KR20000039013A - Apparatus and method for controlling input of switch network of asynchronous transfer mode - Google Patents

Abstract

PURPOSE: An apparatus for controlling an input of a switch network of an asynchronous transfer mode(ATM) and a method for the same are provided to minimize the occurrence of a busy state in the switch network, by generating a test cell for each connection to an input terminal in order to estimate the busy state of the path for the test cell passes, and thereby controlling an input ratio of the network. CONSTITUTION: A de-multiplexer(110) de-multiplexes an input traffic from a member to output the de-multiplex traffics. A speed controller(120) gets a received test cell sent from an ATM switch network, and provides control signals for controlling a scheduling speed with each transmitted test cell. A de-multiplexer(130) de-multiplexes the traffics received from the ATM switch network, and transfers the test cells of the de-multiplex traffic cells to the speed controller(120) and other cells thereof to the member. A scheduler(140) schedules the unreal time traffics from the de-multiplexer(110), according to the control signals. A scheduler(150) schedules the transmitted test cell from the speed controller(120), the real time traffics from the de-multiplexer(110) and the unreal time traffics from the scheduler(140) to transfer them to the ATM switch network.

Description

Input control device and method of asynchronous transfer mode switch network

The present invention relates to an input control apparatus and method for an Asynchronous Transfer Mode (ATM) switch network, and more particularly, to control traffic buffering and scheduling in an ATM switch network input circuit to control the inside of the switch network. The present invention relates to an input control apparatus and a method for solving the congestion state.

Conventionally, there is a fair scheduling between buffers with connection-specific buffers at the output terminal of the ATM switch network, or a connection-specific buffer at the input and output terminals of the ATM switch network. In the beginning and during connection, there is a method of adjusting the input rate by mutual communication according to the degree of filling of the input and output buffers. This method is suitable when there is no buffer in the switch network and it is nonblocking in the strict sense. to be.

However, in the conventional ATM switch network as described above, when there are a plurality of paths from a specific input terminal to a specific output terminal and a congestion condition occurs in a specific unit switch in the path, the occurrence of such a congestion condition is input to all connections. There was a problem that you can not notify quickly by the terminal.

Accordingly, the present invention has been made to solve the above problems, and when there are a plurality of paths from a specific input terminal to a specific output terminal and congestion occurs in a specific unit switch in the path, the input terminal is connected to all the input terminals. In the implementation of a multi-stage ATM switch network without a quick means of informing the fact, a test cell is periodically generated at each input terminal at the input terminal to estimate the relative difference in the delay time that the cell passes through the switch network to estimate the congestion state on the path. And accordingly, by adjusting the switch network input rate of the connection, a computer-readable record of the input control device and method thereof and a program for realizing the ATM switch network that can minimize the occurrence of congestion in the switch network. The purpose is to provide a medium.

1 is a configuration diagram of an embodiment of an input control apparatus of an asynchronous transfer mode switch network according to the present invention.

2 is an exemplary configuration diagram of an ATM multistage switch network to which the present invention is applied.

Explanation of symbols on the main parts of the drawings

110: first demultiplexer 120: speed controller

130: second demultiplexer 140: first scheduler

150: second scheduler

In order to achieve the above object, the present invention provides an input control apparatus of an Asynchronous Transfer Mode (ATM) switch network. First demultiplexing means for outputting; Speed control means for receiving a received test cell multiplexed and transmitted from the ATM switch network and providing a control signal for controlling a scheduling rate for each connection of a transmission test cell and traffic; Second demultiplexing means for demultiplexing the traffic received from the ATM switch network to transmit the received test cell to the speed control means and to transmit the other cell to the subscriber; First scheduling means for scheduling the non-real time traffic transmitted from the first demultiplexing means according to the control signal; And second scheduling means for scheduling the transmission test cell, the real-time traffic, and the non-real-time traffic transmitted from the first scheduling means according to the control signal, respectively, and delivering the same to the ATM switch network. .

In addition, the present invention provides an input control method of an Asynchronous Transfer Mode (ATM) switch network, comprising: a first step of demultiplexing subscriber traffic delivered from a subscriber to separate real-time traffic and non-real-time traffic; Extracting a reception test cell by demultiplexing a traffic received from the ATM switch network; A third step of scheduling non-real-time traffic demultiplexed in the first step for each connection; A fourth step of generating a transmission test cell each time a predetermined number of user cells are transmitted for each connection; And a fifth step of scheduling the real-time traffic, the non-real-time traffic scheduled in the second step, and the transmission test cell according to a predetermined priority and delivering the same to the ATM switch network.

The present invention also provides an information providing system having a processor, comprising: a first function of separating subscriber traffic from real-time traffic and non-real-time traffic; A second function of extracting a receiving test cell from a traffic received from an asynchronous delivery mode switch network; A third function of scheduling the non-real-time traffic for each connection; A fourth function of generating a transmission test cell every time a certain number of user cells are transmitted for each connection; And a program for realizing a fifth function of scheduling the real-time traffic, the non-real-time traffic scheduled by the second function, and the transmission test cell by a predetermined priority, and delivering the same to the asynchronous delivery mode switch network. Provides a record medium that can be.

Hereinafter, with reference to the accompanying drawings will be described in detail a preferred embodiment of the present invention.

1 is a configuration diagram of an input control device of an asynchronous transfer mode switch network according to the present invention.

As shown in FIG. 1, the input control apparatus of an ATM switch network of the present invention is an input control apparatus of an Asynchronous Transfer Mode (ATM) switch network, and demultiplexes input traffic transmitted from a subscriber. The first demultiplexer 110 outputs multiplexed real-time traffic and non-real-time traffic, and a reception test cell multiplexed and transmitted from an ATM switch network, and receives a scheduling rate for each connection of the transmission test cell and traffic. The speed control unit 120 provides a control signal for controlling, and the test cell of the cells demultiplexed by demultiplexing the traffic received from the ATM switch network is delivered to the speed control unit 120, and other cells are transmitted to the subscriber. 2 The non-real time traffic transmitted from the first demultiplexer 110 is scheduled according to the demultiplexer 130 and the control signal transmitted from the speed controller 120. According to the first scheduler 140 and the control signal transmitted from the speed controller 120, the transmission test cell transmitted from the speed controller 120, the real-time traffic and the first demultiplexer 110 transmitted from the first And a second scheduler 150 which schedules each non-real-time traffic delivered from the scheduler 140 to the ATM switch network.

The first scheduler 140 may include buffers 141 to 14n for classifying non-real-time traffic transmitted from the first demultiplexer 110 for each connection, and control signals transmitted from the speed controller 120. The switch 14 (n + 1) selects non-real-time traffic stored for each connection in the buffers 141 to 14n and transmits the selected non-real time traffic to the second scheduler 150.

The second scheduler 150 includes a buffer 151 for storing the real-time traffic, the non-real-time traffic, and the transmission test cell, respectively, transmitted from the first demultiplexer 110, the first scheduler 140, and the speed controller 120. 153 to 153 and a switch 154 for selectively transmitting real-time traffic, non-real-time traffic, and transmission test cell stored in the buffers 151 to 153 to the ATM switch network according to the control signal transmitted from the speed controller 120. )

The operation of the input control device of the ATM switch network of the present invention having the structure as described above will be described in detail as follows.

The first demultiplexer 110 divides the input traffic from the subscriber into real-time traffic and non-real-time traffic, and sends real-time traffic to the real-time buffer of the second scheduler 150 and sends non-real-time traffic to the first scheduler 140. .

The first scheduler 140 divides the non-real-time traffic for each connection and stores them in the buffers 141 to 14n, respectively, and stores them in the buffers 141 to 14n in accordance with the scheduling speed for each connection received from the speed controller 120. The cell is taken out and sent to the non-real time buffer of the second scheduler 150. In addition, the transmission according to the speed means that even if a cell exists in the buffers 141 to 14n, the transmission is not performed unless the time corresponding to the inverse of the transmission speed of the connection has elapsed from the transmission time of the previously transmitted cell. Means that.

The second scheduler 150 is composed of a real-time buffer, a non-real time buffer, and a test cell buffer to take out cells of a high priority buffer and input them to the switch network.

In this case, the priority example is lowered in the order of the real time buffer, the test cell buffer, and the non-real time buffer.

The second demultiplexer 130 extracts the test cell from the cell coming from the switch network and sends the test cell to the speed controller 120 to send the rest to the subscriber.

The speed controller 120 monitors a cell transmitted from the first scheduler 140 to the second scheduler 150 and each time a predetermined number of user cells are transmitted for each connection, the same test identifier is transmitted at the same time. A forward test cell having transmission interval information with the cell (hereinafter referred to as a test cell input interval) is generated (that is, transmitted along the same path) and inserted into the test cell buffer 153, which is forward test cell. When arriving at the traffic control block of the called subscriber circuit via the switch network, the speed controller 120 calculates the interval information (hereinafter referred to as a test cell output interval) with the forward test cell previously arrived on the same connection, and forward test cell. Calculate the switch load factor minus this test cell output interval from the test cell input interval included in the test cell, and immediately generate the reverse test cell of the corresponding connection and input the test cell buffer 153 , Reverse test cell is transmitted through the switch network to the originating traffic control block for the connection with the switch load index.

If the value of the switch load included in the reverse test cell is negative, the traffic controller of the originating subscriber decreases the input rate of the corresponding connection, and if it is positive, increases the input rate of the corresponding connection. (140).

The speed controller 120 has the functions of both the speed controller on the input subscriber side and the speed controller on the output subscriber side so that the same circuit is used on the input and output sides.

2 is an exemplary configuration diagram of an ATM multi-stage switch network to which the present invention is applied and is an embodiment of a switch network in which a traffic controller for performing an input rate control method of an ATM switch network according to the present invention is accommodated.

Referring to Figure 2, the switch network is composed of a small unit ATM switch (hereinafter referred to as a unit switch), the longitudinally arranged switch group is called a stage (stage), the switch considered in the present invention is a plurality of stages It consists of.

The unit switches of each stage are fully interconnected so that there are several paths between specific input terminals and specific output terminals of the switch network.

Each unit switch is a common buffered ATM switch. In such a switch structure, a particular switch in the switch network is congested (that is, a condition in which a large amount of traffic is input into the buffer, causing a buffer overflow or excessive transmission delay). If it occurs, it cannot be notified to the input side immediately. Therefore, it is necessary to control the traffic input to the switch network to prevent congestion or to recover in the shortest time in the event of congestion.

The input control device (that is, the input traffic controller) of the present invention is included in the subscriber circuit connected to each input terminal and output terminal of the switch network, and in the case of the input subscriber circuit, a test cell for measuring the internal congestion degree of the switch on its own path for each connection Is generated, and the output subscriber side where the test cell arrives is configured to return the measured value to the input subscriber side.

The input subscriber side is configured to achieve the purpose of congestion control by determining the congestion state of the switch internal path through which the connection passes from the returned test cell (that is, the reverse test cell) and increasing the input rate.

Although the technical idea of the present invention has been described in detail according to the above preferred embodiment, it should be noted that the above-described embodiment is for the purpose of description and not of limitation. In addition, those skilled in the art will understand that various embodiments are possible within the scope of the technical idea of the present invention.

As described above, the present invention periodically generates a test cell for each connection in the input terminal, estimates the relative difference in delay time through which the cell passes through the switch network, and estimates congestion on the path. By controlling the input rate of the switch network to minimize the occurrence of congestion in the switch network, it is possible to quickly eliminate the congestion generated.

Claims (5)

In the input control device of the asynchronous transfer mode (ATM) switch network, First demultiplexing means for demultiplexing input traffic transmitted from the subscriber to output demultiplexed real-time traffic and non-real-time traffic; Speed control means for receiving a received test cell multiplexed and transmitted from the ATM switch network and providing a control signal for controlling a scheduling rate for each connection of a transmission test cell and traffic; Second demultiplexing means for demultiplexing the traffic received from the ATM switch network to transmit the received test cell to the speed control means and to transmit the other cell to the subscriber; First scheduling means for scheduling the non-real time traffic transmitted from the first demultiplexing means according to the control signal; And Second scheduling means for scheduling the transmission test cell, the real-time traffic, and the non-real time traffic transmitted from the first scheduling means according to the control signal, respectively, and delivering the same to the ATM switch network according to a predetermined priority. Input control device for asynchronous transfer mode switch network made, including. The method of claim 1, The first scheduling means, A plurality of storage means for storing the non-real time traffic transmitted from the first demultiplexing means for each connection; And Switching means for selectively switching the non-real-time traffic stored for each connection in the plurality of storage means to the second scheduling means in accordance with the control signal Input control device for asynchronous transfer mode switch network made, including. The method of claim 1, The second scheduling means, First storage means for temporarily storing the real-time traffic delivered from the first demultiplexing means; Second storage means for temporarily storing the non-real-time trix transmitted from the first scheduling means; Third storage means for storing the transmission test cell transmitted from the speed control means; And Switching means for selectively switching real-time traffic, non-real-time traffic and transmission test cells respectively stored in the first to third storage means according to the control signal to the ATM switch network; Input control device for asynchronous transfer mode switch network made, including. In the input control method of the asynchronous transfer mode (ATM) switch network, Demultiplexing subscriber traffic delivered from the subscriber to separate real-time traffic and non-real-time traffic; Extracting a reception test cell by demultiplexing a traffic received from the ATM switch network; A third step of scheduling non-real-time traffic demultiplexed in the first step for each connection; A fourth step of generating a transmission test cell each time a predetermined number of user cells are transmitted for each connection; And A fifth step of scheduling the real-time traffic, the non-real-time traffic scheduled in the second step, and the transmission test cell by a predetermined priority, and delivering the same to the ATM switch network; Input control method of the asynchronous delivery mode switch network made, including. In an information providing system having a processor, A first function of separating subscriber traffic from real-time traffic and non-real-time traffic; A second function of extracting a receiving test cell from a traffic received from an asynchronous delivery mode switch network; A third function of scheduling the non-real-time traffic for each connection; A fourth function of generating a transmission test cell every time a certain number of user cells are transmitted for each connection; And A fifth function of scheduling the real-time traffic, the non-real-time traffic scheduled in the second function, and the transmission test cell according to a predetermined priority and delivering the same to the asynchronous delivery mode switch network. A computer-readable recording medium having recorded thereon a program for realizing this.