JP2001257699A - Transmitter and its reboot system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress influence on traffic in node rebooting. SOLUTION: The alarm information, K byte information and control status information are backed up in a steady operation state and then read out in a reboot mode. Then a transmitter is started after the switching state concerning APS is reset to a state set directly before the reboot mode. Thereafter, the normal ring APS control procedure is carried out along with other nodes and a traffic control state is restored.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to, for example, SDH (Sy
nchronous Digital Hierarchy) or SONET (Syn
The present invention relates to a transmission device and a system based on a chronous optical network, and more particularly to an improvement in a reboot method of the transmission device.

[0002]

2. Description of the Related Art As is well known, SONET / SDH, which forms the backbone of a communication network, has a self-healing function for autonomously rescuing traffic in order to avoid large-scale traffic interruption when a failure occurs. Have. This type of function is called APS (Automatic Prot.
Section Switching), the details of which are, for example, ITU
−T Recommendation (International Telecommunication Union-T
Recommendation) G. 841 (latest 10/98 version). When a failure related to the main signal system occurs in the system including the APS, a plurality of transmission devices (hereinafter, referred to as nodes) exchange control information with each other, and execute redundancy switching under distributed processing.

When there is no failure in the system, service traffic is transmitted through all working transmission lines, and part-time traffic is transmitted through a protection transmission line as necessary. Such a state of the network is most desirable in operation, and in most cases, this state is maintained. Hereinafter, such a state is referred to as a normal state.

When a failure occurs in the system, each node transfers information via a control signal called K byte,
Redundant switching is performed while sharing the same information between the nodes, and the service traffic is diverted from the working system to the protection system transmission line. As described above, when a switching factor occurs due to the occurrence of a failure or the like, the network is not in the normal state, and the APS is executed. Hereinafter, such a state is referred to as a failure state.

When an unexpected failure occurs in a node, software and hardware are unavoidably reset to recover the device. Such a process is called a reboot. The rebooted node (hereinafter referred to as a reboot node) is a RAM (Random Access Memory).
y) and lose data stored in the idle state (Idl
e State), but it has been pointed out by the inventor that the following problems occur in connection with this.

That is, when the network is in a fail state and the APS is activated, the node is not in an idle state. In the case of ring switching involving all nodes, even in the case of span switching in a specific section, the state of the network is notified to all nodes via K bytes and an alarm signal. It can be seen that almost all nodes are no longer idle.

[0007] In such a case, if any node is rebooted and the node returns to the idle state in the network, information to be shared between the nodes will be inconsistent. For this reason, the function of the APS is hindered, and service traffic leaks to a place where connection should not be made (misconnect), or in the worst case, a signal disconnection occurs.

In addition, when a node restoring traffic at the time of a failure is rebooted,
This node blindly returns the bypassed service traffic to the active transmission line at the time of startup. This is because the node is set to idle and flow service traffic to the active system. For this reason, there is a possibility that a miss connection or a signal disconnection may occur at the time of a reboot event, and it is necessary to take some measures. In particular, during the operation of the APS (hereinafter referred to as Ring APS) executed by involving all the nodes in the network, the bypass processing of the service traffic is executed in all the nodes. The consequences are even worse.

[0009]

As described above, in the conventional transmission system, if the transmission device is rebooted while the network is in a failed state, there is a possibility that service traffic leaks (misconnect) or signal disconnection may occur. There was a problem that the adverse effect on traffic was large.

[0010] The present invention has been made in view of the above circumstances,
An object of the present invention is to provide a transmission apparatus which suppresses the influence on traffic at the time of a node reboot event, and a reboot system for the transmission apparatus.

[0011]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention is used in a ring network in which a plurality of transmission devices are connected in a ring via a transmission line.
Recommendation G. Redundancy switching function (for example, APS: Automatic Protection S)
In the transmission apparatus provided with the redundancy switching control means for realizing the witching, information (at least alarm information, K byte information, control status information) related to the current traffic control state of the transmission apparatus is stored, and the reboot processing is performed. At this time, the information stored in the storage means is read out, and based on the read out information, reproduction information for setting its own traffic control state to a state immediately before the reboot is generated. At this time, the control procedure of the APS is executed based on the reproduction information given from the management means.

In this way, in the process of restarting the device by rebooting, the traffic control state (switch direction of active / standby switch, K
(For example, information described in bytes) is maintained in the state immediately before the reboot.

Therefore, it is possible to avoid a situation in which the node restoring the traffic before the reboot returns to the idle state when the restart is completed. As a result, it is possible to suppress the misconnection and the disconnection of the traffic. Become.

Further, in the present invention, when the information on the traffic control state read during the reboot processing does not match the current network state, the transmission apparatus is started up from the default state. The inconsistency means that the state of the network has changed during the reboot process. In such a case, the traffic control state of the transmission device cannot be determined, and the state before the reboot is maintained. May do harm instead. By restarting by default as in the present invention, adverse effects can be minimized.
The transmission device that has become the default is a squelch control for the protection transmission line and a default APS
Executes code transmission.

Further, the present invention relates to ITU-T Recommendation G. 841
Is a rebooting method of the transmission device in a ring network in which a plurality of transmission devices having a redundancy switching function relating to traffic rescue related to the above are connected via a transmission line in a ring shape, and the rebooted transmission device (hereinafter referred to as a reboot node) ) Sends a reboot notification signal to an adjacent transmission device to enter an idle state;
A second step in which the transmission device that has received the reboot notification signal transfers the reboot notification signal to an adjacent next transmission device to be in an idle state, and the reboot node determines that all other transmission devices in the ring network And a third step of starting a processing procedure based on the APS function after confirming the idle state. The “transmission device that has received the reboot notification signal” referred to in the second step is not limited to “the transmission device that has received the reboot notification signal from the reboot node”, but in other words, “receives the reboot notification signal from an adjacent transmission device. Transmission device ".

[0016] A default APS code can be used as the reboot notification signal, and the idle code is transmitted to the transmission device in an idle state, and when the idle code arrives from adjacent bidirectional nodes,
The reboot node may be made to confirm that all the other transmission devices in the ring network have become idle.

According to the above means, when a reboot operation is performed at any node, the reboot notification signal sent from this node is sequentially transferred to all nodes, and all nodes of the network are idle via the reboot notification signal. State. That is, after the node is rebooted, the ring network temporarily enters a normal state. This is equivalent to the absence of a reboot operation from the point of view of the network. By starting the normal APS processing procedure from this state, there is no danger of inconvenience such as data inconsistency occurring.
Restoration of traffic can be performed.

Note that there is no description of the behavior of the transmission device at the time of reboot in the recommendation at the present time. In this sense, the present specification proposes a new regulation in the transmission system.

[0019]

Embodiments of the present invention will be described below in detail with reference to the drawings. (First Embodiment) FIG. 1 is a system configuration diagram of a transmission system according to an embodiment of the present invention. This system assumes a ring network compliant with SDH, and n transmission devices N1 to Nn are composed of STM-64 (Synchr).
High-speed line OF such as onous Transfer Module-Level 64)
Are connected in a ring shape. The high-speed line OF includes a service line SL and a protection line PL as its backup system, and each of the lines SL and PL has a clockwise (CW: Clockwise) line and a counterclockwise (CCW: C
ounter Clockwise) circuit.

The transmission devices N1 to Nn transmit predetermined time slots among time slots multiplexed to traffic transmitted via the high-speed line OF to low-order group exchanges and the like (without symbols). Drop via line SC. The transmission devices N1 to Nn transmit STM-1, STM-4, and ST transmitted from the exchange via the low-speed line SC.
A low-order group signal such as M-16 is added to a predetermined slot of an STM-64 frame and transmitted to another transmission device.
In this way, a path having a predetermined transmission capacity is set between the transmission devices N1 to Nn.

In the above system, each of the transmission devices N1 to N1
The monitoring control devices M1 to Mn are connected to each Nn. Each of the monitoring control devices M1 to Mn is realized by mounting dedicated application software on a general-purpose workstation, for example, and performs various types of network setting such as path setting and alarm monitoring based on notification information notified from the transmission devices N1 to Nn. Execute control.

FIG. 2 shows a transmission apparatus N1 according to this embodiment.
To Nn. That is, the transmission devices N1 to Nn include an active high-speed interface (HS I / F) 1-0 that terminates the service line SL, and the protection line P
A standby high-speed interface unit 1-1 for terminating L is provided. The STM-64 signal drawn into the device via the active high-speed interface unit 1-0 and the standby high-speed interface unit 1-1 is transmitted to the time slot switching unit (TS
A: Time Slot Assignment) 2-0. The time slot exchange unit 2-0 is provided with the STM-6 given above.
A predetermined time slot among the time slots multiplexed into four signals is dropped and given to the low-speed interface units (LS I / F) 3-1 to 3-k.

Conversely, the low-speed interface units 3-1 to 3-
The low-order group signal from k is supplied to the time slot switching unit 2-0, added to a predetermined time slot of the STM-64 frame, and transmitted via the high-speed line OF. The multiplexing level of the low-order group signal in the above system is STM-
0, STM-1, STM-4, STM-16 or ST
M-64, but not limited to this depending on the expansion of the system.

The time slot exchange section 2-0 is paired with the time slot exchange section 2-1 and is duplexed. In a normal state, the time slot exchange section 2-0 operates as an active system. When a failure occurs in the switching unit 2-0, internal switching is performed to operate the time slot switching unit 2-1 as a standby system. The operation of the time slot exchange unit 2-1 is similar to that of the time slot exchange unit 2-0.
The operation is the same as that described above.

Here, the high-speed interface units 1-0, 1
-1, the time slot exchange units 2-0 and 2-1 and the low speed interface units 3-1 to 3-k are connected to the main control unit 5 via sub-controllers 4H, 4T and 4L, respectively. The sub-controllers 4H, 4T, and 4L are the main control unit 5
Is to assist in giving various operation control by
Various control functions are hierarchically executed by the sub-controllers 4H, 4T, 4L and the main control unit 5.

As an example of the control function, there is a function of relieving service traffic by performing redundancy switching when a failure occurs to cause service traffic to be bypassed from the working transmission line SL to the protection transmission line PL. This function has a main control unit 5 as a core and a high-speed interface unit 1-0,
1-1, time slot exchange units 2-0, 2-1, low-speed interface units 3-1 to 3-k, sub-controller 4
H, 4T, 4L and the like are executed in cooperation with each other. This kind of function is called APS (Auto
The present embodiment is described as an example of the "redundant switching function for traffic rescue according to ITU-T Recommendation G.841" described in the claims.

It should be noted that the AP is related to the configuration of the network.
There are various types of S, but here, an APS method which is characteristic of a ring network and is called Ring APS will be described as an example. This is defined in ITU-T Recommendation G. MS at 841
It corresponds to what is described as shared protection rings.

The main control unit 5 includes a storage unit 6 storing various control programs and the like, and a management network interface (I / F).
7 is connected. Via the management network interface 7,
Information transfer with a monitoring control device (not shown) is performed.

In addition, each of the transmission devices N1 to Nn includes a timing generator 8 for receiving a clock from an in-network clock supply device (DCS) (not shown) and generating an internal operation clock, and a power supply unit 9. . Further, the transmission device N
1 to Nn include a reset button 10 as hardware according to the features of the present invention. The reset button 10 accepts a reboot request operation by the operator and gives this request to the main control unit 5. This triggers the reboot process.

As shown in FIG.
There is a main signal management unit 40 as a functional block spanning H, 4T, and 4L. The sub-controller 4H related to the high-speed side
There is a main signal monitoring unit 41 as a characteristic functional block.

The main signal management unit 40 manages traffic transmitted via the high-speed line OF, and processes data such as fabric (Fabric) indicating a setting state of a time-division multiplexed path. The main signal monitoring unit 41 is connected to the high-speed line O
It monitors the status of the traffic transmitted via F and obtains information directly related to the switching factor, such as mainly alarm information and K byte information. As the alarm information, SD
AU-AIS (Administrative Unit-Ala) in which all bits of the AU pointer and payload of the H frame are 1
rm Indication Signal). The K byte information means information described in K1 and K2 bytes defined in SOH (Section Over Head) of the SDH frame.

As shown in FIG. 4, the main control unit 5 has a Ring APS
A management unit 50 and a Ring APS control unit 51 are provided. Ring A
The PS management unit 50 assists the control by the Ring APS control unit 51, and is stored in the storage unit 6 at the time of executing the Ring APS, prioritizing K-byte information, determining the credibility of the K-byte information, or rebooting. Judgment of the consistency between the updated data and the latest network data, etc.
An environment is prepared so that the control unit 51 can operate in an ideal state. The Ring APS control unit 51 performs overall control mainly related to Ring APS processing, such as updating of K bytes and determination of a processing sequence, using data and the like provided from the Ring APS management unit 50.

As shown in FIG. 5, the storage section 6 has areas for storing control status information 6a, alarm information 6b, and K byte information 6c, respectively. The control status information 6a is information relating to the traffic control state of the own apparatus such as the switching state (Br & Sw or the like) of the own apparatus and the state of part-time traffic, and is provided from the Ring APS control unit 51. As the alarm information 6b and the K-byte information 6c, information detected by the main signal monitoring unit 41 is stored via the Ring APS management unit 50.

The control status information 6a, the alarm information 6b, and the K byte information 6c are all stored while updating the latest data with the passage of time. All of these data are backed up without being lost upon reboot.

FIG. 6 shows a transmission apparatus N1 according to this embodiment.
FIGS. 4A to 4N are more detailed functional block diagrams, and also show how signals are exchanged between the functional blocks. The communication transmission line 100 shown in FIG.
L, protection system transmission line PL, active system high-speed interface unit 1
−0, the standby system high-speed interface unit 1-1, the time slot exchange units (TSA) 2-0, 2-1 and the like, and includes all traffic transmission paths.

The main signal management unit 40 includes a main signal control unit 40
a. The main signal monitoring unit 41 includes an alarm monitoring unit 41a.
And K byte monitoring means 41b. The main signal control unit 40a includes a working high-speed interface unit 1-0, according to a control status instructed from the Ring APS control unit 51,
Switching element control such as switching of the standby high-speed interface unit 1-1 or switching of the time slot switching units (TSA) 2-0 and 2-1 is performed to control the traffic transmission path. Also involved in APS control, AU
-Transmission of AIS is also performed.

The alarm monitoring means 41a is connected to the communication transmission line 10
It monitors the traffic flowing through 0 and acquires alarm information. The K byte monitoring means 41b monitors the K bytes and receives a message from another transmission device in the network in consideration of the alarm status information from the alarm monitoring means 41a. Alarm monitoring means 41a and K byte monitoring means 41
The latest alarm information and K byte information obtained in b are Ring A
It is provided to the PS control unit 51 and the alarm / K byte determination unit 50a.

The Ring APS management section 50 has an alarm / K byte judging means 50a. Alarm / K byte determination means 50a
Are alarm monitoring means 41a and K byte monitoring means 41b
The switching trigger information is generated with reference to the latest alarm information and K byte information given from the
Give to. The switching trigger information (alarm, K
Byte) is backed up in the storage unit 6.

The Ring APS control unit 51 includes a switching trigger provided from the alarm / K byte determination unit 50a, control status information 6a, alarm information 6b, and K byte information 6 in the storage unit 6.
c, a time slot exchange unit (TSA) 2-0,
The switching control for 2-1 and the like is executed.

Next, the operation of the above configuration will be described.
FIG. 7 is a flowchart illustrating a processing procedure of the reboot node according to the present embodiment. Here, it is assumed that one of the transmission devices is rebooted in the ring network in the failed state. By the way, when the network is rebooted from the normal state, no significant inconvenience occurs with respect to traffic transmission since only the idle nodes return to the idle state.

In FIG. 1, the transmission devices N1 to Nn perform normal operations while backing up the latest control status information, alarm information and K byte information in the storage 6 in step S1. From here, reset button 1
When a reboot operation is performed by pressing 0 (Y in step S2), the transmission device (reboot node) first
The data stored in the RAM (not shown) of the Ring APS management unit 50 is deleted and initialized (step S3).

Next, the reboot node reads the control status information, the alarm information, and the K-byte information stored in the storage unit 6, and writes the information into the RAM of the Ring APS management unit 50 (step S4). Next, the reboot node acquires the current K-byte information and the alarm information from the traffic flowing through the communication transmission line 100 (Step S5), and determines the current network state (Step S6).

Next, the reboot node determines whether or not the state of the reboot network has changed in the procedure so far (step S7). That is, it is determined whether the state of the network immediately before the reboot and the state of the network determined in step S6 are the same or different. Here, the control status information, the alarm information, and the K-byte information read out in step S4 and the current network state determined in step S6 are referred to, and the change of the network state is determined based on whether or not both match. Decide whether or not. If there is a match, it is concluded that there is no change;

If it is the same in step S7 (there is no change in the network state), the reboot node calculates its own state immediately before the reboot based on the backup data read in step S4 (step S8). This process is Ri
The data calculated and executed by the ng APS management unit 50
The data is transferred to the Ring APS control unit 51 (step S9). In response to this, the Ring APS control unit 51 determines the switching state and transfers it to the main signal control unit 40a to perform the switching process (Steps S10 and S11).

By the processing procedure from step S8 to step S11, the reboot node returns to the traffic control state immediately before the reboot. That is, in the start-up procedure from the reboot, the control state immediately before the reboot is reproduced.
From this state, the normal Ring APS control procedure is started together with other nodes, and the network state before the reboot is restored.

On the other hand, if there is a change in step S7, the reboot node can no longer determine its own control status, and starts up in the default state in which data has been further erased than in the idle state (step S13). Thereafter, the normal Ring APS control procedure is executed together with the other nodes, and the network state before the reboot is restored (Step S12). In this case, the default node will appear in the failed ring network,
It will take complicated sequence steps before recovery,
Unavoidable Note that a node that has started up by default may perform squelch control on the protection transmission line PL and transmit a default APS code.

As described above, in the present embodiment, the alarm information, the K-byte information, and the control status information are backed up in a normal operation state, and these information are read out at the time of reboot, and the switching state related to the APS is changed to the state immediately before the reboot. And then start up the device.
After this stage, the normal Ring APS control procedure is executed together with other nodes to restore the traffic control state.

Thus, it is possible to minimize the possibility that the rebooted node returns to the idle state and causes inconsistency in information to be shared between the nodes. In addition, since the traffic control state is started in a state where the traffic control state before the reboot is restored, it is possible to avoid a situation in which the bypassed service traffic is blindly returned to the active transmission line SL.

Further, in this embodiment, the control state related to the APS is returned to the state immediately before the reboot in the reboot processing flow. That is, several steps are jumped in the APS processing procedure, so that it is possible to reduce the time particularly in an application such as the Transoceanic method, which requires a long time to send and receive a sequence, and also obtains a great effect in this respect. be able to.

In this embodiment, if the state of the network changes during the reboot in step S7, the nodes are raised by default. For example, A
Such a situation may occur when the system is rebooted during the processing of the PS sequence (the APS processing sequence is performed in a very short time, and such a case hardly occurs).

If the node is returned to the state immediately before the reboot even though the network state has changed, data between the nodes will be inconsistent, which is rather inconvenient. On the other hand, in the present invention, the state of the network is grasped in step S7, and when there is a change, the network is started up by default, so that damage due to data inconsistency can be reduced. Also in this regard, the effect on traffic protection is great.

From the above, it is possible to suppress the influence on the traffic in the event of the node reboot.

(Second Embodiment) Next, a second embodiment of the present invention will be described. The transmission devices N1 to N1 in this embodiment
The configuration of Nn is almost the same as that of FIG. FIG. 8 shows functional blocks of the main control unit 500 of the transmission devices N1 to Nn according to the present embodiment.

The main control unit 500 includes a reboot sequence control unit 501 as a functional block according to the present embodiment. The reboot sequence control unit 501 executes the control procedure shown in FIG. 9 when the own node or another node is rebooted.

The processing procedure of the transmission devices N1 to Nn in this embodiment will be described with reference to the flowchart of FIG.
This flowchart shows the processing procedure of the reboot node and other nodes (hereinafter, referred to as other nodes). The subsequent behavior of the node differs depending on the presence or absence of the reset operation in step S17. That is, if a reset operation is performed, the process proceeds to step S19 as a reboot node. If a default APS code is received without a reset operation, control as another node is started and the process proceeds to step S28.

In FIG. 9, the reboot node initializes the Ring APS management unit 50 in step S19, and reads a ring map and a fabric as configuration information in step S20. In the next step S22, the reboot node performs self-diagnosis by checking the consistency of these data, and
If not (NO), the process stops in step S21 and waits for a predetermined process. If OK (YES), the process proceeds to step S23.

In step S23, the reboot node sends a default APS code to the adjacent node to show that it has been rebooted, and then proceeds to the next step S2.
At 4, the state transits to the idle state. Default APS code is a special form of K bytes, Source Node ID (Destination Node ID) and Destination Node ID (Destination Node ID)
Is the same K byte. Specifically, for example, K
All the bits of the 1 and K2 bytes may be set to 0.

On the other hand, the node that has received the default APS code from the reboot node in step S18 transfers the default APS code to the next node as it is in step S28, so that it passes through, so to speak, transitions to the Idle state in step S29. A node that is not adjacent to the reboot node receives the passed-through default APS code in step S18, and similarly enters the Idle state to pass through the default APS code.

By executing the processing of steps S18, S28, and S29 on other nodes (nodes that have not been rebooted), these nodes are forcibly set to an idle state so as to restore traffic. Service traffic to the active transmission line S
Switch back to L. The node that has become idle is in step S
Idle code (K1
A where the first 4 bits of the byte and the last 4 bits of the K2 byte are 0
(PS byte) to the next node.

As described above, the default APS code sent from the reboot node is passed through by each node one after another, and the passed node is set to the idle state, so that the network state shifts from fail to normal. Become. The node that has become idle determines a failure state relating to the own node in step S31, and starts Ring APS control in step S32.

The idle code sent from the idle node is sequentially transmitted between the nodes and finally reaches the reboot node. The reboot node waits for the arrival of the Idle code in step S25, and after receiving the idle code from both directions, determines the failure state relating to its own node in step S26, and starts Ring APS control such as rewriting of K bytes in step S27.

In steps S32 and S27, complete APS is executed only when Ring APS control is started by all nodes in the network, and each node executes a known APS sequence via K bytes. Perform traffic restoration for failures. Here, the restoration control for the switching factor with the highest switching request is executed.

As described above, in the present embodiment, the default APS is transmitted from the rebooted node, and the default APS is sequentially transmitted through the nodes in the ring one after another. The node that has received the default APS code enters an idle state, and returns service traffic to the working transmission line SL. This is performed for all nodes to bring the network into a normal state, and thereafter, a normal Ring APS control procedure is executed to rescue service traffic.

As described above, when the node is rebooted, the network in the failed state is once returned to the normal state, which is the same as that from the viewpoint of the network as if there was no reboot event, and a failure has apparently occurred from the normal state. The same condition can be created.

By doing so, it becomes possible to operate the APS without inconsistency in the event of a reboot,
It is possible to eliminate the possibility of a fatal state. Strictly speaking, traffic loss can occur between the time the network returns to normal and the completion of the restoration, but this will end very quickly. Rather, in this embodiment,
There is a great merit in that the APS can be executed without inconsistency in data as in the first embodiment.

After the network is returned to the normal state, it is sufficient to execute a normal APS procedure based on the recommendation.
For this reason, it is not necessary to add many functions to existing resources, and it is only necessary to newly add a function of transmitting a default APS code and waiting for an idle code to the transmission device at the time of reboot. Therefore, the reboot method of the present embodiment can be realized more easily.

Further, by returning the network to the normal state during the reboot procedure as in the present embodiment, there is an advantage that a flexible measure can be taken even when the state of the network changes. From these facts, it is possible to suppress the influence on the traffic in the event of the node reboot.

The present invention is not limited to the above embodiment. For example, in the above-described embodiment, the reboot is started by the operation of the reset button 10 by the operator. However, the reboot procedure may be started on its own by providing each of the transmission devices N1 to Nn with a self-check function. Alternatively, a command may be given from the monitoring control devices M1 to Mn to reboot.

In the second embodiment, the default A
Although the PS code was used, instead of this, for example, DCC
It is also possible to notify the other nodes of the reboot via (Data Communication Channel) to cause the transition to the idle state.

Further, in the second embodiment, the Ring APS control procedure is started after the reboot node receives the Idle code from the bidirectional neighbor node. However, depending on the type of failure, the Idle code is transmitted to all nodes. It may not be possible to transfer. In such a case, the arrival of the default APS code instead of the Idle code may be used as a trigger for starting the Ring APS control procedure. In addition, various modifications can be made without departing from the scope of the present specification.

[0071]

As described above in detail, according to the present invention, it is possible to suppress the influence on traffic at the time of a node reboot event.

[Brief description of the drawings]

FIG. 1 is a system configuration diagram of a transmission system according to an embodiment of the present invention.

FIG. 2 shows transmission devices N1 to N1 according to the embodiment of the present invention.
FIG. 3 is a functional block diagram showing a main part configuration of Nn.

FIG. 3 is a diagram used to show functional blocks characteristic of sub-controllers 4H, 4T, and 4L.

FIG. 4 is a functional block diagram showing a configuration of a main control unit 5.

FIG. 5 is a diagram showing information stored in a storage unit 6 of FIGS. 2 and 6;

FIG. 6 is a diagram showing transmission and reception of signals in the transmission device according to the first embodiment of the present invention.

FIG. 7 is a flowchart showing a processing procedure of a reboot node according to the first embodiment of the present invention.

FIG. 8 shows a transmission device N according to a second embodiment of the present invention.
FIG. 3 is a functional block diagram showing a configuration of main control units 500 of 1 to Nn.

FIG. 9 is a flowchart showing a processing procedure of a reboot node and other nodes according to the second embodiment of the present invention.

[Explanation of symbols]

N1 to Nn: transmission devices M1 to Mn: supervisory control device OF: high-speed line SC: low-speed line SL: working transmission line PL: protection transmission line 1-0: working high-speed interface (HS I / F) 1- 1: Reserved high-speed interface unit (HS I / F) 2-0, 2-1: Time slot exchange unit (TSA) 3-1 to 3-k: Low-speed interface unit (LS I / F)
F) 4H, 4T, 4L: sub-controller 40: main signal management unit 40a: main signal control unit 41: main signal monitoring unit 41a: alarm monitoring unit 41b: K byte monitoring unit 5,500: main control unit 50: Ring APS Management unit 50a Alarm / K byte judging means 51 Ring APS control unit 501 Reboot sequence control unit 6 Storage unit 6a Control status information 6b Alarm information 6c K byte information 7 Management network interface (I / F) 8 timing generator 9 power supply 10 reset button 100 communication transmission line

Claims (6)

[Claims] An ITU-R is used in a ring network in which a plurality of transmission devices are connected in a ring via a transmission line.
T Recommendation G. 841. A transmission device comprising a redundancy switching control means for realizing a redundancy switching function for relieving traffic according to 841; a storage means for storing information relating to a current traffic control state of the transmission apparatus; Management means for reading information stored in the means, generating reproduction information for setting its own traffic control state to a state immediately before reboot based on the read information, and providing the reproduction information to the redundancy switching control means, The transmission apparatus, wherein the redundancy switching control unit executes a control procedure of the redundancy switching function based on the reproduction information given from the management unit at the time of a reboot process. 2. The management means compares the information read out at the time of a reboot process and stored in the storage device with a current network state, and generates the reproduction information only when both match. The transmission device according to claim 1, wherein the transmission device is provided to a redundancy switching control unit, wherein the redundancy switching control unit sets a state of the own device to a default when the reproduction information is not provided. 3. The method according to ITU-T Recommendation G. 841 is a rebooting method of the transmission device in a ring network in which a plurality of transmission devices having a redundancy switching function for relieving traffic are connected in a ring via a transmission line. A first step of storing information related to the traffic control state; a second step of reading the stored latest information by a rebooted transmission device (hereinafter, referred to as a reboot node) at the time of recovery processing; A third step in which the reboot node changes its traffic control state to a state immediately before the reboot based on the read information; and after the completion of the third step, the reboot node sets the line connection control procedure based on the redundancy switching function. And a fourth step of executing the rebooting method. formula. 4. The method according to claim 2, further comprising: determining a current state of the ring network by referring to traffic received by the reboot node via the transmission path. The third step includes: When the read information on the traffic control state matches the current state of the ring network determined in the fifth step, the reboot node changes its own traffic control state to a state immediately before the reboot. The reboot method according to claim 3. 5. An ITU-T Recommendation G. 841 is a rebooting method of the transmission device in a ring network in which a plurality of transmission devices having a redundancy switching function for traffic rescue according to 841 are connected in a ring shape via a transmission line, and the rebooted transmission device (hereinafter referred to as a reboot node) A first step of sending a reboot notification signal to an adjacent transmission apparatus to enter an idle state, and the transmission apparatus receiving the reboot notification signal transfers the reboot notification signal to the next adjacent transmission apparatus. And after the reboot node confirms that all other transmission devices in the ring network are idle,
Third to start a processing procedure based on the redundancy switching function
And a reboot method. 6. The reboot notification signal is a default AP.
The transmission device in the idle state sends an Idle code, and the reboot node transmits the I code from the adjacent bidirectional node.
6. The reboot method according to claim 5, wherein the arrival of the dle code confirms that all other transmission devices in the ring network are in an idle state.