JP2527067B2 - ATM cell check method - Google Patents

Description

The present invention relates to a communication information check method in an ATM (Asynchronous Tranfer Mode) method network.

[Conventional technology]

In the conventional ATM network, high-speed flexible packet (hereinafter referred to as cell) communication is performed, so the communication information is not checked in the network, and the cell discard rate is sufficiently small and the delay time is as short as possible. This prevents the occurrence of communication errors. When a communication error such as a cell error occurs, it is dealt with by resending between the terminal devices.

[Problems to be Solved by the Invention]

In the above-mentioned conventional transmission method, there is no problem as long as it is a high-end terminal device having a retransmission function, but if an error occurs in a network using an existing terminal device that does not have a retransmission function, the communication cannot be established. There is also. In addition, even if the error rate such as the cell discard rate is sufficiently small, it may not be possible to deal with important communication information.

An object of the present invention is to add cell check information to a cell to be transmitted and transmit it, and collate the content of the cell with the check cell added to the cell received at the receiving side, and after confirming that there is no error, the terminal device AT that can handle errors during communication even by terminal devices that do not have a resend function by sending
It is to provide an M cell check method.

[Means for solving the problem]

The ATM cell check method of the present invention includes a check cell adding means for adding a check cell to an information cell transmitted by a terminal device, a means for transmitting the check cell attached information, and a received check cell attached information. Means, collation / confirmation means for confirming the normality of the information cell by the check cell added to the received information cell, and means for transmitting the information cell output by the collation / confirmation means to the receiving terminal device, The collation / confirmation means has a cell retransmission request means for requesting retransmission when an information cell error is detected.

〔Example〕

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

FIG. 1 is a block diagram of an embodiment of the present invention. Terminal devices 1 and 2, terminal devices 3 and 4 that perform data communication via the network, interface circuits 5 and 6 that mediate the transmission path from the terminal devices, and check cells are added to the cells to transmit and receive calls. The cell control circuits 7 and 8 for collating and confirming the contents of the selected cells by the check cell, the transmission line 9, and the information cell 1
It is composed of 0 and a check cell 11.

Next, description will be made below assuming that the terminal device 1 is the transmitting side and the terminal device 2 is the receiving side.

The terminal device 1 sends the information cell 10 to the terminal device 3. It is assumed that the terminal device 3 holds information such as a cell compensation request necessary for each terminal device in advance, depending on the type of the terminal device, registration system, and the like. Upon receiving the information cell 10, the terminal device 3 immediately connects to the cell control circuit 7. The cell control circuit 7 adds a check cell 11 to the input information cell 10 and transmits it to the terminal station device 4 via the terminal device 3, the interface circuit 5, the transmission line 9, and the interface circuit 6. The information cell with check cell received by the terminal device 4 is output to the cell control circuit 8. The cell control circuit 8 collates the contents of the cell with the check cell added to the received cell, confirms the normality, and if the cell content is normal, the information cell Send only 10. If there is an error in the cell contents as a result of the collation, correct it by itself or the terminal device 4,
Retransmission is requested to the cell control circuit 7 on the originating side via the interface circuit 6, the transmission path 9, the interface circuit 5, and the terminal device 3, and the correct cell is sent to the terminal device 2.

In the present embodiment, the transmitting terminal device and the receiving terminal device are connected in a one-to-one manner via the transmission line. However, even if the network includes a plurality of terminal devices from the transmission line 3, the effect is not affected. It is clear that there is nothing.

〔The invention's effect〕

As described above, the present invention includes a cell control circuit in both the transmitting end station and the receiving end station, adds a check cell to the information cell output by the transmitting end station, and the information cell contents are checked by the check cell on the receiving side. By collating and confirming, there is an effect that accurate information communication can be performed via a terminal device even between popular terminal devices that do not have a retransmission function.

Needless to say, the loss of the information cell can be remedied by utilizing the check cell such as attaching a sequence number to the check cell.

[Brief description of drawings]

FIG. 1 is a block diagram of an embodiment of the present invention. 1, 2 ... Terminal device, 3, 4 ... Terminal device, 5, 6 ... Interface circuit, 7, 8 ... Cell control circuit, 9 ... Transmission line, 10 ... Information cell, 11 ... Check cell.

Claims (1)

(57) [Claims] 1. In an ATM cell check system in an ATM network system accommodating a plurality of terminal devices, a check cell adding means for adding a check cell to an information cell transmitted by the terminal device and the information with the check cell are transmitted. Means, means for receiving the transmitted information with the check cell, collation / confirmation means for confirming the normality of the information cell by the check cell added to the received information cell, and the collation / confirmation means An ATM cell check method characterized in that it has means for sending an information cell output by the device to a receiving terminal device, and the collation / confirmation means has a cell resend request means for requesting resending when an information cell error is detected.