JP2003348107A - Two-way linked network, route selecting method used therefor, and program thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a two-way linked network capable of relieving the load on the preliminary survey of a ring type network and the labor of setting to an apparatus and performing a route selection appropriate to an actual traffic state to the utmost. <P>SOLUTION: When a transmitter apparatus 1 simultaneously transmits a route searching packet in directions x, y respectively, since an x direction path searching packet 111 arrives in transmission apparatuses 2, 3 earlier and a y direction route searching packet 112 arrives in transmission apparatuses 4 to N earlier, each transmission apparatus sets a flag denoting the reception of the earlier arrived path searching packet to the packet, adds 1 to a list number in the received packet, adds a name of its own apparatus to a shortest route apparatus list and transmits the resulting packet in the transmission direction. Each transmission apparatus transmits the later arrived path searching packet in the transmission direction without applying any modification to the received packet and releases a flag of denoting the reception of other packet in its own apparatus. <P>COPYRIGHT: (C)2004,JPO

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bidirectional ring network, a route selection method used therefor, and a program therefor, and more particularly, to a route selection for searching a shortest route when transmitting a data packet in a ring network using a route search packet. About the method.

[0002]

2. Description of the Related Art Conventionally, in this type of bidirectional ring network route selection method, generally, a data packet of a transmitting apparatus is transmitted to a transmission path between transmission apparatuses connected by a bidirectional ring network. It is used to search for a route that minimizes the time from arrival to arrival at the receiving device.

FIG. 6 shows an example of the above ring network.
Shown in FIG. 7 shows an example of an operation outline of each transmission device connected to the ring network. In FIG. 6, transmission devices 1 to N which perform an interface for data packet transmission / reception between a subscriber side interface and a transmission line side have two transmission lines each having a bidirectional (x / y) transmission line between the transmission devices. Connected to the shape.

Each transmission device has a bidirectional interface of an x-direction transmission line and a y-direction transmission line, so that transmission and reception of data packets can be performed using either the x-direction or the y-direction. I have. In this case, which one to select is selected by the transmission device that transmits the data packet to the transmission path.

Originally, such a configuration allows transmission of data packets between transmission devices even when a failure occurs between any transmission devices in the ring network and one part of the ring is disconnected. The purpose is to make it possible (redundant configuration for transmission line failure). When such a transmission path failure occurs, the transmitting apparatus selects a direction that does not pass through the location where the failure has occurred and transmits the data packet.

However, in a state where no transmission path failure has occurred, data packets can be communicated between the transmission apparatuses regardless of whether the transmission path is selected in the x direction or around the y direction. It is necessary to transmit a data packet from the transmitting device to the receiving device in the shortest possible time.

FIG. 7 shows an example of an outline of the operation of the transmission apparatus 20, but the same operation is performed for the apparatuses 1 to N of FIG. In FIG. 7, the transmission device 2
0 denotes an x-direction packet transmitting / receiving unit 21 and a y-direction packet transmitting / receiving unit 22 connected to the transmission line side interface, and a subscriber side interface multiplexing unit 23 and a subscriber side interface selecting unit 24 connected to the subscriber side interface.
And a transmission destination-transmission direction relationship table 25 for instructing the subscriber-side interface multiplexing unit 23 on a destination to which a data packet is to be delivered. FIG. 8 shows an example of the structure of the transmission destination-transmission direction relation table 25 described above.

Next, the operation of the transmission device 20 will be described. In FIG. 6, a data packet input from a subscriber interface of an arbitrary transmission device a in a ring network reaches a destination transmission device b through a transmission path and is transmitted from a subscriber interface of the transmission device b. Is done.

This operation will be described with reference to FIG. The data packets input from the subscriber-side interface of each transmission device are multiplexed in the subscriber-side interface multiplexing unit 23, and a destination-transmission direction relation table 25 (a table including a destination and a transmission direction) as shown in FIG. ) Is passed to the x-direction packet transmission / reception unit 21 or the y-direction packet transmission / reception unit 22.

The x-direction packet transmission / reception unit 21 (or y-direction packet transmission / reception unit 22) transmits a data packet from the subscriber-side interface multiplexing unit 23 to a transmission line around the x-direction (or y-direction). The device specified as the destination determines the destination device name added to the data packet arriving at the x-direction packet transmission / reception unit 21 (or the y-direction packet transmission / reception unit 22). Capture, subscriber side interface selection unit 24
Pass to. The subscriber-side interface selection unit 24 selects and transmits the corresponding subscriber-side interface.

If the destination device name does not match its own device, the x-direction packet transmitting / receiving unit 21 (or y-direction packet transmitting / receiving unit 22) passes the data packet as it is. For example, when the destination device name receives the data packet of the transmission device 3 from the subscriber-side interface of the transmission device 1, the transmission device 1 transmits the x-direction packet transmission / reception unit according to the destination-transmission direction relationship table 25 shown in FIG. 2
1 and the data packet is transmitted from the x-direction transmission path.

The x-direction packet transmitting / receiving unit 21 of the transmission device 2
Since the destination device name does not match its own device, the data packet is passed as it is. Since the destination device name matches its own device in the x-direction packet transmission / reception unit 21 of the transmission device 3, this data packet is fetched and transmitted from the subscriber interface.

When the destination device name of the data packet is the transmission device N-1, the data packet is transmitted from the transmission device 1 to the y-direction transmission path according to the destination-transmission direction relation table 25 shown in FIG. Captured by N-1 and transmitted from the subscriber interface.

That is, the selection of the x direction / y direction when the data packet is transmitted from the transmission device to the transmission path follows the transmission destination-transmission direction relation table 25 as shown in FIG. At this time, whether the path from an arbitrary transmission apparatus to the destination transmission apparatus is the x-direction transmission path or the y-direction transmission path is determined in a direction in which the transmission time of the data packet is the shortest path, and the transmission is performed. It is set in the destination-transmission direction relation table 25 in advance.

[0015]

In the above-described conventional bidirectional ring network route selection method, the route information (transmission direction) set in the destination-transmission direction relationship table is used.
However, it is necessary to investigate in advance the physical distance between devices in the ring network and the number of connected subscriber-side interfaces, etc., and set them through artificial judgment according to the information. For this reason, labor is required for preliminary investigations and settings for all devices in the network.

Further, in the conventional bidirectional ring network route selection method, since it is determined by accumulation of simple parameters through artificial judgment, the actual state of the traffic dynamically changing in the data packet network is determined. Does not always match.

Accordingly, an object of the present invention is to solve the above-mentioned problems, to reduce the labor required for the preliminary investigation of the ring type network and the setting of the device, and to select a route that is as close as possible to the actual traffic condition. An object of the present invention is to provide a bidirectional ring network that can be performed, a route selection method used therefor, and a program therefor.

[0018]

SUMMARY OF THE INVENTION A bidirectional ring network according to the present invention includes a table for performing an interface for transmitting and receiving data packets between a subscriber side interface and a transmission line side, and for holding a relationship between a transmission destination and a transmission direction. A bi-directional ring network comprising a plurality of transmission devices having a plurality of transmission devices, and two bi-directional transmission lines connecting the plurality of transmission devices in a ring, each of which corresponds to each of the two bi-directional transmission lines. Means for autonomously generating the first and second route search packets to be transmitted and simultaneously transmitting the first and second route search packets to each of the two bidirectional transmission paths, Means for setting a transmission direction in the table based on the information of the above, and means for writing information of the own apparatus in the first and second route search packets from another apparatus and transmitting the information to the next apparatus. It comprises a transmission device each number.

A route selection method according to the present invention comprises: a plurality of transmission apparatuses each having a table for performing an interface for transmitting and receiving data packets between a subscriber side interface and a transmission path side and holding a relation between a transmission destination and a transmission direction; A route selection method for a bidirectional ring network comprising two bidirectional transmission lines connecting a plurality of transmission devices in a ring, wherein a first method corresponding to each of the two bidirectional transmission lines is provided.
And autonomously generating a second route search packet and simultaneously transmitting the route search packet to each of the two bidirectional transmission paths;
Setting a transmission direction in the table based on the information in the first and second route search packets transmitted by the own device; and transmitting the first and second route search packets from another device to the own device. Writing the information and transmitting the information to the next device in each of the plurality of transmission devices.

The program of the route selection method according to the present invention includes a plurality of transmission devices each having a table for performing an interface for transmitting and receiving data packets between a subscriber side interface and a transmission line side and holding a relationship between a transmission destination and a transmission direction. A program for a method of selecting a route in a bidirectional ring network including two bidirectional transmission paths connecting the plurality of transmission devices in a ring shape,
First and second transmission paths corresponding to the two bidirectional transmission paths, respectively.
Autonomously generates the route search packet of
Simultaneously transmitting to each of the transmission paths, setting the transmission direction in the table based on the information in the first and second route search packets transmitted by the own device, and performing the second process from another device. And writing the information of the own device to the first and second route search packets and transmitting the information to the next device.

That is, according to the route selection method of the bidirectional ring network of the present invention, each transmission device is connected in a ring shape by two transmission lines of a bidirectional x-direction transmission line and a y-direction transmission line. By defining a route search packet between each transmission device in the network, the transmission device can autonomously set the route information (transmission direction) of the transmission destination-transmission direction relation table by using the packet.

As described above, according to the present invention, the route information (transmission direction) set in the transmission destination-transmission direction relation table is autonomously set by the device, so that the prior investigation on the ring network and the It is possible to provide a function of reducing the setting labor and selecting a route that is as close as possible to the actual traffic condition.

[0023]

Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram showing an operation example of one embodiment of the present invention. One embodiment of the present invention will be described with reference to FIG.

In the bidirectional ring network according to one embodiment of the present invention, a path search packet is newly defined as a special data packet transmitted and received between each of the transmission devices 1 to N in the configuration of the conventional ring network. ing.

FIG. 2 is a diagram showing an example of an outline of the operation of the transmission apparatus according to one embodiment of the present invention. In FIG.
The transmission apparatus 10 is connected to the transmission path side interface x
The direction packet transmitting / receiving unit 11 and the y-direction packet transmitting / receiving unit 12, the subscriber side interface multiplexing unit 13 and the subscriber side interface selecting unit 14 connected to the subscriber side interface, and the data to the subscriber side interface multiplexing unit 13. It is composed of a destination-transmission direction relation table 15 that indicates a destination to which a packet is to be delivered, and a recording medium 16 that stores a program (a program executable by a computer) for realizing the operation of each unit of the transmission device 10. .

FIG. 3 is a diagram showing an example of the format of a route search packet according to an embodiment of the present invention. In FIG. 3, a route search packet according to an embodiment of the present invention includes a "route search packet identifier", a "source device name", a "search direction", a "number of lists", and a "shortest route device list (device). . # 1, device name # 2,..., Device name #n).

FIG. 4A is a diagram showing an example of the format of a route search packet during transmission according to one embodiment of the present invention, and FIG. 4B is a diagram illustrating a route search during reception according to one embodiment of the present invention. FIG. 3 is a diagram illustrating an example of a packet format.
FIG. 5 is a flowchart showing the operation according to one embodiment of the present invention. The operation of the embodiment of the present invention will be described with reference to FIGS. The processing illustrated in FIG. 5 is realized by the transmission device 10 executing the program on the recording medium 16.

In FIG. 1, when a data packet is transmitted from the transmission apparatus 1 to each of the other transmission apparatuses 2 to N, a newly defined route search packet is determined by x to determine which of the x direction and the y direction is to be selected. Send in the direction / y simultaneously. At this time, the route search packet to be sent out to the x-direction transmission line is the x-direction route search packet 111, and the route search packet to be sent out to the y-direction transmission line is the y-direction route search packet 112.
And

The section indicated by the solid arrow indicates that the route search packet in that direction has arrived before the route search packet in the opposite direction. In the case shown in FIG. 1, among the route search packets transmitted from the transmission device 1, x
The direction search packet 111 arrives first, and the transmission device 4
.About.N indicate that the y-direction route search packet 112 arrives first.

The information contained in the route search packet will be described with reference to FIG. The “route search packet identifier” is used to identify that the transmission device that has received the route search packet is a special packet used only between transmission devices in the ring transmission line, unlike a normal data packet. Unique values are assigned.

The "source device name" indicates the device name of the transmission device that transmitted the route search packet into the ring transmission path. The "search direction" indicates the transmission direction (x direction / y direction) of the route search packet.

In the "shortest path device list", the names of the devices having the shortest route in each direction are shown in a list format. The number of lists indicates the number (n) of device names included in the shortest path device list.

Now, when a route search packet is transmitted from the transmission device 1, as shown in FIG. 4A, the number of lists is set to "0" and no value is entered in the shortest route device list. Packets are transmitted simultaneously in the x direction / y direction.

When receiving the route search packet from the transmission path, each of the transmission devices 2 to N retains the arrival of the route search packet, adds the own name to the received route search packet, and transmits the packet to the next device. I do. However, when a route search packet in the reverse direction has already arrived at the time of receiving the route search packet, the received route search packet is transmitted to the next device without adding the own device name to the received route search packet.

For example, in FIG. 1, the transmission device 2 receives the x-direction route search packet 111 before receiving the y-direction route search packet 112 before receiving the y-direction route search packet 112 (step S1 in FIG. 5). , S3
S4) A flag indicating that the x-direction route search packet 111 has been received is held in the device (step S8 in FIG. 5),
The number of lists in the received x-direction route search packet 111 is changed from “0” to “1” (the value written in the packet + 1)
And the local device name in the shortest path device list (device 2)
Is transmitted in the x direction (step S7 in FIG. 5).

The transmission device 2 transmits the y-direction route search packet 11
2 (steps S1 and S3 in FIG. 5), since a flag indicating that the x-direction route search packet 111 has been received is held in the apparatus (step S1 in FIG. 5).
4) The received y-direction route search packet 112 is transmitted in the y-direction as it is (step S5 in FIG. 5), and the flag indicating that the x-direction route search packet 111 in the device has been received is cleared (step S6 in FIG. 5). .

As described above, since the transmission device 3 also receives the x-direction route search packet 111 before receiving the y-direction route search packet 112, the x-direction route search packet 11
1 (steps S1, S3, S4 in FIG. 5),
A flag indicating that the x-direction route search packet 111 has been received is held in the device (step S8 in FIG. 5), and the number of lists in the received x-direction route search packet 111 is set to “1” (
From “1” rewritten by the transmission device 2 to “2” (
The value is rewritten to the value written in the packet +1), the own device name (the transmission device 3) is added to the end of the shortest path device list, and the packet is transmitted in the x direction (step S7 in FIG. 5).

The operation of the transmission device 3 when receiving the y-direction route search packet 112 is the same as the operation of the transmission device 2 described above.

In FIG. 1, the transmission device N receives the y-direction route search packet 112 before receiving the x-direction route search packet 111 before receiving the x-direction route search packet 111 (step S1 in FIG. 5). , S3, S
4), a flag indicating that the y-direction route search packet 112 has been received is held in the device (step S8 in FIG. 5), and the number of lists in the received y-direction route search packet 112 is changed from “0” to “1” ( 0 + 1 = 1), add its own device name (transmission device N) to the shortest path device list, and transmit it in the y direction (step S7 in FIG. 5).

The transmission device N receives the x-direction route search packet 11
1 (steps S1 and S3 in FIG. 5), since a flag indicating that the y-direction route search packet 112 has been received is held in the device (step S1 in FIG. 5).
4), the received x-direction route search packet 111 is transmitted in the x-direction as it is (step S5 in FIG. 5), and the flag indicating that the y-direction route search packet 112 in the device has been received is cleared (step S6 in FIG. 5). .

Similarly to the above, the transmission device N-1 receives the y-direction route search packet 112 before receiving the x-direction route search packet 111 before receiving the y-direction route search packet 112 (step 5 in FIG. 5). S1, S3, S
4), a flag indicating that the y-direction route search packet 112 has been received is held in the device (step S8 in FIG. 5), and the number of lists in the received y-direction route search packet 112 is set to "1" (rewritten by the device N). From “1” to “2” (the value written in the packet + 1),
At the end of the shortest path device list, the local device name (transmission device N-
1) is added and transmitted in the y direction (step S in FIG. 5).
7).

The operation of the transmission device N-1 when receiving the x-direction route search packet 111 is the same as the operation of the transmission device N described above.

The above operations are performed by the transmission apparatuses 2 to N, respectively, so that the x-direction path search packet 111 and the y-direction path search packet 112 return to the transmission apparatus 1 after making a round of the ring transmission path.

In the transmission apparatus 1, since the transmission source apparatus name of the received route search packet is its own apparatus (step S1 in FIG. 5), this packet is output from the own apparatus and returned after making a round in the ring. And take it into the device. The contents of each route search packet at this time are shown in FIG.
It is shown in (b).

In the case of the example shown in FIG. 1, the shortest route device list of the x-direction route search packet 111 includes device names 2-3 and y.
The device names N to 4 are written in the shortest route device list of the direction route search packet 112. Since the device names assigned to the respective route information packets in the x direction / y direction indicate the first-arrival state of the packets that actually circulated around the transmission path, the route direction that has the shortest time can be accurately indicated.

In the transmission device 1, the transmission direction corresponding to the device name written in the x-direction route search packet 111 is “x direction” and the y-direction route search packet The transmission direction corresponding to the device name written in 112 is set to “y direction”.

As a result, if the transmission device 1 performs the transmission processing of the route search packet autonomously, the setting of the transmission direction in the transmission destination-transmission direction relationship table 15 in the transmission device 1 can be performed autonomously. By performing transmission processing similar to that of the transmission apparatus 1 for the transmission apparatuses 2 to N, it becomes possible to independently select all transmission paths of the ring network.

Further, if a route search is periodically performed using the above-described route search packet in each transmission device, the route direction can be changed as needed in accordance with the traffic state of the data packet which dynamically changes in the ring network. Then, a data packet can be transmitted.

As described above, in this embodiment, in the bidirectional ring network, each transmission device independently performs the shortest path search, thereby reducing the labor required for preliminary investigation and setting of the device, and immediately responding to the actual traffic state. Route selection can be performed. Further, in the present embodiment, data packets can be transmitted in the route direction according to the traffic state in the network.

[0050]

As described above, according to the present invention, a plurality of transmission apparatuses each having a table for performing an interface for data packet transmission / reception between a subscriber side interface and a transmission path side and holding a relationship between a transmission destination and a transmission direction. And a two-way transmission line connecting a plurality of transmission devices in a ring, in a bidirectional ring network, a first and second route search corresponding to each of the two two-way transmission lines. Autonomously generating a packet and simultaneously transmitting it to each of the two bidirectional transmission paths, setting a transmission direction in a table based on information in the first and second route search packets transmitted by the own apparatus, By writing the information of the own device in the first and second route search packets from the other devices and transmitting the information to the next device, the labor for the preliminary investigation on the ring network and the setting for the device are reduced. It can, there is an advantage that it is possible to select a route in line as possible to actual traffic conditions.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing an operation example of one embodiment of the present invention.

FIG. 2 is a diagram showing an example of an outline of operation of the transmission device according to an embodiment of the present invention.

FIG. 3 is a diagram illustrating an example of a format of a route search packet according to an embodiment of the present invention.

4A is a diagram illustrating an example of a format of a route search packet at the time of transmission according to an embodiment of the present invention, and FIG. 4B is an example of a format of a route search packet at the time of reception according to an embodiment of the present invention; FIG.

FIG. 5 is a flowchart showing an operation according to an embodiment of the present invention.

FIG. 6 is a schematic diagram showing an operation example of a conventional example.

FIG. 7 is a diagram illustrating an example of an outline of operation of a transmission device according to a conventional example.

8 is a diagram illustrating a configuration of a transmission destination-transmission direction relation table in FIG. 7;

[Explanation of symbols]

1-N, 10 transmission device 11 x-direction packet transceiver 12 y-direction packet transceiver 13. Subscriber-side interface multiplexing unit 14 Subscriber-side interface selector 15 Transmission destination-transmission direction relation table 16 Recording media 111 x-direction route search packet 112 y-direction route search packet

Claims (9)

[Claims] 1. A plurality of transmission apparatuses each having a table for interfacing data packet transmission / reception between a subscriber side interface and a transmission path side and having a relationship between a transmission destination and a transmission direction, and a plurality of transmission apparatuses each comprising a ring. A bidirectional ring network comprising two bidirectional transmission paths connected in a manner, wherein the first and second path search packets corresponding to each of the two bidirectional transmission paths are independently transmitted. Means for generating and transmitting simultaneously to each of the two bidirectional transmission paths, and means for setting a transmission direction in the table based on information in the first and second route search packets transmitted by the own apparatus And a means for writing information of the own device in the first and second route search packets from another device and transmitting the information to the next device in each of the plurality of transmission devices. Shape Network. 2. The bidirectional ring network according to claim 1, wherein the route direction is a direction in which the data packet output from the transmitting device arrives at the receiving device in the shortest time. 3. The transmission direction of the table is set based on information collected by circulating the first and second route search packets on the two bidirectional transmission paths. A two-way ring network according to claim 1 or claim 2. 4. The bidirectional ring network according to claim 1, wherein a route search using the first and second route search packets is performed periodically. 5. A plurality of transmission apparatuses each having an interface for transmitting and receiving a data packet between a subscriber side interface and a transmission path side and having a table for maintaining a relationship between a transmission destination and a transmission direction, and a ring transmission apparatus comprising: A method for selecting a route in a bidirectional ring network comprising two bidirectional transmission paths connected in a manner, comprising a first and a second path search packet corresponding to each of the two bidirectional transmission paths. Autonomously generating and transmitting simultaneously to each of the two bidirectional transmission paths; and transmitting the transmission directions to the table based on information in the first and second route search packets transmitted by the own apparatus. Setting each of the plurality of transmission devices, and writing the information of the own device in the first and second route search packets from other devices and transmitting the information to the next device. Characteristic route selection method. 6. The route selection method according to claim 5, wherein the route direction is a direction in which the data packet output from the transmitting device arrives at the receiving device in the shortest time. 7. The transmission direction of the table is set based on information collected by circulating the first and second route search packets on the two bidirectional transmission paths. The route selection method according to claim 5 or 6. 8. The route selection method according to claim 5, wherein a route search using the first and second route search packets is performed periodically. 9. A plurality of transmission apparatuses each having an interface for transmitting and receiving data packets between a subscriber side interface and a transmission path side and having a table for maintaining a relationship between a transmission destination and a transmission direction, and a ring transmission apparatus comprising: A method for selecting a route in a bidirectional ring network comprising two bidirectional transmission paths connected in a manner, comprising: a first and a second program corresponding to each of the two bidirectional transmission paths; (2) autonomously generating two route search packets and simultaneously transmitting the route search packets to each of the two bidirectional transmission paths, and based on information in the first and second route search packets transmitted by the own device. A process for executing a process of setting a transmission direction in the table and a process of writing information of the own device in the first and second route search packets from other devices and transmitting the information to the next device. G.