JPH08331164A - Communication control system - Google Patents

Abstract

PURPOSE: To perform the data transfer processing with the optimum efficiency according to the environmental condition at the time, in a communication control system to be connected with plural kinds of LAN. CONSTITUTION: In a communication control system which is connected with plural kinds of LAN and performs the data transfer processing by a transmission confirmation protocol (TCP/IP, etc.,), a buffer control part 1014 and a transmission/reception buffer size table 1015 are provided. In the transmission/ reception buffer size table 1015, the value of the corresponding transmission/ reception buffer size for each of various kinds of environmental conditions (maximum transfer amount of the transmission medium of the LAN, the classification and transmission rate of the LAN and the classification of the user application accompanying a data transfer and a transmission data size, etc.) in a data transfer processing is preliminarily defined. The buffer control part 1014 discriminates the environmental condition when a data transfer processing is started and sets the transmission/reception size corresponding to the environmental condition based on the buffer size table 1015.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication control system, and more particularly to a communication control system for controlling data transmission / reception performed through a plurality of types of local area networks having different data transfer capabilities.

[0002]

[Prior Art] Hereinafter, "UNIX 4.3 BSD Design and Implementation"
Based on (Nakamura et al./Maruzen), a conventional communication control system will be described with reference to FIGS. 17 and 18.

FIG. 17 is a block diagram showing a configuration example of a conventional communication control system. In the figure, the communication control device 1
Reference numeral 7000 denotes an information device such as a workstation or a personal computer, which is connected to a local area network (hereinafter abbreviated as “LAN”) 1
Data transfer processing with another information device is performed via 7013. User application program 17001
Is a transmission data area 17002 or a reception data area 1700 provided in the user space for the protocol control unit 17004 which performs delivery confirmation type protocol control.
A data transmission / reception request in 3 is issued to transmit / receive data. The protocol control unit 17004 uses the transmission buffer 17005 and the reception buffer 17006 to perform data transmission / reception control according to a delivery confirmation type protocol. The adapter control unit 17012 is a LAN 17013.
The network interface controller 17011 controls the interface between the adapter controller 17012 and the protocol controller 17004.

Next, the control performed when transmitting data to another information device via the LAN 17013 will be described. The protocol control unit 17004 holds transmission data in the transmission buffer 17005 until it receives delivery confirmation data (ACK: Acknowledge, control data indicating that data has been normally received by the receiving side). The transmission buffer size at this time is limited to a certain fixed capacity regardless of the type of transmission medium. Then, transmission data 17007 to 17008 are created from the data in the transmission buffer 17005 according to the maximum transfer amount of the transmission medium, and the transmission data is transmitted to another information device.

Next, the control performed when receiving data from another information device via the LAN 17013 will be described. Adapter control unit 17012 is LAN 1701
When data is received from No. 3, the reception is reported to the protocol control unit 17004 by an interrupt via the network interface control unit 17011. The protocol control unit 17004 performs protocol processing on the reception data 17009 to 17010, stores them in the data reception buffer 17006, and notifies the user application program 17001 of the data reception. Then, the user application program 17001 reads the data, releases the reception buffer 17006, and after the buffer becomes empty, the above ACK is transmitted to the other information device of the transmission source.

FIG. 18 is a diagram showing a data transmission / reception control sequence in a conventional communication control system. In the figure, first, connection data is transmitted from the transmission side to the reception side (step 18000). Then, the receiving side accepts the connection data (step 1800).
6), ACK for this is transmitted (step 180)
07), the connection is established. Subsequently, the transmitting side copies data from the user space to the system space in an amount corresponding to the transmission buffer size (a fixed value regardless of the transmission medium) (step 18001). Then, after dividing the data in the send buffer into several pieces,
The maximum transfer amount of the LAN, that is, the maximum transfer unit (MTU: Maximum Transfer Unit) of the transmission medium forming the LAN is divided to create transmission data, and these transmission data are continuously transmitted (steps 18002 to 1800).
3). At this time, the upper limit of the division unit of the transmission data is the transmission buffer size, and the upper limit of the amount of data that can be continuously transmitted is the window size. In the description of the present invention, the values of the transmission or reception buffer size and the window size are always the same. When the receiving side receives the continuously transmitted data (step 18008 to step 1800).
9) After sending ACK to the sender (step 180
10) After copying the data in the reception buffer to the user space (step 18011), the reception buffer is released. This completes one data transfer process.

The transmitting side repeats the continuous transmission of the amount of data corresponding to the transmission buffer size and the reception of the corresponding ACK to complete the entire data transfer process. Further, the receiving side repeats the continuous reception of the amount of data corresponding to the reception buffer size and the transmission of the corresponding ACK, thereby completing the entire data transfer process.

[0008]

In the above-mentioned conventional communication control system, since the transmission buffer size is always a constant value regardless of the transmission medium, the transmission / reception buffer copied between the user space and the system space. The data amount of is also constant regardless of the type of transmission medium. Therefore, when trying to build a communication control system that is connected to multiple types of LANs at the same time,
There is a problem that the efficiency of the data transfer processing in N is deteriorated. This is due to the change of the transmission medium.
This is because when the maximum transfer amount of the AN increases and approaches the transmission / reception buffer size, the ratio of the number of ACK transmissions from the receiving side to the number of data transmissions from the transmitting side also increases.

For example, Ethernet (Fuji Xerox Co., Ltd.)
On multiple types of networks such as
When communicating by TCP / IP, the amount of data (window size) that can be sent and received at once without a delivery confirmation response affects the performance (throughput) of the communication control system. Specifically, if it is desired to maximize the transmission performance of FDDI, it is desirable to set the window size to 40 KB or more (IEICE Transactions BI volJ
77-BI "Transport Protocol Throughput Analysis in FDDI Networks," Ishibashi et al., P92 (see Figure 9). However, with Ethernet, the window size is 4 KB.
If so, the transmission performance can be sufficiently obtained.

Therefore, an object of the present invention is to solve the above problems and to provide a communication control system in which data transfer processing is performed with optimum efficiency according to the maximum transfer amount of the LAN to be used.

[0011]

In order to achieve the above object, the communication control system of the present invention is a communication control system which is connected to a plurality of types of networks and performs data transfer processing by a delivery confirmation type protocol. At the start of the data transfer process, a buffer control unit that sets the buffer size for defining the upper limit of the amount of data that can be collectively processed in one transmission / reception sequence according to the environmental conditions in the data transfer process, or Alternatively, in a communication control system which is connected to a plurality of types of networks and performs data transfer processing by a delivery confirmation type protocol, a corresponding buffer size value is defined in advance for each of various environmental conditions in the data transfer processing. When you start the data transfer process with the buffer size table After identifying the environmental conditions in the data transfer process, in which the buffer size corresponding to the environmental conditions and be provided with a, and a buffer control unit that sets, based on the buffer size table. Here, the specific contents of the environmental conditions include the maximum transfer amount of the transmission medium of the network used for the data transfer processing, the type of the network, the transmission speed in the network, and the user application accompanying the data transfer processing. The type and the size of data transmitted from the user application.

[0012]

The operation based on the above configuration will be described.

The communication control system of the present invention is a communication control system which is connected to a plurality of types of networks and performs data transfer processing by a delivery confirmation type protocol,
At the start of the data transfer process, a buffer control unit may be provided to set the buffer size for defining the upper limit of the amount of data that can be collectively processed in one transmission / reception sequence according to the environmental conditions in the data transfer process. , Or connected to multiple types of networks,
In a communication control system that performs data transfer processing by a delivery confirmation type protocol, a buffer size table in which corresponding buffer size values are defined in advance for each of various environmental conditions in the data transfer processing,
At the time of starting the data transfer process, after identifying an environmental condition in the data transfer process, a buffer control unit that sets a buffer size corresponding to the environmental condition based on the buffer size table is provided. is there. Here, the specific contents of the environmental conditions include the maximum transfer amount of the transmission medium of the network used for the data transfer processing, the type of the network, the transmission speed in the network, and the user application accompanying the data transfer processing. The type and the size of data transmitted from the user application.

If the network interface control unit is provided with the buffer control unit, the communication control device on the connection data transmission side receives the ACK for the connection data from the reception side, and the buffer control unit in the network interface control unit. After determining the type of LAN to be connected, the transmission buffer size value suitable for the LAN obtained by referring to the buffer size table is set in the protocol control table in the protocol control unit. When receiving connection data from the transmission side, the communication control device on the connection data receiving side determines the type of LAN to which the buffer control section in the network interface control section is connected, and then opens the buffer size table in the same manner as above. The reception buffer size value suitable for the LAN obtained by reference is set in the protocol control table in the protocol control unit. After that, the protocol control units of both communication control devices perform continuous transmission or continuous reception of data based on the buffer size value set in the protocol control table. Therefore, by registering in advance the transmission / reception buffer size value corresponding to the transmission medium constituting each LAN in the buffer size table, the transmission / reception buffer size is automatically changed according to the transmission capacity of the transmission medium. Since continuous data transmission / reception is performed, it is possible to realize data transfer processing with optimum efficiency according to the maximum transfer amount of the LAN to be used.

Alternatively, in the case where the above-mentioned buffer control unit is provided in the protocol control unit, in the communication control device on the connection data transmission side, when the connection data transmission process ends, the buffer control unit in the protocol control unit causes the protocol control table. After searching the inside for a pointer to the network interface table, the sending / receiving buffer size table is searched from the LAN identifier in the network interface table, and the corresponding sending / receiving buffer size value is set in the protocol control table. Further, in the communication control device on the connection data receiving side, when the connection data is received from the communication control device on the transmitting side and the connection data receiving process corresponding to this is completed, the buffer control unit in the protocol control unit is set in the same manner as above. After searching the protocol control table for a pointer to the network interface table, LA in the network interface table is searched.
The transmission / reception buffer size table is searched from the N identifier, and the corresponding transmission / reception buffer size value is set in the protocol control table. After that, the protocol control units of both communication control devices perform continuous transmission or continuous reception of data based on the buffer size value set in the protocol control table.

That is, when transmitting data, the protocol control unit copies data from the transmission data area in the user space to the transmission buffer in the system space based on the transmission buffer size set in the protocol control table. Then, the data in the transmission buffer is divided according to the maximum transfer amount of the transmission medium, continuously transmitted for the transmission buffer size, and then transmitted by receiving the delivery confirmation data from the communication control device on the receiving side. The transmission of the data in the buffer is completed. Therefore, as the number of times of continuous transmission at one time is registered, the number of times of the delivery confirmation processing decreases, and the data transfer efficiency can be further improved.

Since the buffer control unit determines the transmission / reception buffer size by referring to the buffer size table in which the transmission / reception buffer size value is registered for each type of transmission medium, the transmission medium having a large maximum transfer amount is determined. A large send / receive buffer size value, and a small send / receive buffer size value for transmission media with a small maximum transfer amount.
If registered in the buffer size table, the data transfer efficiency can be made almost constant regardless of the types of transmission media that compose the LAN.

[0018]

Embodiments of the communication control system of the present invention will be described in detail below with reference to the drawings.

FIG. 1 shows the first part of the communication control system of the present invention.
It is a block diagram showing the whole composition of an example.

First, each control block and table constituting the communication control device 1001 in the communication control system of this embodiment will be described. In FIG. 1, a communication control device 1001 is configured by an information device such as a workstation or a personal computer,
For example, various transmission media that construct a local area network (hereinafter abbreviated as "LAN") such as Ethernet and FDDI, that is, LAN1019, LAN
1020, connected to the LAN 1021 to perform data transfer with other information equipment. The user application 1002 is a memory space (user space) dedicated to the user application provided in the communication control device 1001.
It is a separate program that runs on top. The user application 1002 transmits / receives data by issuing a request for transmitting data stored in the transmission data area 1003 in the user space or a request for receiving data to the reception data area 1004 to the protocol control unit 1005. To do. The protocol control unit 1005, the network interface control unit 1013, the adapter control unit 1016, the adapter control unit 1017, and the adapter control unit 1018 are a group of programs for communication control executed in a system space different from the user space.
The protocol control unit 1005 uses the transmission buffer 1006 and the reception buffer 1008 to perform data transmission / reception control by the delivery confirmation protocol. The adapter control unit 1016, the adapter control unit 1017, and the adapter control unit 1018 are LAN 1019 and LAN 1, respectively.
020, input / output control with the LAN 1021 is performed.
The network interface control unit 1013 includes the adapter control units 1016 to 1018 and the protocol control unit 1.
Interface control with 005 is performed.

Next, the flow of communication control performed when transmitting data will be described. User application 1
002 issues a transmission request for the data stored in the transmission data area 1003 in the user space to the protocol control unit 1005. In response to this transmission request, the protocol control unit 1005 moves from the transmission data area 1003 in the user space to the transmission buffer 100 in the system space.
Copy the data to 6. At this time, regarding the amount of data copied at one time (transmission buffer size value), the protocol control table 10 in the protocol control unit 1005
According to the buffer size value set to 07. The buffer size value is determined by the protocol control unit 1005 when the first data transmission request is received from the user application 1002, the type of the user application 1002 is determined, and the buffer size table is described later.

Next, the flow of communication control performed when receiving data will be described. Adapter control unit 1016-
When any of 1018 receives the data from any of the LANs 1019 to 1021, the network interface control section 1013 reports the reception of the data to the protocol control section 1005 by an interrupt request. In response to this, the protocol control unit 1005 receives the received data 101
After performing a predetermined protocol process on 1 to 1012 and storing it in the data reception buffer 1008, the user application 1002 is notified of the data reception. The reception buffer size value at this time is also determined according to the buffer size value set in the protocol control table 1007 in the protocol control unit 1005. After that, the data reception by the user application 1002 is completed, the reception buffer 1008 is released, and the vacancy in the buffer occurs, and then the ACK is transmitted to the transmission source.

FIG. 2 is a diagram showing the detailed structure of the protocol control table in the protocol control unit in FIG. In the figure, the protocol control table 1007 is composed of two types of items, user application type and buffer size. For each user application type, the values of the send buffer size and the receive buffer size are registered in advance prior to communication control. Keep it. Accordingly, when the protocol control unit 1005 receives a transmission request or a reception request from the user application 1002, the protocol control unit 1005 determines the type of the user application, and the transmission buffer size value or the transmission buffer size value corresponding to the user application registered in the protocol control table 1007. Determine the receive buffer size value.

FIG. 3 is a diagram showing a data transmission / reception control sequence in the communication control system of FIG. Less than,
The procedure for determining the transmission / reception buffer size value in this embodiment will be described with reference to FIG. In the figure, the same components as those in FIG. 1 are designated by the same reference numerals, and the description thereof will be omitted.

First, the communication control device on the transmission side performs a connection start process by transmitting predetermined connection data to the communication control device on the reception side (step 300).
1). The receiving side accepts the transmitted connection data (step 3008), and the LAN used at this time
The reception buffer size value registered in the transmission / reception buffer size table 1015 (corresponding to the “buffer size table” in the claims) in the buffer control unit 1014 according to the type of the protocol control table in the protocol control unit 1005. By registering in 1007, the reception buffer size is changed (step 3009). After that, the receiving side transmits ACK data for the connection data to the transmitting side (step 3010). When the transmission side receives the ACK data for the connection data, the transmission side, depending on the type of LAN used,
The transmission buffer size is changed by registering the transmission buffer size value registered in the transmission / reception buffer size table 1015 in the buffer control unit 1014 in the protocol control table 1007 in the protocol control unit 1005 (step 3002). After this, steps 3003 to 3007 on the transmitting side and step 30 on the receiving side
For 11 to 3015, the same data transfer processing as the steps 18001 to 18005 on the transmitting side and the steps 18008 to 18012 on the receiving side in the conventional technique shown in FIG. 18 is performed.

As described above, by registering the transmission / reception buffer size value corresponding to each LAN in the transmission / reception buffer size table 1015 in advance, the LAN in which the transmission / reception buffer values on the transmitting side and the receiving side are used when setting the connection. Since it is appropriately determined according to the type of, it is possible to realize efficient data transfer.

FIG. 4 is a diagram showing the detailed structure of the transmission / reception buffer size table in the network interface control unit in FIG. In the figure, the transmission / reception buffer size table 1015 is composed of two types of items, LAN type and buffer size. For each LAN type, the values of the transmission buffer size and the reception buffer size are set as initial values in advance prior to communication control. This is a table for registration.

FIG. 5 shows the second part of the communication control system of the present invention.
It is a block diagram showing the whole composition of an example.

First, each control block and table constituting the communication control device 5001 in the communication control system of this embodiment will be described. The same components as those in FIG. 1 are designated by the same reference numerals to simplify the description. In FIG. 5, the communication control device 5001 is configured by an information device such as a workstation or a personal computer as in FIG.
9, LAN1020, LAN1021 is connected to perform data transfer with other information devices. The user application 1002 is executed in a memory space (user space) dedicated to the user application provided in the communication control device 5001, and the protocol control unit 500.
5, the data stored in the transmission data area 1003 in the user space is transmitted or the data reception request to the reception data area 1004 is issued. Protocol control unit 500
5, the network interface control unit 5013 is a group of programs for communication control executed in a system space different from the user space. Protocol control unit 50
05 is a transmission buffer 1006 and a reception buffer 10
08 is used to perform data transmission / reception control by a delivery confirmation type protocol. Network interface controller 50
The interface control unit 13 controls the interface between the adapter control units 1016 to 1018 and the protocol control unit 5005 described above. The transmission / reception buffer control unit 5014 is provided in the protocol control unit 5005, and upon completion of the connection processing, the transmission / reception buffer size table 500.
7, the transmission / reception buffer size value is set in the protocol control table 5015.

FIG. 6 is a diagram showing the detailed structure of the network interface table in the network interface control unit in FIG. In the figure, among the elements constituting the network interface table 5016, the LAN identifier 5016a indicates the type of LAN to be connected, and the maximum transfer unit (MTU) 5016b indicates the maximum value of the data size that can be transferred via the LAN. , Respectively. Here, the value of the MTU 5016b differs depending on the type of transmission medium forming the LAN. The network interface table 5016 is created for each connected LAN, and a pointer indicating its location is registered in the protocol control table 5015 during connection processing. The elements other than the above are not particularly related to the present embodiment, and the description thereof will be omitted.

Next, the processing operation in the communication control system of this embodiment will be described. For convenience, the communication protocol used in the communication control system of the present embodiment is TC
P / IP (Transmission Control Protocol / Internet Prot
ocol) will be explained.

FIG. 7 is a diagram showing an example of the format of a data frame transmitted and received on the network. In the figure, LA
A data frame 70 exchanged via N1019 to 1021 is composed of a MAC (Medical Access Control) header 71, a protocol header 72, and user data 73, and has a different format depending on the type of transmission medium.
In the AC header 71, destination address information or the like according to the transmission path is set. Generation and decoding of the MAC header 71 are performed by the adapter control units 1016 to 1021 in FIG. Also, the protocol header 72 is
It is composed of a CP header 721 and an IP header 722, and its generation and decryption are performed by the protocol control unit 50.
It will take place at 05. The user data 73 is arbitrary data used by the user application 1002, and is used by the user application 1002 to the protocol control unit 5.
Passed to 005.

8 and 9 are diagrams showing the detailed structures of the TCP header and the IP header, which are part of the protocol header in FIG. 7, where FIG. 8 is the TCP header and FIG. 9 is the I header.
It is a P header. In FIG. 8, a window area 721a in the TCP header 721 is an area for registering the reception window size (= transmission / reception buffer size),
Upon connection and data transfer, the transmission / reception buffer control unit 5014 reflects the automatically changed setting value of the transmission / reception buffer size in the protocol control unit 5005 in the communication control device on the transmission side or the reception side.

FIG. 10 is a process flow chart showing an example of a buffer size automatic changing process by the transmission / reception buffer control unit in the protocol control unit in FIG. In the figure, when the connection processing by the protocol control unit 5005 ends (step 10002), the transmission / reception buffer control unit 5
014 searches the protocol control table 5015 for a pointer to the network interface table 5016 (step 10003). And
The network interface table 5016 is searched to find a LAN identifier that identifies the LAN being used (step 10004). Finally, the LAN
Transmission / reception buffer size table 500 based on the identifier
7 is searched for the corresponding transmission / reception buffer size (step 10005), and the value of the transmission / reception buffer size is set in the protocol control table 5015 (step 10006).

FIG. 11 is a process flow chart showing another example of the buffer size automatic changing process by the transmission / reception buffer control unit in the protocol control unit in FIG. 5, and the protocol control unit in the communication control device 5001 shown in FIG. Fifty
The processing in the embodiment of the communication control system which determines the buffer size by calculation without using the transmission / reception buffer size table 5007 in FIG. The same components as those in FIG. 5 are designated by the same reference numerals and the description thereof will be omitted.

In FIG. 11, the protocol control unit 500
When the connection process by 5 (step 11002) is completed, the transmission / reception buffer control unit 5014 searches the protocol control table 5015 for a pointer to the network interface table 5016 in the network interface control unit 5013 (step 11003). Next, the network interface table 5016 is searched based on the pointer (step 11004), and the maximum transfer amount of the LAN connected by the communication control is obtained. Then, an appropriate transmission / reception buffer size value is calculated based on the obtained maximum transfer amount (step 11005).

Hereinafter, four kinds of concrete methods for calculating the value of the above-mentioned appropriate transmission / reception buffer size will be described.

[Calculation Method] The transmission / reception buffer size is the upper limit of the amount of data that can be continuously transmitted or received at one time, and the actual storage area is secured in the system space. In order to efficiently handle the data stored in the system space in the current computer system, it is desirable that the size of the data be an integer multiple of 2 to the nth power (n is a positive integer). On the other hand, when transmitting / receiving data between different models, for example, when transmitting data from a communication control device with a large amount of memory for storing the transmission / reception data to a communication control device with a small amount of memory, continuous transmission is performed if the value of the transmit / receive buffer size is too large. Since the number of times of increasing the number of times increases, the probability that the receiving communication control device with a small amount of memory will fail due to lack of the receiving buffer during continuous data reception increases the number of times of continuous transmission. It is desirable to keep it less than once. In the calculation method based on the above policy, step 1
4 times the value of the maximum transfer amount of LAN obtained in 1005
The quotient obtained by dividing by 096 is the value of the transmission / reception buffer size.

[Calculation Method] A value obtained by subtracting the value of the data size of the above-mentioned protocol header from the value of the maximum transfer amount of the LAN is called MSS (Max Segment Size). When transmitting or storing received data in the transmission / reception buffer, processing is performed in units of the above MSS. That is, when data is continuously transmitted from the transmission / reception buffer, the number of continuous transmissions is a quotient obtained by dividing the value of the transmission / reception buffer size by MSS. Therefore, in the calculation method, in order to efficiently perform continuous transmission or continuous reception using the transmission / reception buffer, the value of the transmission / reception buffer size is set to four times the value of the MSS.

[Calculation Method and] In data transmission / reception performed between communication control devices having a large amount of memory for storing transmission / reception data, the number of times continuous transmission or continuous reception is possible at one time is N (N is a positive integer). In the calculation method, N times the quotient obtained by dividing N times the maximum transfer amount by 4096 is used as the value of the transmission / reception buffer size. Further, in the calculation method, the value of the transmission / reception buffer size is N times the value of the MSS.

When the transmission / reception buffer size value is calculated by any of the above-mentioned four types of calculation methods (step 11005), the transmission / reception buffer control unit 5014 sets the transmission / reception buffer size value in the protocol control table 5015. (Step 11006), the buffer size automatic changing process ends.

Next, referring to FIGS. 12 and 13, FIG.
Another example of the automatic buffer size changing process by the transmission / reception buffer control unit in the inside protocol control unit will be described.

FIG. 12 is a diagram showing the detailed structure of the transmission / reception buffer size table in the protocol control unit in FIG. In the figure, a transmission / reception buffer size table 50
07 has components of user application type, LAN type, and buffer size. An identifier of a user application that transfers data is registered in the user application type. In the LAN type, a LAN identifier that can be used for connection with another communication control device at the time of data transfer is registered. In the buffer size, the optimum transmission / reception buffer size corresponding to each user application type and LAN type is registered.

User applications include a large transfer data amount such as a file transfer program (FTP) and a small transfer data amount such as a virtual terminal program (telnet).
For user applications that transfer a large amount of data,
As the number of continuous transmissions at one time increases, the number of delivery confirmation processes decreases, and the data transfer efficiency improves. That is,
By setting the value of the transmission / reception buffer size to be large, the data transfer efficiency is improved. On the other hand, a user application with a small amount of transfer data does not need such a large send / receive buffer. Based on the above,
By including the user application type in the constituent elements of the send / receive buffer size table, it is possible to automatically change the send / receive buffer size according to the data transfer amount of the user application. It is possible to make the data transfer efficiency more detailed.

FIG. 13 is a process flow chart showing still another example of the buffer size automatic changing process by the transmission / reception buffer control unit in the protocol control unit in FIG.
The flow of the transmission / reception buffer size automatic changing process using the transmission / reception buffer size table 5007 shown in FIG.
In the figure, when the connection processing (step 13002) by the protocol control unit 5005 is completed, the transmission / reception buffer control unit 5014 displays the protocol control table 5015.
For network interface control unit 501
A pointer to the network interface table 5016 in 3 is obtained (step 13003). Next, based on the pointer, the network interface table 5016 is searched (step 13004) to obtain the LAN identifier of the LAN connected by the communication control. Then, based on the LAN identifier and the user application identifier, the transmission / reception buffer size table 5
007 is searched (step 13005). And
The value of the corresponding transmission / reception buffer size is set in the protocol control table 5015 (step 13006), and the buffer size automatic changing process is terminated.

FIG. 14 is a diagram showing a control sequence of data transmission / reception in the communication control system of FIG. 5, and shows a control sequence when data is transferred from the transmission side of the connection data to the reception side. In the figure, when the communication control device on the reception side receives the connection data from the communication control device on the transmission side (step 14009), it changes the value of the reception buffer size of its own station and the transmission / reception buffer in the protocol control table 5015. The size value is changed (step 14010). Then, the connection confirmation response frame is transmitted to the communication control device on the transmitting side (step 14011). At this time, the Window value 721a in the TCP header 721, which is a part of the data frame 70 flowing on the transmission medium shown in FIGS. 7 to 9, is changed to the changed reception buffer size value. The communication control device on the transmitting side receives the connection confirmation response frame and performs connection termination processing (step 1400).
2) Change the transmission / reception buffer size value in the protocol control table of the own station (step 14003). Then, according to the changed value of the transmission / reception buffer size, the data in the transmission data area 1003 in the user application 1002 is transferred to the protocol control unit 5005.
Copy to the send buffer 1006 inside (step 140
04), data transmission is continuously performed (step 1400).
5-step 14006). At this time, the TCP header 721 in the data frame 70 in each data transmission
The Window value 721a therein is changed to the reception buffer size value after the change.

Next, TCP / IP is used as a delivery confirmation type protocol.
(Transmission Control Protocol / Internet Protoco
The dynamic window control in the communication control device that adopts l) will be described.

FIG. 15 shows the communication control system of the present invention as a TC.
FIG. 1 is a block diagram showing an overall configuration of a client / server system (hereinafter abbreviated as “CSS”) applied to a P / IP multi-LAN. In the figure, the communication control device 1
5001 adopts TCP / IP as a delivery confirmation type protocol, and a user application 15002 that transfers data with another communication control device, a network interface control unit 15013, an adapter control unit 1510.
It is composed of 0 to 15300. The communication control device 15001 includes an FDDI 15101 and a Fast Ethernet 1520.
1, under the multi-LAN environment connected to the Ethernet 15301 and the like, control of data transfer is performed with various servers and workstations 15101 to 15202 or communication control devices such as the personal computer 15302 connected thereto. The virtual terminal program (telnet) described above is a specific example of the user application 15002 for data transfer.
And a file transfer program (FTP).
The format of the data frame exchanged on the LAN by the data transfer at this time is as shown in FIGS. 7 to 9, and the window area 72 in the TCP header 721 is shown.
The data stored in 1a indicates the upper limit of the amount of data that can be continuously transmitted or continuously received at a time with the LAN.

FIG. 16 is a diagram showing an example of specific numerical values set in the transmission / reception buffer size table in the protocol control unit in FIG.
16 automatically changes the value in the Window area 721a in the TCP header 721 of each data frame 70 according to the transmission / reception buffer size table as shown in FIG. 16 after the connection processing. That is, by defining the transmission / reception buffer size table in advance as shown in FIG. 16, it is possible to dynamically control the initial value of the window size according to the maximum transfer amount (MTU) of the LAN, the transmission rate, the AP type, and the like. it can.

As described above, according to the embodiment of the communication control system described above, each L is stored in the buffer size table.
By registering the transmission / reception buffer size value according to the transmission medium constituting the AN in advance, the transmission / reception buffer size is automatically changed according to the transmission capacity of the transmission medium, etc., so that continuous data transmission / reception is performed. It is possible to realize data transfer processing with optimum efficiency according to the maximum transfer amount of the LAN to be used.

At this time, the more the number of times of continuous transmission at one time is registered, the smaller the number of delivery confirmation processes becomes, and the data transfer efficiency can be further improved.

If a large transmission / reception buffer size value for a transmission medium with a large maximum transfer amount and a small transmission / reception buffer size value for a transmission medium with a small maximum transfer amount are registered in the buffer size table, LAN
It is possible to make the data transfer efficiency almost constant regardless of the type of transmission medium constituting the.

Furthermore, due to these effects, FDDI and Ether
Networks with different maximum transfer rates such as rnet, and Ether
Even for networks with different transmission speeds such as rnet and Fast Ethernet, and applications with different average transmission data amounts such as telnet and FTP, data transfer that maximizes the LAN transmission performance can be performed.

The communication control system of the present invention is also applicable to an ATM-LAN in which the size of MTU is determined after negotiation is performed between the communication control devices.
When performing data communication between the communication control devices connected to the M-LAN, the window size is automatically changed according to the performance of the communication control device.

[0055]

As described above in detail, according to the communication control system of the present invention, the transmission / reception buffer size value corresponding to the transmission medium constituting each LAN is registered in the buffer size table in advance. Since the transmission / reception buffer size is automatically changed according to the transmission capacity of the transmission medium and the continuous transmission / reception of data is performed, the data transfer processing with optimum efficiency can be realized according to the maximum transfer amount of the LAN to be used. The effect that can be obtained is obtained. At this time, as the number of times of continuous transmission at one time is registered, the number of times of delivery confirmation processing decreases, and the effect that the data transfer efficiency can be further improved is obtained. If a large transmission / reception buffer size value is registered in the buffer size table for a transmission medium having a large maximum transfer amount and a small transmission / reception buffer size value is registered for a transmission medium having a small maximum transfer amount, L
There is an effect that the data transfer efficiency can be made almost constant regardless of the type of the transmission medium forming the AN. Furthermore, due to these effects, networks with different maximum transfer rates such as FDDI and Ethernet, and Ethernet and Fa
Networks with different transmission speeds such as stEthernet,
Even for applications such as telnet and FTP that have different average transmission data amounts, it is possible to perform data transfer that maximizes the transmission performance of the LAN.

[Brief description of drawings]

FIG. 1 is a block diagram showing an overall configuration of a first embodiment of a communication control system of the present invention.

FIG. 2 is a diagram showing a detailed configuration of a protocol control table in a protocol control unit in FIG.

3 is a diagram showing a control sequence of data transmission / reception in the communication control system of FIG.

FIG. 4 is a diagram showing a detailed configuration of a transmission / reception buffer size table in a network interface control unit in FIG.

FIG. 5 is a block diagram showing an overall configuration of a second embodiment of the communication control system of the present invention.

FIG. 6 is a diagram showing a detailed configuration of a network interface table in a network interface control unit in FIG.

FIG. 7 is a diagram showing an example of a format of a data frame transmitted and received on a network.

8 is a part of the protocol header in FIG. 7 TCP
It is a figure which shows the detailed structure of a header.

9 is a diagram showing a detailed configuration of an IP header which is a part of the protocol header in FIG.

10 is a process flow chart showing an example of a buffer size automatic changing process by a transmission / reception buffer control unit in the protocol control unit in FIG.

11 is a process flowchart showing another example of the buffer size automatic changing process by the transmission / reception buffer control unit in the protocol control unit in FIG.

12 is a diagram showing a detailed configuration of a transmission / reception buffer size table in the protocol control unit in FIG.

13 is a process flow chart showing still another example of the buffer size automatic changing process by the transmission / reception buffer control unit in the protocol control unit in FIG.

14 is a diagram showing a control sequence of data transmission / reception in the communication control system of FIG.

FIG. 15 is a block diagram showing an overall configuration of a client server system in which the communication control system of the present invention is applied to TCP / IP multi-LAN.

16 is a diagram showing an example of specific numerical values set in a transmission / reception buffer size table in the protocol control unit in FIG.

FIG. 17 is a block diagram showing a configuration example of a conventional communication control system.

FIG. 18 is a diagram showing a control sequence of data transmission / reception in the conventional communication control system.

[Explanation of symbols]

1001, 5001, 15001 Communication control device 1002, 15002 User application program 1003 Transmission data area 1004 Reception data area 1005, 5005, 15005 Protocol control unit 1006 Transmission buffer 1007, 5015 Protocol control table 1008 Reception buffer 1013, 5013 Network interface control unit 1014 , 5014 Buffer control unit 1015, 5007 Transmission / reception buffer size table 1016-1018, 15100-15300 Adapter control unit 1019-1021 LAN

Claims (7)

[Claims] 1. In a communication control system connected to a plurality of types of networks and performing data transfer processing by a delivery confirmation type protocol, at the time of starting the data transfer processing, the upper limit of the amount of data that can be collectively processed in one transmission / reception sequence. The communication control system is characterized in that a buffer control unit for setting a buffer size for defining the above is set according to an environmental condition in the data transfer process. 2. In a communication control system which is connected to a plurality of types of networks and performs data transfer processing by a delivery confirmation type protocol, a corresponding buffer size value is defined in advance for each of various environmental conditions in the data transfer processing. A buffer size table, and at the start of the data transfer process, after identifying an environmental condition in the data transfer process, a buffer control unit that sets a buffer size corresponding to the environmental condition based on the buffer size table; A communication control system characterized by being provided with. 3. The specific contents of the environmental conditions include a maximum transfer amount of a transmission medium of a network used for the data transfer processing, a type of the network, a transmission speed in the network, and a user accompanying the data transfer processing. The communication control system according to claim 1 or 2, wherein the type of application, the size of data transmitted from the user application, and the like. 4. The buffer control unit and the buffer size table are provided in a network interface control unit, wherein the buffer control unit uses a specific network used for the data transfer process at the start of the data transfer process. After determining the type of the network by determining the type of the adapter control unit that performs input / output control between the and, the buffer size corresponding to the type of the network is set based on the buffer size table. The communication control system according to claim 2. 5. The buffer control unit and the buffer size table are provided in a protocol control unit, and the buffer control unit refers to a network interface table in the network interface control unit when starting the data transfer process. 3. The communication control according to claim 2, wherein after determining the type of a specific network used in the data transfer process in step S1, the buffer size corresponding to the type of the network is set based on the buffer size table. system. 6. A configuration in which the buffer control unit is provided in a network interface control unit, wherein the buffer control unit inputs / outputs data to / from a specific network used for the data transfer process at the start of the data transfer process. After determining the type of the network and the maximum transfer amount of the transmission medium of the network by determining the type of the adapter control unit that performs control, the buffer size is calculated based on the type of the network calculated from the maximum transfer amount. The communication control system according to claim 1, wherein the communication control system is set. 7. The buffer control unit is provided in a protocol control unit, and when the buffer control unit starts the data transfer process, the buffer control unit refers to a network interface table in the network interface control unit to perform the data transfer process. After determining the type of specific network used and the maximum transfer amount of the transmission medium of the network,
2. The communication control system according to claim 1, wherein the buffer size is set based on the type of the network that is calculated from the type of user application accompanying the data transfer process and the maximum transfer amount.