JP2924324B2 - Multiplexer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an ATM (Asynchronous T).
The present invention relates to a multiplexing device for multiplexing data blocked in a cell, such as ransfer mode, and transmitting the multiplexed data to a transmission path.

[0002]

2. Description of the Related Art Conventionally, as a multiplexing device of this kind, a receiving circuit does not have a function of making it impossible to transmit a received cell.
If the buffer capacity is exceeded when the cells are congested, the cells having exceeded the capacity are discarded in the buffer.

[0003]

Discarding one cell can result in loss of the entire block, since cells typically transmit larger blocks of data at the source. In the above-described conventional multiplexing apparatus, if cells generated from a plurality of different information sources are discarded at the time of congestion of cells in the multiplexing apparatus, there is a possibility that a large loss occurs in all of these information sources. There were challenges.

[0004]

SUMMARY OF THE INVENTION A multiplexer according to the present invention comprises:
In a communication system for multiplexing and transmitting blocked information to cells generated from a plurality of information sources, a plurality of receiving circuits for receiving cells from a plurality of information sources, and a cell received by the plurality of receiving circuits. A storage circuit for multiplexing and temporarily storing, a control circuit for recording the number of cells stored in the storage circuit and controlling the reception circuit according to the number of storages, and a transmission for sequentially outputting the contents stored in the storage circuit to a transmission line When the number of cells stored in the control circuit exceeds a predetermined first threshold value, one of the receiving circuits is replaced with a first threshold value having a different cell storage number. The cell transmission is disabled until the value becomes equal to or smaller than the second threshold value smaller than the threshold value, and cells received thereafter by this receiving circuit are discarded.

[0005]

According to the present invention, a cell discarding biased toward a specific information source is executed.

[0006]

FIG. 1 is a block diagram showing an embodiment of the present invention. In FIG. 1, 1-1, 1-2... 1-n
Are multiple receiving circuits that receive cells from multiple sources,
2 is a storage circuit for multiplexing and temporarily storing cells received by the plurality of receiving circuits 1-1 to 1-n, and 3 is a storage circuit for storing the cells.
And the receiving circuits 1-1 to 1-1 according to the stored number.
A control circuit 4 for controlling 1-n is a transmission circuit for sequentially outputting the contents stored in the storage circuit 2 to the transmission line. When the number of cells stored in the control circuit 3 exceeds a predetermined first threshold value, one of the receiving circuits 1-1 to 1-n is set to a first cell whose number of stored cells is separately determined. Is set to a cell transmission disabled state until the threshold value becomes equal to or less than a second threshold value smaller than the threshold value, and the receiving circuit discards cells received thereafter.

Next, the operation of the embodiment shown in FIG. 1 will be described. First, cells generated by a plurality of information sources are received by receiving circuits 1-1, 1-2,... 1-n, time-division multiplexed with each other, and input to the storage circuit 2. The storage circuit 2 has a capability of storing a plurality of cells, and when a cell is input, outputs the number of the input receiving circuit and the current storage number to the control circuit 3. Next, when the input storage number is equal to or larger than the predetermined first threshold value, the control circuit 3 outputs a storage disable signal to the receiving circuit based on the input receiving circuit number at the same time. This storage non-permission signal continues until the number of stored data becomes equal to or less than the second threshold value that is separately determined. Therefore, the receiving circuit discards the cell received while receiving the storage non-permission signal. The output of the storage circuit 2 is output to the transmission line in the order input by the transmission circuit 4.

FIG. 2 is a block diagram showing a configuration example of the control circuit 3 in FIG. In FIG. 2, terminal 3-1
From, the number of storages and the receiving circuit number are input. 3-2, 3-
Numeral 3 is a comparison circuit, which compares the first threshold value and the second threshold value with the inputted number of storages, respectively.
The pulse is output when the number of stored data exceeds the threshold value and when the number of stored data decreases below the threshold value in the comparison circuit 3-3. 3-
Reference numerals 4, 3-5,..., 3-6 denote set-reset flip-flop circuits capable of setting and resetting. Then, the flip-flop circuit designated by the receiving circuit number received from the terminal 3-1 is set by the pulse from the comparison circuit 3-2, and all the flip-flop circuits 3-4 to 3-6 are compared. It is reset by a pulse from the circuit 3-3. The flip-flop circuits 3-4, 3-
Each output of 5 ... 3-6 is connected to terminals 3-7, 3-8 ... 3
Each of the receiving circuits is connected to the corresponding receiving circuit via -9, and a storage disapproval number is given to the receiving circuit.

[0009]

As described above, the multiplexing apparatus of the present invention has an effect that the overall transmission efficiency can be improved by executing the cell discarding biased to a specific information source with a simple configuration.

[Brief description of the drawings]

FIG. 1 is a block diagram showing one embodiment of the present invention.

FIG. 2 is a block diagram illustrating a configuration example of a control circuit in FIG. 1;

[Explanation of symbols]

 1-1 to 1-n reception circuit 2 storage circuit 3 control circuit 4 transmission circuit

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁶ , DB name) H04L 12/28 H04L 12/56

Claims (1)

(57) [Claims] 1. A communication system for multiplexing and transmitting block information to cells generated from a plurality of information sources, a plurality of receiving circuits for receiving cells from a plurality of information sources, and the plurality of receiving circuits. A storage circuit for multiplexing and temporarily storing the cells received in, a control circuit for recording the storage number of the cells of the storage circuit and controlling the reception circuit according to the storage number,
A transmission circuit for sequentially outputting the contents stored in the storage circuit to a transmission line, and when the storage number of cells in the control circuit exceeds a predetermined first threshold value, One of them is in a cell transmission disabled state until the number of stored cells becomes equal to or less than a second threshold value smaller than a first threshold value set separately, and cells received thereafter by this receiving circuit are discarded. Multiplexing device.