JP2000253056A - Transmission band controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To control an oscillation band where a transfer device connected to a network performs data transfer by allowing a data transfer means to calculate a cycle in which data should be transferred from request band information designating data quantity to be transmitted within a certain prescribed time and fixed data quantity and instructing the calculated value to the data transfer means. SOLUTION: A protocol processing part 11 divides transmission data stored primarily in a data buffer 12 into packets and adds a header to each divided packet. Such packet generation processing is performed for all transmission data and the size of data to be transmitted is instructed to a data transfer part 13. The buffer 12 stores the transmission data temporarily and executes operations such as the writing of data designated from the part 11 and reading of data designated from the part 13. The part 13 reads data quantity which is instructed from a transmission band instructing part 16 and transferred at a time and transfers it.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to data transfer performed by a plurality of data transfer devices sharing a network, and more particularly to transmission band control for controlling a transmission band in which data transfer devices connected to a network transfer data. Related to the device.

More specifically, the present invention relates to a network
Regardless of the type of interface, the present invention relates to a transmission band control device for performing data transfer without an error between a requested transmission band and an actual transmission band. The present invention relates to a transmission band control device for performing shaping that eliminates an error between a requested transmission band and an actually transmitted transmission band, regardless of an interface method.

[0003]

2. Description of the Related Art Two or more data transfer devices (DTE: Data Terminal Eq.)
Research and development on "data communication" for exchanging data between devices have been actively performed. The main significance of such data communication lies in sharing computer resources and sharing and distributing information.

[0004] Here, each data transfer device connected to the network is essentially a communication terminal constituted by dedicated hardware, or a general-purpose computer system (for example, a workstation or a personal computer) into which communication software is introduced. ). Each data transfer device is connected to a line termination device (DCE: Data Cir).
It is connected to a network via a "quit Terminal Equipment".

As a communication medium for connecting the data transfer devices, a LAN (Local Area) is used.
Network (WAN) that is configured by connecting two or more LANs with a dedicated line
There is a wide variety of things, such as a wide area such as ide Area Network (PSTN) and a general public telephone line (PSTN), and even the "Internet" which has become a huge network worldwide as a result of interconnection between servers.

[0006] If the communication medium is an analog line such as PSTN, DCE is a modem / Decoder.
modulator). Also, ISDN (Int
Egrated Services Digital
Network), the DCE is a TA (Terminal Adapter) and a DSU (Digital Service).
ce Unit). In the case of a LAN, the DCE is a network interface card (NIC).

The NIC is generally mounted in the form of a so-called “adapter card”, and is used by being mounted in a bus slot on a motherboard of a computer system that performs data transfer.

[0008] A network is typically shared by a number of data communication devices. When a network is occupied for data exchange between certain data communication devices, other data transfer devices cannot perform communication during that time (for example, while data or messages are interrupted). . Therefore, packet communication has been devised and widely used as a communication method for realizing a plurality of communications by a plurality of data transfer devices.

In packet communication, data passing through a network is treated as data of a predetermined length called a "packet". According to the packet switching method, the transmission data is intermittent, so that the network can be shared, and the transmission line is not occupied for a long time by the communication between the specific data transfer devices. The packet includes, in addition to the data body, protocol control information for correctly transporting the packet over the network as a header or a trailer. It should be noted that data communication via a network can be performed by each data transfer device performing communication processing according to a predetermined communication protocol.

By the way, recently, Q
The concept of oS (Quality of Service) has begun to be introduced. QoS in a network is composed of three elements: an error rate, a delay, and a band. In terms of the bandwidth, the data transfer device on the transmission side has to transmit data in accordance with the transmission band required by the network or the reception side.

For example, as shown in FIG. 6, in a network system that performs scheduling by time and bandwidth when a plurality of clients request data transfer to the same server at the same time, accuracy is low in terms of communication cost. It is becoming essential to control the transmission band well. Such transmission band control is generally called "shaping".

Also, as shown in FIG.
The above-described shaping is also required when data is transferred between networks having different physical medium bandwidths, such as data transferred to N.

As a shaping method, a credit control method and a rate control method are widely known in the art. Hereinafter, these methods will be described.

The credit control method is a method of controlling the transmission band according to "credit", that is, the free space of the packet reception buffer. The data transfer device on the receiving side notifies its credit to the transmitting side sequentially. The data transfer device on the transmission side limits the number of continuous transmissions of data packets (that is, the maximum window size) to less than the credit, and subtracts the credit for the transmission packets to continuously transmit packets exceeding the size of the packet reception buffer. Do not send.

In the rate control method, the amount of data that can be transmitted per unit time is determined before the start of data transfer or during data transfer, and the transmitting side transmits data over a determined data amount (ie, rate). This is a method of controlling the transmission band by not transmitting.

On the other hand, a data transfer device connected to a network is generally configured using a general-purpose computer system (described above). This type of general-purpose computer system includes an arithmetic unit that can execute data communication processing and other various application processing. This arithmetic unit is, for example, a CPU (Central Processing Unit).
nit). In addition, the arithmetic unit usually has a memory for loading an execution program code and temporarily storing work data, which is provided locally to the CPU. FIG. 8 schematically illustrates a hardware configuration of a data transfer device connected to a network. Hereinafter, this figure will be described.

Inside the computer, the arithmetic unit and the adapter card and other peripheral devices are interconnected via a common transmission path called a bus.

The arithmetic unit includes a protocol processing unit for performing a predetermined protocol process for network connection, and a data buffer for temporarily storing transfer data. However, these are physically the same as the communication protocol entity executed in the CPU and the local
It should be understood to mean a program load area and a transfer data storage area allocated on the memory.

One example of a peripheral device connected to the bus is a network interface card (NIC) for establishing a network connection. As shown, two or more NICs may be provided on one host computer.

Another example of the peripheral device is a disk interface card for connecting a disk-type mass storage device such as a hard disk device. In the industry, IDE (Integrated Drive)
Electronics) and SCSI (Small C)
output System Interface)
Is a standard disk interface standard. A hard disk device or the like is provided locally on the disk interface card.

As shown in FIG. 8, the network interface card includes a data transfer unit, a transmission data buffer, and a data transmission unit. The data transfer unit generally controls processing operations on the card, such as reception of transmission data from the operation unit, transmission of reception data, and transmission of transmission data temporarily stored in a transmission data buffer. The transmission data buffer is a buffer for temporarily storing the transmission data transmitted from the operation unit. The data transmitting section transmits the transmission data in the transmission data buffer in synchronization with the clock of the transmission line.

In a computer system having such a hardware configuration, data input / output between a memory and a peripheral device is often performed by a DMA (Direct Memory Access) so as not to waste processing resources of an arithmetic unit.
ss) method. For example, the above-described data transfer unit in the NIC has a so-called “bus master” function, and a memory (that is, a data buffer in the arithmetic unit) is used to transfer data from the NI.
Data transfer to the transmit data buffer in C
It can be performed in a system, that is, without the intervention of an arithmetic unit. During the DMA transfer, the processing resources of the operation unit are used for other processing.

As a function of such a data transfer device,
The data size that can be transferred to the network at one time and the transfer cycle are set according to the characteristics of the connected network interface.

Here, after considering the above-described DMA transfer function of the host computer, transmission band control on the network, that is, shaping will be considered again.

As an example of credit control, TCP (T
transmission Control Proto
col) protocol using flow control. Hereinafter, a shaping method by credit control will be described with reference to FIG.

In the data transfer device on the transmitting side, first,
The protocol processing unit in the arithmetic unit divides the transmission data stored in the data buffer unit into packets,
Further, protocol control information is added to each packet (hereinafter, protocol control information is added as a "header" to the data body of the packet). The protocol control information includes the order in which the transmission data is divided, that is, the sequence number (well-known).

Next, the protocol processing unit instructs the data transfer unit to transfer the generated packet from the data buffer in the operation unit to the transmission data buffer. The data transfer unit performs the designated data transfer by the DMA transfer method.

Incidentally, the flow control in the TCP protocol is based on the sequence control based on the acknowledgment number. That is, when the data transfer device on the receiving side successfully receives a packet, it returns an acknowledgment (ACK) packet including an acknowledgment number obtained by adding 1 to the sequence number (described above) of the packet. The data transfer device confirms that the packet has arrived correctly based on the received acknowledgment number.

Further, since the data transfer is not efficient in the sequential control based on the sequential acknowledgment numbers, the data transfer device on the transmitting side collectively transmits some packets and one receiving side collectively confirms the delivery. The method of performing is also adopted. The amount of data that can be continuously transmitted without acknowledgment is predetermined between the data transfer devices on the transmission side and the reception side (usually specified in a TCP header),
This is called "window size".

When the packet is transferred to the transmission data buffer, the data transmission section extracts the packet and sends it to the network in synchronization with the clock of the transmission line.
At this time, the size of the packet is the maximum length (MTU (Maximum Tr) allowed on the network.
In other words, if the transmission data exceeds the size of the transfer unit (transmission unit size), the transmission data may be further divided and transmitted (so-called “fragmentation.” Fragmentation is performed by IP (Internet Protocol).
l)).

The data transfer device on the receiving side performs error checking on packets received continuously. If the received packet is normal, an acknowledgment (ACK) including information on the amount of data that can be received is sent to the transmitting data transfer device. In the data transfer device on the receiving side, this error
For the checking operation, it is necessary to have a function of monitoring the data transfer amount per unit time and calculating the remaining data transfer amount from the data transfer amount and the required bandwidth.

On the other hand, in the transmission-side data transfer device that has received the acknowledgment, the protocol processing unit performs acknowledgment (ACK)
The packet to be transmitted next is divided and a header is added according to the amount of receivable data included in the packet. Then, the next packet transfer request is made to the data transfer unit.

As described above, the acknowledgment (AC) notified from the receiving data transfer device to the transmitting data transfer device is performed.
Shaping is performed by controlling the cycle of returning K) and the amount of data that can be transmitted.

Next, a shaping method by the rate control method will be described.

In the rate control method, the data is shaped into a band determined in advance by the network interface. For example, ATM (Asynchronous T)
A data flow (in the case of the ATM, the transfer mode is the same as that of the transfer mode) in which the transmission cycle of the minimum transfer data unit (called the "cell" in the case of the ATM) can be changed. , VPI
(Virtual path identifier) / VCI (virtual channel identifier))
A transmission buffer is provided for each. Then, shaping is realized by removing cells from the transmission buffer and changing the transmission cycle.

For example, Japanese Patent Application Laid-Open No. 6-276209 discloses a plurality of VPs (virtual paths) or VCs (virtual channels).
Discloses a traffic shaping device in an ATM network that handles the traffic.

This traffic shaping device is:
An ATM cell memory for temporarily storing cells input to the line until transmission is possible;
An output timing discriminator for discriminating a time outputted from C, a read control memory for storing cells outputted at each time, and a clock indicating the current time are provided.

At the time of cell input, at the same time as writing to the ATM cell memory, the output timing discriminator determines the time at which the cell is to be output from the current time determined by the characteristics and history set corresponding to VP or VC. Judge,
The cell read information for reading the cell corresponding to the determined time is written in the read control memory, and the readable cell is detected by the read control memory using the current time information of the clock unit,
The detected cell is read from the ATM cell memory.

According to this traffic shaping device, by determining the output time in advance at the time of cell input in the ATM network, there is no need to determine whether or not transmission is possible to a plurality of VPs or VCs at the same time. The configuration can be simplified.

This method will be described below with reference to FIG. In this method, in addition to the procedure described in the credit control, a request rate monitoring unit that monitors reception of rate information notified from the receiving device and notifies the transmission band instruction unit of the rate information, The shaping is realized by further converting the rate into a transmission cycle and further including a transmission band instructing section for activating the data transmission / reception section in the cycle.

However, in the former shaping using credit control, the data transfer amount per unit time is monitored for the data transfer device on the receiving side, and the remaining data transfer amount is calculated from the data transfer amount and the required bandwidth. A new function to perform the above-mentioned functions is required, or another device having the above-mentioned functions is required. In other words, a rise in costs is inevitable for shaping.

Further, the data transfer device on the transmission side controls the communication protocol processing by software in order to use the existing mechanism. Therefore, accurate shaping control as controlled by hardware is not required.

Also, the network interface A
A network interface that does not have a function to change the transmission cycle such as TM, for example, Ethernet
(Registered trademark of US XEROX Corporation), a shaping function must be newly added. Adding a function inevitably leads to an increase in cost.

In the case of the latter rate control, it is monitored that the rate information notified from the receiving device has been received,
It is necessary to further include a request rate monitoring unit for notifying the rate information to the transmission band instruction unit, and a transmission band instruction unit for converting the notified rate into a transmission cycle and activating the data transmission / reception unit in the cycle. In addition, when it is desired to change the transmission band value for each data path, a buffer for temporarily storing transmission data is provided for each data path. That is, also in this case, the cost is inevitable.

[0045]

SUMMARY OF THE INVENTION An object of the present invention is to provide an excellent transmission band control device capable of controlling a transmission band in which data is transferred by a data transfer device connected to a network.

A further object of the present invention is to provide an excellent transmission band control device capable of performing data transfer without error between a requested transmission band and an actual transmission band regardless of the type of a network interface. Is to do.

A further object of the present invention is to provide an apparatus for temporarily storing transmission data without increasing the number of buffers, and irrespective of the type of the network interface, to determine the difference between the requested transmission band and the actually transmitted transmission band. An object of the present invention is to provide an excellent transmission band control device capable of performing shaping that eliminates the problem.

[0048]

The present invention has been made in consideration of the above problems, and a first aspect of the present invention is a transmission band for controlling a transmission band in a data transfer device connected to a network. A control device, a data buffer for temporarily storing transmission data, a data transmission unit for adding predetermined protocol information to the transmission data and transmitting the transmission data on the network, and a data buffer between the data buffer and the data transmission unit. A data transfer unit that performs data transfer at a predetermined cycle for each fixed data amount and that can change the data amount and the cycle; and a request bandwidth information specifying a data amount to be transmitted within a predetermined time and the fixed data amount. A transmission band instructing unit for calculating a period in which the data transfer unit should transfer data and instructing the calculated value to the data transfer unit. It is a transmission bandwidth control device according to claim.

A second aspect of the present invention is a transmission band control device for controlling a transmission band in a data transfer device connected to a network, comprising: a data buffer for temporarily storing transmission data; Data transmission means for adding predetermined protocol information to data and transmitting the data on the network; and performing data transfer between the data buffer and the data transmission means at a predetermined period for each predetermined data amount, A predetermined data amount to be transferred by the data transfer means from the required band information designating the amount of data to be transmitted within a certain predetermined time and the predetermined period, and calculating the calculated value. And a transmission band instructing means for instructing the data transfer means.

The transmission band control device according to each of the first and second aspects of the present invention receives requested band information from another device connected to the network and notifies the data transfer means of the presence or absence of the received data. The apparatus may further include a receiving unit and a data buffer for temporarily storing received data. Further, the transmission band instructing means may extract required bandwidth information from the received data stored in the data buffer, and instruct the data transfer means with a fixed data amount and a predetermined cycle.

Further, in the transmission band control device according to the first aspect of the present invention, the transmission band instructing means corrects the calculated cycle in consideration of a ratio between the data body to be transmitted and the protocol control information. And instruct the data transfer means.

Further, in the transmission band control device according to the second aspect of the present invention, the transmission band instructing means considers a ratio of a data body to be transmitted and protocol control information to a calculated constant data amount. Then, the correction may be performed, and the data transfer unit may be instructed.

Further, in the transmission band control device according to each of the first and second aspects of the present invention, the data transfer device has a user interface for receiving a user input,
The transmission band instruction means extracts required band information from data input from the user interface,
You may make it instruct | indicate the fixed data amount and period to the said data transfer means. This can be applied to a case where the user knows in advance that a network with a narrow band exists on the data transfer path.

Further, in the transmission band control device according to each of the first and second aspects of the present invention, the data transfer device can execute an application, and the transmission band instructing means is notified from the application being executed. Requested bandwidth information may be extracted from the received data, and the data transfer means may be instructed to have a fixed data amount and a fixed cycle. This can be applied to a case where an application knows in advance that a network with a narrow band exists on a data transfer path.

Further, in the transmission band control device according to each of the first and second aspects of the present invention, a plurality of data transfer means for transferring data between the data buffer and the data transmission means are provided. A plurality of transmission band designating means for designating a transmission band for each of the data transfer means may be provided. For example, by providing a plurality of sets of data transfer means and transmission band designating means for each data path, shaping according to each data path can be performed.

[0056]

The data transfer unit mounted on the network interface card controls operations on the card, such as data transmission / reception via the network and data transmission / reception to / from the host receiving the card, that is, the data transfer device itself. This is a module that is controlled dynamically.

The data transfer unit has conventionally been provided with a function for changing the amount of data that can be transferred within a certain time and the cycle thereof. This change feature was originally
It is provided for versatility. For example, when a data transfer device incorporating a network interface also incorporates another interface operating at the same time, the data transfer device is provided in order to avoid a bus conflict between the two and not to hinder the performance. Further, the data transfer cycle is accurately engraved because a bus clock is used.

The present invention utilizes such a change function of the data transfer unit to perform shaping on a requested transmission band without error without increasing a transmission data buffer for temporarily storing transmission data. It is possible.

More specifically, the required bandwidth input means notifies the required bandwidth passed from outside to the transmission data amount designating means. The transmission data amount instructing means calculates the amount of data to be transferred at one time and the transfer cycle based on the required bandwidth, and instructs the data transfer means.

On the other hand, the transmission data is temporarily stored in the data buffer after the protocol processing is performed. The data transfer means receives a notification that the transmission data has been stored in the data buffer. Further, the data transfer means transfers the transmission data in the data buffer to the data transmission means in accordance with an instruction on the data amount and the transfer cycle instructed by the transmission data amount instruction means. The data transmitting means transmits the data to the network when receiving the data.

According to the above operation procedure, data can be transferred in the requested band.

According to the present invention, the error between the required transmission band and the actual transmission band can be suppressed to the amount of data that can be transferred to the minimum unit of the hardware clock. Such an operation and effect can be achieved by adding the transmission band instruction means, and there is no need to increase the buffer for temporarily storing transmission data.

The transmission band indicating means according to the present invention comprises:
Since the function is added to a portion that is not related to the network interface, it can be easily applied to any network interface.

Still other objects, features and advantages of the present invention are:
It will become apparent from the following more detailed description based on the embodiments of the present invention and the accompanying drawings.

[0065]

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

FIG. 1 schematically shows a configuration (first embodiment) of a network system 100 provided for implementing the present invention. The network system 100 includes a network 1 as a data transmission medium, and two or more data transfer devices 10A,
10B...

The data transfer devices 10 A are connected via a network interface card (NIC) 20
Connected to the network. In addition, each data transfer device 1
.. 0A, 10B... Can perform data transmission and reception via the network 1 by performing processing according to a predetermined communication protocol. The standard model of such a communication protocol is OSI (Open Systems Inte
rconnection: interconnection between open systems)
Basic reference model. The OSI basic reference model is composed of seven layers: a physical layer, a data link layer, a network layer, a transport layer, a session layer, a presentation layer, and an application layer (well-known). Incidentally, the above-mentioned TCP protocol corresponds to the transport layer, and the IP protocol corresponds to the network layer.

Each of the data transfer devices 10A, 10B,... Connected to the network 1 is generally constructed by introducing communication software into a general-purpose computer system called a "workstation" or "personal computer".

A general-purpose computer system of this kind is:
In addition to an operation unit that can execute data communication processing and other various application processing, memory for loading execution program code and temporarily storing work data, display as user interface, keyboard and mouse, external storage Hard disk drive (HDD) and floppy disk drive (FD)
D) and a CD-ROM drive. The arithmetic unit and these peripheral devices are interconnected via a common signal transmission path called a bus. However, these hardware components are well known to those skilled in the art, and FIG.
A ... are not specifically shown.

In the present embodiment, the arithmetic unit comprises a protocol processing unit 11 for executing predetermined communication protocol software.
Function as

The data transfer device 10A of the present embodiment
Is a transmission band control device 3 for controlling a transmission band in which a data transfer device connected to a network transfers data.
Contains 0. The transmission band control device 30 includes a data buffer 12, a data transfer unit 13, a data transmission unit 14, a required band input unit 15, and a transmission band instruction unit 16. The data transfer unit 13 and the data transmission unit 14 are mounted on a network interface card (NIC) 20 as shown in the figure. Hereinafter, each block constituting the transmission band control device 30 will be described.

The data buffer 12 is a device for temporarily storing data to be transmitted,
3 outputs the data requested by the read request. The substance of the data buffer 12 is, for example, a memory locally provided in the arithmetic unit (CPU).

The data transfer unit 13 is a device for generally controlling the operation in the NIC 20. The data transfer unit 13 according to the present embodiment transmits the transmission data buffer 1 according to the transfer data length notified from the transmission band instruction unit 16 (described later).
2 and reads the data from the data transmission unit 1
Transfer to 4. In addition, this data read operation is executed by the number of repetitions in accordance with the data transfer cycle notified from the transmission band instruction unit 16.

The data transmission unit 14 adds protocol control information to the data transferred from the data transfer unit 13 and transmits the data to the network 1 in synchronization with the clock of the transmission line.

The requested band input unit 14 receives requested band information specifying the amount of data that can be transmitted in time from outside the transmission band control device 30, and notifies the transmission band instruction unit 16 of this. I have. Requested bandwidth information is, for example,
It is described in a format such as an amount of data that can be transmitted per second for transmission by the data transmission unit 14 or a transmission cycle of a minimum data unit transmitted over the network 1. The required bandwidth information used here may be statically stored from the start of the system.

Transmission band instructing section 16 requests bandwidth input section 1
5, one transfer data length according to the band notified from 5,
The data transfer cycle and the number of repetitions are calculated according to the following [Equation 1], and the calculation result is notified to the data transfer unit 13.

[0077]

## EQU1 ## B [Mbps] = L [bits] × 100
0000 / R [μs]

Here, B is the required bandwidth, L is the amount of data transferred by the data transfer unit 13 at one time, and R is the data transfer unit 13
Indicates the data transfer cycle, and the requested bandwidth is expressed in Mbps.

For example, if a transfer data amount is 64 bits and a bandwidth of 64 Mbps is required, the transfer cycle is 1 microsecond.

When transmitting a packet to the network 1, protocol control information such as header information for specifying a transmission destination and trailer information for detecting an error in data to be transmitted is added to the packet. The transmission band instructing unit 16 may perform the correction in consideration of the data amount of the protocol control information. For example, when header information and trailer information are added by 100 bytes in total to 1000-byte data, the transmission cycle may be increased by 10%.

Next, a data transmission operation by the data transfer device 10A will be described.

First, the protocol processing unit 11
The transmission data temporarily stored in the buffer 12 is divided into packets, and a header is added to each divided packet.
Such packet generation processing is performed for all transmission data, and the size of data to be transmitted is determined by the data transfer unit 13.
To instruct. Note that the entity of the protocol processing unit 11 is a CPU (Cen) that executes a communication protocol processing program.
(Tral Processing Unit).

The data buffer 12 temporarily stores transmission data, and executes operations such as writing data specified by the protocol processing unit 11 and reading data specified by the data transfer unit 13.

The data transfer unit 13 includes a transmission band instructing unit 16
The amount of data to be transferred at one time specified by
The data is read from the buffer 12 and is read from the subsequent data transmission unit 14.
Transfer to Further, the data reading process is performed in the cycle specified by the transmission band specifying unit 16 by the amount of data specified by the protocol processing unit 11.

The data transmission section 14 transmits the transmission data transferred from the data transfer section 13 onto the network 1 in synchronization with the clock of the transmission line.

FIG. 2 shows an example in which the transmission band control device 30 inputs required band data. As described above, the general-purpose computer system that constitutes the data transfer device 10 usually includes a user interface 17 such as a mouse, a keyboard, and a display as standard. In the example shown in FIG. 2, the required bandwidth is determined based on the requested transfer data notified from the user interface 17.

The method shown in FIG. 2 can be applied, for example, when the user knows in advance that there is a narrow band network on the data transfer path.

FIG. 3 shows another embodiment in which the transmission band control device 30 inputs required band data. A general-purpose computer constituting the data transfer device 10
In the system, various applications are executed in addition to the communication protocol processing. In this embodiment, the requested bandwidth data is notified from the application 18 positioned at the upper level of the protocol processing.

The method shown in FIG. 3 can be applied, for example, when the application 18 knows in advance that a network with a narrow band exists on the data transfer path.

FIG. 4 schematically shows a configuration of a transmission band control device 30 according to the second embodiment of the present invention.

As shown in the figure, the transmission band control device 30 includes a plurality of data transfer units 13-1, 13-2,.
13-n, and a plurality of transmission band indicating sections 16-1, 16-2,..., 16-n corresponding to the respective data transfer sections. However, the configurations of the individual data transfer units 13-1 and the transmission band instructing units 16-1 may be substantially the same as those of the first embodiment shown in FIG.

For example, the data transfer unit 1 for each data path
.. and a plurality of sets of the transmission band designating sections 16-1... Enable shaping according to each data path. In this case, the requested bandwidth instructing unit 15 determines which data path the input requested bandwidth data indicates to which data path, and determines the transmission bandwidth instructing unit 1 corresponding to the data path.
6 and so on. Then, the transmission band instructing section 16 ...
Is the same as in the first embodiment shown in FIG.
The data amount and the period are calculated, and the corresponding data transfer unit 13 is calculated.
.. May be notified of the calculation result.

Data buffer 12 and data transmission unit 14
Has a configuration and operation characteristics similar to those of the above-described first embodiment, and thus can support a plurality of data paths.

FIG. 5 schematically shows a configuration of a transmission band control device 30 according to the third embodiment of the present invention.

As shown in FIG. 5, in this embodiment, the requested band data is notified from another data transfer device connected via the network 1. The data transfer device referred to here is specifically a data transfer device on the receiving side.

Requested band data notified from the network or another data transfer device connected to the network is received by the data receiving unit 19. The data receiving unit 19 notifies the data transfer unit 13 that the requested band data has been received.

The data transfer unit 13 transfers the requested bandwidth data to the data buffer 12.

The protocol processing unit 11 analyzes the required bandwidth data transferred to the data buffer 12, extracts the required bandwidth, and notifies the required bandwidth input unit 15.

Required Band Input Unit 15 and Transmission Band Instructing Unit 1
6 operates in the same manner as in the first embodiment. That is, the transmission band instructing unit 16 calculates the data amount and the cycle, and gives the calculation result to the data transfer unit 13.

[Supplement] The present invention has been described in detail with reference to the specific embodiments. However, it is obvious that those skilled in the art can modify or substitute the embodiment without departing from the spirit of the present invention. That is, the present invention has been disclosed by way of example, and should not be construed as limiting. In order to determine the gist of the present invention, the claims described at the beginning should be considered.

[0101]

As described above in detail, according to the present invention,
An excellent transmission band control device capable of controlling a transmission band in which a data transfer device connected to a network transfers data can be provided.

Further, according to the present invention, there is provided an excellent transmission band control device capable of performing data transfer without error between a requested transmission band and an actual transmission band regardless of the type of a network interface. can do.

According to the present invention, the error between the requested transmission band and the actually transmitted transmission band is increased without increasing the number of buffers for temporarily storing transmission data and irrespective of the type of the network interface. It is possible to provide an excellent transmission band control device that can perform shaping that eliminates the problem.

According to the present invention, the error between the required transmission band and the actual transmission band can be suppressed to the amount of data that can be transferred to the minimum unit of the hardware clock. Such an operation and effect can be achieved by adding a transmission band instruction unit, and there is no need to increase the buffer for temporarily storing transmission data. Also,
The transmission band designating unit according to the present invention is a function addition to a part unrelated to the network interface, so that it can be easily applied to any network interface.

[Brief description of the drawings]

FIG. 1 is a diagram schematically showing a configuration of a network system 100 provided for implementing the present invention.

FIG. 2 is a diagram conceptually showing a configuration for receiving required band information for transmission band control via a user interface.

FIG. 3 is a diagram conceptually showing a configuration for receiving a requested band for transmission band control from an application.

FIG. 4 is a diagram schematically illustrating a configuration of a transmission band control device according to a second embodiment of the present invention.

FIG. 5 is a diagram schematically illustrating a configuration of a transmission band control device according to a third embodiment of the present invention.

FIG. 6 is a diagram showing a schematic configuration of a network system (conventional example).

FIG. 7 is a diagram schematically showing how data is transferred via a plurality of networks.

FIG. 8 is a diagram showing a schematic configuration of a conventional data transfer device.

FIG. 9: TCP (Transmission Con)
FIG. 7 is a diagram schematically illustrating an operation sequence (conventional example) of credit control using a control protocol (control protocol).

FIG. 10 shows an ATM (Asynchronous Tr).
FIG. 2 is a diagram illustrating a schematic configuration of a data transfer device that performs rate control using an transfer mode (an asynchronous mode).

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Network, 10 ... Data transfer apparatus, 12 ... Data buffer, 13 ... Data transfer part, 14 ... Data transmission part, 15 ... Requested band input part, 16 ... Transmission band instruction part, 1
7 user interface, 18 application, data receiving section 19, 20 network interface card, 30 transmission band control device, 100
Network system.

Claims (8)

[Claims] 1. A transmission band control device for controlling a transmission band in a data transfer device connected to a network, comprising: a data buffer for temporarily storing transmission data; and a predetermined protocol information added to the transmission data. Data transmission means for transmitting the data on the network by a predetermined period between the data buffer and the data transmission means at a predetermined period, and a data transfer unit capable of changing the data amount and the period. Request bandwidth information that specifies the amount of data to be transmitted within a predetermined time, and from the fixed amount of data, calculates a cycle at which the data transfer unit should transfer data, and sends the calculated value to the data transfer unit. Transmission band control means for instructing transmission band control. 2. A transmission band control device for controlling a transmission band in a data transfer device connected to a network, comprising: a data buffer for temporarily storing transmission data; and a device for adding predetermined protocol information to the transmission data. Data transmission means for transmitting the data on the network by a predetermined period between the data buffer and the data transmission means at a predetermined period, and a data transfer unit capable of changing the data amount and the period. Calculating a constant data amount to be transferred by the data transfer means from the requested band information designating the data amount to be transmitted within a predetermined time and the predetermined period, and calculating the calculated value by the data transfer means; Transmission band instructing means for instructing
A transmission band control device comprising: 3. A data receiving means for receiving requested bandwidth information from another device connected to a network and notifying the data transfer means of the presence or absence of received data, and a data buffer for temporarily holding the received data. The transmission bandwidth instructing means extracts required bandwidth information from received data stored in a data buffer, and instructs the data transfer means of a fixed data amount and a period. Or the transmission band control device according to any one of 2. 4. The transmission band instructing means corrects the calculated cycle in consideration of the ratio between the data body to be transmitted and the protocol control information, and instructs the data transfer means. The transmission band control device according to claim 1. 5. The transmission band instructing means corrects the calculated constant data in consideration of the ratio between the data body to be transmitted and the protocol control information, and instructs the data transfer means. The transmission band control device according to claim 2, wherein: 6. The data transfer device has a user interface for receiving a user input, and the transmission band instruction means extracts required band information from data input from the user interface,
3. The transmission band control device according to claim 1, wherein a predetermined data amount and a predetermined period are instructed to the data transfer unit. 7. The data transfer device is capable of executing an application, and the transmission band instructing unit extracts required band information from data notified from the application being executed, and sends a predetermined data to the data transfer unit. 3. The transmission band control device according to claim 1, wherein the amount and the period are specified. 8. A plurality of data transfer means for performing data transfer between the data buffer and the data transmission means, and a plurality of transmission band designating means for designating a transmission band for each of the plurality of data transfer means. The transmission band control device according to claim 1, comprising: