JPH06164670A - Network repeater - Google Patents

Abstract

PURPOSE:To process data transfer at high speed and to enable the various kinds of protocol processing. CONSTITUTION:Data sent from an end system 3A are inputted to an HW protocol processing part 110A of a network repeater 100 and after protocol processing is performed to a low-order layer, the presence/absence of a transfer request is identified by an SW processing identification part 111A. When executing transfer, the protocol processing to a high-order layer is performed at the HW protocol processing part 111A and when performing the other processing, it is performed by an SW protocol processing part 120A. When transferring data, the protocol processing corresponding to a network B is performed similarly to the protocol processing by using an HW protocol processing part 110B, SW protocol processing part 120B and SW processing identification part 111B further after prescribed processing is performed at a relay processing part 130, and the data are sent to an end system 3B.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a network relay device applied to data communication requiring protocol processing between end systems on a plurality of networks.

[0002]

2. Description of the Related Art Generally, data transmitted and received between networks are classified into a predetermined hierarchy based on a protocol. The higher the layers of the classified protocols, the more complicated the processing becomes. The network relay device performs protocol processing corresponding to the transmission-side network on the data input from the transmission-side end system, and converts the data into a common expression format between the networks. After that, the processing is executed according to the transmitted data content. When the data requires transfer, the data is subjected to relay processing such as checking various fields, further subjected to protocol processing corresponding to the receiving side network, and sent to the end system on the receiving side network.

Conventionally, a network relay device employs one of two methods described later in order to speed up the protocol processing.

FIG. 4 shows a functional configuration of a network relay device to which the first method is applied. Network relay device 1
Are network A and network B different from each other.
Installed between each end system (not shown). The network relay device 1 is HW (hardware)
Protocol processing units 11A and 11B, SW (software) protocol processing units 12A and 12B, and relay processing unit 1
It is composed of 3.

The HW protocol processing unit 11A is configured by hardware to perform protocol processing according to the network A, which is performed on the lower layer of data, and the SW protocol processing unit 12A operates on the upper layer of data. The protocol processing according to the network A that is executed by the software is configured by software. Further, the HW protocol processing unit 11B is configured by hardware to perform protocol processing according to the network B, which is performed on the lower layer of data, and the SW protocol processing unit 12B operates on the upper layer of data. The protocol processing executed according to the network B is implemented by software. That is, the protocol process for the lower layer, which is a relatively simple process, is implemented by hardware, and the protocol process for the upper layer, which is a complicated process, is realized by software. The relay processing unit 13 also checks each field of the data.

When data is transferred from the end system of network A to the end system of network B,
First, data is sent from the end system of the network A to the network relay device 1. In the network relay device 1, the data is sent to the relay processing unit 13 via the HW protocol processing unit 11A and the SW protocol processing unit 12A. At this time, the lower layer of the data is subjected to protocol processing relating to electrical / mechanical conditions in the HW protocol processing section 11A, and the upper layer of the data is converted into a character code in the SW protocol processing section 12A as necessary. The protocol processing of is performed. The data subjected to such protocol processing is subjected to processing such as data path selection and field check in the relay processing unit 13.

The data output from the relay processing section 13 is
It is sent to the end system on the network B via the SW protocol processing unit 12B and the HW protocol processing unit 11B. At this time, the upper layer of the data is subjected to protocol processing such as character code conversion in the SW protocol processing unit 12B as necessary, and the lower layer of the data is related to electrical / mechanical conditions in the HW protocol processing unit 11B. Protocol processing is performed.

The data transferred from the end system of the network B to the end system of the network A is subjected to the protocol processing by the reverse procedure of the above processing,
It is sent to the end system on network A.

Next, FIG. 5 shows a functional configuration of a network relay device to which the second method is applied. The network relay device 2 is installed between the end systems (not shown) of the network A and the network B different from each other. The network relay device 2 includes HW (hardware) protocol processing units 21A and 21B and a relay processing unit 22.
Composed of and.

The HW protocol processing unit 21A is configured by hardware by simplifying the protocol processing corresponding to the network A for each layer (upper layer and lower layer) of the input data, and the HW protocol processing unit 21B.
Is the network B for each layer of the input data.
The hardware is configured by simplifying the protocol processing according to. The relay processing unit 22 also performs processing such as checking each field of data.

When data is transferred from the end system of network A to the end system of network B,
The data transmitted from the end system of the network A is input to the HW protocol processing unit 21A of the relay processing device 2. The input data is subjected to protocol processing according to the network A for each layer, and is sent to the relay processing unit 2. The data is subjected to processing such as data path selection and field check in the relay processing unit 2.

After that, the data is sent to the HW protocol processing unit 21B, and the protocol processing according to the network B is performed on each layer. The data output from the HW protocol processing unit 21B is sent to the end system of the network B.

The data transferred from the end system of the network B to the end system of the network A is subjected to protocol processing by the reverse procedure of the above processing,
It is sent to the end system on network A.

The conventional network relay device has the above-mentioned 2
Be configured using one of two methods.

[0015]

However, the network relay device to which the first method is applied can flexibly deal with connection / disconnection processing with end systems, error processing, option processing, etc. in the upper layer of data. On the other hand, the data transfer process is performed by software, so that there is a problem that data cannot be transmitted at high speed.

In the network relay device to which the second method is applied, the data transfer process can be executed at high speed by the hardware configuration, but the content of the protocol process in the communication with the end system is limited. There is a problem that the range to which is applicable is limited.

In order to solve the above problems, it is an object of the present invention to provide a network relay device which can carry out data transfer processing at high speed without limiting the content of protocol processing.

[0018]

A network relay device according to the present invention is a network relay device for connecting networks having different protocol processing systems, and is a protocol for data transfer for transmitting received data to a partner network. A protocol conversion circuit that executes conversion processing, a protocol conversion unit that executes extended protocol processing other than the protocol conversion processing for data transfer according to a predetermined software program, and the protocol conversion circuit that is connected to the protocol conversion circuit and that receives the received data. Selecting means for selectively activating the protocol converting means.

[0019]

In this network relay device, the protocol processing executed during data communication between networks having different protocol processing systems includes a protocol conversion circuit for executing protocol conversion processing for data transfer, and a protocol conversion circuit for data transfer. The protocol conversion circuit is implemented by hardware, and the protocol conversion means is implemented by a software program.

As described above, by executing the protocol processing by the protocol conversion circuit related to the data transfer and the protocol conversion means related to the protocol processing other than the data transfer, the normal data transfer processing can be performed at high speed.
With respect to protocol processing other than data transfer, it is not necessary to limit the processing content, and flexible handling is possible.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows a functional configuration of the network relay device according to the present invention. The network relay device 100 is
For example, routers, gateways for connecting between LANs,
It is a relay device such as a bridge, and each end system of network A and network B different from each other, that is,
It is installed between the end system 3A and the end system 3B. The network relay device 100 includes HW (hardware) protocol processing units 110A, 110B, and S.
W (software) protocol processing units 120A and 120
B and the relay processing unit 130. Also, H
Each of the W protocol processing units 110A and 110B has a SW
It has (software) identification units 111A and 111B.

The HW protocol processing section 110A is connected to the network A and the relay processing section 130 and sends and receives data. Further, it is also connected to the SW protocol processing unit 120A and transmits / receives the upper layer of the received data according to the identification result of the SW process identification unit 111A. The HW protocol processing unit 110A is configured by hardware for protocol processing for a lower layer of input data and upper layer protocol processing for data transfer. These protocol processes correspond to the mechanism of network A and end system 3
The data format input from A is converted into a common expression format, and the data input from the relay processing unit 130 is converted into an expression format compatible with the network A. Also, the SW process identification unit 111A
Determines whether or not there is a transfer request for the received data, and when it determines that there is a transfer request, the HW protocol processing unit 110A.
Inside, the received data is sent to predetermined hardware so as to execute the protocol processing of the upper layer. When it is determined that there is no transfer request, the received data is sent to the SW protocol processing unit 120A.

The SW protocol processing unit 120A is configured so that software other than the above-mentioned data transfer, for example, protocol processing such as link connection / disconnection processing for data transfer, error processing, and option processing can be executed by software. . These protocol processes are performed by network A
It corresponds to the mechanism of.

The HW protocol processing section 110B is connected to the network B and the relay processing section 130 to send and receive data. Further, it is also connected to the SW protocol processing unit 120B and transmits / receives the upper layer of the received data according to the identification result of the SW process identification unit 111B. Similar to the HW protocol processing section 110A, the HW protocol processing section 110B is configured by hardware such that protocol processing for a lower layer of input data and upper layer protocol processing for data transfer. However, these protocol processes correspond to the mechanism of the network B and convert the data format input from the end system 3B into an expression format and the data input from the relay processing unit 130 into an expression format corresponding to the network B. Also, the SW process identification unit 111B is
Whether or not there is a transfer request for the received data is determined, and when it is determined that there is a transfer request, the received data is sent to predetermined hardware so that the protocol processing of the upper layer is executed in the HW protocol processing unit 110B. If it is determined that there is no transfer request, the received data is sent to the SW protocol processing unit 120B.

The SW protocol processing unit 120B is configured so that software can realize protocol processing corresponding to the network B, such as link connection / disconnection for data transfer, error processing, and option processing.

The relay processing unit 130 receives the protocol-processed data and outputs it to the HW protocol processing unit on the network side which is the transmission target. That is, the data received from the HW protocol processing unit 110A is output to the HW protocol processing unit 110B, or the data received from the HW protocol processing unit 110B is output to the HW protocol processing unit 110A. At this time, a data transfer route is selected and each field is checked based on the protocol-processed data.

Next, the HW protocol processing units 110A, 1
FIG. 2 shows the relationship between the protocol processing executed by the 10B and SW protocol processing units 120A and 120B and the hierarchy of the data to be relayed (in the figure, n and m are predetermined numbers, respectively). In the data having the layer structure of n layers, the lower layer (layers of 1 to m) is the HW protocol processing unit 110.
Protocol processing is performed by A and 110B. The upper layers (m to n layers) are the SW process identification units 111A and 11A.
According to the determination of 1B, the HW protocol processing units 110A, 1
10B or SW protocol processing units 120A and 120B
Protocol processing is performed by either of the above.

Next, FIG. 3 shows a functional configuration of the SW process identification units 111A and 111B. The SW process identification unit 111A receives the data subjected to the protocol processing (111a), and detects / determines whether or not there is a data transfer request in this data (111).
b) Do. In accordance with the result of this determination, the data transmission destination is switched (111c) and the data is transmitted. That is, when it is determined that there is a transfer request, the target data is sent to the HW protocol processing unit 110A, and when it is determined that there is no transfer request, it is sent to the SW protocol processing unit 120A. Also, S
The same process is performed for the W process identification unit 111B, and if it is determined that there is a transfer request, the target data is set to H.
It is sent to the W protocol processing unit 110B, and when it is determined that there is no transfer request, it is sent to the SW protocol processing unit 120B.

Next, the operation of the embodiment will be described. As an example, when transmitting data from the end system 3A of the network A to the end system 3B of the network B,
Link connection / disconnection and data transfer will be described.

When data transfer is performed, the end system 3A sends a link connection request to the network relay device 100 when a link connection with the network relay device 100 is required in each layer. The data of the transmitted link connection request is the network relay device 100.
Is received by the HW protocol processing unit 110A. The received data, after being subjected to protocol processing in the lower layer,
The SW process identification unit 111A recognizes the presence / absence of a data transfer request. Since this data is the data of the link connection request and not the data of the data transfer request, the upper layer protocol processing is performed by the SW protocol processing unit 120A.
Executed in. After this, the SW protocol processing unit 1
By performing communication between 20A and the end system 3A, a link for data transfer is connected in each layer.

After the link connection is completed, the end system 3A transfers the data to be transferred to the network relay device 10
Send to 0. Similar to the data of the link connection request, the HW protocol processing unit 110A performs lower layer protocol processing on the transmitted data, and the SW processing recognition unit 111A recognizes the presence or absence of a data transfer request. Since this data is data to be transferred from the end system 3A to the end system 3B, the HW protocol processing unit 110A performs upper layer protocol processing.

In the HW protocol processing section 110A,
By performing the protocol processing on all layers, the data is converted from the expression format corresponding to the network A to the expression format common to the networks. The converted data is sent to the relay processing unit 130. The relay processing unit 130 outputs the data to the HW protocol processing unit 110B after performing predetermined processing such as data path selection and checking of each field. The HW protocol processing unit 110B performs protocol processing on the lower layer of the input data. After this, the SW processing recognition unit 111B
Determines whether there is a data transfer request. Since the determined data is the data sent to the end system 3B,
In the HW protocol processing unit 110B, protocol processing of the upper layer of data is performed. HW protocol processing unit 1
In 1B, protocol processing is performed on all layers, so that the data is converted into a representation format corresponding to the network B. The converted data is output from the network relay device 100 and the network B
To the end system 3B.

After the link connection is completed, necessary data is sent to the end system 3B of the network B by repeating the above-mentioned transfer process. When the data transfer is completed, the end system 3A outputs a link disconnection request to the network relay device 100. Similar to the link connection request, the link disconnection request is subjected to lower layer protocol processing in the HW protocol processing section 110A, and the SW processing identification section 110A determines whether or not there is a data transfer request. In this case, since the request is for a link disconnection, the SW protocol processing unit 120A performs upper layer protocol processing. After this, end system 3
By performing communication between A and the SW protocol processing unit 120A, the link of each layer is disconnected.

As described above, link connection / disconnection and data transfer from the end system 3A of the network A to the end system 3B of the network B are executed.

In this embodiment, the link connection / disconnection and the data transfer from the end system 3A to the end system 3B have been described, but the same processing can be performed in the reverse direction from the end system 3B to the end system 3A. Also, SW
The protocol processing units 120A and 120B connect the link /
It is also possible to configure so that error processing at the time of disconnection, optional processing unique to the system, and the like can be performed. Furthermore, when the relay processing unit 130 is configured to have a protocol mapping function, it can operate even if protocol conversion is performed.

Further, the SW process identification units 111A and 111B
Determines whether or not there is a data transfer request from the data on which the lower layer protocol processing has been performed, but it may be configured to determine whether or not there is a transfer request immediately after the HW protocol processing units 110A and 110B input data. Is.

[0038]

As described above in detail, according to the present invention,
The data transfer process can be performed at high speed by implementing the data transfer process by hardware and implementing the protocol process other than the data transfer by software, for example, link connection / disconnection process, error process, option process, etc. At the same time, it is not necessary to limit the processing functions other than the above-mentioned data transfer.

Further, since only the data transfer process is realized by hardware, the hardware structure is simplified and the cost can be reduced. Further, when it becomes necessary to add a new protocol process, it is possible to add the new protocol process based on software. Therefore, it is possible to flexibly deal with the addition of the new protocol process.

[Brief description of drawings]

FIG. 1 is a block diagram showing a functional configuration of a network relay device according to the present invention.

FIG. 2 is a block diagram showing a correspondence relationship between each layer of data handled in the embodiment and each processing unit.

FIG. 3 is a block diagram showing a functional configuration of a SW (software) process identification unit in the embodiment.

FIG. 4 is a block diagram showing a functional configuration of a network relay device to which the first conventional method is applied.

FIG. 5 is a block diagram showing a functional configuration of a network relay device to which a second conventional method is applied.

[Explanation of symbols]

3A, 3B ... End system, 100 ... Network relay device, 110A, 110B ... HW (hardware) protocol processing device, 111A, 111B ... SW (software) process identification unit, 120A, 120B ... SW protocol processing unit, 130 ... Relay Processing unit.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location H04L 12/66 8732-5K H04L 11/20 B

Claims (1)

[Claims] 1. In a network relay device connecting between networks having different protocol processing systems, a protocol conversion circuit for executing protocol conversion processing for data transfer for transmitting received data to a partner network, and for the data transfer. The extended protocol processing other than the protocol conversion processing described above is executed according to a predetermined software program, and the selection means is connected to the protocol conversion circuit and selectively activates the protocol conversion means in response to a request for received data. A network relay device characterized by the above.