JPH0888642A - Data transfer system and node for lan suitable to the system - Google Patents

Abstract

PURPOSE: To revise a band in use dynamically by eliminating the need for a central management node and allowing each node to send synchronization data in response to a transmission end request time. CONSTITUTION: Synchronization data fed from a communication application are given to a data share processing section 3, from which the data are stored in a synchronization data storage queue 4 for each connection. In the case of setting up a connection prior to the processing, a communication application applies a maximum transmission end request time and a maximum operating band to a control information management section 7 and the synchronization data transmission time corresponding to them is registered in a transmission control section 6 in cross reference with the connection when the application is approved. In the case of transmission, the synchronization data of each connection are sent depending on the registered synchronization data transmission time. The control information management section 7 monitors the band operating state and expands or reduces the maximum operating band depending on the monitored result. The control information management section 7 expands/reduces the maximum transmission end request time and the maximum operating band depending on the application from the communication application program.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data transfer method in a token passing LAN, and more particularly, to a time-critical, that is, a synchronization requiring a punctuality that the data must be transferred to a destination within a specified time. The present invention relates to a data transfer system for data and a LAN node suitable for this.

[0002]

2. Description of the Related Art Token passing LANs include token ring type / token bus type and IS defined by ISO (International Organization for Standardization) standard 8802.
There is a Token Ring FDDI network defined by O Standard 9314. The medium access control in the token-passing LAN is to circulate the transmission right information called “token” in one direction on the transmission path.
This is executed by the procedure in which the node receiving the token acquires the right to use the transmission path.

FIG. 12A shows, for example, Japanese Patent Laid-Open No. 3-15.
An example of a data transfer system in a conventional token passing LAN is shown in Japanese Patent No. 9436.
In the example of this figure, a fixed data transfer band allocation method is adopted so that the band use efficiency does not decrease even during dynamic traffic, that is, when the length and arrival interval of synchronous data are undefined. In the data transfer band fixed allocation method of this figure, the transmission source node applies a band allocation to the management node every time the synchronization data is received, and the management node allocates a fixed transmission band according to the application. The synchronous data referred to here is high-priority data such as voice, and when transmitting and receiving the same, strictness regarding data transfer delay, that is, time criticality is required.

In this method, as shown in FIG. 12B, step S11 relating to bandwidth application from the source node 2b to the management node 2a, and transfer of synchronous data from the source node 2b to the destination node 2c. By the procedure including step S12 and step S13 relating to the band return from the transmission source node 2b to the management node 2a,
Synchronous data is transmitted and received. Also, the management node 2a
Is a band management station, which manages the band of the synchronous data. The procedure composed of steps S11 to S13 is a procedure relating to communication between the nodes in which the token circulates, that is, the nodes belonging to the logical ring among the plurality of nodes coupled to the management node 2a by the token passing system LAN1. is there. In the following description, of the stations participating in the token passing LAN 1, the station that has issued a request for sending synchronous data is called the source node 2b, and the destination to which this source node 2b is going to send the synchronous data. The station is called the destination node 2c.

In step S11, the source node 2b first sends the band use request frame 11 to the management node 2
Send to a. The band use request frame 11 is normally transmitted in response to a source node 2b receiving a synchronous data transmission request from a communication application (communication application software realized by LAN). Further, the band use request frame 11 has the maximum transmission rate requested by the transmission source node 2b (the band [b requested by the transmission source node 2b [b
ps]. Hereinafter, it is also referred to as an application band), information regarding whether or not it is broadcast, information regarding whether it is unidirectional, and the like. Upon receiving the band use request frame 11, the management node 2a transmits a request response frame 12 indicating this reception to the transmission source node 2b. The management node 2a is the source node 2b
Synchronous data that can be transferred when the source node 2b is allowed to transfer synchronous data based on the information in the bandwidth use request frame 11 received from Is calculated, and it is determined whether the calculated maximum amount of synchronous data violates the protocol. If it can be considered that there is no violation, the management node 2a
Transmits a band use permission frame 13 that permits the band use and allocates the band to the transmission source node 2b. If it can be regarded as a violation, the band usage is rejected.

The source node 2b executes step S12 after receiving the band use permission frame 13. In step S12, the transmission source node 2b transmits the connection request frame 14 requesting the setting of the connection (logical connection) to the destination node 2c. Destination node 2
When the connection can be set, the c transmits the acknowledgment frame 15 indicating the setting of the connection to the transmission source node 2a. After receiving the acknowledgment frame 15, the transmission source node 2a transmits the synchronization data frame 20a to the destination node 2c according to the acquisition of the token.

When the transmission of the synchronous data frame 20a is completed, the transmission source node 2b executes step S13. In step S13, first, the source node 2b
Transmits a band return frame 16 indicating the end of band use to the management node 2a. The management node 2a transmits a return response frame 17 indicating reception of the band return frame 16. As a result, the procedure relating to the synchronous data transmission from a certain arbitrary source node 2b to another arbitrary destination node 2c is completed.

[0008]

In the above method, since there is a management node that determines permission of synchronous data transfer, the overhead of the control procedure necessary for bandwidth acquisition becomes large. Furthermore, control becomes complicated, such as a procedure or a redundant node required for dealing with a failure in the management node. In addition, since the bands are permitted to be used in the order in which they are applied to the management node, there is an unfairness in the bands that can be used among the nodes connected to the LAN.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem, and the distributed bandwidth management of the network band among the nodes in the LAN enables the data transfer system of the LAN passing system. It is an object of the present invention to eliminate the need for a centralized management node in and to enable each node to execute synchronous data transmission according to a transmission completion request time.

[0010]

In order to achieve such an object, a LAN node according to claim 1 of the present invention comprises:
A means to decide whether to permit the application of the maximum bandwidth and the maximum transmission completion request time from the communication application installed in the own node based on the token holding time that can be used by the own node, and the maximum when it is allowed. The medium includes means for determining a synchronous data transmission time based on the used bandwidth and the maximum transmission completion request time, and means for transmitting the synchronous data over the synchronous data transmission time determined according to the acquisition of the token, and the medium is formed by circulating the tokens. When used in a token passing LAN for access control,
It is characterized in that the time-critical synchronous data that must be transmitted within the maximum transmission completion request time is transmitted while managing the bandwidth for each node.

In the LAN node according to claim 2 of the present invention, in the LAN node according to claim 1, the means for deciding whether or not to permit the application has a requested maximum use band and maximum transmission completion. A means for obtaining the amount of synchronization data that the self node should transmit when holding the token based on the request time, and a means for obtaining the amount of synchronization data that the self node can transmit when holding the token based on the token holding time that the self node can use, Means for determining whether or not to permit the application by comparing the amount of synchronous data that should be transmitted by the own node when holding the token with the amount of synchronous data that can be transmitted by the own node when holding the token. And

According to a third aspect of the present invention, there is provided a LAN node according to the first aspect of the present invention, wherein the LAN application according to the first aspect includes means for monitoring the band usage status of the communication application and the communication application from the viewpoint of the band usage status. When it can be considered that the bandwidth is used beyond the requested maximum usage bandwidth, a means for discarding the synchronization data for the bandwidth exceeding the maximum usage bandwidth is provided.

A LAN node according to a fourth aspect of the present invention is the LAN node according to the first aspect, wherein the means for monitoring the band use status by the communication application and the communication application from the communication application as viewed from the band use status. And a means for changing the synchronous data transmission time so that the maximum used bandwidth of the communication application is expanded when it can be considered that the bandwidth is being used beyond the requested maximum used bandwidth. To do.

According to a fifth aspect of the present invention, in a LAN node according to the first aspect of the present invention, the LAN node according to the first aspect monitors the bandwidth usage status of the communication application and the bandwidth usage status of the communication application. If it can be considered that the maximum used bandwidth can be reduced, the maximum used bandwidth of the communication application is reduced.
Means for changing the synchronous data transmission time.

A LAN node according to a sixth aspect of the present invention is a token for the LAN node according to the first aspect, when the maximum use band is extended in response to an application for extension of the maximum use band from the communication application. Based on the expanded maximum used bandwidth and the maximum transmission completion request time, and the token holding time that can be used by the own node,
Based on the method to determine the amount of synchronization data that can be sent by the own node when holding the token, the amount of synchronization data that the own node should send when holding the token when the maximum bandwidth is expanded, and the token holding time that can be used by the own node By comparing with the amount of synchronous data that can be sent by the own node when holding the token, a means to decide whether or not to permit the application for the above extension without extending the token holding time of the own node, and the maximum use when allowing Means for changing the synchronous data transmission time so that the band is extended.

The LAN node according to claim 7 of the present invention, in the LAN node according to claim 6, determines that the application for the extension cannot be permitted without extension of the token holding time of the own node, Based on the maximum used bandwidth and the maximum transmission completion request time that applications have been permitted so far, a means to find the insufficient bandwidth as the increase required time of the token holding time and the obtained increase required time are assigned to the own node. And a means for permitting the application for the above expansion when it can be covered by the spare token holding time.

In the LAN node according to claim 8 of the present invention, in the LAN node according to claim 7, the increased required time obtained cannot be covered by the spare token holding time allocated to the own node. In this case, it is characterized by comprising means for requesting a partial transfer of the token holding time to another node, and means for permitting an application for the above expansion when the token holding time is transferred from another node.

A LAN node according to a ninth aspect of the present invention is the LAN node according to the eighth aspect, wherein a spare token in which a token holding time for which a partial transfer is requested from another node is assigned to the own node. When the holding time can be covered, a means for transferring the token holding time to a node that has requested a partial transfer of the token holding time is provided.

A LAN node according to a tenth aspect of the present invention is the token for the LAN node according to the first aspect, when the maximum use band is reduced in response to an application for reduction of the maximum use band from the communication application. Based on the reduced maximum used bandwidth and the maximum transmission completion request time, the maximum used bandwidth is calculated based on the reduced amount of synchronous data that should be transmitted by the own node at the time of holding. And means for changing the synchronous data transmission time so as to be reduced.

The LAN node according to claim 11 of the present invention is the LAN node according to claim 1, wherein the maximum transmission completion request time is reduced in response to an application from the communication application for reducing the maximum transmission completion request time. In this case, the amount of synchronous data to be transmitted by the node when holding the token is calculated based on the maximum bandwidth used and the reduced maximum transmission completion request time. A means to determine the amount of synchronous data that can be sent by the node, and a token retention based on the amount of synchronous data that the node should transmit when retaining the token when the maximum transmission completion request time is reduced, and the token retention time that the node can use At the same time, by comparing with the amount of synchronous data that can be sent by the node, the request for reduction can be made by the node itself. Means for determining whether to permit, without extension of retention time, characterized in that it comprises a means for changing the synchronous data transmission time to the maximum transmission completion request time is reduced if permitted.

A LAN node according to a twelfth aspect of the present invention is, in the LAN node according to the eleventh aspect, means for determining whether or not a predetermined time is exceeded when the maximum transmission completion request time is shortened, and a predetermined number. And a means for permitting the application for the reduction when it is determined that the time is exceeded.

A LAN node according to a thirteenth aspect of the present invention, in the LAN node according to the eleventh aspect, determines that the application for the reduction cannot be permitted without extending the token holding time of the own node. Based on the maximum used bandwidth and the maximum transmission completion request time that applications have been permitted so far, a means to find the insufficient bandwidth as the increase required time of the token holding time and the obtained increase required time are assigned to the own node. And a means for permitting the application for the reduction when it can be covered by the spare token holding time.

A LAN node according to a fourteenth aspect of the present invention is not able to cover the increased required time obtained in the LAN node according to the thirteenth aspect with a spare token holding time allocated to the own node. In this case, a means for requesting a partial transfer of the token holding time to another node, and a means for permitting the reduction application when the token holding time is transferred from the other node are provided.

According to a fifteenth aspect of the present invention, in the LAN node according to the fourteenth aspect, in the LAN node according to the fourteenth aspect, a spare token in which a token holding time for which a partial transfer is requested by another node is assigned to the own node. When the holding time can be covered, a means for transferring the token holding time to a node that has requested a partial transfer of the token holding time is provided.

A LAN node according to a sixteenth aspect of the present invention is the LAN node according to the first aspect, wherein the maximum transmission completion time is extended in response to an application for extension of the maximum transmission completion time from the communication application. Based on the maximum bandwidth used and the extended maximum transmission completion request time, the maximum amount of synchronous data that the node should send when holding the token Means for changing the synchronous data transmission time so as to extend the transmission completion time.

According to a seventeenth aspect of the present invention, in the LAN node according to the first aspect, in the LAN node according to the first aspect, the maximum use band and the maximum transmission completion request time are different between the communication application installed in the own node and another node. It is applied for each connection that is a logical connection with the installed communication application, the token holding time is used for each node and by all the connections related to the own node, and the synchronous data transmission time is determined for each connection It is characterized by

A LAN node according to an eighteenth aspect of the present invention is characterized in that, in the LAN node according to the first aspect, there is provided means for transmitting / receiving asynchronous data which has no limitation on a transmission completion time and which is not time-critical.

In the data transfer method according to claim 19 of the present invention, the token is circulated in a predetermined direction along the cyclic transmission line of the LAN, and each node starts or restarts data transmission in response to acquisition of the token, In the token passing system LAN, which suspends or terminates the transmission after passing the token holding time and abandons the token and passes it to the subsequent node,
Each node is a LAN according to any one of claims 1 to 18.
It is a feature node.

[0029]

According to the first aspect of the present invention, whether or not the application of the maximum used bandwidth and the maximum transmission completion request time from the communication application installed in the own node is allowed is determined by the token holding time that the own node can use. It is decided based on. When permitting, the synchronous data transmission time is determined based on the maximum used bandwidth and the maximum transmission completion request time. After that, when the own node acquires the token, the time-critical synchronous data that must be transmitted within the maximum transmission completion request time within the token holding time frame given to the own node is transmitted accordingly. The transmission is
It is performed over the determined synchronous data transmission time. Therefore, in the present invention, permission of transfer of synchronous data is determined within the node, and the bandwidth is managed by the node in relation to the maximum transmission completion request time and the token holding time. Is unnecessary. As a result, the overhead of the control procedure necessary for bandwidth acquisition can be suppressed, and it is not necessary to deal with the occurrence of a failure in the management node. In addition, there is no unfairness in the usable bandwidth between the nodes connected to the LAN.

In claim 2 of the present invention, when determining whether or not to permit the application of the maximum used bandwidth and the maximum transmission completion request time from the communication application installed in the own node, first, from this communication application, Based on the requested maximum bandwidth and maximum transmission completion request time,
The amount of synchronization data that the node should send when holding the token is calculated. Further, based on the token holding time that the own node can use, the amount of synchronization data that the own node can transmit when holding the token is calculated. Whether or not the application can be accepted by comparing the two calculation results,
It can be determined in relation to the maximum transmission completion request time and the token holding time. In the present claim, whether or not to permit the application is suitably determined based on the comparison result.

In the third aspect of the present invention, the band use status by the communication application is monitored. If it can be considered that the band is used beyond the maximum used band requested by the communication application in view of the band use situation, the synchronous data in excess of the maximum used band is discarded. As a result, it is possible to prevent bandwidth usage exceeding the maximum bandwidth usage. That is, the other nodes are not adversely affected.

Also in claim 4 of the present invention, the band use status by the communication application is monitored. In view of bandwidth usage, if it can be considered that the bandwidth is being used beyond the maximum bandwidth requested by this communication application, the synchronous data transmission time should be increased so that the maximum bandwidth of the communication application is expanded. Be changed. Therefore, it is possible to automatically expand the maximum used band according to the situation of the band use by the communication application, and it is possible to prevent the band use exceeding the maximum used band. That is, highly adaptable control is realized, and adverse effects on other nodes are prevented.

Also in claim 5 of the present invention, the band use status by the communication application is monitored. If it can be considered that the maximum usage band of this communication application can be reduced from the viewpoint of the band usage situation, the synchronous data transmission time is changed so that the maximum usage band of this communication application is reduced. Therefore, the maximum used band can be automatically reduced according to the state of band use by the communication application, and the band can be used efficiently. That is, highly adaptive control is realized.

According to claim 6 of the present invention, in response to a request from the communication application to extend the maximum usable bandwidth, when the maximum usable bandwidth is extended, the amount of synchronous data to be transmitted by the own node when holding the token is extended. It is calculated based on the maximum used bandwidth and the maximum transmission completion request time. On the other hand, based on the token holding time that the own node can use, the amount of synchronization data that the own node can transmit when holding the token is calculated. Further, based on the results of both calculations, it is determined whether or not to permit the extension request without extending the token holding time of the own node. That is, the amount of synchronization data that the node should send when holding the token corresponds to the maximum bandwidth that the communication application is allowed to use, and the amount of synchronization data that the node can send when holding the token is the token that the node can use. Since it corresponds to the holding time, it is possible to know, based on the results of both calculations, whether there is a new band that can be granted within the token holding time that is currently allowed for the node. When permitting the extension of the requested maximum use bandwidth, the synchronous data transmission time is changed so that the maximum use bandwidth is extended. In this way, it is possible to expand the maximum bandwidth used for the synchronous data while the connection is being used, and the communication application can optimally set the bandwidth according to the time and the business content.

In claim 7 of the present invention, when it is determined that the extension application cannot be permitted without extension of the token holding time of the own node, the maximum use bandwidth and the maximum transmission to which the application has been permitted so far. Based on the completion request time, the insufficient bandwidth is obtained as the required time for increasing the token holding time. If the increased required time obtained can be covered by the spare token holding time assigned to the own node,
Applications for expansion are permitted. In this way, by setting the preliminary token retention time in advance, the frequency of partial transfer requests for token retention time to other nodes, which will be described later, can be suppressed, and processing with high completion within the node can be performed. realizable.

According to the eighth aspect of the present invention, when the obtained required increase time cannot be covered by the spare token holding time allocated to the own node, a part of the token holding time is transferred to another node. Required. If the token holding time is transferred from another node, the extension application is permitted. As a result, the token holding time can be flexibly allocated to each node constituting the LAN.

In claim 9 of the present invention, when the token holding time for which a partial transfer is requested by another node can be covered by the spare token holding time assigned to the own node, a part of the token holding time The token holding time is transferred to the node that requested the transfer. As a result, the token holding time can be flexibly allocated to each node constituting the LAN.

According to the tenth aspect of the present invention, in response to a request from the communication application for reduction of the maximum bandwidth,
When the maximum usable bandwidth is reduced, the amount of synchronous data to be transmitted by the own node at the time of holding the token is calculated based on the reduced maximum usable bandwidth and the maximum transmission completion request time. Further, based on the result, the synchronous data transmission time is changed so that the maximum use band is reduced. As a result, the communication application can optimally set the band according to the time of day and the work content, and the band use efficiency is improved.

According to the eleventh aspect of the present invention, in response to a request from the communication application to reduce the maximum transmission completion request time, when the maximum transmission completion request time is reduced, the synchronization data to be transmitted by the own node at the time of holding the token The amount is calculated based on the maximum used bandwidth and the reduced maximum transmission completion request time. On the other hand, based on the token holding time that the own node can use, the amount of synchronization data that the own node can transmit when holding the token is calculated. Further, claim 6
By the same principle as above, it is determined whether or not to permit the reduction request without extending the token holding time of the own node.
When permitting, the synchronous data transmission time is changed so that the maximum transmission completion request time is shortened. As a result, for example, the maximum transmission completion request time can be changed according to the type of synchronization data.

In the twelfth aspect of the present invention, when the reduced maximum transmission completion request time exceeds the predetermined time, the reduction application is permitted. In other words, reducing the maximum transmission completion request time is a condition for strengthening the transfer of synchronous data, but if the degree of strengthening exceeds the extent that it does not affect the transfer of synchronous data, the amount of data must be met. The application for reduction is permitted without calculation, and the processing load such as data volume calculation is reduced.

In claim 13 of the present invention, if it is determined that the application for reducing the maximum transmission completion request time cannot be granted without extending the token holding time of the own node, the application has been granted so far. Based on the maximum used bandwidth and the maximum transmission completion request time, the insufficient bandwidth is calculated as the increase required time of the token holding time. Furthermore, when the calculated increase required time can be covered by the spare token holding time allocated to the own node, the request for reduction of the maximum transmission completion request time is permitted as in the case of claim 7.
In this way, by setting the preliminary token retention time in advance, the frequency of partial transfer requests for token retention time to other nodes, which will be described later, can be suppressed, and processing with high completion within the node can be performed. realizable.

In the fourteenth aspect of the present invention, when the calculated required increase time cannot be covered by the spare token holding time allocated to the own node, a part of the token holding time is transferred to another node. Required. If the token holding time is transferred from another node, the extension application is permitted. As a result, the token holding time can be flexibly allocated to each node constituting the LAN.

According to the fifteenth aspect of the present invention, when the token holding time for which a partial transfer is requested from another node can be covered by the spare token holding time assigned to the own node, a part of the token holding time The token holding time is transferred to the node that requested the transfer. This allows LAN
It is possible to flexibly allocate the token holding time to each node constituting the.

According to claim 16 of the present invention, the amount of synchronous data to be transmitted by the own node at the time of holding the token when the maximum transmission completion time is extended in response to an application for extension of the maximum transmission completion time from the communication application. Is calculated based on the maximum used bandwidth and the extended maximum transmission completion request time. Further, based on the result, the synchronous data transmission time is changed so that the maximum transmission completion time is extended. As a result, the communication application can optimally set the band according to the type of synchronous data, and the band use efficiency is improved.

In the seventeenth aspect of the present invention, a plurality of connections are generally established between the communication application installed in the own node and the communication application installed in another node. Therefore, the maximum usable bandwidth and the maximum transmission completion request time are applied for each connection, the token holding time is used for each node and by all the connections related to the own node, and the synchronous data transmission time is determined for each connection. As described above, in the present invention, band management can be performed for each connection, and band usage efficiency is improved.

According to the eighteenth aspect of the present invention, the transmission completion time is not limited and asynchronous data which is not time-critical can be transmitted and received. That is, it is possible to obtain a configuration capable of transferring both synchronous data and asynchronous data.

In the data transfer system according to claim 19 of the present invention, the LAN node according to the present invention is used for each node. That is, since a node suitable for distributed management of bandwidth is used, a centralized management node is not required in a broken-passing LAN. At the same time, each node can execute synchronous data transmission according to the transmission completion request time.

[0048]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to the drawings. The same components as those in the conventional example shown in FIG. 12 are designated by the same reference numerals and the description thereof will be omitted.

I. First Embodiment FIG. 1 shows the system configuration of a token passing LAN according to an embodiment of the present invention. In this figure, a plurality of nodes 2 serving as a source or a destination at the time of data transfer are connected by a token passing LAN 1, particularly a transmission line thereof. In FIG. 2, each node 2
The configuration of is shown. The node 2 includes a data distribution processing unit 3, a synchronous data storage queue 4, an asynchronous data storage queue 5, a transmission control unit 6, a control information management unit 7, and a reception processing unit 8. In addition, N communication application software (Applicat
ion 1, Application 2,…) are installed. Hereinafter, the operation of each node 2 will be described first for each component of the node 2.

(1) Data distribution processing unit 3 The data distribution processing unit 3 has a function of distributing data to be transmitted given from the communication application into synchronous data and asynchronous data. That is, the data distribution processing unit 3 supplies the data provided from the communication application to the synchronous data storage queue 4 when the data is synchronous data, and the asynchronous data storage queue 5 when the data is asynchronous data. Distribute the data that has been collected. Synchronous data here is time-critical data that needs to be transmitted within a certain time (data that specifies the time from the communication application to the completion of transmission), and asynchronous data is data other than synchronous data (until the completion of transmission). Is the data for which the time is not specified). The data distribution processing unit 3 also has a function of distributing the reception data supplied from the reception processing unit 8 to communication applications that should receive this data.

FIG. 3 shows the operation flow of the data distribution processing unit 3. As shown in this figure, the data distribution processing unit 3 receives the data (S
101) Determine where this data came from (S102). When it is determined in S102 that the received data is the data from the reception processing unit 8, the data distribution processing unit 3 passes this data to the communication application that should receive this data (S106). The reception processing unit 8 is a unit that executes a reception process of data transmitted from another node 2.

When the received data is data from the communication application, the data distribution processing unit 3
Further determines whether this data is bandwidth control data (S103). When it is determined that the data is band control data, the data distribution processing unit 3 passes this data to the control information management unit 7 (S104). On the contrary, when it is determined that the data is not data related to bandwidth control, the data distribution processing unit 3 queues this data in the synchronous data storage queue 4 or the asynchronous data storage queue 5 (S1).
05).

When the data to be queued is synchronous data, the data distribution processing unit 3 determines that the corresponding connection on the synchronous data storing queue 4 (Connection in the figure).
Queuing the data in the queue of 1, Connection 2, ...). The term "connection" as used herein refers to a correspondence relationship (logical connection) between the application of the transmission source node and the application of the destination node. The synchronous data storage queue 4 stores synchronous data until transmission.
In addition, the queue of each connection forming the synchronous data storage queue 4 also stores the maximum transmission completion request time indicating the deadline or time at which the transmission of the synchronous data stored in this queue should be ended. If the data to be queued is asynchronous data, the data distribution processing unit 3
Queues the data in the asynchronous data storage queue 5. The asynchronous data storage queue 5 stores asynchronous data until transmission.

(2) Transmission control section 6 The transmission control section 6 executes data transmission. FIG. 4 shows the configuration of the transmission control unit 6. As shown in this figure, the transmission control unit 6 is composed of a transmission rate management unit 9 having a transmission time question management table 10 and a transmission execution unit 11 that actually performs transmission. The sending time question management table 10 associates a connection number, which is a number for identifying each connection, with a synchronous data transmission time corresponding to each connection. Therefore, by referring to the transmission time management table 10 using the connection number as a key, the synchronous data transmission time can be known for each connection. The transmission rate management unit 9 uses the transmission time question management table 10 to manage the synchronous data transmission rate for each connection.

FIG. 5 shows the flow of operation of the transmission rate management unit 9. The transmission rate management unit 9 determines the type of the input data according to the data input to the transmission rate management unit 9 (S201).

When the input data is the synchronous data related to any connection on the synchronous data storage queue 4, the transmission rate management unit 9 refers to the transmission time management table 10 to establish the connection. Find the corresponding sync data transmission time. The transmission rate management unit 9 sends the synchronization data corresponding to the obtained synchronization data transmission time to the transmission execution unit 11, and when the input data is asynchronous data on the asynchronous data storage queue 5, The transmission rate management unit 9 sends the asynchronous data for a predetermined time to the transmission execution unit 11 (S202). Transmission execution unit 1
The data passed to 1 is sent out on LAN 1 when this node 2 receives the token.

When the transmission rate management unit 9 determines in S201 that the input data is the data from the control information management unit 7, the transmission data management time for each connection is controlled based on this data. Register in the table 10 (S203). The contents of the data from the control information management unit 7 will be described later.

(3) Control Information Management Unit 7 The control information management unit 7 manages the synchronous data storage queue 4 and bandwidth. FIG. 6 shows the configuration of the control information management unit 7. As shown in this figure, the control information management unit 7 includes a band monitoring unit 12, a transmission rate calculation unit 13, and a token holding time transfer control unit 14.
The band monitoring unit 12 monitors the currently used band of the synchronous data storage queue 4. The transmission rate calculation unit 13 executes band control at the time of establishing a connection or when changing the maximum used band and the maximum transmission completion request time. When the bandwidth is insufficient, the token holding time transfer control unit 14 determines whether another node 2
Negotiate with the other node 2 to receive the transfer from the other node 2.

(3a) Bandwidth Monitoring Unit 12 FIG. 7A shows the flow of operation of the bandwidth monitoring unit 12. As shown in this figure, the bandwidth monitoring unit 12 is
The bandwidth used for each connection in the synchronous data storage queue 4 is monitored (S301). Next, the bandwidth monitoring unit 12 determines whether the used bandwidth of each connection has exceeded the maximum used bandwidth currently assigned to the connection (S302). When it is determined that the bandwidth exceeds the maximum bandwidth, the bandwidth monitoring unit 12 requests the transmission rate calculation unit 13 to extend the bandwidth used (S303).

On the contrary, when it is determined that the maximum used bandwidth is not exceeded, the bandwidth monitoring unit 12 determines whether the used bandwidth can be reduced (S304). As a method of determining whether or not reduction is possible, for example, a threshold specific to a certain system is set, and if the used bandwidth becomes smaller than this threshold in view of the current used bandwidth, it is determined that it can be reduced. There is a way to do it. When it is determined in S304 that the used bandwidth of the connection can be reduced, the bandwidth monitoring unit 12 requests the transmission rate calculation unit 13 to reduce the used bandwidth of the connection (S305).

In this way, in the present embodiment, in bandwidth management, bandwidth expansion or reduction is automatically performed according to the monitoring result of the bandwidth used by each connection.

(3b) Transmission Rate Calculation Unit 13 ... Operation at Connection Establishment The transmission rate calculation unit 13 executes bandwidth control at the time of connection establishment and at the time of changing the maximum used bandwidth and the maximum transmission completion request time. For example, when a communication application tries to establish a connection with a communication application installed in another node 2, the communication application applies the bandwidth control data for applying the maximum use bandwidth (application bandwidth) to the data distribution processing unit. Supply to 3. The data distribution processing unit 3 uses the above-described S103 and S104.
Processing is executed and the bandwidth control data from the communication application is passed to the control information management section 7. This band control data is input to the transmission rate calculation unit 13 inside the control information management unit 7. The transmission rate calculation unit 13 determines whether the maximum use band (application band) requested by the communication application in this way is acceptable.

FIG. 8 shows the transmission rate calculation unit 1 in this case.
The operation flow of No. 3 is shown. Transmission rate calculation unit 13
When receiving a request for the maximum bandwidth from the communication application, the node 2 sets the requested maximum bandwidth first.
Converts the amount of data to be transmitted each time the token is acquired (S401). The conversion is executed by the following formula.

[0064]

[Equation 1] Data amount to be transmitted each time a token is acquired [bit] = Maximum application transmission request data amount [bit] / {Maximum transmission completion request time [sec] / (2 x target token circulation time [sec]) } When the maximum transmission completion request time is less than 1 second = application maximum transmission request data amount [bit] / {1 [second] / (2 x target token circulation time [second])} ... maximum transmission completion request time 1 When more than a second, the maximum application transmission request data amount in this formula is the maximum application transmission request data amount [bit] = application bandwidth [bps] × 1
The value is the unit conversion of the application band by the calculation of [second],
It represents the amount of transmitted data corresponding to the requested bandwidth. Also,
The target token circulation time is a value that limits the token circulation time only for synchronous data transfer in order to prevent the token circulation time from becoming too long. That is, in the token passing LAN, it has been theoretically proved that the time required for a node to hold a token and then hold it for the next token is within twice the target token circulation time. Therefore, in this embodiment, considering the worst case, it is assumed that the token traveling time is twice the target token traveling time. Furthermore, the maximum transmission completion request time indicates the deadline or time at which the transfer of the synchronous data has to be completed for the connection as described above. This time is set according to the application at the time of establishing the connection, but can be changed appropriately as described later. A value obtained by dividing the maximum transmission completion request time by 2 × the target token circulation time, that is, the denominator in the above equation, is the minimum number of token circulations within the maximum transmission completion request time.
Therefore, by the above equation, the amount of data to be transmitted can be obtained each time a token is acquired.

Next, the transmission rate calculation unit 13 determines the maximum bandwidth (substantial bandwidth) that the node 2 can use when holding the token.
[Bps] is calculated, and the amount of synchronization data [bit] that can be transmitted each time a token is acquired is calculated (S402).
That is, the calculation based on the following equation is performed.

[0066]

## EQU00002 ## Real bandwidth [bps] = total bandwidth of LAN1 [bp
s] × time in which the node 2 holds the token [second] / (2
× Target token circulation time [sec])

## EQU00003 ## The amount of synchronous data that can be transmitted each time a token is acquired [bit] = 2.times.target token circulation time [seconds] .times.real bandwidth [bps] Thus, the time for which the node 2 holds the token is the target token It is possible to know the ratio of the bandwidth used by the node 2 that can occupy the entire bandwidth of the LAN 1 by dividing by twice the traveling time, that is, the maximum token traveling time when transferring both synchronous data and asynchronous data. . Also, by multiplying this by twice the target token circulation time, it is possible to know the amount of synchronization data that can be transmitted each time a token is acquired.

The transmission rate calculation unit 13 compares the information thus obtained (S403), and according to the result,
The connection establishment is permitted (S404) or rejected (S405). That is, the transmission rate calculation unit 13 has already permitted “the amount of data to be transmitted each time a token is acquired” for a connection established so far.
And the "data amount to be transmitted each time a token is acquired" calculated in S401 for the connection for which it is currently determined whether or not to establish it. The transmission rate calculation unit 13 determines whether or not this total value is less than or equal to the “synchronous data amount that can be transmitted each time a token is acquired” obtained in S402. When the former is equal to or less than the latter, the transmission rate calculation unit 13 permits the requested connection establishment. On the contrary, when the former exceeds the latter, the transmission rate calculation unit 13 rejects the request for establishment of the requested connection.

By such processing, the bandwidth application is permitted / rejected for each connection inside the node 2 and the used bandwidth is allocated.

(3c) Transmission rate calculation unit 13 and token holding time transfer control unit 14 ... Operation when maximum usable bandwidth is changed The transmission rate calculation unit 13 is provided in addition to the connection establishment time.
The following bandwidth control is executed when the requested maximum bandwidth is changed. At that time, the token holding time transfer control unit 14 also operates if necessary. FIG. 9 shows the operation of the transmission rate calculation unit 13 when an explicit request for changing the used band is received from the communication application or when a request for changing the used band by the automatic band management is received from the band monitoring unit 12. The flow is shown.

In this case, the transmission rate calculation unit 13 first determines whether the requested use is expansion or contraction of the used band (S501). When the usage bandwidth is requested to be reduced, other connections will not be inconvenient. Therefore, the transmission rate calculation unit 13 acquires the token every time the connection is requested to be used. The amount of data to be transmitted is recalculated and the value is transmitted to the transmission control unit 6 (S502). The formula used in S401 is used for recalculation. The transmission rate management unit 9 constituting the transmission control unit 6 calculates the synchronous data transmission time based on the amount of data supplied from the transmission rate calculation unit 13 in S203 and synchronizes the connection on the transmission time management table 10 Correct the data transfer time.

When the extension of the used band is requested, the transmission rate calculation unit 13 recalculates the amount of data to be transmitted each time a token is acquired for this connection (S503). The formula used in S401 is used for recalculation. The transmission rate calculation unit 13
The amount of data to be sent each time a token is acquired is summed over all established connections, and S
The amount of data calculated in 503 is added. The transmission rate calculation unit 13 compares the result with the amount of synchronous data that can be transmitted each time the node 2 acquires a token (S50).
4). When the former is equal to or less than the latter, the transmission rate calculation unit 13 permits expansion of the maximum usable band for this connection (S505).

When the former is larger than the latter, the transmission rate calculation unit 13 converts the band required to permit the maximum use band extension application of this connection into the time required to increase the token holding time of the node 2. (S506). The following formula is used for conversion.

[0073]

## EQU00004 ## Increase required time of token holding time [sec] = {2 × target token circulation time [sec] × (sum of application bandwidth of all connections [bps] / maximum transmission completion request time [sec])} / Total bandwidth of LAN 1 [bps] -Token holding time of node 2 [seconds] In this equation, 2 × target token circulation time means the maximum time required for a token to travel through LAN 1 as described above. Sum of application bandwidth for all connections /
The maximum transmission completion request time indicates how much of the maximum transmission completion request time is consumed when the current bandwidth expansion is permitted. Therefore, the numerator of the first term in the above equation is
This means the maximum amount of synchronous data transfer that can be performed when the bandwidth extension used this time is permitted. By dividing this by the total bandwidth of LAN1, you can see how much token holding time will be required if the current bandwidth expansion is permitted. If the current token holding time is further reduced, It is possible to know how much time should be increased, that is, the token holding time.

The transmission rate calculation unit 13 determines whether or not the token holding time may be increased, that is, whether or not only the own node 2 needs to deal with the increase required time calculated in S506 (S507). ). When only the own node 2 can cope with this increase required time and accordingly the requested bandwidth extension can be executed only by the own node 2, the transmission rate calculation unit 13 determines the token according to the calculated increase required time. The holding time is extended and the use bandwidth extension of the requested connection is permitted (S508). The bandwidth monitoring unit 12 thereafter executes the above bandwidth monitoring based on the expanded used bandwidth. A case where the token holding time can be extended only by the own node 2 is, for example, a case where a preliminary token holding time for extension is assigned to each node 2 in advance.

When the transmission rate calculation unit 13 determines that the node 2 alone cannot deal with this increase required time and should be solved in relation to the other nodes, the transmission rate calculation unit 13 uses the LAN 1 in some other way. Request the transfer of the token holding time (S509). FIG. 10 shows an example of this operation.

As shown in this figure, when the other node 2 is requested to transfer the token holding time, the reception processing unit 8 of the other node 2 first receives the data for the transfer via the LAN 1. Yes (S601). The other node 2
The reception processing unit 8 then determines the type of the received data (S602). When the received data is a token holding time transfer (bandwidth transfer), the reception processing unit 8 of the other node 2 transfers the received data to the token holding time transfer control of the control information management unit 7 of the other node 2. It is passed to the section 14 (S603). This token holding time transfer control unit 14
Passes a part of the unused token holding time in its own node 2 to the node 2 that requested the transfer of the token holding time in accordance with the passed data. At node 2, which asked for the transfer,
The transmission rate calculation unit 13 extends the token holding time as in S710 (S711). When the received data is general data for the communication application, the reception processing unit 8 of the other node 2 passes the reception data to the data distribution processing unit 3 (S604).

As described above, the change of the maximum use band in response to the request from the communication application or the change request of the use band according to the automatic band management by the band monitoring unit 12 is suitably executed.

(3d) Transmission rate calculation unit 13 and token holding time transfer control unit 14 ... Operation when changing maximum transmission completion request time The transmission rate calculation unit 13 further performs the following when changing the maximum transmission completion request time. Perform bandwidth control. When an explicit request to change the maximum transmission completion request time is received from the communication application, the transmission rate calculation unit 13 determines
The processing shown in is executed. The transmission rate calculation unit 13
First, it is determined whether the maximum transmission completion request time is requested to be expanded or contracted (S701). In the case of extension, the limitation related to the synchronous data transfer is relaxed and the inconvenience does not affect other connections, so the extension of the maximum transmission completion request time of the requested connection is permitted (S702).

In the case of reduction, the transmission rate calculation unit 13
Determines whether the maximum transmission completion request time after reduction is less than 1 second (S703). If the maximum transmission completion request time after reduction is 1 second or more, the amount of data to be transmitted does not change each time a token is acquired, so reduction of the maximum transmission request completion time is permitted (S704). If the maximum transmission completion request time after reduction is less than 1 second,
For the connection related to the request, the amount of data to be transmitted is recalculated each time a token is acquired (S705). For the recalculation, for example, the formula used in S401 is used.

The transmission rate calculation unit 13 totals the amount of data to be transmitted each time a token is acquired for all established connections, and further adds the amount of data recalculated in S705 to this total value. The result is compared with the amount of data that the node can transmit each time the token is acquired (S7).
06). If the former is equal to or less than the latter, the transmission rate calculation unit 13 permits reduction of the maximum transmission completion request time (S707). When the former is larger than the latter, the transmission rate calculation unit 13 converts the band required to permit the maximum transmission completion request time reduction application into the required time for increasing the token holding time of this node (S708). The calculation formula for conversion is the same as that in S708, for example.

The transmission rate calculation unit 13 then proceeds to S708.
When dealing with the increase required time calculated in
It is determined whether or not it is necessary to deal with this (S)
709). If it can be expanded only by the own node 2, the transmission rate calculation unit 13 expands the token holding time to allow reduction of the maximum transmission completion request time of the connection (S).
710). The case in which the token holding time question can be expanded only by the own node 2 is, for example, the case where a preliminary token holding time for expansion is assigned to each node 2 in advance. When the token holding time cannot be extended only by the own node 2, the transmission rate calculation unit 13 requests the other node 2 to transfer the token holding time by some method (S711). The process related to this transfer is shown in FIG.
It can be realized by the same processing as.

Therefore, in the present embodiment, when an explicit request for changing the maximum transmission completion request time is received from the communication application, this can be appropriately dealt with.

(4) Overall Operation Next, the overall operation of this embodiment will be described by focusing on the functional relation of each part.

Here, first, it is assumed that a certain communication application requests the establishment of a connection with a communication application installed in another node 2. That is, it is assumed that a certain communication application outputs band control data for requesting the establishment of a connection, designating the maximum transmission completion time, and applying for the maximum used band (application band). This data is once input to the data distribution processing unit 3. Since the received data is band control data (S103), the data distribution processing unit 3 passes this data to the control information management unit 7 (S104). In this way, the data requesting the establishment of the connection is supplied to the control information management unit 7, especially the transmission rate transmission unit 13.

The transmission rate calculation unit 13 obtains the amount of data to be transmitted each time the own node 2 acquires a token, based on the received bandwidth control data, specifically, the applied bandwidth and the maximum transmission completion time (S401). Further, it calculates the amount of synchronization data that can be transmitted each time the node 2 acquires a token (S402). The transmission rate calculation unit 13 determines whether the sum of the “data amount to be transmitted each time a token is acquired” which has already been permitted for the connections established so far is established, and whether or not the connection is established at the present time. Connection is established by summing the "data amount to be sent each time a token is acquired" calculated in S401 for the existing connections and comparing the total value with the calculated "amount of synchronous data that can be sent each time a token is acquired". Is permitted / rejected (S404, S405). By such processing, the bandwidth application is permitted / rejected for each connection inside the node 2 and the bandwidth used is allocated. The transmission data management unit 9 registers a corresponding synchronization data transmission time in the transmission time management table 10 according to the amount of data to be transmitted each time a token is acquired.

When the connection establishment is permitted, one of the queues forming the synchronous data storage queue 4 is assigned to the connection. When the synchronization data related to this connection is supplied from the communication application, the data distribution processing unit 3 distributes and stores this synchronization data in the corresponding queue. The synchronous data storage queue 4 is
The synchronization data is stored until the transmission together with the maximum transmission completion request time. The asynchronous data supplied from the communication application is distributed to the asynchronous data storage queue 5 by the data distribution processing unit 3.

Another node 2 holds the token,
When the data is transferred from the node 2 holding the token, the reception processing unit 8 determines the type of the received data (S602), and when the data is to the communication application, the received data is distributed. It is passed to the processing unit 3 (S604). In this case, the data distribution processing unit 3
Allocates the data supplied from the reception processing unit 8 to the communication application that should receive this data (S1).
06). On the contrary, when the data received from the node 2 holding the token is the data requesting the transfer of the token holding time, the reception processing unit 8 passes this data to the control information management unit 7 of its own node 2. (S604). When possible, the control information management unit 7 that has received the data holds the unused token in the own node 2 under the control of the token holding time transfer control unit 14 to the node 2 requesting the transfer of the token holding time. The process of passing a part of the time is executed.

When the own node 2 acquires the token, the transmission control unit 6 executes data transmission. When the data to be transmitted is synchronous data, the transmission rate management unit 9 sends the synchronous data related to the connection to the transmission execution unit 11 according to the synchronous data transmission time obtained by referring to the transmission time management table 10. It is transmitted to the corresponding other node 2 (S202). When the data to be transmitted is asynchronous data, the transmission rate management unit 9 sends the asynchronous data for a predetermined time to the transmission execution unit 11 and causes it to be transmitted to the corresponding other node 2 (S202). In this way, the transmission rate management unit 9 manages the synchronous data transmission rate for each connection.

The band monitoring unit 12 monitors the current band used in the synchronous data storage queue 4 when executing such a transmission procedure (S301). The bandwidth monitoring unit 12 compares the bandwidth used for each connection with the application bandwidth at the time of establishing the connection or the application bandwidth expanded / reduced after the application (S302), and the application bandwidth can be expanded if necessary. If so, the reduction rate is applied to the transmission rate calculation unit 13 (S3).
03, S305).

The transmission rate calculation unit 13 that received this application
If the requested use is reduction of the used bandwidth, recalculates the amount of data to be transmitted each time a token is acquired, and sends the value to the transmission control unit 6 (S502). Based on this data, the transmission rate management unit 9 in the transmission control unit 6 registers the synchronization data transmission time for each connection in the transmission time management table 10 (S203). As a result, the automatic reduction of the applied bandwidth is realized by the internal processing of the node 2. The bandwidth monitoring unit 12 thereafter executes the above bandwidth monitoring based on the reduced used bandwidth.

On the other hand, when the requested bandwidth extension is requested, the transmission rate calculation unit 13 can extend the bandwidth based on the amount of synchronous data that can be transmitted each time the node 2 acquires a token. Immediately permit expansion if there is (S50
4, S505), the recalculated value of the amount of data to be transmitted each time a token is acquired is transmitted to the transmission control unit 6 (S50).
2). Based on this data, the transmission rate management unit 9 registers the synchronous data transmission time for each connection in the transmission time management table 10 (S203). If the bandwidth cannot be expanded, the transmission rate calculation unit 13 determines the insufficient bandwidth based on the recalculated value of the amount of data to be transmitted each time a token is acquired,
That is, the time required to increase the token holding time is calculated (S
506). When the shortage band can be compensated only by the own node 2 (S607), the transmission rate calculation unit 13 extends the token holding time according to the increase required time and permits the band extension (S607). The transmission rate management unit 9 also executes the same processing in this case (S203). When the own node 2 alone cannot cope with the increase required time, the transmission rate calculation unit 1
3 requests the other node 2 to transfer the token holding time (S509). In the node 2 that has received the token holding time transfer request, the token holding time transfer control unit 14 executes the token holding time transfer process when the spare token holding time allocated to the own node 2 has a margin. The node 2 that has requested the transfer executes the process of transferring the token holding time. After receiving the transfer of the token holding time, the transmission rate calculation unit 13 extends the token holding time according to the required increase time and permits the band extension (S607). The transmission rate management unit 9 also executes the same processing in this case (S203). In this way, the automatic reduction of the applied bandwidth is realized by the internal processing of the node 2. The bandwidth monitoring unit 12 thereafter executes the above bandwidth monitoring based on the expanded used bandwidth.

Each communication application, if necessary,
Expansion / reduction of bandwidth used, expansion of maximum transmission completion request time
Request reduction. That is, band control data for expanding / reducing the used band or expanding / contracting the maximum transmission completion request time is supplied to the data distribution processing unit 3. The data distribution processing unit 3 gives this information to the transmission rate calculation unit 13 of the control information management unit 7. The transmission rate calculation unit 13 executes processing related to expansion / reduction of the used bandwidth and expansion / reduction of the maximum transmission completion request time based on the bandwidth control data. The processing related to the expansion / reduction of the used bandwidth is executed in the same procedure as the automatic bandwidth control.

When expanding / reducing the maximum transmission completion request time, the transmission rate calculation unit 13 permits the expansion if the requested maximum transmission completion request time is extended (S
702), and informs the transmission control unit 6 (S502). Based on this data, the transmission rate management unit 9 registers the synchronous data transmission time for each connection in the transmission time management table 10 (S203).

In the case of reduction, the transmission rate calculation unit 13
Allows the reduction of the maximum transmission request completion time if the maximum transmission completion request time after reduction is 1 second or more (S704), and notifies the transmission control unit 6 (S502). Transmission rate management unit 9
Registers the synchronization data transmission time for each connection in the transmission time management table 10 based on this data (S
203). When the maximum transmission completion request time after reduction is less than 1 second, the transmission rate calculation unit 13 determines whether there is a bandwidth shortage based on the recalculated value of the amount of data to be transmitted each time a token is acquired (S706). ). If not insufficient, the transmission rate calculation unit 13 permits reduction of the maximum transmission completion request time (S707) and notifies the transmission control unit 6 (S50).
2). The transmission rate management unit 9 executes the same processing as described above (S203). If insufficient, the transmission rate calculation unit 13
Determines the shortage of bandwidth, that is, the time required to increase the token holding time (S708), and determines whether this can be covered by only the own node 2 (S709). If it can be covered, the transmission rate calculation unit 13 permits the extension of the token holding time and the reduction of the maximum transmission completion request time (S710), and transmits the data to that effect to the transmission control unit 6 (S502). The transmission rate management unit 9 also executes the same processing as described above (S
203). If the node 2 alone cannot cover the request, the other node 2 is requested to transfer the token holding time, as in the case of extending the application band (S711).

II. Second Embodiment In the above-described first embodiment, the bandwidth is automatically expanded or reduced according to the result of the bandwidth monitoring by the bandwidth monitoring unit 12, but the present invention is limited to such an operation. It shouldn't be. As shown in FIG. 7B, the configuration may be such that automatic bandwidth management is not performed. In this figure, if it is determined in S302 that the used bandwidth exceeds the maximum used bandwidth of the connection, the excess synchronization data is discarded (S306).

[0096]

As described above, according to the first aspect of the present invention.
According to the above, since the permission to transfer the synchronous data is determined inside the node and the bandwidth is managed by the node in relation to the maximum transmission completion request time and the token holding time, a management node dedicated to bandwidth management is not required. Become. As a result, the overhead of the control procedure necessary for bandwidth acquisition can be suppressed, and it is not necessary to deal with the occurrence of a failure in the management node. In addition, there is no unfairness in the usable band between the nodes connected to the LAN.

According to claim 2 of the present invention, when deciding whether or not to permit the application of the maximum used bandwidth and the maximum transmission completion request time, the amount of synchronous data to be transmitted by the own node at the time of holding the token and the token holding Since the amount of synchronous data that can be transmitted by the own node is obtained at some times, the decision can be executed in relation to the maximum transmission completion request time and the token holding time. Therefore, according to this claim, whether or not to permit the application can be suitably determined based on the comparison result.

According to the third aspect of the present invention, when it can be considered that the band exceeds the maximum usable band in view of the band use situation obtained by monitoring, the synchronization data for the amount exceeding the maximum usable band is obtained. Since the information is discarded, it is possible to prevent the band usage exceeding the maximum usage band, and thus the adverse effect on other nodes.

According to the fourth aspect of the present invention, the maximum usable bandwidth of the communication application is expanded when it can be considered that the bandwidth is used beyond the maximum usable bandwidth in view of the bandwidth use situation obtained by monitoring. As described above, since the synchronous data transmission time is changed, it is possible to prevent the band usage exceeding the maximum usage band, and thus the adverse effect on other nodes, similarly to the third aspect. In addition, since the maximum usable band can be automatically expanded according to the band use situation, highly adaptive control can be realized.

According to the fifth aspect of the present invention, when it can be considered that the maximum usable bandwidth can be reduced in view of the bandwidth use situation obtained by monitoring, the synchronous data transmission is performed so that the maximum usable bandwidth of this communication application is reduced. Since the time is changed, the maximum usable band can be automatically reduced according to the band use condition, the band can be efficiently used, and highly adaptive control is realized.

According to claim 6 of the present invention, when the communication application requests extension of the maximum usable bandwidth, the amount of synchronous data to be transmitted by the own node at the time of holding the token after extending the maximum usable bandwidth, and Since the amount of synchronous data that can be sent by the own node is calculated when holding the token, it is decided based on the results of both calculations whether or not to permit the application for the extension without extending the token holding time of the own node. You can As a result, it becomes possible to expand the maximum bandwidth of the synchronous data while the connection is being used, and the communication application can optimally set the bandwidth according to the time of day and the business content.

According to claim 7 of the present invention, when it is determined that the application for extension cannot be permitted without extension of the token holding time of the own node, the insufficient bandwidth is obtained as the required time for increasing the token holding time, When the required increase time required can be covered by the spare token holding time allocated to the own node, application for expansion is allowed, so the frequency of partial transfer requests for token holding time to other nodes is suppressed. Therefore, it is possible to realize highly complete processing within the node.

According to the eighth aspect of the present invention, when the obtained required increase time cannot be covered by the spare token holding time allocated to the own node, a part of the token holding time is transferred to another node. When the token holding time is requested from another node and the extension holding application is permitted, the token holding time can be flexibly allocated to each node constituting the LAN.

According to claim 9 of the present invention, when the token holding time for which a partial transfer is requested by another node can be covered by the spare token holding time assigned to the own node, Since the token holding time is transferred to the node requesting the partial transfer, it is possible to flexibly allocate the token holding time to each node configuring the LAN.

According to claim 10 of the present invention, in response to a request from the communication application for reduction of the maximum used bandwidth, when the maximum used bandwidth is reduced, the amount of synchronous data to be transmitted by the own node at the time of holding the token is: It is calculated based on the reduced maximum bandwidth and maximum transmission completion request time. Further, based on the result, the synchronous data transmission time is changed so that the maximum use band is reduced. As a result, the communication application can optimally set the band according to the time of day and the work content, and the band use efficiency is improved.

According to claim 11 of the present invention, in response to a request from the communication application to reduce the maximum transmission completion request time, when the maximum transmission completion request time is reduced, the synchronization data to be transmitted by the own node at the time of holding the token. The amount of synchronization data that can be sent by the own node at the time of holding the token is calculated based on the amount of tokens and the token holding time that the own node can use. Since the determination is made, it becomes possible to change the maximum transmission completion request time according to the type of synchronization data, for example.

According to the twelfth aspect of the present invention, when the reduced maximum transmission completion request time exceeds the predetermined time, the reduction application is permitted, so that the processing load such as data amount calculation is reduced.

According to the thirteenth aspect of the present invention, when it is determined that the request for the reduction of the maximum transmission completion request time cannot be granted without extending the token holding time of the own node, the insufficient bandwidth is set to the token holding time. Calculated as the increase required time, and when the calculated increase required time can be covered by the reserve token holding time assigned to the own node, the request for reduction of the maximum transmission completion request time is allowed It is possible to suppress the frequency of partial transfer requests of token holding time, and to realize highly complete processing within the node.

According to the fourteenth aspect of the present invention, when the calculated required increase time cannot be covered by the spare token holding time allocated to the own node, a part of the token holding time is transferred to another node. When the token holding time is requested from another node and the extension holding application is permitted, the token holding time can be flexibly allocated to each node constituting the LAN.

According to the fifteenth aspect of the present invention, when the token holding time for which a partial transfer is requested by another node can be covered by the spare token holding time assigned to the own node, Since the token holding time is transferred to the node requesting the partial transfer, it is possible to flexibly allocate the token holding time to each node configuring the LAN.

According to claim 16 of the present invention, the amount of synchronous data to be transmitted by the own node when holding the token when the maximum transmission completion time is extended in response to an application from the communication application for extending the maximum transmission completion time. Based on the result of calculation, the synchronous data transmission time is changed so that the maximum transmission completion time is extended, so that the communication application can optimally set the bandwidth according to the type of synchronous data. , Band use efficiency is improved.

According to the seventeenth aspect of the present invention, a plurality of connections are generally established between the communication application installed in the own node and the communication application installed in another node. The bandwidth can be optimally managed, and the bandwidth usage efficiency is improved.

According to the eighteenth aspect of the present invention, since the asynchronous data transmission / reception means is provided, asynchronous data that is not time-critical can be transmitted / received without any limitation on the transmission completion time.

According to the nineteenth aspect of the present invention, since the LAN nodes suitable for the distributed management of the band according to the present invention are used as the respective nodes, the central management node is not required in the broken-path LAN. . at the same time,
Each node can execute synchronous data transmission according to the transmission completion request time.

[Brief description of drawings]

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

FIG. 2 is a block diagram showing an internal configuration of a node in this embodiment.

FIG. 3 is a flowchart showing a processing flow of a data distribution processing unit.

FIG. 4 is a block diagram showing an internal configuration of a transmission control unit.

FIG. 5 is a flowchart showing a processing flow of a transmission rate management unit.

FIG. 6 is a block diagram showing an internal configuration of a control information management unit.

FIG. 7 is a flowchart showing a processing flow of the bandwidth monitoring unit, where (1) shows the flow in the first embodiment and (2)
FIG. 6 is a diagram showing a flow in the second embodiment, respectively.

FIG. 8 is a flowchart showing a processing flow of a transmission rate calculation unit at the time of establishing a connection.

FIG. 9 is a flowchart showing a processing flow of a transmission rate calculation unit when a request for changing the maximum usable band is made.

FIG. 10 is a flowchart showing a processing flow of a reception processing unit.

FIG. 11 is a flowchart showing a processing flow of a transmission rate calculation unit when the maximum transmission completion request time is changed.

FIG. 12 is a diagram showing a conventional example, (a) is a network configuration diagram of a token passing LAN according to this conventional example, and (b) is a diagram showing a data transfer sequence in this conventional example.

[Explanation of symbols]

1 LAN, 2 nodes, 3 data distribution processing unit,
4 synchronous data storage queue, 5 asynchronous data storage queue, 6 transmission control unit, 7 control information management unit, 8 reception processing unit, 9 transmission rate management unit, 10 transmission time management table, 11 transmission execution unit, 12 band monitoring unit, 13 transmission rate calculation unit, 14 token holding time transfer control unit.

Claims (19)

[Claims] 1. A means for deciding whether or not to permit an application for a maximum used bandwidth and a maximum transmission completion request time from a communication application installed in the own node, based on a token holding time that the own node can use, A means for determining the synchronous data transmission time based on the maximum used bandwidth and the maximum transmission completion request time when permitting, and means for transmitting the synchronous data over the synchronous data transmission time determined according to the acquisition of the token, When using in a token passing method LAN that performs medium access control by circulating tokens, time-critical synchronous data that must be transmitted within the maximum transmission completion request time must be transmitted while managing the bandwidth for each node. Characterized by L
Node for AN. 2. The LAN node according to claim 1, wherein the means for deciding whether or not to permit the application is based on the requested maximum used bandwidth and maximum transmission completion request time A means for obtaining the amount of synchronization data to be transmitted, a means for obtaining the amount of synchronization data that the own node can transmit when holding the token based on the token holding time that the own node can use, and a synchronization data that the own node should transmit when holding the token. By comparing the amount of synchronization data that can be sent by the own node when holding the token,
A node for LAN, comprising: means for determining whether or not to permit the application. 3. The LAN node according to claim 1, wherein the means for monitoring the bandwidth usage status of the communication application and the bandwidth usage status exceeds the maximum usage bandwidth requested by the communication application. And a means for discarding the synchronization data exceeding the maximum usable bandwidth when it can be considered that the LAN node is used. 4. The LAN node according to claim 1, further comprising means for monitoring a band usage status of the communication application, and a band exceeding a maximum usage band requested by the communication application in view of the band usage status. And a means for changing the synchronous data transmission time so that the maximum use band of the communication application is expanded when it can be considered that the LAN node is used. 5. The LAN node according to claim 1, further comprising means for monitoring the band usage status of the communication application, and if it can be considered that the maximum usage band of the communication application can be reduced in view of the band usage status. A node for LAN, comprising: means for changing the synchronous data transmission time so that the maximum bandwidth used by the communication application is reduced. 6. The LAN node according to claim 1, wherein synchronization data to be transmitted by the own node at the time of holding a token when the maximum use bandwidth is extended in response to an application for extension of the maximum use bandwidth from the communication application. A method for determining the amount based on the expanded maximum bandwidth and maximum transmission completion request time, a method for determining the amount of synchronization data that the local node can transmit when holding the token based on the token holding time that the local node can use, and a maximum usage By comparing the amount of synchronization data that should be sent by the node when holding the token when the bandwidth is extended and the amount of synchronization data that the node can send when holding the token based on the token holding time that the node can use A means to decide whether or not to permit the extension application without extending the token holding time of the own node, and when permitting And a means for changing the synchronous data transmission time so that the maximum usable bandwidth is extended to the LAN node. 7. The LAN node according to claim 6, wherein, when it is determined that the application for the extension cannot be permitted without extending the token holding time of the own node, the maximum use permitted by the application so far. Based on the bandwidth and the maximum transmission completion request time, a means for obtaining the insufficient bandwidth as the increase required time of the token holding time, and when the obtained increase required time can be covered by the spare token holding time assigned to the own node, Means to allow applications for the above extensions,
A LAN node, comprising: 8. The LAN node according to claim 7, wherein when the obtained required increase time cannot be covered by the spare token holding time allocated to the own node, the other node holds the token holding time. L comprising means for requesting a copy transfer, and means for permitting an application for the above expansion when a token holding time is transferred from another node.
Node for AN. 9. The LAN node according to claim 8, wherein the token holding time required for partial transfer from another node can be covered by the spare token holding time assigned to the own node. A node for LAN, comprising means for transferring the token holding time to the node that requested the partial transfer of the token. 10. The LAN node according to claim 1, wherein when the maximum use bandwidth is reduced in response to a request from the communication application to reduce the maximum use bandwidth, the amount of synchronization data is reduced to the maximum use bandwidth and Change the sync data transmission time so that the maximum bandwidth can be reduced based on the method to obtain based on the maximum transmission completion request time and the amount of synchronization data to be transmitted by the own node when holding the token requested in response to the application for reduction. A node for LAN, comprising: 11. The LAN node according to claim 1, wherein when the maximum transmission completion request time is reduced in response to a request from the communication application to reduce the maximum transmission completion request time, the own node transmits the token when holding the token. Means for determining the amount of synchronization data to be transmitted based on the maximum used bandwidth and the reduced maximum transmission completion request time, and means for determining the amount of synchronization data that can be transmitted by the own node when holding the token, based on the token holding time that the own node can use And the amount of synchronous data that the node should send when holding the token when the maximum transmission completion request time is reduced, and the amount of synchronous data that the node can send when holding the token based on the token holding time that can be used by the node. By comparing the above, it is decided whether to permit the above reduction application without extending the token holding time of the own node. A node for LAN, comprising: a means for setting a synchronization data transmission time; 12. The LAN node according to claim 11, wherein the maximum transmission completion request time is shortened, the means for determining whether or not the predetermined time is exceeded, and the reduction when the predetermined time is determined to be exceeded. And a means for permitting the application of 1. The LAN node. 13. The LAN node according to claim 11, wherein when it is determined that the application for the reduction cannot be permitted without extending the token holding time of the own node, the maximum use permitted by the application so far. Based on the bandwidth and the maximum transmission completion request time, a method for obtaining the insufficient bandwidth as the increase required time of the token holding time and the obtained increase required time can be covered by the spare token holding time assigned to the own node, A node for LAN, comprising: means for permitting the application for reduction. 14. The LAN node according to claim 13, wherein when the required increase time obtained cannot be covered by the spare token holding time allocated to the own node, the other node holds the token holding time. A means for requesting a department transfer,
A node for LAN, comprising means for permitting the application for reduction when the token holding time is transferred from another node. 15. In the LAN node according to claim 14, when the token holding time for which a partial transfer is requested from another node can be covered by the spare token holding time assigned to the own node, the token holding time A node for LAN, comprising means for transferring the token holding time to the node that requested the partial transfer of the token. 16. The synchronization for the node for LAN according to claim 1, when the maximum transmission completion time is extended in response to an application for extension of the maximum transmission completion time from the communication application, the own node should transmit when holding the token. A method for obtaining the amount of data based on the maximum bandwidth used and the extended maximum transmission completion request time, and synchronous data transmission so that the maximum transmission completion time is extended based on the amount of synchronous data obtained in response to an extension application. A node for LAN, comprising: means for changing time. 17. The LAN node according to claim 1, wherein the maximum bandwidth and the maximum transmission completion request time are logically linked between a communication application installed in the own node and a communication application installed in another node. A node for LAN, characterized in that the token holding time is applied for each connection, is used for each node and by all the connections related to the own node, and the synchronous data transmission time is determined for each connection. 18. The LAN node according to claim 1, further comprising means for transmitting / receiving asynchronous data which has no limitation on transmission completion time and which is not time-critical. 19. A token is circulated in a predetermined direction along a cyclic transmission line of a LAN, each node starts or restarts data transmission in response to acquisition of the token, and transmission is interrupted or terminated after a predetermined token holding time has elapsed. Token passing method LA that abandons the token and passes it to the subsequent node
19. A data transfer system, wherein each node in N is the LAN node according to any one of claims 1 to 18.