JP2001086087A - Device and method for line switching controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently perform line switching control by automatically detecting operation specification of the opposite station. SOLUTION: An external switching command is decided whether it exists in an MSP message or not by an MSP message analyzing means 11. Station switching mode information is detected and set as station switching mode of its own station 1 by a first station switching mode information setting means 12a. Fault priority information based on the operation specification of the opposite station 2 is set in its own station 1 by a first fault priority information setting means 12b. The station switching mode information is detected and set as the station switching mode information of its own station 1 by a second station switching mode information setting means 13a. Signal transmission from the side of reserve line to the opposite station 2 is stopped by a signal transmission stopping means 13c. The fault priority information based on the operation specification of the opposite station 2 is set as fault priority information of its own station 1 based on the MSP message transmitted from the opposite station 2 after stop of the signal transmission by a second fault priority information setting means 13b.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a line switching control device and a line switching control method, and more particularly to an SDH (Synchrono).
us Digital Hierarchy) specifications and SONET (Synchro
nous Optical NETwork) For the communication in the network where the station of the specification is mixed, the line switching control device which performs the line switching control and the communication in the network where the station of the SDH specification and the station of the SONET specification are mixed. And a line switching control method for performing line switching control.

[0002]

2. Description of the Related Art SDH / SON at the core of multiplexing technology
The ET transmission system defines an interface for effectively multiplexing various high-speed services and existing low-speed services, and the SDH specification conforms to ITU G.783, SON
The ET specifications are standardized in GR-253.

On the other hand, the SDH / SONET transmission system has a redundant configuration in order to realize high reliability. As a result, even if a failure occurs in the working line, switching to the protection line can prevent signal interruption. This line switching function is referred to as MSP (Multiplex Sec).
tion Protection).

[0004]

However, in the conventional SDH / SONET transmission system as described above, the device itself does not know whether the opposing station operates in the SDH or SONET specification. For this reason, in a system in which stations are connected to each other with different specifications, when a failure or the like occurs in a line, the MSP function does not operate normally and a problem such as a signal disconnection occurs.

[0005] In recent years, the reorganization of the communication field, such as the merger of telecommunication companies, has been actively carried out, and synchronous communication in which terminal stations operating in the SDH specification and terminal stations operating in the SONET specification are mixed. A net is also conceivable. Therefore, it is important to construct a system in consideration of the difference between the SDH specification and the SONET specification in terms of operation and maintenance.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a line switching control device for automatically detecting the operation specifications of an opposite station and performing line switching control efficiently. I do.

Another object of the present invention is to provide a line switching control method for automatically detecting the operation specifications of the opposite station and efficiently performing line switching control.

[0008]

According to the present invention, in order to solve the above-mentioned problems, operation specifications are different as shown in FIG.
An MSP message that is a message for line switching transmitted from the opposite station 2 in the line switching control device 10 that performs line switching control for communication in a network in which stations of the SDH specification and stations of the SONET specification are mixed. MSP message analysis means 11 for determining whether or not there is an external switching command;
A first station that detects station switching mode information in which either the single station switching mode or the dual station switching mode is set from the message, and sets the detected station switching mode information as the station switching mode information of the own station 1. A switching mode information setting unit for recognizing the operation specifications of the opposite station and setting the failure priority information based on the operation specifications as the failure priority information of the own station;
b, the first MSP operation coincidence control means 1 comprising
2 and second station switching mode information setting means 13a for detecting the station switching mode information from the MSP message when there is no external switching command and setting the detected station switching mode information as the station switching mode information of the own station 1. A signal transmission stopping means 13c for stopping the signal transmission from the protection line side to the opposite station 2, and an operation specification of the opposite station 2 based on the MSP message transmitted from the opposite station 2 after the signal transmission is stopped. A second fault priority information setting means 13b for setting fault priority information based on the operation specifications of the station 2 as fault priority information of the own station 1;
And a line switching control device 10 having SP operation matching control means 13.

Here, the MSP message analyzing means 11
Determines whether there is an external switching command in the MSP message, which is a line switching message transmitted from the opposite station 2. The first station switching mode information setting means 12a detects, from the MSP message, station switching mode information in which either the single station switching mode or the dual station switching mode is set, and transmits the detected station switching mode information to its own station. 1 is set as the station switching mode information. The first failure priority information setting means 12b recognizes the operation specification of the opposite station 2 and sets the failure priority information based on the operation specification as the failure priority information of the own station 1. The second station switching mode information setting means 13a detects the station switching mode information from the MSP message, and sets the detected station switching mode information as the station switching mode information of the own station 1. The signal transmission stopping means 13c stops signal transmission from the protection line to the opposite station 2. Second fault priority information setting means 13
b is the MS transmitted from the opposite station 2 after the signal transmission is stopped.
The operation specification of the opposite station 2 is recognized from the P message, and the failure priority information based on the operation specification of the opposite station 2 is set as the failure priority information of the own station 1.

A line switching control method for performing line switching control for communication in a network in which stations of the SDH specification and stations of the SONET specification having different operation specifications are mixed as shown in FIG. It is determined whether or not the MSP message, which is a message for line switching transmitted from the opposite station, includes an external switching command. If there is an external switching command, the MSP message is used to switch to the single station switching mode or the dual station switching mode. Detects the station switching mode information for which one is set, sets the detected station switching mode information as the station switching mode information of its own station, recognizes the operation specifications of the opposite station, and gives priority to failure based on the operation specifications. Station information is set as the failure priority information of the own station, and if there is no external switch command, the station switch mode information is detected from the MSP message. Then, the detected station switching mode information is set as the station switching mode information of the own station, the signal transmission from the protection line to the opposite station is stopped, and the MSP message transmitted from the opposite station after the signal transmission is stopped, There is provided a line switching control method characterized by recognizing an operation specification of an opposite station, and setting failure priority information based on the operation specification of the opposite station as failure priority information of the own station.

Here, the MSP message is analyzed, and if there is an external switching command, station switching mode information detected from the MSP message and fault priority information based on the recognized operation specification are set in the own station. When there is no external switching command, the station switching mode information detected from the MSP message is set, and then the signal transmission from the protection line is stopped. The failure priority information based on the operation specifications of the station is set in the own station.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a principle diagram of a line switching control device of the present invention. The line switching control device 10 performs 1 + 1 line switching control for communication in a network in which stations of the SDH specification and stations of the SONET specification having different operation specifications are mixed. 1 + 1 means a configuration in which one working line is provided with one protection line.

In the figure, the own station 1 is an SDH station and the opposite station 2 is an SOH station.
As a NET station, the line switching control device 10 of the present invention is arranged in the SDH station of the own station 1. The own station 1 and the opposite station 2
1 + 1 connected by two working lines and two protection lines
The maintenance terminal 3 is connected to the opposite station 2.

An MSP (Multiplex Section Protection) message analysis means 11 determines whether or not the MSP message, which is a message for line switching received first after the start of the own station 1, includes an external switching command.

The external switching command is a line switching command that is manually set from outside by a maintenance person when the line is to be forcibly switched. Here, an external switching command for switching from the working line to the protection line is transmitted from the maintenance terminal 3 to the opposite station 2. The details of the external switching command and the MSP message will be described later.

When the MSP message analyzing means 11 determines that the external switching command is included in the MSP message transmitted from the opposite station 2, the first MSP operation matching control means 12 is used.

First station switching mode information setting means 12a
Detects the station switching mode information in which either the single station switching mode or the dual station switching mode is set from the MSP message, and sets the detected station switching mode information as the station switching mode information of the own station 1.

The first fault priority information setting means 12b comprises:
The operation specification of the opposite station 2 is recognized. Specifically, if the external switching command is included in the received MSP message immediately after the startup of the line switching control device 10, the opposite station 2 will
The station can be recognized as a NET specification station (the reason will be described later with reference to FIG. 8). Then, the failure priority information based on the operation specifications is set as the failure priority information of the own station 1.

Here, the station switching mode information includes two modes: a single station switching mode and a dual station switching mode. Further, the fault priority information is information indicating the priority of a fault occurrence factor when performing line switching. The station switching mode information and the failure priority information will be described later.

On the other hand, if the MSP message analyzing means 11 determines that there is no external switching command in the MSP message, the second MSP operation matching control means 13 is used.

Second station switching mode information setting means 13a
Detects the station switching mode information from the MSP message, and sets the detected station switching mode information of the opposite station 2 as the station switching mode information of its own station.

The signal transmission stopping means 13b stops transmission of a signal to be transmitted from the protection line side to the opposite station 2. That is, the opposite station 2 is made to show a pseudo failure occurrence using the protection line. The stop time measuring unit 13d measures the stop time of the signal transmission, and releases the stop of the signal transmission when the time is up.

The second fault priority information setting means 13b comprises:
Recognize the operation specification of the opposite station 2 from the MSP message transmitted from the opposite station 2 after the signal transmission is stopped, and set the failure priority information based on the operation specification of the opposite station 2 as the failure priority information of the own station 1 I do.

Next, the operation will be described. FIG. 2 is a sequence diagram showing an operation procedure of the line switching control device. The operation of the first MSP operation coincidence control means 12 will be described. [S1] The first station switching mode information setting means 12a
Station switching mode information is detected from the MSP message M1 (including the external switching command) received first after the start of the own station 1, and the detected station switching mode information is set as the station switching mode information of the own station 1. [S2] The first fault priority information setting means 12b sets the MS
Since the P message M1 includes the external switching command, the operation specification of the opposite station 2 is recognized as a station of the SONET specification, and the fault priority information based on the SONET specification is set as the fault priority information of the own station 1. .

As described above, when the external switching command is included in the MSP message M1, the MSP message M1
Is set as the station switching mode information of the own station 1. Then, the opposite station 2 receives the SO
Recognizing that the station is of the NET specification, the failure priority information based on the SONET specification is set as the failure priority information of the own station 1.

Thus, even when the own station 1 is SDH and the opposite station 2 is SONET, different line switching settings can be automatically matched according to the respective operation specifications (ie, the line switching setting on the SDH side). The specification of S
It is possible to execute line switching without error in accordance with the ONET side).

FIG. 3 is a sequence diagram showing an operation procedure of the line switching control device. The operation of the second MSP operation coincidence control means 13 will be described. [S10] Second station switching mode information setting means 13a
Detects the station switching mode information from the MSP message M2 (not including the external switching command), and sets the detected station switching mode information as the station switching mode information of the own station 1. [S11] The signal transmission stopping means 13c stops transmission of a signal to be transmitted from the protection line side to the opposite station 2. In this way, by displaying the pseudo failure occurrence to the opposite station 2, the MSP message M2a carrying the failure priority information is transmitted to the opposite station 2.
To send from. [S12] The second fault priority information setting unit 13b recognizes the operation specification of the opposite station 2 from the MSP message M2a transmitted from the opposite station 2 after the signal transmission is stopped (can be recognized from the failure priority information). Then, failure priority information based on the operation specifications of the opposite station 2 is set as failure priority information of the own station 1.

As described above, when there is no external switching command in the MSP message M2, the station switching mode information set in the MSP message M2 is set as the station switching mode information of the own station 1.

Then, transmission of a signal to be transmitted from the protection line side to the opposite station 2 is temporarily stopped. Thereafter, the MSP message M2 transmitted from the opposite station 2 after the signal transmission is stopped.
From a, the operation specification of the opposite station 2 is recognized, and the failure priority information based on the operation specification of the opposite station 2 is set as the failure priority information of the own station 1.

This makes it possible to automatically match line switching settings that differ depending on the operation specifications of the own station 1 and the opposing station 2, so that line switching can be executed without error.

Next, the station switching mode will be described. The station switching mode includes a single station switching mode and a dual station switching mode. Hereafter, the single station switching mode is set to Uni-dire
ctional mode, the bi-station switching mode is Bi-directi
Call it onal mode.

FIG. 4 is a diagram for explaining the station switching mode. Stations A and B are connected by two working lines for transmission and reception and two protection lines for transmission and reception. The maintenance terminal 3 is connected to the station B. Station A has a multiplexing / demultiplexing unit 1a and an optical transmitting / receiving unit 1b. The multiplexing / demultiplexing unit 1a multiplexes / demultiplexes signals. The optical transceiver 1b converts the multiplexed signal into an optical signal and transmits it to the B station, or converts the optical signal into an electric signal and converts the multiplexed signal into an electric signal.
Send to a. Further, the optical transmitting / receiving unit 1b includes a switch SW
With 10.

Station B has a multiplexing / demultiplexing unit 2a and an optical transmitting / receiving unit 2b.
Having. The multiplexing / demultiplexing unit 2a multiplexes / demultiplexes signals. The optical transceiver 2b converts the multiplexed signal into an optical signal and transmits it to the B station, or converts the optical signal into an electric signal and transmits it to the multiplexing / demultiplexing unit 2a. The optical transmission / reception unit 2b includes a switch SW20.

Here, first, when communication is performed on the working line, the terminal sw1 of the switch SW10 is connected to the terminal a, and the terminal sw2 of the switch SW20 is connected to the terminal c.

Thereafter, when a failure occurs at the position shown in the figure, the station switching mode in which the terminal sw2 of the switch SW20 is switched to the terminal d for recovery is called a uni-directional mode. The uni-directional mode is a switching mode in which a working line and a protection line are mixed after switching.

When a failure occurs at the position shown in the figure, the terminal sw2 of the switch SW20 is switched to the terminal d,
In addition, a station switching mode in which the terminal sw1 of the switch SW10 is switched to the terminal b for restoration is referred to as a Bi-directional mode. The bi-directional mode is a switching mode in which the switched line is unified as a protection line for both transmission and reception.

Here, when executing the external switching command during operation in the bi-directional mode, first, the maintenance terminal 3
Transmits an external switching command for switching from the working line to the protection line to station B. The station B notifies the station A that the external switching command has been received. Then, the station A transmits the response signal to the station B. Only when station B receives the response signal from station A does both stations switch to the protection line.

Even when the main signal is transmitted and received on the working line without any trouble or the like, each station receives the MSP message on the protection line. Next, the MSP message will be described. MSP message is SD
It is represented using the K1 and K2 bytes of the H frame.

FIG. 5 is a diagram showing the structure of an SDH frame. The SDH frame is represented by a two-dimensional byte array of 9 rows and 270 columns. The first 9 rows and 9 columns are composed of an overhead as control information and an AU pointer, and the next 9 rows and 261 columns are a payload containing multiplexed information.

The K1 byte is located at the fourth row and the fourth column in the overhead, and the K2 byte is located at the fifth row and the seventh column in the overhead. FIG. 6 is a diagram showing an allocation configuration of K1 and K2 bytes. For the K1 byte, bits 1 to 4 indicate the type of request (described later in FIG. 7). Also, 5
８8 bits indicate the line number for which the request has been issued, and
000 is a protection line and 0001 is a working line.

In the K2 byte, 1 to 4 bits indicate a bridge line number. 5 bits are
0 indicates 1 + 1, and 1 indicates 1: n (n multiple working lines for one protection line). Also, 6 ~
The 8 bits are reserved in the SDH specification (which can be used arbitrarily with an extension bit), and in the SONET specification,
A discriminating value is set for either the directional mode or the bi-directional mode, and 100 is Uni-directional.
The mode 101 is a bi-directional mode. FIG. 7 is a diagram showing an MSP request type. MSP request type 4
0 has a priority order, with Lockout being the highest and No Request being the lowest.

The external switching command is executed by Lockou in order of priority.
t, Forced switch, Manual switch, Exercise (1+
1 is unused). No. 3-No. 6 Signal f
ail (hereinafter, SF) and Signal degrade (hereinafter, SD)
Is a request that rises when a line failure occurs, and SF and SD have high and low priorities respectively. This high,
The low information corresponds to the fault priority information of the present invention.

Wait to Restore is a request used in the Revertive mode. The revertive mode is a mode in which the failback is not performed for a fixed time after recovery from the failure, and the failback is performed if the failure has not occurred for a fixed time. During this fixed time, a Wait to Restore request is transmitted to the opposite station.

Do not revert is used in a non-Revertive mode (mode in which switching back is not performed after recovery from a failure), and is transmitted when neither a signal failure nor an external switching command exists in both the own station and the opposite station.

The Reverse Request (hereinafter RR) is Bi-d
In the irectional mode, this is a response signal to a request from the opposite station. No Request (hereinafter, NR) is used in the Revertive mode, and is transmitted when there is no signal failure and no external switching command in both the own station and the opposite station.

FIG. 8 is a diagram showing the difference between the SDH specification and the SONET specification for the MSP request. In the case of the SDH specification, the failure priority information setting 41 is high or low. That is, when a failure occurs, the MSP request type 40 shown in FIG. 3-No. 6 is set.

The 6 to 8 bit setting 42 of the K2 byte is
uni / Bi setting or Uni / Bi not set, and Uni-Bi
If either the directional mode or the Bi-directional mode discriminating value can be set, nothing needs to be set (for example, 000).

The behavior 43 of the external switching command in the Bi-directional mode is canceled when the RR does not come from the opposite station for a predetermined time. For example, in contrast to FIG. 4, when the maintenance terminal 3 transmits an external switch command to the station B, and when the RR serving as the response signal is not returned from the opposite station A, the external switch command is canceled ( It is not held at station B).

In the case of the SONET specification, the fault priority information setting 41 is low. That is, when a failure occurs,
No. of the MSP request type 40 shown in FIG. 3-No.
No. 6 in No. 6 4 or No. 6 is set.

The 6 to 8 bit setting 42 of the K2 byte is Un
Set the discrimination value of either i-directional mode or Bi-directional mode. The behavior 43 of the external switching command in the bi-directional mode is not canceled even if the RR does not come from the opposite station for a certain period of time. For example,
In contrast to FIG. 4, when an external switching command is transmitted from the maintenance terminal to the station B, the external switching command is not canceled (held at the station B) even if no RR is returned from the opposite station A.

Therefore, if the received MSP message includes an external switching command immediately after the start of the line switching control device 10, the opposite station can be recognized as a station of the SONET specification.

Next, in a system in which stations are connected to each other with different specifications, when a failure or the like occurs in a line, a state in which the MSP function does not operate normally and a failure such as a signal break occurs will be described in detail. .

FIG. 9 is a sequence diagram when a signal interruption occurs. This is communication between the SDH station and the SONET station, and the station switching mode is the Bi-directional mode. Also, S
In the DH station, the failure priority information setting 41 is set to high, and the 6- to 8-bit setting 42 of the K2 byte is set to Bi-direction.
al mode is set. [S20] The SDH station has K1 = 00000000 (NR for the protection line; that is, the working line is used, and there is no request to switch to the protection line), K2 = 00000101 (the protection line is bridged. , 1 + 1, Bi-directional mode) to the SONET station. [S21] It is assumed that a failure has occurred on the working line side. [S22] The SONET station has K1 = 00000000, K2 = 00
000101 is transmitted to the SDH station. [S23] The SDH station has K1 = 11010001 (SF (high) for the working line. That is, SF for the working line.
Is generated, and a request for switching to a protection line is issued), and K2 = 00000101 is transmitted to the SONET station. [S24] Even when the SONET station receives the SF (high) code 1101, it cannot recognize that the SF notification has been received from the SDH station, and again K1 = 00000000 and K2 = 0000.
0101 to the SDH station.

Because, in the SONET station, only the low level of the fault priority information setting 41 is defined, even if the high level of the fault priority information setting 41 is received,
This is because it is ignored. [S25] Since the RR does not come from the SONET station, the SDH station cannot be switched to the protection line, resulting in a signal loss.

As described above, conventionally, SDH and SONE
There was a problem that line switching could not be performed normally due to differences in the specifications of T. Next, the line switching control of the line switching control device 10 of the present invention will be described with reference to a sequence diagram.

FIG. 10 is a diagram showing a sequence of line switching control. The case where the MSP message received first after the start of the SDH station 1 includes an external switching command, that is, the operation of the first MSP operation coincidence control means 12 will be described. The station switching mode is Bi-directional mode, and the external switching command is Lockout. [S30] The SONET station 2 has K1 = 11110000 (the working line is specified and a lockout switching request is issued to the protection line side), and K2 = 00000101 (the protection line is bridged, the protection line is 1 + 1, in the bi-directional mode). To the SDH station 1. [S31] First station switching mode information setting means 12a
Copies 101 into 6 to 8 bits of its own K2 byte and sets the mode to Bi-directional mode. [S32] The first fault priority information setting unit 12b sets
Lock which is external switching command after DH station 1 starts up
out received, the opposite station is recognized as a SONET station,
Set low in the failure priority setting. That is, at the time of a line failure, No. 1 in FIG. 4 or No. 6 is set. [S33] The SDH station transmits K1 = 00100000 (transmission of RR) and K2 = 00000101 to the SDH station.

FIGS. 11 and 12 are diagrams showing the sequence of line switching control. The case where there is no external switching command in the MSP message, that is, the operation of the second MSP operation coincidence control means 13 is shown. The station switching mode is the bi-directional mode. [S40] The SDH station 1 has K1 = 00000000 (NR for the protection channel. That is, the SDH station 1 uses the working channel,
No switching request), K2 = 00000000 (Bridge is a protection line, 1 + 1, Uni / Bi code not set) SO
Transmit to NET station 2. [S41] The SONET station 2 has K1 = 00000000, K2 =
00000101 (Bridge is protection line, 1 + 1, Bi
-directional mode setting) to the SDH station 1. [S42] The first station switching mode information setting means 12a of the SDH station 1 sets 10 to 6 to 8 bits of its own K2 byte.
Copy 1 and set it to Bi-directional mode. [S43] The signal transmission stopping means 13c stops signal transmission on the protection line side. And the stop time measuring means 13d
Starts a timer. [S44] Since no signal is sent from the SDH station 1 through the protection channel, the SONET station 2 recognizes that a failure has occurred in the protection channel. [S45] The SONET station 2 sets K1 = 110000000 (notifies the protection channel of the occurrence of SF (low)), and K2 = 0000.
0101 to the SDH station. [S46] The second fault priority information setting means 13b of the SDH station 1 recognizes the opposite station as the SONET station 2, and sets the fault priority setting to low. [S47] The time is up in the stop time measuring means 13d of the SDH station 1. Then, the SDH station 1 obtains K1 = 0010
0000, K2 = 00000101 are transmitted to the SONET station 2. [S48] The SONET station 2 recognizes that the protection line has been restored.

Next, the line switching control method of the present invention will be described. FIG. 13 is a diagram showing a flowchart of the line switching control method of the present invention. [S50] It is determined whether or not the MSP message, which is a message for line switching transmitted from the opposite station, includes an external switching command. If there is, go to step S51.
If not, go to step S53. [S51] The station switching mode information in which either the single station switching mode or the dual station switching mode is set is detected from the MSP message, and the detected station switching mode information is set as the station switching mode information of the own station. [S52] Recognize the operation specifications of the opposite station, and set the failure priority information based on the operation specifications as the failure priority information of the own station. [S53] The station switching mode information is detected from the MSP message, and the detected station switching mode information is set as the station switching mode information of the own station. [S54] Signal transmission from the protection line to the opposite station is stopped. [S55] M transmitted from the opposite station after the stop of signal transmission
The operation specification of the opposite station is recognized from the SP message, and the failure priority information based on the operation specification of the opposite station is set as the failure priority information of the own station.

When the signal transmission is stopped in step S54, the signal transmission stop time is measured, and when the time is up, the signal transmission stop is released. As described above, the line switching control device 10 and the line switching control method of the present invention automatically match their operation specifications when using MSP, which is a function of automatically switching between a working line and a protection line. Therefore, the line switching control can be performed normally, and the setting work of the synchronous communication network can be reduced.

[0060]

As described above, the line switching control device of the present invention analyzes an MSP message, and when there is an external switching command, the station switching mode information detected from the MSP message and the recognized operation specification. In the case where there is no external switching command, the station switching mode information detected from the MSP message is set, then the signal transmission from the protection line is stopped, and the signal transmission is performed. Then, from the MSP message transmitted from the opposite station after the stop, the failure priority information based on the operation specifications of the opposite station is set in the own station. As a result, the operation specification of the opposite station is automatically detected, and M
SP operation can be performed.

The line switching control method of the present invention
The SP message is analyzed, and if there is an external switching command, the station switching mode information detected from the MSP message and the fault priority information based on the recognized operation specification are set in the own station. Is
Set the station switching mode information detected from the MSP message, and then stop the signal transmission from the protection line. From the MSP message transmitted from the opposite station after the signal transmission is stopped, give priority to the failure based on the operation specifications of the opposite station. The degree information is set to the own station. This makes it possible to automatically detect the operation specification of the opposite station and perform the MSP operation efficiently.

[Brief description of the drawings]

FIG. 1 is a principle diagram of a line switching control device of the present invention.

FIG. 2 is a sequence diagram illustrating an operation procedure of the line switching control device.

FIG. 3 is a sequence diagram illustrating an operation procedure of the line switching control device.

FIG. 4 is a diagram for explaining a station switching mode.

FIG. 5 is a diagram showing an SDH frame configuration.

FIG. 6 is a diagram showing a configuration of K1 and K2 bytes.

FIG. 7 is a diagram showing an MSP request type.

FIG. 8: SDH specification and SONET for MSP request
FIG. 6 is a diagram showing different points of the specification.

FIG. 9 is a sequence diagram when a signal interruption occurs.

FIG. 10 is a diagram showing a sequence of line switching control.

FIG. 11 is a diagram showing a sequence of line switching control.

FIG. 12 is a diagram showing a sequence of line switching control.

FIG. 13 is a diagram showing a flowchart of a line switching control method of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Own station (SDH station) 2 Opposite station (SONET station) 3 Maintenance terminal 10 Line switching control device 11 MSP message analysis means 12 First MSP operation coincidence control means 12a First station switching mode information setting means 12b First Failure priority information setting means 13 Second MSP operation coincidence control means 13a Second station switching mode information setting means 13b Second failure priority information setting means 13c Signal transmission stopping means 13d Stop time measuring means

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[Procedure amendment]

[Submission date] June 9, 2000 (200.6.9)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0022

[Correction method] Change

[Correction contents]

The signal transmission stopping device 13 c stops the transmission of the signal to be transmitted to the opposite station 2 from the protection line side. That is, the opposite station 2 is made to show a pseudo failure occurrence using the protection line. The stop time measuring unit 13d measures the stop time of the signal transmission, and releases the stop of the signal transmission when the time is up.

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0056

[Correction method] Change

[Correction contents]

FIG. 10 is a diagram showing a sequence of line switching control. The case where the MSP message received first after the start of the SDH station 1 includes an external switching command, that is, the operation of the first MSP operation coincidence control means 12 will be described. The station switching mode is Bi-directional mode, and the external switching command is Lockout. [S30] The SONET station 2 has K1 = 11110000 (the working line is specified and a lockout switching request is issued to the protection line side), and K2 = 00000101 (the protection line is bridged, the protection line is 1 + 1, in the bi-directional mode). To the SDH station 1. [S31] First station switching mode information setting means 12a
Copies 101 into 6 to 8 bits of its own K2 byte and sets the mode to Bi-directional mode. [S32] The first fault priority information setting unit 12b sets
Lock which is external switching command after DH station 1 starts up
out received, the opposite station is recognized as a SONET station,
Set low in the failure priority setting. That is, at the time of a line failure, No. 1 in FIG. 4 or No. 6 is set. [S33] The SDH station transmits K1 = 00100000 (transmission of RR) and K2 = 00000101 to the SONET station 2 .

[Procedure amendment 3]

[Document name to be amended] Statement

[Correction target item name] 0057

[Correction method] Change

[Correction contents]

FIGS. 11 and 12 are diagrams showing the sequence of line switching control. The case where there is no external switching command in the MSP message, that is, the operation of the second MSP operation coincidence control means 13 is shown. The station switching mode is the bi-directional mode. [S40] The SDH station 1 has K1 = 00000000 (NR for the protection channel. That is, the SDH station 1 uses the working channel,
No switching request), K2 = 00000000 (Bridge is a protection line, 1 + 1, Uni / Bi code not set) SO
Transmit to NET station 2. [S41] The SONET station 2 has K1 = 00000000, K2 =
00000101 (Bridge is protection line, 1 + 1, Bi
-directional mode setting) to the SDH station 1. [S42] The first station switching mode information setting means 13a of the SDH station 1 adds 10 to the 6 to 8 bits of its K2 byte.
Copy 1 and set it to Bi-directional mode. [S43] The signal transmission stopping means 13c stops signal transmission on the protection line side. And the stop time measuring means 13d
Starts a timer. [S44] Since no signal is sent from the SDH station 1 through the protection channel, the SONET station 2 recognizes that a failure has occurred in the protection channel. [S45] The SONET station 2 sets K1 = 110000000 (notifies the protection channel of the occurrence of SF (low)), and K2 = 0000.
0101 to the SDH station. [S46] The second fault priority information setting means 13b of the SDH station 1 recognizes the opposite station as the SONET station 2, and sets the fault priority setting to low. [S47] The time is up in the stop time measuring means 13d of the SDH station 1. Then, the SDH station 1 obtains K1 = 0010
0000, K2 = 00000101 are transmitted to the SONET station 2. [S48] The SONET station 2 recognizes that the protection line has been restored.

[Procedure amendment 4]

[Document name to be amended] Drawing

[Correction target item name] FIG.

[Correction method] Change

[Correction contents]

FIG. 11

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI theme coat ゛ (reference) 9A001 F term (reference) 5K014 AA01 EA07 FA01 HA01 5K021 AA05 BB08 CC11 DD02 FF05 FF11 5K028 AA14 BB08 CC02 KK01 KK03 MM05 PP02 PP04 PP22 PP27 QQ01 5K030 GA12 HA01 HB15 HB17 JL03 JL10 KA21 KX23 LA03 MA04 MA08 MB01 MC06 MD02 MD08 5K035 AA03 BB04 CC05 CC08 DD01 FF02 GG04 HH07 JJ01 KK07 LL03 LL18 9A001 BB04 CC09 CC56 JJ12 KK12 KK12

Claims (4)

[Claims] 1. An SDH specification station and an SH station having different operation specifications.
For communication in a network where stations with the ONET specification coexist,
A line switching control device for performing line switching control, comprising: an MSP message analysis unit that determines whether an external switching command is included in an MSP message that is a line switching message transmitted from an opposite station; If there is, the station switching mode information in which either the single station switching mode or the dual station switching mode is set is detected from the MSP message, and the detected station switching mode information is set as the station switching mode information of the own station. First station switching mode information setting means for recognizing the operation specification of the opposite station, and setting the failure priority information based on the operation specification as the own station failure priority information. A first MSP operation coincidence control unit comprising: a setting unit; Second station switching mode information setting means for detecting the station switching mode information from the SP message and setting the detected station switching mode information as the station switching mode information of the own station; Signal transmission stopping means for stopping the signal transmission of the opposite station, and recognizing an operation specification of the opposite station from an MSP message transmitted from the opposite station after the stop of the signal transmission, and a failure priority based on the operation specification of the opposite station. Second failure priority information setting means for setting information as failure priority information of its own station.
A line switching control device, comprising: P operation matching control means. 2. The line switching control according to claim 1, further comprising a stop time measuring unit that measures a stop time of the signal transmission and cancels the stop of the signal transmission when the time is up. apparatus. 3. An SDH specification station and an SH specification station having different operation specifications.
For communication in a network where stations with the ONET specification coexist,
In a line switching control method for performing line switching control, it is determined whether an MSP message, which is a message for line switching transmitted from the opposite station, includes an external switching command. Detecting, from the message, station switching mode information in which either the single station switching mode or the dual station switching mode is set, and sets the detected station switching mode information as the station switching mode information of the own station; Recognize the operation specifications of the station, set the failure priority information based on the operation specifications as the failure priority information of the own station, and detect the station switching mode information from the MSP message when there is no external switching command. Then, the detected station switching mode information is set as the station switching mode information of the own station. MS that said stop signal transmission to the opposite station, transmitted from the opposite station after stopping of the signal transmission
Recognize the operation specifications of the opposite station from the P message,
A line switching control method, wherein failure priority information based on the operation specifications of the opposite station is set as failure priority information of the own station. 4. The line switching control method according to claim 3, wherein a stop time of the signal transmission is measured, and when the time is up, the stop of the signal transmission is released.