sends a BER measurement signal for measuring the BER (bit error rate) to the other node. A BER that executes a series of processes in which the other node receives the BER measurement signal and performs a step of measuring a BER from the received BER measurement signal in both directions of the optical path. The continuity confirmation method according to any one of claims 1 to 8, wherein a measurement process is performed. One node on the start point side of the continuity test target section is
Before the BER measurement process, a message indicating that the BER measurement process is performed between both end points of the optical path following the continuity test of the continuity test target section is sent as the normality confirmation notification of the continuity test target section. Send to the other node on the end point side,
The optical path start point node and the optical path end point node are:
Before the BER measurement process, the setting of the optical switch of the switching unit is switched from the setting for continuity test to the setting for BER measurement.
10. The continuity according to claim 9, wherein after the BER measurement process, the setting of the optical switch of the switching unit is switched from the setting for BER measurement to the setting for data input / output for transferring the data. Confirmation method.   A continuity confirmation program for causing a computer of a communication apparatus functioning as one node on the start point side of the continuity test target section to execute the continuity confirmation method according to any one of claims 1 to 10.   A continuity check program for causing a computer of a communication device functioning as the other node on the end point side of the continuity test target section to execute the continuity check method according to any one of claims 1 to 10. A communication device that transfers wavelength and TDM data by switching the route of the optical path, a signal transmission / reception device that has a function of transferring packets by passing the data to the communication device, the communication device, and the signal A data link connected between a plurality of nodes each indicating a transmission / reception device and transmitting an optical signal; and a control link connected between the nodes and transmitting a control signal; and a start node and an end node of the optical path, A communication device that functions as the start node in a continuity confirmation system that performs continuity confirmation of the optical path by transmitting an optical signal generated by a light source in both nodes between the two communication devices shown in FIG.
A switching unit having an optical switch for switching the path of the optical path;
A signaling message for securing a band resource for the end point of the optical path is transmitted as an optical signal, and a band resource for the start point of the optical path based on the reception status of the signaling message transmitted as an optical signal from the end point node A signaling message transmission / reception means for performing the conduction check for the starting point by determining whether or not the conduction of
When it is determined that continuity is normal in the continuity confirmation toward the start point, signaling message control means for transmitting a normality confirmation notification indicating the fact to the end point node;
When it is determined that conduction is normal in the conduction check, switching control means for controlling the optical switch of the switching unit so as to be able to input and output the data passed from the signal transmitting and receiving device;
A communication apparatus comprising: A communication device that transfers wavelength and TDM data by switching the route of the optical path, a signal transmission / reception device that has a function of transferring packets by passing the data to the communication device, the communication device, and the signal A data link connected between a plurality of nodes each indicating a transmission / reception device and transmitting an optical signal; and a control link connected between the nodes and transmitting a control signal; and a start node and an end node of the optical path, A communication device functioning as the end point node in a continuity confirmation system for confirming the continuity of the optical path by transmitting an optical signal generated by a light source in both nodes between the two communication devices shown in FIG.
A switching unit having an optical switch for switching the path of the optical path;
The continuity check for the end point is performed by determining whether or not the continuity of the band resource for the end point is normal based on the reception status of the signaling message transmitted as an optical signal from the start point node, and the end point A signaling message transmission / reception means for transmitting a signaling message as an optical signal toward the start node when it is determined that the continuity of the band resource in the direction is normal;
A signaling message control means for receiving a normality confirmation notification transmitted from the start point node and indicating that continuity is determined to be normal in the continuity confirmation toward the start point;
When receiving the normality confirmation notification, switching control means for controlling the optical switch of the switching unit so as to be able to input and output the data passed from the signal transmitting and receiving device,
A communication apparatus comprising: A communication device that transfers wavelength and TDM data by switching the route of the optical path, a signal transmission / reception device that has a function of transferring packets by passing the data to the communication device, the communication device, and the signal A data link connected between a plurality of nodes each indicating a transmission / reception device and transmitting an optical signal; and a control link connected between the nodes and transmitting a control signal; and a start node and an end node of the optical path, A continuity confirmation system for confirming the continuity of the optical path by transmitting an optical signal generated by a light source in both nodes between the two communication devices shown in FIG.
A communication device according to claim 13 is provided as the start node,
A continuity confirmation system comprising the communication device according to claim 14 as the end point node.

Images