JP2802408B2 - Path setting method for ring transmission network - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention is used for packet or ATM (asynchronous transfer mode) information transmission using a ring transmission line. In particular, the present invention relates to setting a path identification number indicating a transmission path of a packet or a cell.

[0002] In packet communication, an information unit is called "packet".
In ATM, these are called "cells", but in the present specification, these are collectively called "information units".

[0003]

2. Description of the Related Art FIG. 2 is a diagram for explaining a conventional path setting method, and shows a ring transmission line network in which six nodes are connected by a double ring transmission line facing each other. The transmission line is provided with a left-handed ring transmission line 21 and a right-handed ring transmission line 22, and nodes 11 to 16 are arranged on this.

As an example, a case where an information unit (packet or cell) is transmitted from node 11 to node 15 will be described.

[0005] In this case, the working path is set to the path of the node 11 → the counterclockwise ring transmission line 21 → the node 12 → the counterclockwise ring transmission line 21 → the node 13 → the counterclockwise ring transmission line 21 → the node 14. This path is shown by the solid line in FIG. As for the backup path, on the clockwise ring transmission line 22 side, node 14 → clockwise ring transmission line 22 → node 13 → clockwise ring transmission line 22 → node 12 → clockwise ring transmission line 22 → node 11 → right The setting is made as follows: the ring transmission line 22 → the node 16 → the clockwise ring transmission line 22 → the node 15 → the clockwise ring transmission line 22 → the node 14. The backup path is shown in FIG.

[0006] Such a path is assigned to each of the nodes 11 to 16 when an information unit having a path identification number indicating a transmission path is input to each node (a ring transmission path, a node output terminal, etc.). This is done by writing in a table that instructs whether or not to output, ie, a link map.

As a method of setting a path identification number, there has been proposed a method of assigning the same path identification number to both a working path and a protection path on a ring. FIG. 2 shows the path identification number in that case as “1”. By this setting, the counterclockwise ring transmission line 21 in which the working path is set and the clockwise ring transmission line 2 in which the protection path is set
2 becomes one transmission line due to loop back,
The connection to the backup path can be made without changing the path identification number. However, the path identification number assigned to the working path is not used on the remaining transmission paths to which the working path is assigned. The reason is that the same path identification number is connected at the time of loopback, so if the same path identification number is also present on the remaining transmission paths, a ring path will be generated at the time of multiple failures, which may cause multi-turn cells. Because there is.

[0008]

However, when one working path is set in this way, a path identification number for one ring is used for each ring as a result in any path route. become. For this reason, there is a problem that the number of paths that can be set per circuit of the transmission line is fixed.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a path setting method for a ring transmission line network capable of effectively setting a path identification number while having a function of looping back when a failure occurs in a double ring transmission line.

[0010]

A path setting method for a ring transmission line network according to the present invention assigns a path identification number to a working path and a protection path for each node, and a work path and a corresponding path between the same nodes. The same path identification number is assigned to the backup path.

[0011]

By assigning the same path identification number to the working path and the corresponding backup path, the node detecting the transmission path failure can connect and loop back the same path identification number between the double ring transmission paths. . In this case, each node is provided with means for distinguishing the working path and the protection path from the transmission path identification number, enabling a loopback connection from the working path to the protection path, and connecting the protection path to the working path. It is desirable to prevent the information from circling by not doing so.

By allocating a path identification number for each node, it is not necessary to use a path identification number for one round of the ring, and a path identification number indicating a protection path for a certain working path in one ring transmission line. The value can be used as a path identification number indicating a protection path for another working path. Therefore, the path identification number can be used effectively.

[0013]

FIG. 1 is a diagram for explaining a path setting method according to an embodiment of the present invention. As shown in FIG.
1 shows a ring transmission line network in which a plurality of nodes are arranged.

This ring transmission network is configured to transmit a packet or cell having a path identification number indicating a transmission path, and includes a left-hand ring transmission line 21 and a right-hand ring transmission line 2
2 in which nodes 11 to 16 are arranged.

When the information unit is transmitted from the node 11 to the node 15, the working path is changed from the node 11, the counterclockwise ring transmission line 21, the node 12, the counterclockwise ring transmission line 21, the node 13, the counterclockwise ring as in the conventional example. The route is set to the route from the transmission line 21 to the node 14. As for the backup path, on the clockwise ring transmission line 22 side, node 14 → clockwise ring transmission line 22 → node 13 → clockwise ring transmission line 22 → node 12 → clockwise ring transmission line 22 → node 11 → right The setting is made as follows: the ring transmission line 22 → the node 16 → the clockwise ring transmission line 22 → the node 15 → the clockwise ring transmission line 22 → the node 14; the ring-shaped backup path is cut off at the node 14 which is the receiving node; The reception end of the cut-off protection path and the reception end of the working path are multiplexed to obtain a reception output end of the reception node.

Up to this point, the method is the same as the conventional example, but the present embodiment differs from the conventional example in the method of setting the path identification number. That is, (1) the same number as the working path on the reverse ring transmission line is assigned to the protection path path identification number. (2) The path identification number of the working path can be set arbitrarily.
The basic matter is that the path identification number can be changed for each transmission path even in one path. According to the item (1), the transmission path in which the working path is set (the counterclockwise ring transmission path 21 in the example shown in FIG. 1) and the transmission path in which the protection path is set (the clockwise ring transmission path 22) Becomes a single transmission line due to loopback, it is possible to connect to the backup path without converting the path identification number. However, in each node, the working path and the protection path are identified from the transmission path and the path identification number, and the loopback connection from the protection path to the working path is not performed. It is desirable. Further, according to the item (2), the path identification number can be set using the free path identification number for each transmission path without considering the path length of the working path.

That is, conventionally, there is a path identification number that cannot be used on a transmission path other than the path of the transmission path to which the working path is allocated, and the backup path is set for one round of the ring with the same path identification number as the working path. However, this cannot be set as another working path or protection path. In this embodiment the contrary, by using the above basics, made available as a path identification number of another protection path.

FIG. 3 is a diagram showing an example of setting a path identification number, and shows a case where four paths are set. In this figure, (a) shows a set path, and (b) to (e) show examples of path identification numbers of the respective paths. (B), (c)
7A and 7B are examples of counterclockwise and clockwise settings by the method shown in the conventional example, and FIGS. 7D and 7E show examples of counterclockwise and clockwise settings according to the present invention. In the figure, the working path is indicated by W1 to W4, and the backup path is indicated by P1 to P4.

In this example, the working path W1 is set, for example, in the order of node 11 → counterclockwise ring transmission line 21 → node 12 → counterclockwise ring transmission line 21 → node 13 → counterclockwise ring transmission line 21 → node 14. Is set to a constant value in the conventional example as shown in FIG. On the other hand, in the method of the present invention, the path identification number can be set to a different value for each transmission line.
In the example shown in (1), the path identification number is changed from 1 → 1 → 3. If the path identification number is allowed to change in this way,
In the method described in the conventional example, four path identification numbers are used, whereas in the method of the present invention, four paths can be set only by using three path identification numbers.

FIG. 4 shows the result of calculating the number of settable paths for each connection condition shown in Table 1 when the number of nodes is 10, and the number of paths that can be set per transmission path is 4096. In the conventional method shown as the path form A, the maximum number of paths that can be set is 409 in any of the path forms.
There are six. In contrast, the number of configurable paths can be further increased by using the method according to the present invention. In particular, when the shortest path is set equally from each node to the adjacent node, that is, in the path form D, the number of paths that can be set increases by 80%.

[0021]

[Table 1] In the above embodiment, an example is shown in which a single double ring transmission line is used. However, the present invention can be similarly applied to a mesh network in a portion that can be disassembled into a connected double ring.

[0022]

As described above, according to the path setting method of the present invention, the connection from the working path to the protection path can be performed without converting the path identification number after the occurrence of the transmission path stage. By allocating a path identification number for each route to be transmitted without using the path identification number, the path identification number can be effectively used and the path accommodation efficiency can be improved.

[Brief description of the drawings]

FIG. 1 is a view for explaining a path setting method according to an embodiment of the present invention.

FIG. 2 is a view for explaining a conventional path setting method.

FIGS. 3A and 3B are diagrams illustrating examples of setting path identification numbers, where FIG. 3A illustrates a path to be set, and FIGS. 3B and 3C illustrate examples of setting counterclockwise and clockwise path identification numbers according to the method illustrated in the conventional example. , (D),
(E) is an example of counterclockwise and clockwise settings according to the present invention.

FIG. 4 is a diagram showing a result of obtaining the number of settable paths for each connection condition shown in Table 1.

[Explanation of symbols]

 11, 12, 13, 14, 15, 16 Node 21 Left-handed ring transmission line 22 Right-handed ring transmission line W1-W4 Working path P1-P4 Backup path

Continuation of the front page (56) References JP-A-5-268234 (JP, A) JP-A-5-63601 (JP, A) JP-A-4-172035 (JP, A) JP-A-4-100343 (JP) JP-A-4-84535 (JP, A) JP-A-6-508967 (JP, A) IEEE JOURNAL ON SELECTED AREAS IN COMMUNICATIONS, VOL. 12 NO. 1 JAN 1994, YOSH IO KAJIYAMA ET AL, "AN ATM VP-BASED SELF-HEALING RING", PP. 171-178 IEEE JOURNAL ON SELECTED AREAS IN COMMUNICATIONS, VOL. 10 NO. 9 DEC 1992, YSON G-HO WU ET AL, "AN ECONOMIC FEASIBILITY TY STUDY FOR A BRO ADBAND VIRTUAL PATH H SONET / ATM SELF-HEALING RING ARCHITEC. 1459-1473 Proc. Of the 1991 Autumn Meeting of the Institute of Electronics, Information and Communication Engineers, Proceedings, Volume 3, B-480 IEICE Technical Report, IEICE Technical Report, Vol. 90, No. 246, CS 90-48, PP19 −24, Nobuyuki Tokura et al., “System Experiment of ATM Transmission Network Based on Virtual Path Concept”, October 18, 1990, Transactions of the Institute of Electronics, Information and Communication Engineers, BI, VOL. J72-BI NO. 11, Nobuyuki Tokura et al., "Study of Distributed Remote Multiplexing System", PP. 1120-1129, November 25, 1989, Transactions of the Institute of Electronics, Information and Communication Engineers, BI, VOL. J76-BI NO. 6, Hideo Takino et al., "Instantaneous Path Switching in ATM Networks". PP. 421-430, June 25, 1993 (58) Fields surveyed (Int. Cl. ⁶ , DB name) H04L 12/28 H04L 12/42-12/437 INSPEC (DIALOG) JICST file (JOIS) WPI ( DIALOG)

Claims (1)

(57) [Claims] 1. A working path and a protection path are set in an opposite double ring transmission line in which a plurality of nodes are connected in a ring shape and an information unit provided with a path identification number is transmitted to a path indicated by the path identification number. Setting a working path between a transmitting node and a receiving node of one ring transmission path of the opposed dual ring transmission path, and setting the receiving node on a ring transmission path opposite to the working path. In the ring transmission path network in which the receiving end establishes an open ring-shaped protection path multiplexed with the receiving end of the working path , the working path and the protection path include the respective paths. Pass in
And allowing the identification number is changed, assign the path identification number for each between nodes, the backup path, its is between there is a corresponding working path nodes
A path setting method for a ring transmission line network, wherein the same path identification number as the current working path is assigned.