JPH06301606A - Communication route selector and its method - Google Patents

Abstract

PURPOSE:To provide a communication route selector capable of uniforming the using rates of respective communication routes and improving the efficiency of communication. CONSTITUTION:Using status information indicating the using status of corresponding communication routes L1 to Ln is respectively stored in plural route management tables P1 to Pn. Retrieval starting point route numbers indicting the retrieval starting points of respective tables P1 to Pn are stored in a retrieval starting point route storing part 30. A transmission route selecting part 20 successively retrieves the using status information of the tables P1 to Pn based upon the retrieval starting point route numbers stored in the storing part 30 and detects a communication route with free status. The selecting part 20 updates the retrieval starting point route numbers stored in the storing part 30 after the data sending.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication route selecting device and a communication route selecting method for selecting a communication route for transmitting data in data communication between two data processing devices connected by a plurality of communication routes.

[0002]

2. Description of the Related Art Conventionally, in order to send and receive a large amount of data between two computers, a plurality of communication paths are provided between these computers and data is sent and received between the two computers in parallel at the same time. There is a communication method.

In this data communication method, when transmitting data, it is necessary to select from which communication path the data should be transmitted. As a selection method, there is a method in which a business process that should use the communication route is assigned to each communication route, and the data generated in the business process is always transmitted through the assigned communication route.

According to this selection method, when the amount of data to be transmitted and received differs depending on the type of business process, the amount of data varies among the communication paths, and the communication efficiency decreases.

Therefore, in such a case, a business process is not assigned to each communication route, a communication route in a free state (empty state) is detected when transmission data is generated, and the communication in the free state is detected. A selection method of transmitting data using a route is adopted.

In this selection method, the busy status (in-use status) and the free status of each communication path are determined by storing information indicating the busy status or the free status for each communication path in the line management table and transmitting the data. It is sometimes performed by sequentially searching each information in the line management table.

FIG. 4 is a block diagram showing a conventional data communication system including two computers connected by a plurality of data communication paths. A communication path selection method in the conventional data communication system will be described with reference to FIG.

In FIG. 4, computers C100, C
The 200 are connected by a plurality of communication paths L1, L2, ..., Ln. The computer C100 includes a plurality of line control units 101, 102, ..., 10n respectively connected to the plurality of communication paths L1, L2, ..., Ln, a line management table 300, and an application program 400 for performing various business processes. In the line management table 300,
A plurality of usage status information indicating the usage statuses of the plurality of communication paths L1, L2, ..., Ln are stored.

The computer C200 includes a plurality of line control units 201, 202, ..., 20n respectively connected to the plurality of communication paths L1, L2, ..., Ln. , 20n are connected to the plurality of line control units 201, 202, ..., 20n, respectively.

Now, consider data transmission from the computer C100 to the computer C200. When the transmission data is generated, the application program 400 sequentially searches the plurality of pieces of usage status information stored in the line management table 300 from the beginning, and detects the communication path in the free state.

For example, when the communication paths L1 and L2 are busy and the communication path L3 is free, the application program 400 gives transmission data to the line controller 103. The line control unit 103 sends data to the line control unit 203 of the computer C200 via the communication path L3. The line control unit 203 gives the received data to the data check program 503. The data check program 503 checks the received data and gives it to the corresponding application program (not shown).

[0012]

As described with reference to FIG. 4, according to the conventional communication route selection method, the plurality of pieces of usage status information stored in the line management table 300 are stored at the top. Situation information is used as a starting point to search sequentially.

Therefore, the frequency of use of the communication path corresponding to the use status information stored at the head of the line management table 300 becomes higher than the frequency of use of other communication paths. As a result, there arises a problem that the communication efficiency of the entire system is lowered.

In particular, when the transmission recovery process as described below is performed, the decrease in communication efficiency becomes remarkable.

Here, the transmission recovery process when a failure occurs in the data check program will be described with reference to FIG. In FIG. 5, it is assumed that the data check program 50i has failed. i represents an arbitrary integer of 1 to n.

When the application program 400 in the computer C100 gives the data D1 to the line controller 10i, the line controller 10i sends an inquiry ENQ to the line controller 20i in the computer C200. When the line control unit 20i gives a positive response ACK0 to the line control unit 10i, the line control unit 10i sends data D1 to the line control unit 20i. Then, when the line control unit 20i gives a positive response ACK1 to the line control unit 10i,
The line controller 10i informs the line controller 20i of the end of transmission EOT
To notify.

Thereafter, the line controller 20i gives the received data D1 to the data check program 50i.
Since a failure has occurred in the data check program 50i, the data check program 50i gives a failure response NG to the line controller 20i.

In this case, the line control unit 20i gives an inquiry ENQ to the line control unit 10i. When the line control unit 10i gives a positive response ACK0 to the line control unit 20i,
The line control unit 20i sends a failure response NG to the line control unit 10i. When the line control unit 10i gives an affirmative response ACK1 to the line control unit 20i, the line control unit 20i notifies the line control unit 10i of a transmission end EOT.

As a result, the line controller 10i causes the data D
1 is returned to the application program 400. Therefore, the application program 400 uses the data D
1 is diverted to another communication path. If the data check program corresponding to another communication path is normal, the data D1 is transmitted from the computer C100 to the computer 200 by the bypass processing.

In the above case, the data check program 5
Since the communication path Li corresponding to 0i is normal, the data D1 is once transmitted from the line control unit 10i to the line control unit 20i via the communication path Li, and the line control unit 20i sends a bad response NG to the line control unit 10i. After being returned, it is diverted to another communication route. Therefore, during the period T1 from the transmission of the data D1 to the reception of the defective response NG, the communication path L
1 is busy. Then, after the data D1 is returned to the application program 400, the communication path L1 becomes free.

Then, the next data D2 is also sent from the line control unit 10i to the line control unit 20i in the same manner as the data D1. After the defective response NG is returned, it is diverted to another communication path. In this way, when a failure occurs that normally ends in communication processing but becomes abnormal in business processing, the transmission recovery processing as shown in FIG. 5 is performed.

In particular, when an abnormality in business processing as shown in FIG. 5 occurs in the communication path corresponding to the usage status information stored at the head of the line management table 300, the transmission recovery processing frequently occurs. It will be. As a result, there arises a problem that the communication efficiency of the entire communication system becomes extremely low.

An object of the present invention is to provide a communication path selection device and a communication path selection method which can equalize the usage rate of communication paths and improve communication efficiency.

[0024]

[Means for Solving the Problems]

(1) First Invention A communication path selection device according to the first invention comprises a usage status storage means, a search start point storage means, a transmission path selection means, and an update means.

The usage status storage means stores a plurality of usage status information respectively indicating usage statuses of a plurality of communication paths.
The search starting point storage means stores, as search starting point information, information regarding a search starting point of the plurality of usage status information stored in the usage status storage means.

The transmission path selecting means sequentially searches the respective usage status information stored in the usage status storage means based on the search starting point information stored in the search starting point storage means during data transmission to find a usable communication path. The communication path detected and the first detected communication path is selected as the communication path to which the data should be transmitted.
The updating means updates the search starting point information stored in the search starting point storing means for each data transmission.

(2) Second Invention In the communication path selection method according to the second invention, it is possible to sequentially investigate the usage status of each communication path from any of the plurality of communication paths as a starting point when transmitting data. Detect the communication path. Then, the first detected communication path is selected as the communication path to which the data should be transmitted. The starting point of the survey is updated for each data transmission.

[0028]

[Action]

(1) First Invention In the communication route selection device according to the first invention, each usage status information in the usage status storage means is sequentially searched based on the search starting point information in the search starting point storage means at the time of data transmission. , Available communication paths are detected. Then, data transmission is performed through the communication path detected first.

When the search starting point information indicates the search starting point at the time of the next data transmission, each usage status information is sequentially searched from the search starting point indicated by the search starting point information at the next data transmission, and the search is performed after the data transmission. The starting point information is updated.

When the search start point information indicates the search start point at the time of the previous data transmission, the next time the data is transmitted, the search start point information is updated, and then each usage status information is sequentially searched from the updated search start point. It

In this way, since the search starting point information stored in the search starting point storage means is updated for each data transmission,
The usage rate of each communication path is equalized, and the communication efficiency is increased.

(2) Second Invention In the communication route selection method according to the second invention, the usage status information of each communication route is sequentially investigated from one of the plurality of communication routes as a starting point at the time of data transmission. Possible communication paths are detected. Then, the data is transmitted through the first detected communication path. Since the starting point of the survey is updated for each data transmission, the usage rates of the communication paths are equalized and the communication efficiency is increased.

[0033]

1 is a block diagram showing the structure of a communication path selecting apparatus according to an embodiment of the present invention.

In FIG. 1, the computers C1 and C2 are connected by a plurality of communication lines L1, L2, ..., Ln. Each communication path is composed of a communication line. Computer C1
, 1n, a plurality of route management tables P1, P2, ..., Pn, a transmission route selection unit 20, a search origin route storage unit 30, a data transmission instruction unit 40.
And an application program 50.

, 1n are provided corresponding to the respective communication routes L1, L2, ..., Ln. Similarly, a plurality of route management tables P1,
, Pn are plural communication paths L1, L2, ..., Ln
It is provided corresponding to each.

Usage information indicating the usage status of the corresponding communication path is stored in each path management table. The usage status information indicates whether the corresponding communication path is free (empty) or busy (in use). For example, the route management table P1 has a communication route L1.
Of the communication route L2 is stored in the route management table P2.

The search starting point route storage unit 30 stores the search starting point route number indicating the search starting point of the route management tables P1 to Pn. The transmission route selection unit 20 sequentially searches the usage status information stored in the route management tables P1 to Pn starting from the route management table corresponding to the search origin route number stored in the search origin route storage unit 30 to obtain the data. Select the communication path to be used for transmission. Also, the transmission path selection unit 2
0 updates the search origin route number stored in the search origin route storage unit 30 for each data transmission.

The data transmission instructing section 40 passes through the buffers B1, B2, ...
..., connected to 1n. The data transmission instructing unit 40 sends the transmission data generated by the application program 50 to
It is given to the route control unit selected by the transmission route selection unit 20.

Each path control unit controls data transmission relating to the corresponding communication path, sends the transmission data given from the data transmission instructing section 40 to the corresponding communication path, and depending on the usage status of the corresponding communication path. And updates the usage information of the corresponding route management table.

For example, when the route control unit 11 receives the transmission data from the data transmission instructing unit 40, the communication route L1
Then, the data is sent to and the use status information stored in the route management table P1 is set to the "busy state". When the data transmission is completed, the usage status information stored in the path management table P1 is set to the "free state".

Next, the operation of the communication path selection device of FIG. 1 will be described with reference to the flowchart of FIG. here,
The path numbers of the communication paths L1 to Ln are set to 1 to n, respectively. In this case, the maximum route number is n.

Waiting for transmission data generation (step S
In 1), when transmission data is generated in the application program 50, the transmission route selection unit 20 fetches the search origin route number from the search origin route storage unit 30 (step S2).

Then, the transmission route selection unit 20 searches the usage information of the route management table corresponding to the route number and detects whether the communication route corresponding to the route number is busy or free. (Step S3).

If the communication route is busy, the route number is incremented by 1 (step S4). If the incremented route number is less than or equal to the maximum route number n, the process returns to step S3 (step S5). If the incremented route number is larger than the maximum route number n, the route number is set to 1 and the process returns to step S3 (steps S5 and S6).

In step S3, when the communication route corresponding to the route number is in the free state, the transmission route selection unit 20 determines the communication route as the data transmission route, and the route control unit corresponding to the communication route is determined. The data transmission instructing unit 40 is instructed to give the data (step S7). The data transmission instruction unit 40 gives the transmission data to the corresponding route control unit, and the route control unit sends the transmission data to the corresponding communication route. In this way, the data is transmitted.

Thereafter, the transmission route selection unit 20 increments the search starting route number stored in the search starting route storage unit 1 by 1 (step S8). If the search start route number is less than or equal to the maximum route number n, the process returns to step S1 (step S9). If the search start route number is larger than the maximum route number n, the search start route number is set to 1 and the process returns to step S1 (steps S9 and S10).

FIG. 3 is a diagram showing the search order of the route management table. Before the first data transmission, the search start route number stored in the search start route storage unit 30 is set to 1. Therefore, at the time of the first data transmission, the use status information of the route management tables P1 to Pn is sequentially searched from the route management table P1 as a starting point until a free communication route is detected. Then, after the first data transmission, the search origin route number stored in the search origin route storage unit 30 is updated to 2.

At the time of the second data transmission, since the search starting route number is 2, the use status information of the route management tables P2 to Pn is sequentially searched from the route management table P2 as a starting point, and finally the route management table P1. The usage information of is retrieved. After the second data transmission, the search start route number stored in the search start route storage unit 30 is updated to 3.

At the time of the third data transmission, the search starting route number is 3, so that the use status information of the route management tables P3 to Pn is sequentially searched from the route management table P3 as a starting point, and the route management table P1, The usage status information of P2 is sequentially searched. After the third data transmission, the search start route number stored in the search start route storage unit 30 is updated to 4.

Similarly, at the time of the nth data transmission, since the search starting route number is n, the usage status information of the routing management table Pn is searched first, and then the usage status information is returned to the routing management table P1. The information is retrieved in order.

As described above, in the above embodiment, the route starting from the communication route indicated by the search starting route number stored in the search starting route storing unit 30 is used until the communication route in the free state is detected. The usage information stored in the management table is sequentially searched. Then, the data is transmitted by the first detected free communication path,
After the data is transmitted, the search starting point route number stored in the search starting point route storage unit 30 is updated.

In the above embodiment, the search origin route number stored in the search origin route storage unit 30 indicates the number of the communication route serving as the search origin when the next data is transmitted. If the search origin route number stored in the above indicates the communication route that was the search origin at the time of the previous data transmission, the search origin route number must be updated before the next data transmission.

[0053]

As described above, according to the present invention, the starting point of the search or survey is updated for each data transmission.
The usage rates of the communication paths are equalized and the communication efficiency is improved.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a communication path selection device according to an embodiment of the present invention.

FIG. 2 is a flowchart for explaining the operation of the communication route selection device in FIG.

3 is a diagram showing a search order of a route management table in the communication route selection device of FIG.

FIG. 4 is a block diagram showing a configuration of a conventional data communication system.

FIG. 5 is a diagram for explaining a transmission recovery process.

[Explanation of symbols]

 C1, C2 Computers 11, 12, 1n Route control unit 20 Transmission route selection unit 30 Search origin route storage unit 40 Data transmission instruction unit 50 Application program L1, L2, Ln Communication route P1, P2, Pn Route management table B1, B2 Bn buffer In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (2)

[Claims] 1. A communication path selection device for selecting a communication path to which data is to be transmitted in data communication between two data processing devices connected by a plurality of communication paths, the usage status of the plurality of communication paths being determined. A usage status storage unit that stores a plurality of usage status information items, respectively, a search starting point storage unit that stores information related to a search starting point of the plurality of usage status information stored in the usage status storage unit as search starting point information, and data. At the time of transmission, based on the search starting point information stored in the search starting point storage means, each usage status information stored in the usage status storage means is sequentially searched to detect a usable communication path, and first detected. Transmission path selecting means for selecting a communication path as the communication path to which the data is to be transmitted, and the detection path stored in the search starting point storage means for each data transmission. A communication path selecting device, comprising: an updating unit that updates the search origin information. 2. A communication path selecting method for selecting a communication path to which data should be transmitted in data communication between two data processing devices connected by a plurality of communication paths, wherein the plurality of communication paths are selected at the time of data transmission. Starting from either of the above, the usage status of each communication route is sequentially investigated to detect available communication routes, and the first detected communication route is selected as the communication route to which the data should be transmitted. A method for selecting a communication path, wherein the starting point of the investigation is updated.