JPH01194545A - Packet transferring system - Google Patents

Abstract

PURPOSE:To prevent transmitting data from being stopped in a transmitting side terminal equipment or from being abandoned by executing control to directly transfer a data packet between communicating terminal equipments when a data accumulating device can not accumulate the data by a trouble, etc. CONSTITUTION:When a transmitting side communicating device 2 transmits the packet, which is for a receiving side communicating device 4, to an accumulating device 6, the accumulating device 6 accumulates this packet and the receiving side communicating device 4 investigates the accumulating device 6. When there is the packet addressing to the self-device, this receiving side communicating device 4 receives the packet to be accumulated in the accumulating device 6 and to be addressing for the self-device. Here, when the accumulating device 6 can not accumulate the packet from the communicating device, the transmitting side communicating device 2 directly transmits the packet to the receiving side communicating device 4 and the receiving side communicating device 4 directly receives this packet. Thus, the transmitting data can be prevented from being stopped or being abandoned in the communication terminal equipment in the transmitting side.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a packet transfer method for a communication system that transmits and receives data between communication terminal devices, and particularly relates to a packet transfer method for a communication system equipped with a daily storage device. .

[Conventional technology]

Some communication systems include a plurality of communication terminal devices and data storage devices in a packet communication network within the system. A data transmission/reception control method for such a communication system includes a method of transferring packets using a data storage device. In other words, the communication terminal device on the sending side stores the destination and packets in the data storage device, and the terminal device on the communication partner checks whether there is a packet addressed to itself in the data storage device, and if it exists, it receives it. method.

[Problem to be solved by the invention]

In the conventional data transmission/reception control method described above, if the data storage device becomes unable to store data due to some kind of failure, such as a lack of storage area, even if the communication terminal device of the other party and the communication to this communication terminal device of the other party are Even if the communication channel is normal, the communication terminal device on the sending side becomes unable to send data.

At this time, there is a drawback that the data transmitted from the transmitting side may be retained or discarded, causing a problem in the operation of the communication system.

An object of the present invention is to eliminate such drawbacks, and to prevent transmission data from being accumulated in the communication terminal device on the transmitting side when the data storage device of the communication system becomes unable to store data due to lack of storage area, etc. An object of the present invention is to provide a packet transfer method that can prevent packets from being lost, discarded, or otherwise.

[Means to solve the problem]

The present invention provides a packet transfer method for a communication system including a plurality of communication devices and a storage device, in which when a transmitting communication device transmits a packet to the receiving communication device to the storage device, the storage device transfers the packet to the storage device. The receiving communication device checks the storage device, and if there is a packet addressed to the device itself, the receiving communication device receives the packet addressed to the device stored in the storage device, and the storage device The present invention is characterized in that when it becomes impossible to store packets from a communication device, the transmitting side communication device directly transmits the packet to the receiving side communication device, and the receiving side communication device directly receives this packet.

〔Example〕

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

FIG. 1 is a block diagram showing an example of a communication system for implementing the present invention. In FIG. 1, communication terminal devices 2 and 4 connected to packet communication network y41 are connected to data storage device W6, which is also connected to packet communication network 1.
Send and receive data via. Communication terminal device 2.4
is equipped with a receiving buffer 3.5 and a data storage device 6.
is equipped with a receiving buffer 7. Further, a storage device 8 for storing data is connected to the data storage device 6.

The operation of such a communication system will be explained with reference to FIGS. 2, 3, and 4. In addition, FIG. 2 is a control flow diagram showing the processing operation of transmission by the communication terminal device, FIG. 2 is a control flow diagram showing the processing operation of the data storage device, and FIG. 3 is a control flow diagram showing the processing operation of reception by the communication terminal device. It is a control flow diagram.

When performing data transmission with the communication terminal device of this communication system, for example, when the communication terminal device 2 transmits a data packet related to data transmission to the communication terminal device 4, first the data storage device 6 The data packet is transmitted to the communication terminal device 4 as a data packet (step SL). If "YES" in step S1, that is, the transmission was successful, the process ends (step S2).However, if "No" in step S1, that is, the transmission was unsuccessful due to insufficient storage area of the data storage device 6, etc. If there is, the data packet is directly transmitted to the communication terminal device 4, and the process ends (step S3).

In such a control flow, the case where a data packet is transmitted to the data storage device 6 will be explained in more detail. In this case, the data storage device 6 first checks whether there is received data in the reception buffer 7 of its own device (step 511), according to the control flow shown in FIG.
). If "No" in step S11, it is checked again whether there is received data in the reception buffer 7 of the own device.

If "YES", the received data in the receive buffer 7 is received (step 512). It is checked whether this data is a data packet (step 513), and if "YES", the data packet is stored in the storage area corresponding to the destination communication terminal device (step 514), and the process returns to step Sll. If “No” in step S13, it is checked whether the received data is a timing packet (step 515).
). If "YES" in step S15, that is, if the received data is a delay packet, the storage area corresponding to the requesting communication terminal device is investigated (step 816).
). Then, it is determined whether a data packet exists in this storage area (step 517).

If "YES" in step 317, information that the data packet exists is sent to the requesting communication terminal device (step 518), and the process returns to step 311.

If "No" in step S17, information that the data packet does not exist is sent to the requesting communication terminal device (step 319), and the process returns to step 311. If "No" in step S15, it is checked whether the received data is a reception request bucket (step 520). Step 32
If “NO” at 0, perform error handling (step 52).
1) Return to Ste Nobu Sll. Also, step 32
0 and YES", that is, if this data is a reception request packet, the oldest data packet is sent to the requesting communication terminal from the data storage area corresponding to the requesting communication terminal (step 522), and the original The process returns to step Sll.

Next, the transmission processing operation of the communication terminal device 2 described above, that is, the case where the communication terminal device 2 directly transmits the data bucket to the communication terminal device 4 in the control flow shown in FIG. 2 will be explained in more detail. . The communication terminal device 4 transmits the directly transmitted data packet to the communication terminal device 4.
The data is stored in the receiving buffer 5 of the computer. According to the control flow shown in FIG. 4, the communication terminal device 4 first checks the reception buffer 5 of its own terminal device (step 531). Then, it is determined whether a data packet exists in the reception buffer 5 (step 532). “YE” in step S32
S", the data packet is received from the reception buffer 5 (step 533), and the process returns to step S31 again to check the reception buffer 5 of the own terminal device. In this way, the data packet is received from the communication terminal device 2. It is directly transmitted to the terminal device 4. If "No" in step S32, that is, if the data packet does not exist in the reception buffer 5 of the own terminal device, the data packet addressed to the own terminal device is transmitted to the data storage device 6. An inquiry is made as to whether a data packet exists (step 534), and a check is made to see if there is a data packet (step 535). Based on the makeshift bucket related to this inquiry, the data storage device 6 checks whether a data packet exists in the storage area corresponding to the communication terminal device 4 that is the request source communication terminal device, as described above. Then, information on whether or not the data packet exists is transmitted to the requesting communication terminal device 4. If there is a data packet, the communication terminal device 4 returns “YE” in step S35.
S", the data storage device 6 transmits a reception request to the data storage device 6 (step 836). As described above, the data storage device 6 receives the request source communication terminal device 4 from the reception request packet from the communication terminal device 4. The oldest data packet is transmitted from the data storage area corresponding to the data storage area to the requesting communication terminal device 4.The communication terminal device 4 receives the data packet from the data storage device 6 (Step 537), Step S3
1 and checks the reception buffer 5 of the own terminal device again. If "No" in step S35, that is, if no data exists, the process returns to step S31.

As described above, according to the embodiment, when the data storage device becomes unable to store data due to lack of storage area or the like, it is possible to prevent transmitted data from being retained or discarded at the transmitting side communication terminal device.

〔Effect of the invention〕

As explained above, according to the present invention, when the data storage device becomes unable to store data due to a failure or the like, by controlling the direct transfer of data packets between communication terminal devices, the transmitted data is transferred to the sending terminal. This has the effect of preventing data from being stored in devices or being discarded, thereby preventing problems in communication system operation.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an example of a communication system for implementing the present invention, FIG. 2 is a control flow diagram showing transmission processing operations of a communication terminal device, and FIG. 3 is a processing flow of a data storage device. Control Unit Flow Diagram Showing Operation FIG. 4 is a control flow diagram showing the reception processing operation of the communication terminal device. 1...Bucket communication network 2.4...Communication terminal device 3.5.7...Reception buffer 6...Data storage device 8...Storage device agent Patent Attorney Yoshiyuki IwasaFigure 1Figure 2

Claims (1)

[Claims] (1) A packet transfer method for a communication system consisting of a plurality of communication devices and a storage device, wherein when the sending communication device transmits a packet to the storage device to the receiving communication device,
The storage device stores this packet, and the receiving communication device checks the storage device, and if there is a packet addressed to the device itself, the receiving communication device receives the packet addressed to the device stored in the storage device. If the storage device is unable to store packets from the communication device, the sending communication device directly transmits the packet to the receiving communication device, and the receiving communication device directly receives the packet. Packet transfer method.