JP4854188B2 - Detour configuration method for double loop transmission - Google Patents

Description

  The present invention relates to a detour configuration method in the case of a single loop failure on a loop transmission line in a double loop transmission system with detour.

A detour configuration method for configuring a detour in loop transmission involving detours has been proposed previously. In the proposed bypass configuration method, each transmission control device so that the message is transmitted to, the reliable host control unit (hereinafter referred to as host) if Oite fault loop transmission path is present (Network Control Processor : Hereinafter abbreviated as NCP) A detour is configured to transmit a message via NCP or NCP (for example, see Patent Document 1).

  The loop transmission detour configuration method will be described in detail below. FIG. 1 is a diagram for explaining the configuration of a loop-shaped loop transmission system, which has a loop 1 for transmitting a message clockwise and a loop 2 for transmitting a message counterclockwise. Further, NCPs 11 to 18 are connected to the loop 1, and NCPs 21 to 28 paired with the NCPs 11 to 18 are connected to the loop 2, respectively. The paired NCPs have detour transmission paths 31 to 38 that can transmit data in both directions, respectively, and the hosts 61 to 68 that perform message exchange are the transmission paths 41 to 48 and the transmission paths 51 to 51, respectively. 58 connects.

  As shown in FIG. 2, when Loop 1, Loop 2, and each NCP are in a normal state, the loop 1 transmission line between the host 67 and the host 68 is disconnected (disconnection A1), and transmission is impossible. Shall be.

  If a message is transmitted from the host 61 to the loop 1 via the NCP 11 in this state, the message is not returned to the originating NCP 11 due to the disconnection A1. For this reason, the NCP 11 detects that there is an abnormality on the loop 1 transmission path, transmits itself as a transmission source, transmits the small loop check data 100, and further requests the NCP 21 to transmit the small loop check data 200. .

  The NCP 12 that has received the small loop check data 100 from the NCP 11 transmits the small loop check data 100 to the NCP 22 and transmits the small loop check data 101 as a transmission source. In this way, the small loop check data 102 to 105 of the loop 1 are sequentially transmitted to the downstream NCP. When the small loop check data 105 reaches the NCP 17, the NCP 17 itself becomes a transmission source and transmits the small loop check data 106 in the same manner as the NCP 12, but the small loop check data 106 returns to the transmission source NCP 17 by the disconnection A1. Therefore, the NCP 17 satisfies one condition constituting a detour. Then, the NCP 17 further transmits the large loop check data 300 as the transmission source, but the large loop check data 300 is not returned to the transmission source NCP 17 due to the disconnection A1, so that the detour configuration condition is satisfied and the NCP 27 is established. Thus, the detour path 37 is configured.

  In the loop 2, the NCP 28 similarly becomes the transmission source and transmits the small loop check data 201. However, since the small loop check data 201 is not fed back, one condition constituting the detour is satisfied. Then, the NCP 28 becomes a transmission source and further transmits the large loop check data 400. In the loop 2, the detour configuration condition is not satisfied when the large loop check data 400 returns normally, and the detour configuration is not performed.

  Thereafter, as shown in FIG. 3, the message 500 from the NCP 11 passes through the loop 1 in the transmission direction of the NCP 12 and NCP 13 and reaches the NCP 17, and then moves to the loop 2 through the detour 37. Reaches looper NCP21 through loop 2. Since there is an NCP that has not yet passed through the NCP in the loop 2, the loop 2 is made another round and returned to the source NCP pair NCP 21.

In this way, the message 500 sent by the NCP 11 has a longer loop transmission path, and particularly when the NCP that is the last loop when viewed from the source NCP fails, the loop transmission path becomes longer and there is no detour. The loop transmission time is tripled and the round-trip feedback time of the loop transmission is increased.
JP-A-57-52249

It is an object of the present invention to shorten a loop return time for loop transmission by shortening a redundant loop transmission line in the detour configuration method when a fault exists on a loop transmission line of a double loop transmission system. And

In order to solve the above-described problem, the present invention provides an NCP transmission function that is paired with an NCP that constitutes a detour when there is a failure at only one location on the loop transmission path in a double loop transmission involving a detour. To stop. In other words, a transmission path that is paired with a transmission path that has failed at only one location on the loop transmission path is set to a logically disconnected state (the loop transmission path is disconnected from both ends) to form a new detour.
That is, the detour configuration method of the present invention includes two loop transmission lines that perform data transmission in opposite directions, and a transmission control device (Network Control Processor: hereinafter abbreviated as NCP) provided in pairs with the transmission lines. ) And a detour configuration method of double loop transmission configured by detours that perform bidirectional data transmission between each pair of NCPs, when there is only one failure on the loop transmission path, Since the large loop check data from the NCP does not return due to a failure, a detour is configured, and the NCP that configures the detour stops the function of transmitting the large loop check data received from the paired NCP loop transmission path. The transmission path that is paired with the transmission failure point is logically disconnected to shorten the detour path length.

That is, the present invention provides two loop transmission lines that perform data transmission in opposite directions, an NCP that is provided as a pair on the transmission line, and a detour that performs bidirectional data transmission between each pair of NCPs. In the double loop transmission detour configuration method configured from a path, when a fault exists on the loop transmission path, the NCP that configured the detour has received the large NCP received from the loop transmission paths 1 and 2 of the paired NCP. The function of transmitting loop data was stopped, the transmission path paired with the transmission failure location was logically disconnected, and the detour path length was shortened.

According to the present invention, in the detour configuration method described above, the NCP that has detected that a failure has occurred on one loop transmission path transmits small loop check data to the adjacent NCP, and receives the small loop check data. NCP sends small loop check data sequentially to NCP downstream of loop, and NCP that could not receive small loop check data issued by itself sends large loop check data downstream of loop and cannot receive large loop check data When the pair NCP receives large loop data from the upstream of the loop transmission paths 1 and 2, the large loop data is transferred to the bypass or loop transmission paths 1 and 2 by setting to refuse to transmit downstream, logically break the loop transmission path to be transmitted fault location and pairs

Further, according to the present invention, in the above detour configuration method, when there is a failure on the loop transmission line, the NCP that configures the detour stops the transmission function of the paired NCP, and the paired transmission with the transmission failure location In the configuration in which the path is logically disconnected, when the fault on the loop transmission path is recovered, the logically disconnected transmission path is released.

  Furthermore, the present invention provides the detour configuration method as described above, wherein a loop configuration state table is provided in the host connected to the NCP and the pair NCP, and includes a small loop check result, a large loop check result, a detour state, and a NCP transmission rejection request. The loop configuration state was memorized.

In other words, the present invention provides (1) a means for detecting a failure location on a loop transmission path and requesting a NCP transmission rejection request to a pair of NCPs in a host connected to an NCP that configures a detour. (2) When a message excluding small loop check data is received from the loop transmission lines 1 and 2 in the NCP for which the NCP transmission rejection request is set, a means for discarding the received message is provided. (3) In the NCP to which the self-originated small loop check data is returned, there is provided means for canceling the bypass of the own NCP and canceling the NCP transmission rejection request.

  As described above, according to the present invention, even if a failure occurs only at one location on the loop transmission path, the loop transmission path can be shortened while protecting the purpose of the message transmission by the host to each NCP (NCP or NCP). In addition, the round-trip feedback time for loop transmission can be shortened.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 4 shows a loop configuration state table 1000 for storing the loop configuration state provided in the host connected to the double loop transmission system. Each of the hosts 61 to 68 has a loop configuration table, and uses an area corresponding to each of loop (loop transmission path) 1 and loop 2.

The small loop check results 1001 and 1005 store whether or not the small loop check data has returned normally, and are set to “0” for OK and “1” for NG. The large loop check results 1002 and 1106 store whether or not the large loop check data has returned normally, and is set to “0” for OK and “1” for NG. The bypass states 1003 and 1007 store whether the current NCP bypass state is bypassing or not bypassing, and is set to “0” when not bypassing and to “1” when bypassing. The NCP transmission rejection requests 1004 and 1008 are requests that do not transmit the large loop check data received from the loop transmission paths 1 and 2 and set the result of the large loop check to be NG, and are rejected to “0” in the case of a non-rejection request. Set to “1” for request. In the case of the transmission rejection request, the NCP does not transmit the message of the large loop check data received from the loop transmission paths 1 and 2 to the next adjacent NCP. However, other data is transmitted to the adjacent NCP or to the NCP regardless of the transmission rejection request.

  The outline of the first embodiment of the present invention will be described with reference to FIGS. FIG. 5 shows changes in the loop configuration state table 1000 of the hosts 67 and 68 until the logical disconnection. In FIG. 6, as in FIG. 2, it is assumed that the loop transmission between the host 67 and the host 68 is disconnected (disconnection A1) and transmission is impossible. If a message is transmitted from the host 61 to the loop via the NCP 11 in this state, the message is not returned to the NCP 11 as in FIG. Therefore, the host 61 itself becomes a transmission source and requests the small loop check 100 and the NCP 21 to transmit the small loop check data 200.

  Thereafter, as in FIG. 2, when the small loop check data circulates in the loop transmission direction and the small loop check data 106 transmitted from the NCP 17 is transmitted, it is not returned to the transmission NCP 17 due to the disconnection A1, and Since the large loop check data 300 from which the NCP 17 has been transmitted does not return to the NCP 17 due to the disconnection A 1, the NCP 17 constitutes a bypass 37.

  At this time, the host 67 sets the loop 1 small loop check result and the large loop check result of the loop configuration state table 1000 to (1: NG), sets the detour state (1: detouring), and requests to reject NCP transmission. (1: Rejection request) is set. (The states of FIGS. 5 and 1010) At this time, all items of the loop 2 of the loop configuration state table of the host 67 and the loop 1 and loop 2 of the loop configuration state table of the host 68 are all set to 0.

By setting the state 1010, the NCP 27 transitions to an operation of discarding the message of the large loop check data transmitted from the NCP 28 when the NCP transmission rejection request is set.

  In the loop 2, as in FIG. 2, the NCP 28 becomes the transmission source and transmits the small loop check data 201. However, the small loop check data 201 is not returned due to the disconnection A1, and one condition constituting a detour is satisfied. Thereafter, the NCP 28 becomes a transmission source and transmits the large loop check data 400, but the NCP 27 is in a request to reject transmission to the NCP, so the large loop check data 400 is not returned. Therefore, the NCP 28 constitutes a bypass 38.

  Further, the host 68 sets the loop 2 small loop check result and the large loop check result of the loop configuration state table 1000 to (1: NG), sets the detour state (1: detouring), and requests to reject NCP transmission. (1: Rejection request) is set. (State of FIGS. 5 and 1011)

  After the NCP 17 and the NCP 28 configure the detour 37 and the detour 38, as shown in FIG. 7, when the message 500 from the NCP 11 reaches the NCP 17 through the loop 1, the message 500 passes through the detour 37 to the loop 2. This time, it passes through loop 2 and reaches the source NCP21. Further, it reaches the NCP 28 through the loop 2, moves to the loop 1 through the detour 38, and returns to the NCP 11 of the source NCP.

When a failure occurs in the loop transmission in this way, the NCP that forms the detour and the NCP that is adjacent to the NCP simultaneously form a detour so that the loop transmission path during detouring can be compared to the case where one detour is configured. And the round trip feedback of loop transmission is shortened.

  The outline of the second embodiment 2 of the present invention will be described with reference to FIGS. In this embodiment, a description will be given of the release of the detour configuration by the failure point recovery of the disconnection A1 when the detour configuration is performed by the detour configuration method of the first embodiment.

  FIG. 8 shows changes in the loop configuration state table 1000 of the host 67 and the host 78 when the detour is configured by the detour configuration method from the disconnected state.

  In FIG. 9, as in FIG. 6, it is assumed that the loop transmission between the host 67 and the host 68 is disconnected (disconnection A1) and transmission is impossible. In this state, the NCP 17 and the NCP 28 are configured as the detour 37 and the detour 38 according to the detour configuration method described in the first embodiment.

  In this state, the NCP 17 periodically transmits the small loop check data 106, but the small loop check data 106 is not fed back due to the disconnection A1.

  The NCP 28 also periodically transmits the small loop check data 201, but the small loop check data 201 is not fed back due to the disconnection A1.

  That is, the NCP 17 and the NCP 28 continue to form the detours 37 and 38. (State of FIGS. 8, 1012)

  When the disconnection A1 recovers from the failure from this state, the small loop check data 106 transmitted by the NCP 17 returns to the NCP 17 that is the transmission source, and the bypass 37 is released. At this time, the host 67 sets the small loop check result and the large loop check result of loop 1 in the loop configuration state table 1000 to (0: OK), sets the detour state (0: not detouring), and transmits to NCP. (0: Non-rejection request) is set in the rejection request. (State of FIGS. 8, 1013)

  Similarly, in the NCP 28, the small loop check data 201 transmitted by the NCP 28 returns to the NCP 28 that is the transmission source, and the detour path 38 is released.

  At this time, the small loop check result of loop 2 and the large loop check result of the loop configuration state table 1000 of the host 68 are set to (0: OK), and the detour state is set to (0: not detouring), and NCP transmission rejection is performed. Set (0: Non-rejection request) in the request. (State of FIGS. 8 and 1014)

  After the NCP 17 and NCP 28 have recovered the detour configuration, the message from the NCP 11 returns to the source NCP 11 through the loop 1 only.

  In this way, it is possible to detect the recovery of the location where the failure has occurred and cancel the configured detour.

The block diagram explaining the structure of the transmission system of the double loop form which this invention presupposes. The figure explaining the detour configuration procedure at the time of failure occurrence in the double loop transmission line which is the technical background of the present invention. The figure explaining the transmission path | route of the message at the time of performing the detour | route path | route structure in the double loop transmission path | route which is the technical background of this invention. The table format of the loop structure state in each host in the Example of this invention. The figure explaining the detour configuration procedure of the loop transmission line in the first embodiment of the present invention. The figure explaining the transmission path | route of the message at the time of performing the detour structure of the loop transmission path | route in 1st Example of this invention. The figure explaining the detour configuration cancellation | release procedure of the loop transmission path in 1st Example of this invention. The figure explaining the table state of the loop structure state until the detour structure cancellation | release of the loop transmission line in 2nd Example of this invention. The figure explaining the detour configuration cancellation | release procedure of the loop transmission line in 2nd Example of this invention.

Explanation of symbols

1 Loop transmission line 1
2 Loop transmission line 2
11-18 NCP connected to loop transmission line 1
21 to 28 NCP connected to loop transmission line 2
31-38 Detour 41-48 NCP, inter-host transmission line 1
51-58 NCP, transmission path 2 between hosts
100 to 106 Small loop check data (Loop 1 direction)
200-201 Small loop check data (loop 2 direction)
300 Large loop check data (Loop 1 direction)
400 large loop check data (loop 2 direction)
500 message 1000 loop configuration state table 1001, 1005 small loop check result 1002, 1006 large loop check result 1003, 1007 detour state 1004, 1008 to NCP transmission rejection request

Claims (1)

Two loop transmission lines that perform data transmission in opposite directions, a transmission control device (Network Control Processor: hereinafter abbreviated as NCP) provided in a pair with the transmission line, and bidirectional communication between each pair of NCPs In a double loop transmission detour configuration method comprising a detour that performs data transmission,
If a fault in the loop transmission path is present only one location, the configuration detour from the fact that the large loop check data from the source NCP is not fed back due to a failure, NCP configured the detour, paired NCP of A detour configuration method characterized by stopping a transmission function of large loop check data received from a loop transmission path, logically disconnecting a transmission path paired with a transmission failure location, and shortening a detour path length.

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