JP2970304B2 - Transmission frame configuration method for loopback formation - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a loopback caused by a transmission failure in a local area network system (hereinafter referred to as LAN) for transmitting synchronous data (circuit-switched data) and asynchronous data (packet-switched data) in a mixed manner. The present invention relates to a transmission frame configuration method at the time of formation.

[0002]

2. Description of the Related Art FIG. 4 shows a LAN system configuration related to the present invention. In FIG. 4, reference numeral 1 denotes a network monitoring device (hereinafter, referred to as an SC device) for monitoring and controlling the entire network; 2, a center node device (hereinafter, referred to as a CN device); Hereinafter, LN
6, 7, and 8 are terminal devices accommodated in the LN devices 3, 4, and 5, respectively, and 9 and 10 are optical transmission lines connecting the CN device 2 and the LN devices 3, 4, and 5, respectively. It is a clockwise working loop communication path and a counterclockwise standby loop communication path.

The CN device 2 and the plurality of LN devices 3, 4 and 5 are connected to each other in a loop by a duplicated optical transmission line of a clockwise active loop communication line 9 and a counterclockwise standby loop communication line 10. , CN device 2 has SC device 1 for monitoring and controlling it
Are connected.

When data is transmitted and received between terminal devices, one of the clockwise loop communication path 9 and the counterclockwise loop communication path 10 is used as a communication path. That is, the use side is the active system and the non-use side is the standby system. In this example, the clockwise loop communication path 9 is an active system, and the counterclockwise loop communication path 10 is a standby system.

FIGS. 5 (a) and 5 (b) show a transmission frame configuration of the active loop communication path 9 and a transmission frame configuration of the standby loop communication path 10 in a conventional example, respectively.

In FIG. 5A, reference numeral 31 denotes an LN device 3,
Reference numerals 4 and 5 denote frame headers for establishing frame synchronization in the active loop communication path 9, reference numeral 32 denotes a communication control area used for performing communication control between the LN devices 3, 4, and 5 by the active loop communication path 9. Reference numeral 33 denotes a data area, of which 33a is a synchronous data area for transmitting synchronous (circuit-switched) data, 33b is an asynchronous data area for transmitting asynchronous (packet-switched) data, and 34 is a data area divided into left and right fixed data amounts. Indicates the threshold position.

In FIG. 5B, reference numeral 35 denotes a frame header for the LN devices 3, 4, and 5 to establish frame synchronization in the standby loop communication path 10, and 36 denotes an LN apparatus LN3 via the standby loop communication path 10. , 4 and 5, a communication control area used for performing communication control, and 37 is an unused area.

[0008] The LN devices 3, 4, 5 are terminal devices 6, 7, 8
When synchronous (circuit-switched) data and asynchronous (packet-switched) data are transmitted to each other in response to a transmission request, a synchronous data area 33a or an asynchronous data area 33b is secured using the communication control area 32 to establish a data communication path. Form.

When the amount of synchronous data transmitted through the active loop communication path 9 increases, the synchronous data 33a is used from left to right. On the other hand, when the transmission amount of the asynchronous data transmitted through the active loop communication path 9 increases, the asynchronous data 34b is used from right to left.

In the state shown in FIG. 5A, the synchronous data area 33a (shaded area) of the data area 33 in the transmission frame of the active loop communication path 9 has not reached the threshold position 34. On the other hand, the asynchronous data area 33 b (vertical line portion) has not yet reached the threshold position 34.

However, when the number of terminals is increased in addition to the terminal devices 6, 7, and 8, the amount of synchronous data increases, and a state in which the synchronous data area 33a exceeds the threshold position 34 occurs.

FIG. 6A shows a transmission frame configuration of the active loop communication path 9 in which the synchronous data area 33 exceeds the threshold position 34, and FIG. 9 shows a transmission frame configuration of the standby loop communication path 10 corresponding to the transmission frame configuration state 9.

When the CN device 2 detects that the synchronous data area 33a of the active loop communication path 9 exceeds the threshold position 34, the CN control 2 transmits the transmission of the active loop communication path 9 to each LN apparatus by the communication control area 32. A command is issued to secure the asynchronous data area 38 in the unused area 37 of the standby loop communication path 10 for all the asynchronous data areas 33b in the frame. In response to this command, the LN devices 3, 4, and 5 respectively secure the asynchronous data area 33b in the transmission frame of the active loop communication path 9 in the unused area 37 of the standby loop communication path 10. This is responded to the CN device 2 by the communication control area 36. Next, the LN devices 3, 4, and 5 delete the asynchronous data area 33b in the transmission frame of the active loop communication path 9 (the synchronous data area 33b).
And release).

Conversely, when the asynchronous data in the active loop communication path 9 increases and the asynchronous data area 33b crosses the threshold position 34 from right to left, the same processing as described above is performed.
And transfer asynchronous data.

Further, when the synchronous data area 33a (or the asynchronous data area 33b) returns to the threshold position or less again after exceeding the threshold position 34, the communication control area is set after the lapse of a certain time as before. Using the communication control area 32 and the communication control area 36, the asynchronous data area 38 secured on the transmission frame of the standby loop transmission path 10 is deleted , and the asynchronous data area 33b is secured again on the transmission frame of the active loop transmission path 9. .

As described above, even in the above-mentioned conventional method, in the active loop communication path, the synchronous data area increases to a certain threshold or more, and the asynchronous data area is used, and the asynchronous data area increases. If it is not possible, when the synchronous data area increases in advance and reaches a certain threshold, an asynchronous data area is secured in the standby loop communication path, and the synchronous data area is The asynchronous data area can be transmitted by the standby loop communication path.

[0017]

However, in the above-described conventional method, when a transmission failure (line disconnection, node device failure, etc.) occurs on the active loop communication path, an asynchronous data area is secured in the standby loop communication path. Therefore, it cannot be used as a standby system for a synchronous data area on the active loop communication path.

Further, the active loop communication path and the standby loop
When a transmission failure occurs in both communication paths, the active loop communication path and the standby loop communication path loop back on both sides of the failure point to form one ring communication path (formation of a loopback state). In this case, however, there is a problem that the securing of a synchronous data area on the active loop communication path and an asynchronous data area of the standby loop communication path cannot be guaranteed.

The present invention solves such a conventional problem, and provides an excellent method capable of securing an asynchronous data area of a standby loop communication path and retaining a synchronous data area even when a transmission failure occurs. The purpose is to do.

[0020]

In order to achieve the above object, in a LAN for simultaneously transmitting synchronous data (circuit switching) and asynchronous data (packet switching), a synchronous data area is added to a transmission frame of an active loop communication path. A first threshold for identifying an asynchronous data area is provided, and when the amount of synchronous data exceeds the first threshold, data in the asynchronous data area is transferred to a transmission frame of a standby loop communication path and transmitted. In the transmission frame configuration method at the time of loopback formation due to the occurrence of a transmission failure, a second threshold value for identifying a synchronous data area and an asynchronous data area in the transmission frame at the time of loopback formation is provided. The value of the second threshold value depends on the data amount of asynchronous data to be preferentially secured in the transmission frame of the standby loop communication path. It is characterized in determining the.

In the above-mentioned transmission frame configuration method, the position of the second threshold value for identifying the synchronous data area and the asynchronous data area in the transmission frame at the time of loopback formation is determined by setting the predetermined synchronous data area and asynchronous data area. Is determined on the basis of the distribution ratio.

Next, a minimum asynchronous data area to be secured in advance is provided in a transmission frame at the time of loopback formation, and the position of the second threshold value is set outside the minimum asynchronous data area.

Further, the synchronous data area of the transmission frame of the active loop communication path is divided into a plurality of blocks in advance according to the transmission order, and the position of the second threshold value is in any of the data areas of the plurality of blocks. At this time, the data area of the block having the position of the second threshold value and the synchronous data area of the block whose transmission order is later than the block are set as the asynchronous data area.

[0024]

As described above, according to the transmission frame forming method of the present invention at the time of forming a loop-back due to the occurrence of a transmission failure in a LAN, the transmission failure occurs in the transmission frame when a transmission failure occurs in the loop communication path and the loop-back state occurs. If the synchronous data in the active loop communication path occupied a certain amount or more beforehand, the asynchronous data area transferred to the standby loop communication path is preferentially secured. In the area transfer, by securing a minimum asynchronous data area for emergency use in the active loop communication path, it is possible to reliably maintain the asynchronous data area against transmission failure in the loop communication path.

[0025]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings.

FIG. 1 shows a system configuration according to an embodiment of the present invention. However, in FIG. 1, a loopback is formed in the active loop transmission line 9 and the standby loop transmission line 10 when a transmission failure occurs.

In FIG. 1, the same reference numerals as those in the prior art denote the same components and functions as those in the conventional example. In FIG. 1, 1
Reference numeral 1 denotes a network monitoring device (hereinafter, referred to as an SC device) for monitoring and controlling the entire network; 12, a center node device (hereinafter, referred to as a CN device) for monitoring and controlling the local node devices 13, 14, and 15; , 14,1
5 is a local node device (hereinafter referred to as L
N device).

Reference numeral 16 denotes a transmission failure point which has occurred simultaneously in both the active loop communication path 9 and the standby loop communication path 10 between the LN devices 13 and 14.

FIG. 2A shows a transmission frame configuration of the active loop communication channel 9 in the system configuration of FIG. 1, and FIG. 2B shows a transmission frame configuration of the standby loop communication channel 10.

In FIG. 2A, reference numeral 21 denotes the LN device 1.
Reference numerals 3, 14, and 15 denote frame headers for establishing frame synchronization in the standby loop communication path 10, and reference numeral 22 denotes communication used for performing communication control between the LN devices 13, 14, and 15 by the active loop communication path 9. The control area 23a is a synchronous data area for transmitting synchronous (circuit-switched) data, and is further divided into synchronous data areas # 1, # 2, and # 3.

Numeral 24 denotes a minimum asynchronous data area of the asynchronous (packet exchange) data area of the standby communication path, which is reserved for re-assigning a minimum of asynchronous data. When the area is relocated, it is empty, but cannot be used as a synchronous data area.

In FIG. 2B, reference numeral 25 denotes the LN device 1.
Reference numerals 3, 14, and 15 denote frame headers for establishing frame synchronization in the standby loop communication path 10, and reference numeral 26 denotes communication used for controlling communication between the LN devices 13, 14, and 15 by the standby loop communication path 9. A control area 27 is an asynchronous data area for transmitting asynchronous (packet exchange) data. Reference numeral 28 denotes a second threshold value for designating a range for securing asynchronous data in forming a loopback when a transmission failure occurs.

FIGS. 3 (a) and 3 (b) show that, as shown in FIG. 1, a transmission failure occurs at the transmission failure location 16 and both the active loop communication path 9 and the standby loop communication path 10 As a result, the LN device 13 cannot be used as a standby system.
, The clockwise active loop communication path 9 loops back to the counterclockwise standby loop communication path 10 (loopback), and LN
A transmission frame configuration is shown in the case where a left-handed standby loop communication path 10 is turned back to a right-handed operation loop communication path 9 (loopback) in the device 14 to form one ring-shaped communication path. (Hereinafter, this is referred to as loopback formation). In this case, the minimum asynchronous data area 24 is always reserved for securing asynchronous (packet exchange) data.

FIG. 3A shows that the asynchronous data area 27 in the transmission frame of the standby loop communication path 10 has a larger data amount than the minimum asynchronous data area 24 as shown in FIG. A transmission frame configuration when a transmission failure occurs and a loop-back state is formed at times. In this figure, reference numeral 23a denotes a synchronous data area;
b denotes an asynchronous data area, 29 denotes a minimum asynchronous data area, and a minimum asynchronous data area 2 before transmission failure occurs.
4 has the same data amount. Reference numeral 28 denotes an asynchronous data range setting threshold position.

FIG. 3 (b) shows a transmission frame configuration when a loopback state is formed when a transmission failure occurs, as in FIG. 3 (a). Is a case where the data amount of the asynchronous data area 27 is smaller than the minimum asynchronous data area 24.

Next, a method of configuring a transmission frame when a loopback is formed due to a transmission failure in one embodiment of the present invention will be described.

In FIG. 1, the CN device 12 constantly monitors the amount of synchronous data on the active loop communication path 9 and the amount of asynchronous data on the standby loop communication path 10.

When the synchronous data or the asynchronous data exceeds a predetermined first threshold value, a command for transferring the asynchronous data to the standby loop communication path 10 is issued to each of the LN devices 13, 14, and 15. Do.

Each of the LN devices 13, 14, and 15 transfers the asynchronous data being used to a transmission frame of the standby loop communication path 10.

This result is returned from the LN devices 13, 14, 15 to the CN device 12. CN device 12 has all L
When a response is received from the N device, this information is stored.
Hereinafter, as the asynchronous data increases, the asynchronous data area 27 of the standby loop communication path 10 expands.

When the synchronous data area 23a returns to the first threshold value position or less again after exceeding the first threshold value position 34, the communication control area 22 and the communication control area 22a and the communication control area 22a are transmitted after a lapse of a predetermined time in the same manner as before the excess. The asynchronous data area secured on the transmission frame of the standby loop communication path 10 by using the control area 26.
The area 27 is deleted , and the asynchronous data area 23b is secured on the transmission frame of the active loop transmission path 9 again.

When the synchronous data area 23a exceeds the first threshold value position 34 and the asynchronous data area 23b communicates with the asynchronous data area 27 on the standby loop communication path 10, FIG.
Suppose that a transmission failure has occurred at the transmission failure location 16 as shown in FIG.

This transmission failure is detected as an abnormal frame synchronization in both the active loop transmission line 9 and the standby loop transmission line 10 in the CN device 12.

The CN device 12 sends a command for reallocating the data area to all the LN devices through both the active loop transmission line 9 and the standby loop transmission line 10.

The CN device 12 sets a second threshold value in the command . Each LN device compares the synchronous data area of the active loop transmission line 9 used by itself with the second threshold, and secures the synchronous data area on the right side of the second threshold as an asynchronous data area. I do.

[0046] On the other hand, non-each LN device using self
The synchronous data area is compared with the second threshold value, and the asynchronous area on the right side of the second threshold value is reallocated.

[0047] non-same you want to save this time, at the time of transmission failure
When the data amount of the initial data area 27 is larger than the data amount of the minimum asynchronous data area, the area on the right side of the threshold position 28 is continuously set as the asynchronous area.

When the data amount of the asynchronous data area to be secured does not exceed the minimum asynchronous data area 24,
It is assumed that the threshold position 28 matches the left boundary of the minimum asynchronous data area 24 and does not fall within the minimum asynchronous data area 24 .

Asynchronous area of the above standby loop transmission line 10
The reallocation of the area is detected in the CN device 12 by a response command from each LN device. CN device 12 is connected to each LN
When a response command from the device is detected, both the active loop transmission line 9 and the standby loop transmission line 10 send a loopback command command to all LN devices.

The loopback command is received by all the LN devices, but the LN devices 13 and 14 adjacent to the transmission failure point 16 maintain the loopback state.

Therefore, as shown in FIG. 1, a transmission failure occurs at the transmission failure location 16, and the LN device 13 and the LN device 14 perform a loopback process to connect the active communication line 9 and the standby communication line 10. Thus, a ring-shaped communication path is formed.

When a transmission failure (transmission failure location 16) occurs between the LN devices 13 and 14, the transmission frame from the CN device 12 passes through the clockwise active loop communication path 9 and is looped back by the LN device 13, and this time. Passes through the CN device 12 and the LN device 15 by the counterclockwise standby loop communication path 10, returns to the LN device 14, and returns to the CN device 12 via the LN device 15 again by the clockwise operation loop communication channel 9. Returning, a closed loop ring communication path is formed.

When a transmission failure occurs, the asynchronous data area of the standby loop transmission line 10 of all the LN devices is transferred to the closed loop transmission line and transmitted by the closed loop ring communication path.

As shown in FIG. 2A, the synchronous data area is divided in advance into a plurality of synchronous data areas # 1, # 2, and # 3, and the synchronous data area Data area # 3 can also be invalidated.

[0055] If there are a threshold position 28 in advance synchronization data area # 2, the synchronization data area # 2, disables the synchronous data area # 3 together, including the minimum asynchronous data area 24 instead Up to the synchronous data area # 2 is secured as an asynchronous data area.

In either method, the threshold position 2
The setting of 8 includes a method of fixedly determining and a method of sliding according to the data amount of the standby asynchronous data area 27.

Therefore, in the method of fixing the setting of the threshold position 28, when the asynchronous data area is larger than the synchronous data area invalidated by the fixed threshold position 28, the excess is set. Is not saved.

Next, in the method of sliding according to the data amount of the standby asynchronous data area 27, the threshold position 28 is always located on the left side of the standby asynchronous data area 27, and the threshold position 28 is increased or decreased. Slides with. In this case, all areas on the right side of the threshold position 28 can be continuously formed as asynchronous data areas.

When the synchronous data area is divided into a plurality of synchronous data areas # 1, # 2, and # 3 in advance, a plurality of synchronous data areas # 1, # 2, It is possible to delete the data in the synchronous data area (the synchronous data area # 3 in the case of FIG. 2A) including the above-described threshold position 28 in # 3 and secure it as an asynchronous data area when a transmission failure occurs. it can.

[0060] If there are a threshold position 28 in advance synchronization data area # 2, the synchronization data area # 2, disables the synchronous data area # 3 together, including the minimum asynchronous data area 24 instead Up to the synchronous data area # 2 is secured as an asynchronous data area.

The maximum amount of data in the synchronous data area 23a is when the threshold 28 is on the left boundary of the minimum asynchronous data area 24. At this time, if a transmission failure occurs, the minimum asynchronous data area is secured even if the data amount of the asynchronous data area of the standby loop communication path 10 is larger than the data amount of the minimum asynchronous data area 24.

As described above, according to the above embodiment, when a transmission failure occurs during asynchronous data transmission by the standby loop communication path, the asynchronous data transmitted on the standby communication path before the transmission failure occurs is given priority. Or the distribution ratio to be secured in the transmission frame between the synchronous data range and the asynchronous data range can be changed by controlling the threshold position.

[0063]

As is apparent from the above description, according to the transmission frame configuration method for loopback transmission in the event of transmission failure according to the present invention, it is possible to control the range in which synchronous data and asynchronous data are to be secured according to the transmission situation. It has the effect that it becomes possible.

[Brief description of the drawings]

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

2A is a diagram illustrating a transmission frame configuration of an active loop communication channel; FIG. 2B is a diagram illustrating a transmission frame configuration of a standby loop communication channel;

FIG. 3A is a diagram of a transmission frame when a transmission failure occurs (when the amount of asynchronous data is larger than the minimum asynchronous data). FIG. 3B A diagram of a transmission frame when a transmission failure occurs (the amount of asynchronous data is smaller than the minimum asynchronous data). Case)

FIG. 4 is a block diagram showing a LAN system configuration;

5A is a diagram illustrating a transmission frame configuration of an active loop communication channel in a conventional example. FIG. 5B is a diagram illustrating a transmission frame configuration of a standby loop communication channel in a conventional example.

FIG. 6 is a configuration diagram of a transmission frame of an active loop communication path and a standby loop communication path when a threshold position is exceeded in a conventional example.

[Explanation of symbols]

 6, 7, 8 Terminal device 9 Active loop communication channel 10 Standby loop communication channel 11 Network monitoring device (SC) 12 Center node device (CN) 13, 14, 15 Local node device (LN) 16 Transmission failure point 21 Frame Header 22 Communication control area 23a Synchronous data area 23b Asynchronous data area 24 Minimum asynchronous data area 25 Frame header 26 Communication control area 27 Asynchronous data area 28 Threshold position

Claims (4)

(57) [Claims] 1. A system comprising a plurality of node devices interconnected by a redundant loop communication path comprising an operation system and a standby system and terminal devices accommodated in each node device, wherein synchronous data (circuit switching) and asynchronous data ( In a LAN that simultaneously transmits packet switching), a first threshold for identifying a synchronous data area and an asynchronous data area is provided in a transmission frame of an active loop communication path, and the synchronous data amount is set to the first value.
A transmission frame configuration method in which data in an asynchronous data area is transferred to a transmission frame of a standby loop communication channel when the data exceeds a threshold value, and the transmission data is transmitted. And a second threshold value for identifying an asynchronous data area, wherein the second threshold value is determined according to the amount of data to be preferentially secured for asynchronous data in the transmission frame of the standby loop communication path when a transmission failure occurs. A transmission frame configuration method at the time of loopback formation, characterized by determining a position. 2. A second method for identifying a synchronous data area and an asynchronous data area in a transmission frame when forming a loopback.
2. The transmission frame configuration method according to claim 1, wherein the position of the threshold value is determined based on a predetermined distribution ratio between the synchronous data area and the asynchronous data area. 3. The method according to claim 1, wherein a minimum asynchronous data area to be secured is provided in advance in a transmission frame at the time of loopback formation, and the position of the second threshold value is set outside the minimum asynchronous data area. 2. The transmission frame configuration method at the time of loopback formation according to 1. 4. A synchronous data area of a transmission frame of an operation loop communication path is divided into a plurality of blocks in advance according to a transmission order, and the position of the second threshold value is in one of the data areas of the plurality of blocks. 2. The loopback forming method according to claim 1, wherein the data area of the block having the position of the second threshold value and the synchronous data area of a block whose transmission order is later than the second threshold value are set as asynchronous data areas. Transmission frame configuration method.