JPH0897845A - Communication controller - Google Patents

Abstract

PURPOSE: To provide a communication controller with improved transmission efficiency provided between first and second networks. CONSTITUTION: Priority conditions for determining transmission priority orders for frames F to be transmitted from a terminal inside a certain network to the terminal inside the other network are held in a priority condition registration part 340. A buffer queue 140 composed of queues for holding the frames of the corresponding priority order provided corresponding to the respective priority orders is provided. The frames F are tentatively held in the queue inside the buffer queue 140 corresponding to the priority conditions held in the registration part 340 and the one of a higher priority order among the held frames is preferentially transmitted. Thus, when the priority conditions are appropriately set, even when the frames provided with the data of high emergency and the data addressed to a specified terminal are inputted later, they are preferentially transmitted and the transmission efficiency is improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication control device, and more particularly to a communication control device provided between a first network and a second network to connect these networks.

[0002]

2. Description of the Related Art Conventionally, in this type of communication control device,
Frames received from a certain LAN (Local Area Network) or WAN (Wide Area Network) were processed in the order of reception, except for unnecessary packet suppression by the filtering function. The filtering function is disclosed in Japanese Patent Laid-Open No. 3-49330.
It is disclosed in Japanese Patent Publication No.

That is, in the conventional communication control device, an address (destination address, source address) and a protocol (TCP / IP (Transmission Continuation) are used.
rollProtocol / Internet Prot
ocol), Network), and other conditions, the frames are processed in the order in which they are received and the line (L
It was sent over AN or WAN).

[0004]

In the above-mentioned conventional communication control device, since the received frames are processed in order and sent out on the line, the data is highly urgent and the device to be used, the communication partner, or the like can be operated under certain conditions. A frame including data to be preferentially processed is transmitted similarly to other frames. Therefore, there is a drawback that the transmission efficiency is not good.

The present invention has been made in order to solve the above-mentioned drawbacks of the prior art, and an object thereof is to provide a communication control device with high transmission efficiency.

[0006]

A communication control apparatus according to the present invention has a priority that holds a priority condition that determines a transmission priority of a frame to be transmitted from a terminal in a first network to a terminal in a second network. Condition holding means,
Frame holding means for temporarily holding the frame in accordance with the held priority condition, and transmission control means for preferentially transmitting the held frame with the higher priority. .

[0007]

The priority condition for defining the transmission priority of the frame to be transmitted from the terminal in the first network to the terminal in the second network is held. The frame is once held according to the held priority condition. Among the held frames, the one with a higher priority is preferentially transmitted. The transmission priority includes a first priority and a second priority having a higher priority than this priority, and the first and second first-in first-out buffers corresponding to these first and second priorities are set. The frame in the provided correspondence priority order is held, and the frame in the second first-in first-out buffer is transmitted with priority over the frame in the first first-in first-out buffer.

[0008]

Next, the present invention will be described with reference to the drawings.

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

Referring to FIG. 1, a communication control apparatus according to an embodiment of the present invention has an external input / output processing unit 310 that forms an interface with an external keyboard (KB) or a display (CRT), and a priority is given through an external input / output processing unit 310. A priority frame setting unit 320 that registers the condition of the priority frame in the condition registration unit 340 and also registers in the priority identification unit that there is a priority frame, a priority identification unit 330 that checks whether there is a priority frame, and a priority condition is registered. The priority condition registering unit 340 is included.

Further, the communication control apparatus according to the present embodiment has the frame receiving section 110 for receiving the frame F from the line.
A received frame check unit 120 that checks whether or not this received frame satisfies the condition registered in the priority condition registration unit 340; a buffer management unit 130 that manages registration of each frame in the buffer queue 140;
A queue that holds frames to be preferentially transmitted (que
ue) and a queue that holds frames that are not so, and a buffer queue 14
The frame transmission unit 210 includes a frame transmission unit 210 that sequentially transmits to the line from the frame registered in the queue holding the frame with the highest priority among the frames registered in 0.

The operation of the communication control apparatus of this embodiment having such a configuration will be described with reference to FIG.

First, the priority frame setting unit 320 registers the conditions of the priority frame in the priority condition registration unit 340 when it is desired to designate a frame to be preferentially processed from the outside through the external input / output processing unit 310. At the same time, the priority frame setting unit 320 registers in the priority identification unit that there is a priority frame.

When the frame receiving section 110 receives a frame from the line (step 401), the priority identifying section 330 checks whether or not there is a priority frame (step 4).
02).

If there is no priority frame, the buffer management unit 130 registers the frame in a queue with a low priority in the buffer queue 140 (steps 402 → 40).
5). On the other hand, when there is a priority frame, the reception frame check unit 120 further checks whether the reception frame satisfies the condition registered in the priority condition registration unit 340 (step 402 → 403).

When the received frame does not satisfy the priority condition, the buffer management unit 130 sequentially registers the queues in the buffer queue 140 as usual (step 403 →
405). If the priority condition is satisfied, the buffer management unit 130 sequentially registers the high-priority queues in the buffer queue 140 (step 403 → 404). The internal structure of the buffer queue 140 will be described later.

The frames registered in the buffer queue 140 are transmitted by the frame transmission unit 210 on the line in order from the highest priority (step 406).

Here, the structure of the frame F processed by the communication control apparatus of this embodiment will be described with reference to the drawings.

FIG. 3 is a diagram showing an example of the structure of the frame F. In the figure, frame F has a destination address (DA) 3
1, source address (SA) 32, and length (L)
33, protocol header 34, and data (DATA)
And 35.

The destination address 31 includes an address for specifying the terminal on the other side to which the own frame is to be transmitted. The source address 32 includes an address for identifying the terminal that is the source of the own frame. The length 33 includes information indicating the length of the frame. However, the above configuration is merely an example, and various configurations are conceivable according to the contents of each protocol.

Next, the configuration of the priority condition registration section in FIG. 1 will be described.

FIG. 4 is a schematic configuration diagram of the priority condition registration section in FIG. 1, and the same parts as those in FIG. 1 are designated by the same reference numerals. In the figure, the priority condition registration unit 340 indicates that the priority condition 1
~ N are registered from the outside.

Regarding the priority conditions 1 to n, various conditions can be registered depending on the protocol used. For example, to preferentially process a frame addressed to a specific terminal, it is sufficient to register that the destination address 31 in FIG. 3 has a specific value as a priority condition. Further, when preferentially processing a frame including data with a high degree of urgency, it is sufficient to register that the data 35 in FIG. 3 has a specific value as a priority condition. In addition, the line manager can freely register priority conditions such as conditions for the protocol header 34. As a result, it is possible to preferentially transmit a frame including highly urgent data or data addressed to a specific terminal. Information or flags for identifying the priority may be provided in the frame.

Further, the structure of the buffer queue in FIG. 1 will be described.

FIG. 5 is a schematic diagram of the buffer queue in FIG. In the figure, the buffer queue 140 includes queues corresponding to respective priorities. In this embodiment, whether or not transmission is performed preferentially, that is, since the priority order is two steps, m in the figure is "2".

That is, the buffer queue for temporarily holding the frame is configured to include the first-in first-out buffer which is provided corresponding to each priority and holds the frame relating to the corresponding priority. Then, of the frames in the first-in first-out buffer, the frame in the first-in first-out buffer having a higher priority is transmitted in preference to the frame in the first-in first-out buffer having a lower priority. As a result, even if a frame including data with a high degree of urgency or data addressed to a specific terminal is later input to the communication control device, these can be preferentially transmitted.

However, it is obvious that a larger number of priorities may be set such as three steps, four steps, etc. instead of two steps. In this case, queues may be provided corresponding to the respective priorities, and the frames in the queues in which the frames with higher priorities are held may be preferentially transmitted in order.

Although the line manager sets the priority condition in the above-mentioned embodiment, it is obvious that the priority condition may be set by the sending terminal.
In this case, the sending terminal may send a frame for setting a priority condition and set a priority condition in response to the frame. If the user of each terminal is informed of the registered priority condition, the user of each terminal can freely set the priority of the frame to be transmitted.

[0029]

As described above, according to the present invention, a frame is temporarily held according to a priority condition, and a frame having a higher priority order among the held frames is preferentially transmitted, so that the transmission efficiency is improved. There is an effect that a communication control device can be realized.

[Brief description of drawings]

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

FIG. 2 is a flowchart showing an operation of the communication control device of FIG.

3 is a diagram showing a configuration example of a frame processed by the communication control device of FIG.

4 is a schematic configuration diagram of a priority condition registration unit in FIG.

5 is a schematic configuration diagram of a buffer queue in FIG.

[Explanation of symbols]

 110 frame receiving unit 120 received frame checking unit 130 buffer managing unit 140 buffer queue 210 frame transmitting unit 310 external input / output processing unit 320 priority frame setting unit 330 priority identifying unit 340 priority condition registering unit

Claims (3)

[Claims] 1. A priority condition holding means for holding a priority condition for determining a transmission priority order of a frame to be transmitted from a terminal in the first network to a terminal in the second network, and to the held priority condition. Accordingly, the communication control device includes: a frame holding unit that temporarily holds the frame; and a transmission control unit that preferentially transmits the held frame having the higher priority. 2. The transmission priority includes a first priority and a second priority having a higher priority than this first priority,
The frame holding means includes first and second first-in first-out buffers which are provided corresponding to the first and second priorities and hold the frames relating to the corresponding priority order, and the transmission control means includes the first-in first-out buffer. 2. The communication control device according to claim 1, wherein among the frames in the output buffer, the frame in the second first-in first-out buffer is transmitted with priority over the frame in the first first-in first-out buffer. 3. The priority condition held in the priority condition holding means is set by a terminal in the first network,
3. The communication control device according to claim 2, wherein the frame holding unit holds a frame that meets the set priority condition in any of the first and second first-in first-out buffers.