JPH01147940A - Priority packet transmission method - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Summary] Regarding a priority packet transmission method in a throttling communication system in which a plurality of communication control devices are connected in a ring shape, packets to be sent preferentially can be sent by preferentially inserting them into slots. In order to provide a priority packet transmission system, the communication control device has an evacuation buffer for evacuation of packets sent in a slot, and when a priority packet is generated, even if the slot in which it arrived is busy, the busy slot is not able to carry it. evacuation of the packets in the evacuation buffer,
The configuration includes an insertion control circuit that controls the insertion circuit, inserts the priority packet into the packet, and causes the packet to be transmitted.

[Industrial application field]

The present invention provides a throttling communication system in which a plurality of communication control devices are connected in a ring, in which a packet addressed to the device sent through a slot is branched in a branch circuit, and a packet to be transmitted is inserted in an insertion circuit. Related to priority packet transmission method.

The configuration of a throttling communication system to which the present invention is applied is shown in FIG. 4, with communication control devices 10, 11,
The terminals 20, 21, 22, and 23 that perform packet communication are connected to each of the communication control devices 10 to 13, respectively.

The format of the slot is shown in Figure 5, and the slot header section includes a busy-idle area that indicates whether a packet is inserted into this slot or not, and a destination area that carries the destination address. There is an address area, a source address area where the source address is placed, a data length area where the data length is placed, and next to the slot header there is a data area where data is placed, and when inserting a packet, the contents of the packet are Insert into the corresponding area.

In such a throttling communication system, it is desired to be able to send preferentially the packets to be sent preferentially when performing packet communication.

[Prior Art] A communication control device of a conventional throttling communication system does not insert a packet when a busy slot in which a packet is inserted comes, but waits until an idle slot comes and inserts the packet. Since it is a method of communication,
It was not possible to prioritize packets.

For this reason, when accommodating synchronous communication such as voice, a specific slot is allocated exclusively for synchronous communication and a combination of time division multiplexing and time division multiplexing is used.

In communications such as voice, where once traffic is allocated, a certain percentage of traffic continues to occur, the overhead (wasted time) for allocation can be ignored and this is fine, but when the traffic is generated asynchronously and the transmission path It was not possible to support communications such as those described below, which have strict requirements regarding delay.

If transmission line control commands such as fault notifications and control for switching to backup can be sent out on a priority basis, prompt control of the transmission line becomes possible, shortening the failure time, and making it possible to switch to backup quickly, thereby increasing the reliability of the system. You can expect sex.

For this purpose, there is a demand for preferentially inserting transmission line control commands into slots.

Furthermore, in file transfer, a transfer control command is transferred in addition to the actual file, but if the transfer control command can be sent out preferentially, file transfer can be expected to be faster.

For this purpose, there is a demand for preferentially inserting transfer control commands into slots.

[Problem that the invention seeks to solve]

Conventionally, when a busy slot in which a packet is being inserted arrives, the packet is not inserted, and communication is performed by waiting until an idle slot arrives and inserting the packet. Even if there is, there is a problem that it cannot be sent until the idle slot comes.

An object of the present invention is to provide a priority packet transmission system in which packets to be sent preferentially can be inserted into slots and sent preferentially.

[Means for solving problems]

FIG. 1 is a diagram explaining the principle of the present invention, (A) is a diagram showing the configuration, and (B) to (D) are diagrams explaining the principle of operation.

As shown in FIG. 1 (A), packets sent through a slot and destined for the own device are branched at a branch circuit 1, and packets to be transmitted are inserted into an insertion circuit 2 in a communication control device that sends the packets to the slot. and an evacuation buffer 3 for evacuation of packets sent through the evacuation buffer 3, and when a priority packet occurs, evacuation of the packet carried by the busy slot to the evacuation buffer 3 even if the arriving slot is busy, and controls the insertion circuit 2. The configuration includes an insertion control circuit 4 that inserts the priority packet into the packet and causes it to be transmitted.

[For production]

According to the present invention, when the priority packet #3 is generated as shown in FIG. 1(B), even if the slot which arrived at that time is busy, the insertion control circuit 4 controls the slot #3 as shown in FIG. 1(C). The packet #l carried by No. 1 is saved to the save buffer 3.

Packet #3 is inserted into slot #1 and transported.

Next, when idle slot #3 arrives, the evacuated packet #1 is inserted into slot #3 and transported as shown in (D).

In other words, it is possible to send packets that are desired to be sent preferentially.

【Example〕

FIG. 2 is a block diagram of a communication control device according to an embodiment of the present invention;
FIG. 3 is a diagram showing an insertion control pattern of the insertion control circuit of FIG. 2.

In FIG. 2, the slot is input to the branch circuit 1, and if the packet is addressed to the own device, it is branched and sent to the terminal via the reception buffer 5, and if the packet is not addressed to the own device, the insertion control circuit 4 is sent to the insertion circuit 2 under the control of the third
As shown in Figures (A) and (B), if there is no priority packet transmission request and there is no evacuation packet in the evacuation buffer 3 (there is no evacuation packet transmission request), the slot is inserted into the slot insertion circuit 2 without evacuation in the evacuation buffer 3. If it is idle as shown in (A) and there is a transmission packet in the transmission buffer 6, it is inserted; if it is busy as shown in (B), even if there is a transmission packet in the transmission buffer 6, it is not inserted, and the next communication control device.

As shown in (E) and (F) of FIG. 3, when there is a priority packet in the transmission buffer 6 (there is a priority packet transmission request) and there is no evacuation packet in the evacuation buffer 3, the slot is idle as shown in (E). If so, the priority packet is not saved to the save buffer 3, but the insertion circuit 2 inserts the priority packet into the slot and sends it to the next communication control device.

If the slot is busy as shown in (F), the packet being carried is saved in the save buffer 3, and then the insertion circuit 2 inserts a priority packet and sends it to the next communication control device.

As shown in (C) and (D) of FIG. 3, when there is no priority packet transmission request and there is an evacuation packet in the evacuation buffer 3, and the slot is idle as shown in (C), the insertion circuit 2 If it is busy as shown in (D), the save packet is then sent to the next communication control device.

As shown in (G) and (H) of FIG. 3, when there is a priority packet transmission request and there are evacuation packets in the evacuation buffer 3, and as shown in (G), if the slot is idle,
The insertion circuit 2 inserts the priority packet and sends it to the next communication control device.

If it is busy as shown in (H), the incoming packet is saved in the save buffer 3, and the insertion circuit 2 inserts a priority packet and sends it to the next communication control device.

Since the insertion control circuit 4 performs control in this manner, priority packets can be transmitted preferentially.

〔Effect of the invention〕

As explained in detail above, according to the present invention, priority packets can be transmitted preferentially.

Therefore, it has the effect of being able to withstand the above-described system for transmitting file transfer and transmission line control commands, etc., which occur asynchronously and have strict requirements for transmission line delay.

[Brief explanation of the drawing]

FIG. 1 is a diagram explaining the principle of the present invention, FIG. 2 is a block diagram of a communication control device according to an embodiment of the present invention, FIG. 3 is a diagram showing an insertion control pattern of the insertion control circuit of FIG. 2, and FIG. 5 is a diagram showing the configuration of an example of a throttling communication system, and FIG. 5 is a diagram showing an example of a slot formant. In the figure, l is a branch circuit, 2 is an insertion circuit, 3 is a save buffer, 4 is an insertion control circuit, 5 is a reception buffer, 6 is a transmission buffer, 10 to 13 are communication control devices, and 20 to 23 are terminals.

Claims (1)

[Claims] Packets addressed to the device sent through the slot are branched at the branch circuit (1), and packets to be sent are branched at the insertion circuit (2).
In a throttling communication system in which multiple communication control devices inserted in a slot are connected in a ring, the communication control device has an evacuation buffer (3) that saves packets sent in a slot, and a priority packet is generated. Even if the arriving slot is busy, the insertion control circuit saves the packet carried by the busy slot to the evacuation buffer (3), controls the insertion circuit (2), and inserts the priority packet into the packet and transmits it. A priority packet transmission method characterized by providing (4).