JP5280953B2 - Communication device, flow control method in communication device, and program therefor - Google Patents

Description

  The present invention relates to a flow control technique in a communication device, and in particular, a communication device capable of preventing an increase in a buffer amount and a delay time in a communication device by estimating a communication port that causes congestion and performing flow control. And a flow control method thereof, and a program therefor.

  In general, a relay apparatus connected to an access network does not perform traffic congestion control, and therefore a buffer design is performed so that no frame loss occurs even under worst traffic conditions. For this reason, in the past, it was assumed that worst-case conditions would occur in all devices where traffic could be congested due to concentrating, and a buffer with sufficient capacity to prevent frame loss in any case should be implemented. It was.

  However, in reality, the probability that the worst condition will occur is very low. In the entire network, most buffers are usually free and buffer resources are wasted. In order to reduce the buffer amount for the purpose of avoiding such waste, flow control for preventing the worst condition from occurring is necessary.

  As a conventional technique related to the flow control technique, a PAUSE function is defined in IEEE 802.3. According to this PAUSE function, flow control in a full-duplex Ethernet (registered trademark) link is possible. When the traffic input to a device temporarily increases and frame loss due to buffer overflow may occur, the PAUSE frame is received by transmitting the PAUSE frame to the other side of the full-duplex link. The other party can stop sending data frames and prevent buffer overflow. In addition, the PAUSE frame suppresses the transmission of the data frame, but does not affect the transmission of the MAC control frame (for example, the PAUSE frame from the reverse direction) (for example, see Non-Patent Document 1).

  As another conventional technique related to the flow control technique, a PFC function is defined in IEEE 802.1. According to this PFC function, flow control in a full-duplex Ethernet (registered trademark) link is possible. If traffic of a specific priority input to a device temporarily increases and frame loss due to buffer overflow may occur, specify the priority for the other side of the full-duplex link. By transmitting the PAUSE frame, the partner side that has received the PAUSE frame can stop the transmission of the data frame and prevent buffer overflow (for example, see Non-Patent Document 2).

  As a conventional technique using a PAUSE frame, it is determined whether or not the amount of data accumulated for each priority queue exceeds a stop threshold, and a transmission stop of a data frame including priority class information and stop time is notified. A device that transmits a flow control message and receives the flow control message stops reading data frames accumulated in the class queue until the stop time included in the flow control message elapses after reception. There is a method (for example, refer to Patent Document 1).

  Also, as a conventional technique, when there is one output port, the amount of data input for each input port is monitored, and transmission is stopped for an input port with a large amount of input data. There is a flow control method in which only the traffic of the user is limited, and the traffic from other users or the traffic to be given priority is not limited.

JP 2006-020027 A

IEEE Std. 802.3-2005 Annex 31B IEEE Std. 802.1Qbb / D0.2

  By using the existing prior art described above, frame loss due to buffer overflow can be prevented, and high priority traffic can be transferred with a short delay time even when low priority traffic is congested. Further, when there is only one output port, only the traffic causing the congestion is stopped, and flow control that does not affect other traffic can be performed.

  On the other hand, in order to prevent frame loss, a buffer of the maximum burst × the number of communication ports is required at a minimum, the PAUSE timing is synchronized with all communication ports, and there is a possibility that an increase in delay occurs. When there are a plurality of traffics, there is a possibility that traffic that is not the cause of congestion may be stopped.

  For example, in the method of Patent Document 1, an apparatus having a plurality of input-side communication ports and output-side communication ports has an algorithm for estimating a communication port that causes congestion in a communication port where congestion occurs. Therefore, there is a possibility that traffic that is not causing congestion may be stopped, the congestion cannot be effectively controlled, and the utilization efficiency of the entire network is lowered, and the delay may be increased.

  The present invention solves the above-described problems, estimates a communication port that causes congestion, performs flow control, and prevents an increase in buffer amount and delay, and its flow control method, and therefore The purpose is to provide a program.

The present invention employs the following configuration in order to achieve the above object.
a) A communication apparatus according to the present invention includes a plurality of input-side communication ports, a plurality of output-side communication ports, a plurality of output queues, and a controller for controlling a flow, and receives a frame received from the input-side communication port. A communication device that buffers the output queue according to a destination communication port and priority, reads the frame buffered in the output queue having a high priority first, and transmits the frame from the output communication port, the input communication port Initial stop means for stopping the frame transmission by sending a transmission stop message by designating a priority corresponding to the priority of the output queue, and the initial stop performed by the initial stop means. Stop effect determination means for determining effectiveness, and frame transmission stop when it is determined by the stop effect determination means that the initial stop is effective A restart determination means for determining whether to cancel or not, and when it is determined by the determination of the stop effect determination means that there is no effect on the initial stop, it is transmitted next from the input side communication ports that are not the stop ports Select a port to be stopped, specify a priority corresponding to the priority of the output queue, send a transmission stop message to stop the frame transmission, and an additional stop means for stopping the frame transmission, and restart by the restart determination means then when it is determined, possess a total stop port resuming means for resuming the transmission to frames transmitted a transmission resumption message specifying the priority has stopped the entire stop port, said controller of each of the output queues Means for measuring a buffer amount (queue length) and means for measuring a flow rate of a frame input from the input side communication port, wherein the initial stop means is predetermined. Step S1a that waits for the normal standby time t0, step S1b that measures the communication amount of each input side communication port, sorts and stores the input side communication ports in descending order of flow for each normal standby time t0, Step S1c for measuring the queue length qn of each output queue, Step S1d for determining the size of the queue length qn and a predetermined stop threshold value x0, and Step S1a when the queue length qn is less than the stop threshold value x0 When the queue length qn is equal to or greater than the stop threshold x0, the priority corresponding to the priority of the output queue is designated from the port with the highest flow rate among the input side communication ports, and a transmission stop message is sent. The stop effect determining means executes the process consisting of step S1e for stopping the frame transmission from the port with the largest flow rate. Step S2a for storing the queue length qm, step S2b for waiting for a predetermined redetermination time t1, step S2c for measuring the queue length qn of the output queue, the queue length qn and the queue length qm When the queue length qn is greater than or equal to the queue length qm, the process proceeds to the process by the additional stop unit, and when the queue length qn is less than the queue length qm, the process proceeds to the process by the restart determination unit. Step S2d to be transferred is executed, and the restart determination means initializes the storage of the difference Δ between the queue length qn and the queue length qm, and the queue length qn is a predetermined restart. The threshold value x1 is determined to be large or small, and if the queue length qn is smaller than the restart threshold value x1, the process proceeds to the processing by the all-stop port restarting means, If the queue length qn is equal to or greater than the restart threshold value x1, if a stop time for stopping frame transmission has been designated in advance, a stop instruction is issued again, and the process consisting of step S3b that shifts to the process by the stop effect determining means is performed. The addition stop means 4 executes step S4a for determining the size of the queue length qn and a predetermined additional stop threshold x2, and if the queue length qn is smaller than the additional stop threshold x2, the queue length difference (qn− step S4b for storing qm) as Δ, step S4c for transmitting a transmission resumption message by designating the priority stopped from the stop port, and the port having the next largest flow rate after the previous stop port among the input side communication ports. Step S4 for designating a priority corresponding to the priority of the output queue and transmitting a transmission stop message to stop frame transmission If the queue length qn is greater than or equal to the additional stop threshold x2 in step S4a, step S4e determines whether or not the determination that the queue length qn is greater than or equal to the additional stop threshold x2 is the second or subsequent time in step S4a. As a result of the determination in step S4e, if it is the first time, from step S4f for transmitting the transmission resumption message by designating the priority stopped from the stop port, and from the input side communication port where Δ is not 0 and the minimum As a result of the determination in step S4g and step S4e in which a transmission stop message is transmitted by specifying a priority corresponding to the priority of the output queue and the frame transmission is stopped, if the second and subsequent times, Δ Specify a priority corresponding to the priority of the corresponding output queue from the smallest input side communication port that is not 0 and send stop message A step S4h stopping the transmitted frame transmission, to execute the processing consisting of is characterized in Rukoto.

b) A flow control method according to the present invention includes a plurality of input communication ports, a plurality of output communication ports, a plurality of output queues, and a controller for controlling a flow, and a frame received from the input communication port. A flow control method based on computer control in a communication device that reads a frame from a buffer buffered in an output queue having a high priority and transmits it from an output side communication port. An initial stop step S1 for selecting the input-side communication port, specifying a priority corresponding to the priority of the output queue, transmitting a transmission stop message, and performing an initial stop to stop frame transmission; and A stop effect determination step S2 for determining the effectiveness of the initial stop performed in the initial stop step, and the stop effect determination step When it is determined that the initial stop is effective by the determination of the loop, the restart determination step S3 for determining whether or not to cancel the frame transmission stop, and the effect of the initial stop by the determination of the stop effect determination step If it is determined that there is no port, select the next port to stop transmission from the input communication ports that are not stop ports, specify the priority corresponding to the priority of the output queue, and send a stop transmission message. An additional stop step S4 for transmitting and stopping the frame transmission, and when it is determined to restart at the restart determination step S3, a stop transmission message is transmitted by designating the priority level to all stop ports. All-stop port resuming step S5 for resuming frame transmission.

c) In the above b), the controller includes means for measuring a buffer amount (queue length) for each output queue, and means for measuring a flow rate of a frame input from the input side communication port. Step S1 waits for a predetermined normal standby time t0, measures the communication volume of each input side communication port, and sets each input side communication port in order of increasing flow rate for each normal standby time t0. Step S1b for sorting and storing, step S1c for measuring the queue length qn of each output queue, step S1d for determining the size of the queue length qn and a predetermined stop threshold value x0, and the queue length qn being the stop threshold value x0 If the queue length qn is greater than or equal to the stop threshold value x0, the flow rate is set to be within the input side communication port. Step S1e which transmits a transmission stop message by designating a priority corresponding to the priority of the output queue from the large port, and stops frame transmission from the port with the maximum flow rate. Includes a step S2a for storing the queue length qm of the output queue, a step S2b for waiting for a predetermined redetermination time t1, a step S2c for measuring the queue length qn of the output queue, the queue length qn and the The queue length qm is determined to be large or small. When the queue length qn is equal to or greater than the queue length qm, the process proceeds to the additional stop step S4. When the queue length qn is less than the queue length qm, the restart determination step. Step S2d that shifts to S3, and the restart determination step S3 includes the queue length qn and the queue length q. Step S3a for initializing the storage of the difference Δ, and the queue length qn and a predetermined restart threshold value x1 are determined, and when the queue length qn is smaller than the restart threshold value x1, the all-stop port restart step S5 If the queue length qn is greater than or equal to the restart threshold value x1, if a stop time for stopping frame transmission has been designated in advance, a stop instruction is issued again and the process proceeds to the stop effect determination step S2. The additional stop step S4 includes a step S4a for determining the size of the queue length qn and a predetermined additional stop threshold x2, and a queue length difference (qn−) if the queue length qn is smaller than the additional stop threshold x2. qm) is stored as Δ, and a transmission restart message is transmitted by designating the priority level stopped from the stop port. In step S4c, a transmission stop message is transmitted from the port having the next highest flow rate among the communication ports on the input side, the priority corresponding to the priority of the output queue, and the frame transmission is stopped. If the queue length qn is greater than or equal to the additional stop threshold x2 in step S4d and step S4a, it is determined in step S4a whether or not the determination that the queue length qn is greater than or equal to the additional stop threshold x2 is the second and subsequent times. As a result of the determination in step S4e and step S4e, if it is the first time, step S4f that designates the priority stopped from the stop port and transmits a transmission restart message, and input side communication in which Δ is not 0 and is the minimum A step to stop frame transmission by sending a transmission stop message by specifying a priority corresponding to the priority of the output queue from the port. If the result of the determination in S4g and step S4e is the second or later, the priority corresponding to the priority of the output queue is designated from the smallest input side communication port that is not 0 and is not a stop port. It is characterized by comprising step S4h of transmitting a transmission stop message and stopping frame transmission.

d) In the above c), the controller further includes means for calculating and storing a token for each input communication port using a token bucket method from the flow rate of the frame, Change the step S1ba to observe and calculate and sort the tokens of each input side communication port, and change the step S1e to a priority corresponding to the priority of the output queue from the port with the smallest token among the input side communication ports. A transmission stop message is designated and transmitted to change to step S1ea to stop frame transmission, and step S4d is changed to step S4dc in which the number of tokens stops next to the previous stop port.

e) In the above c), the controller further includes means for measuring a flow rate for each priority of a frame input from the input side communication port, and the step S1b is used to measure the flow rate for each priority. The flow rate for each priority measured by the means is changed to step S1bb in which each input side communication port is sorted and stored in descending order of flow rate, and the step S1e is changed to the priority of the output queue in the input side communication port. Specify a priority corresponding to the priority from the port with the highest flow rate, send a transmission stop message, change to step S1eb to stop frame transmission, and change step S4d in the input side communication port , Specify the priority corresponding to the priority from the port with the next highest flow rate corresponding to the priority of the output queue It sends a stop message, which is characterized in that changed in step S4db stopping the frame transmission.

f) In the above e), the controller further includes means for calculating and storing a token for each priority for each of the input side communication ports from the flow rate using a token bucket method, and performing the step S1bb. Change to step S1bc for observing the flow rate and calculating and sorting tokens for each priority of each input side communication port, and change the step S1eb to the priority corresponding to the priority of the output queue in the input side communication port Specify a priority corresponding to the priority from the port with the least number of tokens, transmit a transmission stop message, change to step S1ec to stop frame transmission, and change the step S4db to the token corresponding to the priority. The feature is that the step is changed to step S4dc in which the number of ports stopped next to the previously stopped port is stopped.

g) In the above c), the controller further includes means for measuring a flow rate of each destination output side communication port for each priority of a frame input from the input side communication port, and the step S1b is set for each input. The communication amount for each communication port priority is measured for each destination communication port, and each input communication port is sorted and stored in the descending order of flow rate, and the step S1bd is changed to the step S1b in the input communication port. In step S1ed, the transmission stop message is transmitted from the port with the highest priority flow rate to the output queue by specifying the priority corresponding to the priority, and the frame transmission is stopped. If the queue length qn is smaller than the additional stop threshold x2 in step S4a, the process proceeds to step 2 as it is. If the queue length qn is greater than or equal to the additional stop threshold x2, step S4e is performed, and the priority corresponding to the priority from the port having the highest priority flow rate to the output queue next to the previous stop port among the input side communication ports. Is transmitted, and a transmission stop message is transmitted to change to step S4ed for stopping frame transmission.

h) In the above g), the controller uses a token bucket method based on the flow rate of each destination output side communication port for each priority of the frame input from the input side communication port and the flow rate. Means for calculating and storing a token for each output side communication port according to priority for each input side communication port, and the step S1bd is a destination port for each priority level of each input side communication port by observing the flow rate. The step S1be is changed to step S1be for calculating and sorting each token, and the step S1ed is changed from the port corresponding to the priority of the output queue and the port having the smallest token of the destination port among the input side communication ports. Change to step S1ee to specify the priority corresponding to, send a transmission stop message, and stop frame transmission Said step S4ED, it is characterized in that the token corresponding to the priority and the destination port is changed to step S4ee of next small port stop last stop port.

i) Also, in the above c), the controller measures and stores the buffer amount for each queue, the priority of the frame input from the input communication port, and the frame for each destination communication port. The step S1b measures the number of distribution frames for each priority of each input side communication port and each destination communication port, and sorts and stores each input side communication port in descending order of the distribution number. The step S1bf is changed to the step S1bf, and the transmission stop message is designated by specifying the priority corresponding to the priority from the port with the highest priority distribution number to the output queue among the input side communication ports. Is changed to step S1ef to stop frame transmission, and the step S4d is A change to step S4df in which a transmission stop message is transmitted from a port whose distribution number corresponding to the priority of the power queue is the second highest after the previous stop port by specifying a priority corresponding to the priority, and frame transmission is stopped. It is characterized by.

j) In step c), the step S1b is not performed, and the step S1e is transmitted from the input side communication port-k by designating a priority corresponding to the priority of the output queue, A procedure for sending a transmission restart message specifying a priority level that has been stopped after a certain time dt and storing a difference Δk between the queue length at the time of restart and the queue length at the time of stop is performed for all communication ports on the input side. It changes to step S1eg to perform, and uses the formula fk = (Δ1 + Δ2 +... + Δn− (n−1) Δk) / (n−1) from the result of step S1eg (where n is the number of communication ports on the input side) ) Calculate the flow rate fk from the input side communication port to the queue for the time dt, and change to step S1fg to sort and store the flow rates of all the input side communication ports. A transmission stop message is transmitted from the port by specifying a priority corresponding to the priority of the output queue, and the step S1gg is changed to stop the frame transmission. The step S4a is changed to the non-stop port and the maximum fk input. It is characterized by changing to step S4ag in which a transmission stop message is transmitted from the side communication port by specifying a priority corresponding to the priority of the output queue, and frame transmission is stopped.

k) In the above c), the controller measures and stores a frame input / output time for each output queue instead of means for measuring a buffer amount (queue length) for each output queue. An average queue residence time that is a value obtained by calculating an elapsed time from the input to the queue to the output using the queue input / output time measurement unit and averaging the steps S1c over a predetermined number of frames. Is changed to step S1c for measuring and storing as tx, and step S1d is changed to step S1dh for determining the magnitude relationship between the average queue stay time tx and a predetermined stop threshold y0, and the average queue stay time tx is stopped. If the threshold value y0 is greater than or equal to the threshold value y0, the process proceeds to step S1e. If the average queue stay time tx is less than the stop threshold value y0, the process proceeds to step S1a. After step S1e, a step S1fh for calculating an average queue input time interval between predetermined redetermination times t1 and storing it as tm is provided, and step S2a is a step of observing the average queue stay time and storing it as tx Change to S2ah, change step S2c to step S2ch to calculate the average queue input time interval and store it as tn, and change step S2d to the average queue input time interval tn calculated in step S2ch and the previous step S196 Is changed to step S2dh for determining the magnitude relationship of the average queue input time interval (previous average queue input time interval) tm calculated in step S2. If the average queue input time interval tn is larger than the previous average queue input time interval tm, the process proceeds to step S3. The average queue input time interval tn is the previous average queue. If it is equal to or less than the force time interval tm, the process proceeds to step S4, and the step S3a is changed to step S3ah to determine the magnitude relationship between the average queue stay time tx and a predetermined restart threshold y1, and the average queue stay time tx Is smaller than the restart threshold y1, the process proceeds to step S5, and if the average queue stay time tx is equal to or greater than the restart threshold y1, the process proceeds to step S2. Further, step S4a is added in advance as the average queue stay time tx. The process changes to step S4dh for determining the magnitude relationship of the stop threshold y2, and if the average queue stay time tx is smaller than the additional stop threshold y2, the process proceeds to step S2. If the average queue stay time tx is equal to or greater than the additional stop threshold y2, the above step is performed. S4e in the input side communication port, the flow of the priority to the output queue A feature is characterized in that a transmission stop message is transmitted from a port that is next to the stop port by specifying a priority corresponding to the priority, and step S4eh is changed to stop frame transmission.

l) In addition, in the flow control method by computer control in the communication device according to any one of the above b) to k), the communication device includes means for storing a history of transmitting a transmission stop message from the input side communication port, and the input side When selecting a communication port as a stop port, refer to the history of sending a transmission stop message, and if a certain history number or time has not elapsed since the port sent a transmission stop message, the communication The feature is that stop processing is not concentrated on a specific port by reselecting the stop port except for the port.

m) A program according to the present invention is a program for causing a computer to execute each step in the flow control method according to any one of the above b) to l).

  According to the present invention, it is possible to appropriately estimate a communication port causing congestion and perform flow control, and to prevent an increase in buffer amount and delay time in the communication device. A flow control method and a program therefor can be realized.

It is a common processing flow in the communication apparatus which concerns on this invention. It is a block diagram which shows an example of the flow control using the communication apparatus which concerns on Embodiment 1 of this invention. In the first embodiment of the present invention, the initial stop of step S1 in FIG. 1, the stop effect determination of step S2 (determining the effect of stopping transmission), the restart determination of step S3 (determining whether to restart transmission), step It is a figure which shows the detail of the addition stop (transmission is stopped by addition) of S4. It is a figure for demonstrating Embodiment 2 of this invention (processing flow). It is a figure for demonstrating Embodiment 3 of this invention (structure figure). It is a figure for demonstrating Embodiment 3 of this invention (processing flow). It is a figure for demonstrating Embodiment 4 of this invention (processing flow). It is a figure for demonstrating Embodiment 5 of this invention (structure figure). It is a figure for demonstrating Embodiment 5 of this invention (processing flow). It is a figure for demonstrating Embodiment 6 of this invention (processing flow). It is a figure for demonstrating Embodiment 7 of this invention (structure figure). It is a figure for demonstrating Embodiment 7 of this invention (processing flow). It is a figure for demonstrating Embodiment 8 of this invention (structure figure). It is a figure for demonstrating Embodiment 8 of this invention (processing flow). It is a figure for demonstrating Embodiment 9 of this invention (structure figure). It is a figure for demonstrating Embodiment 9 of this invention (processing flow). It is a figure for demonstrating Embodiment 10 of this invention (processing flow).

  Embodiments of the present invention will be described below in detail with reference to the drawings. In addition, this invention is not limited by the following description, In the range which does not deviate from the summary of this invention, it can change suitably.

Hereinafter, FIGS. 1, 2, and 3 are diagrams for explaining the first embodiment of the present invention.
FIG. 1 is a common processing flow in the communication apparatus according to the present invention. FIG. 2 is a configuration diagram illustrating an example of flow control using the communication apparatus according to the present embodiment.

  In FIG. 2, 1 is a communication apparatus according to the present invention, 2 is a transmission side communication node, and 3 is a reception side communication node. The communication device 1, the transmission side communication node 2, and the reception side communication node 3 are respectively connected via a communication port (input side communication port or reception side communication port) 12 and a communication port (output side communication port or transmission side communication port) 13. Connected.

  In the communication device 1, the frame received by the input side communication port 12 from the transmission side communication node 2 is queued in the output queue 16 by the distribution unit 14 according to the destination port and priority. There can be any number of output queues (FIG. 2 shows four cases). The queue reading unit 18 reads the frame queued in the queue with the higher priority first, and the read frame is transmitted from the output side communication port 13 to the reception side communication node 3.

  The controller 11 performs the processing shown in the flowchart of FIG. 1 (more specifically, the processing shown in the flowcharts of FIGS. 3, 4, 6, 7, 9, 10, 12, 14, 16, and 17) for each output queue 16. Execute flow control. At this time, the output queues 16 to be processed may be selected one by one in any order, or all the output queues 16 may be processed in parallel. Alternatively, some queues may be processed one by one and other queues may be processed in parallel. Reference numeral 15 denotes a flow rate measuring unit that measures the flow rate, and 17 denotes a cue length measuring unit that measures the queue length.

  In the figure, symbols such as -1, -2, -11, -12, -21, -22 assigned to 2, 3, 12, 13, 15, 16, 17, 18, etc. are plural. This is a symbol for distinguishing elements, but in the following, when there is no need to distinguish between them, they are omitted for the sake of simplicity.

  The processing of the flowchart of FIG. 1 performed by the controller 11 (more specifically, the processing shown in the flowcharts of FIGS. 3, 4, 6, 7, 9, 10, 12, 14, 16, 17) is performed as the communication device 1. This is performed by executing a program corresponding to each process using hardware such as a CPU and a memory of a functioning computer. Needless to say, programs corresponding to these processes can be distributed to the market via a network such as the Internet or a recording medium such as a CD-ROM, DVD, or FD.

Next, processing in each step of FIG. 1 will be described.
In step S1, the input side communication port 12 is selected, a priority corresponding to the priority of the output queue 16 is designated, a transmission stop message is transmitted, and an initial stop is performed to stop frame transmission, and the process proceeds to step S2. .

  When transmitting a transmission stop message, in any case, a stop time for stopping frame transmission may be designated in advance. Here, the case where the VLAN to be stopped is specified at the same time is also included. Hereinafter, the input-side communication port 12 that transmits a transmission stop message to stop frame transmission is referred to as a “stop port”.

  In step S2, a stop effect determination for determining the effectiveness of the initial stop performed in step 1 is performed. If it is determined that the initial stop is effective (step S2: Y), the process proceeds to step S3, and the initial stop is effective. If it is determined that there is not (step S2: N), the process proceeds to step S4.

  If there is an effect on the initial stop, in step S3, it is determined whether or not to cancel the frame transmission stop, and if it is determined to restart (step S3: Y), it is determined not to restart to step S5. In the case (step S3: N), the process proceeds to step S2.

  If the initial stop is not effective, in step S4, the next port to stop transmission is selected from the input side communication ports 12 that are not stop ports, and the priority corresponding to the priority of the output queue 16 is specified. Then, an additional stop is performed to stop the frame transmission by transmitting a transmission stop message, and then the process proceeds to step S2.

  In step S5, the stop priority is specified for all the stop ports, a transmission restart message is transmitted to restart frame transmission, and then the process proceeds to step S1.

  3 shows an initial stop in step S1 in FIG. 1, a stop effect determination in step S2 (determining the effect of stopping transmission), a restart determination in step S3 (determining whether to restart transmission), and an additional stop in step S4. It is a figure which shows the detail in a present Example of (stop transmission by addition).

  In step S1 (initial stop), as shown in the figure, first, it waits for a predetermined normal standby time t0 (step S111), and the communication of each input side communication port 12 using the flow rate measurement unit 15 is performed. The amount is measured, and the input communication ports 12 are sorted and stored in descending order of flow rate at each normal standby time t0 (step S112).

  Next, the queue length qn of each output queue 16 is measured using the queue length measurement unit 17 (step S113). Then, the queue length qn and a predetermined stop threshold value x0 are determined (step S114). If the queue length qn is less than the stop threshold value x0, the process returns to step S1, and the queue length qn is greater than or equal to the stop threshold value x0. If there is, a transmission stop message is transmitted from the port with the highest flow rate among the input side communication ports 12 by specifying a priority corresponding to the priority of the output queue 16, and from the port with the highest flow rate. Frame transmission is stopped (step S115), and the process proceeds to the next step S2.

  In step S2 (stop effect determination), as shown in the figure, the queue length qm of the output queue 16 is stored (step S211), and after waiting for a predetermined re-determination time t1 (step S212), the queue length The measurement unit 17 is used to measure the queue length qn of the output queue 16 (step S213).

  Next, the size of the queue length qn and the queue length qm are determined (step S214). If the queue length qn is equal to or greater than the queue length qm (step S214: N), there is no port that has stopped transmission so far. When it is determined that it is appropriate (no stop effect), the process proceeds to step S4. When the queue length qn is less than the queue length qm (step S214: Y), the port for which transmission is stopped is appropriate ( It is determined that there is a stop effect) and the process proceeds to step S3.

  In step S3 (resumption determination), as shown in the figure, first, the storage of the queue length difference Δ (= qn−qm) is initialized (Δ = 0: step S311), and the queue length qn and a predetermined resumption threshold value are set. x1 is determined (step S312). If the queue length qn is smaller than the restart threshold value x1 (step S312: Y), it is determined that the queue length has become sufficiently short, and the process proceeds to step S5 to restart transmission. If the queue length qn is equal to or greater than the restart threshold value x1 (step S312: N), if a stop time for stopping frame transmission has been designated in advance, a stop instruction is issued again, and the process proceeds to step S2. The difference Δ is indicated by a right triangle in FIG. 3 (the same applies to FIGS. 4, 6, 7, 12, and 14 described later).

  In step S4 (additional stop), as shown in the figure, first, the queue length qn and a predetermined additional stop threshold value x2 are determined (step S411). If the queue length qn is smaller than the additional stop threshold value x2, If the selection of the port whose transmission is stopped is inappropriate, the queue length difference (qn−qm) is stored as Δ (step S412), and the transmission restart message is transmitted by designating the priority level from the stopped port. (The additional stop threshold value x2 may be the same as the stop threshold value x0) (step S413).

  Next, the priority corresponding to the priority of the output queue 16 is designated from the port whose flow rate is next to the previous stop port, which is considered to be more effective in stopping transmission among the input side communication ports 12. Then, a transmission stop message is transmitted to stop frame transmission (step S414), and the process proceeds to step S2.

  If the queue length qn is greater than or equal to the additional stop threshold value x2 in step S411, it is determined in step S411 whether or not the determination that the queue length qn is greater than or equal to the additional stop threshold value x2 is the second or subsequent time (step S415). If it is the first time, a priority for stopping from the stop port is specified and a transmission restart message is transmitted (step S416), and the priority of the output queue 16 from the input side communication port 12 where Δ is not 0 and is the minimum. The transmission stop message is transmitted by designating the priority corresponding to, and frame transmission is stopped (step S417), and the process proceeds to step S418.

  If it is the second time or later in step S415, a transmission stop message is sent by designating a priority corresponding to the priority of the output queue 16 from the smallest input side communication port 12 that is not a stop port, and Δ is not 0. The frame transmission is stopped (step S418), and the process proceeds to step S2.

  According to the present embodiment, it is possible to determine a port having a large flow rate to the output queue and stop transmission by the series of processes described above.

  FIG. 4 is a diagram for explaining the second embodiment of the present invention. The second embodiment has substantially the same configuration as that of the first embodiment, but differs in the following points.

  In the second embodiment, in place of step S112, step S122 is performed in which the flow rate is observed, the tokens of the input communication ports 12 are calculated and sorted. Instead of step S115, a transmission stop message is transmitted by designating a priority corresponding to the priority of the output queue 16 from the port having the smallest token in the input side communication port 12, and the frame transmission is stopped. I do. Instead of step S414, step S424 is performed in which the number of tokens stops next to the previous stop port.

  According to the present embodiment, it is possible to determine a port having a large flow rate to the output queue and stop transmission by the token bucket method by the above-described processing.

  5 and 6 are diagrams for explaining the third embodiment of the present invention. FIG. 5 is a configuration diagram, and FIG. 6 is a processing flow diagram. In FIG. 5, reference numeral 4 denotes a communication apparatus according to the present invention, which has substantially the same configuration as in FIG. 2, but a priority sorting unit 19 is connected in front of the flow rate measuring unit 15.

  The third embodiment has substantially the same configuration as that of the first embodiment, but differs in the following points. In the third embodiment, instead of step S112, the communication amount for each priority distributed by the priority distribution unit 19 of each input communication port 12 is measured, and each input communication port 12 is set in descending order of flow rate. Sort and store (step S132).

  Instead of step S115, a transmission stop message is transmitted by designating the priority corresponding to the priority from the port having the maximum flow rate corresponding to the priority of the output queue 16 in the input side communication port 12, and sending the frame Transmission is stopped (step S135). Instead of step S414, transmission is stopped by designating the priority corresponding to the priority from the port having the flow rate corresponding to the priority of the output queue 16 next to the previous stop port in the input side communication port 12. A message is transmitted and frame transmission is stopped (step S434).

  According to the present embodiment, it is possible to determine a port having a large flow rate to the output queue and stop transmission by the above-described processing.

  FIG. 7 is a diagram for explaining the fourth embodiment of the present invention. The fourth embodiment has substantially the same configuration as that of the third embodiment, but differs in the following points.

  In the fourth embodiment, in place of step S132, step S142 is performed in which the flow rate is observed, the tokens for each priority of the input communication ports 12 are calculated and sorted. Instead of step S135, a transmission stop message is transmitted by designating a priority corresponding to the priority from the port having the least priority token corresponding to the priority of the output queue 16 in the input side communication port 12. Then, step S145 for stopping frame transmission is performed. Instead of Step S434, Step S444 is performed in which the number of tokens corresponding to the priority is the second smaller than the previous stop port.

  According to the present embodiment, it is possible to determine a port having a large flow rate to the output queue and stop transmission by the token bucket method by the above-described processing.

  8 and 9 are diagrams for explaining the fifth embodiment of the present invention. In FIG. 8, reference numeral 5 denotes a communication apparatus according to the present invention, which has almost the same configuration as that in FIG. 2, but uses a distribution unit 54 with a flow measurement function instead of the distribution unit 14 and does not use the flow measurement unit 15. The fifth embodiment has substantially the same configuration as that of the first embodiment, but differs in the following points.

  In the fifth embodiment, instead of step S112, the communication volume for each priority communication port 12 is measured for each input communication port 12, and the input communication ports 12 are sorted and stored in descending order of flow rate. (Step S152).

  Instead of step S115, a transmission stop message is transmitted by designating a priority corresponding to the priority from the port with the highest priority flow rate to the output queue 16 in the input side communication port 12, Transmission is stopped (step S155). Step S312 is performed without performing step S311.

  If the queue length qn is smaller than the additional stop threshold value x2 in step S411, the process proceeds to step 2 as it is. If the queue length qn is equal to or larger than the additional stop threshold value x2, the input communication port 12 uses A transmission stop message is transmitted by designating a priority corresponding to the priority from the port having the next highest priority flow rate to the output queue 16 after the previous stop port, and frame transmission is stopped (step S455).

  According to the present embodiment, it is possible to reliably determine a port having a large flow rate to the output queue and stop transmission by the above-described processing.

  FIG. 10 is a diagram for explaining the sixth embodiment of the present invention. The sixth embodiment has substantially the same configuration as that of the fifth embodiment, but differs in the following points.

  In the sixth embodiment, instead of step S152, step S162 of observing the flow rate, calculating and sorting tokens for each destination port for each priority of each input-side communication port 12 is performed. Instead of step S155, transmission is stopped by specifying the priority corresponding to the priority of the output queue 16 in the input side communication port 12 and the priority corresponding to the priority from the port having the smallest token of the destination port. A message is transmitted and step S165 for stopping frame transmission is performed. In place of step S454, step S464 is performed in which the port corresponding to the priority and the destination port has the next few ports after the previous stop port.

  According to the present embodiment, by the above-described processing, it is possible to determine a port having a large flow rate to the output queue and stop transmission by the token bucket method.

  11 and 12 are diagrams for explaining the seventh embodiment of the present invention. In FIG. 11, reference numeral 6 denotes a communication apparatus according to the present invention, which has almost the same configuration as in FIG. 2, but uses a distribution unit 64 with a distribution destination measurement function instead of the distribution unit 14 and does not use the flow rate measurement unit 15. . The seventh embodiment has substantially the same configuration as that of the first embodiment, but differs in the following points.

  In the seventh embodiment, instead of step S112, the number of distribution frames for each priority communication port 12 is measured for each input communication port 12, and the input communication ports 12 are sorted in descending order of the distribution number. (Step S172).

  Instead of step S115, a transmission stop message is transmitted by designating the priority corresponding to the priority from the port with the highest priority distribution to the output queue 16 in the input side communication port 12. Frame transmission is stopped (step S175). Instead of step S414, the input side communication port 12 designates the priority corresponding to the priority from the port whose distribution queue corresponding to the priority of the output queue 16 is the second largest after the previous stop port, and transmits. A stop message is transmitted to stop frame transmission (step S474).

  According to the present embodiment, the above-described processing makes it possible to predict a port having a large flow rate to the output queue from the number of distribution and stop transmission. Further, since the distribution unit 64 only needs to have a function of counting the number of frames, there is an advantage that the configuration can be simplified.

  13 and 14 are diagrams for explaining the eighth embodiment of the present invention. In FIG. 13, reference numeral 7 denotes a communication device according to the present invention, which has substantially the same configuration as that in FIG. 2, but does not use the flow rate measurement unit 15. The eighth embodiment has substantially the same configuration as that of the first embodiment, but differs in the following points.

  In the eighth embodiment, step S112 is not performed, and instead of step S115, a priority corresponding to the priority of the output queue 16 is specified from the input-side communication port 12-k, and a transmission stop message is transmitted. A procedure for sending a transmission restart message specifying a priority level that has been stopped after time dt and storing the difference Δk between the queue length at the time of restart and the queue length at the time of stop is performed for all the communication ports 12 on the input side. This is performed (step S185).

  Assuming that the communication device 7 includes n input-side communication ports 12 greater than 1, the expression fk = (Δ1 + Δ2 +... + Δn− (n−1) Δk) / (n−1) is obtained from the result of step S185. The flow rate fk during the time dt from the input side communication port 12-k to the queue is calculated, and the flow rates of all the input side communication ports 12 are sorted and stored (step S186).

  After that, a priority corresponding to the priority of the output queue 16 is designated from the input side communication port 12-k having the maximum fk, a transmission stop message is transmitted, and frame transmission is stopped (step S187). Instead of step S411, a transmission stop message is transmitted from the non-stop port and fk maximum input side communication port 12-k by specifying a priority corresponding to the priority of the output queue 16, and frame transmission is stopped. (Step S481) to stop the addition.

  According to the present embodiment, it is possible to estimate a port with a large flow rate to the output queue and stop transmission while observing only the queue length by the above-described processing.

  15 and 16 are diagrams for explaining the ninth embodiment of the present invention. In FIG. 15, reference numeral 8 denotes a communication apparatus according to the present invention, which has almost the same configuration as in FIG. 2, but uses a queue input / output time measurement unit 79 instead of the queue length measurement unit 17. The ninth embodiment has substantially the same configuration as that of the first embodiment, but differs in the following points.

  In the ninth embodiment, instead of step S113, the average queue stay time is observed and stored as tx (step S193). Here, the average queue stay time means a value obtained by calculating an elapsed time from an input to an output queue 76 for an arbitrary frame until it is output, and measuring a queue input / output time. The unit 79 is used to store the cue input time and cue output time of each frame, calculate the difference between them, and observe the average value of a certain number of frames.

  Instead of step S114, the magnitude relationship between the average queue stay time tx and the predetermined stop threshold y0 is determined (step S194). Is less than the stop threshold y0, the process proceeds to step S111. After step S115, an average queue input time interval between predetermined redetermination times t1 is calculated and stored as tm (step S196).

  The average cue input time interval means the value obtained by calculating the elapsed time from the input of an arbitrary frame to the queue until the next frame is input, and averaging the values for a certain number of frames. Using the unit 79, the queue input time of each frame is stored, the difference between the queue input times of one frame and the next frame is calculated, and the average value of a certain number of frames is calculated and observed.

  Instead of step S211, the average queue stay time is observed and stored as tx (step S291). Instead of step S213, an average queue input time interval is calculated and stored as tn (step S293).

  Instead of step S214, the magnitude relationship between the average queue input time interval tn calculated in step S293 and the average queue input time interval previously calculated in step S196 (referred to as the previous average queue input time interval) tm is determined (step S294). If the average queue input time interval tn is larger than the previous average queue input time interval tm, the process proceeds to step S3. If the average queue input time interval tn is equal to or less than the previous average queue input time interval tm, the process proceeds to step S4.

  Instead of step S311, the magnitude relationship between the average queue stay time tx and the predetermined restart threshold value y1 is determined (step S392). If the average queue stay time tx is smaller than the restart threshold value y1, the process proceeds to step S5. If the stay time tx is greater than or equal to the restart threshold y1, the process proceeds to step S2.

  Instead of step S411, the magnitude relationship between the average queue stay time tx and the predetermined additional stop threshold y2 is determined (step S491). If the average queue stay time tx is smaller than the additional stop threshold y2, the process proceeds to step S2. If the average queue stay time tx is equal to or greater than the additional stop threshold value y2, instead of step S415, the priority-level flow rate to the output queue 16 in the input-side communication port 12 is the port next to the previous stop port. A transmission stop message is transmitted by designating a priority corresponding to the priority, and frame transmission is stopped (step S495).

  According to the present embodiment, it is possible to determine the necessity of flow control by observing the average queue stay time instead of observing the queue length by the above-described processing.

  FIG. 17 is a diagram for explaining the tenth embodiment of the present invention. The tenth embodiment has substantially the same configuration as that of the first embodiment, but differs in the following points.

  The tenth embodiment includes means for storing a history of transmitting a transmission stop message from the input-side communication port, and instead of step S115, the port having the maximum flow rate among the input-side communication ports 12 is stored last time. It is determined whether or not it is a stop port at the time of stop (step S1105), and if it is a previous stop port, the port with the next highest flow rate among the input side communication ports 12 corresponds to the priority of the output queue 16 The transmission stop message is transmitted by designating the priority and the frame transmission is stopped (step S1106), and the process proceeds to step S2.

  If it is not the previous stop port, a priority corresponding to the priority of the output queue 16 is designated from the port, a transmission stop message is transmitted, frame transmission is stopped (step S1107), and the process proceeds to step S2. Note that the input communication port 12 for which frame transmission was stopped in step S196 or step S197 is stored as the previous stop port (step S1108).

  According to the present embodiment, as described above, when selecting the input-side communication port as the stop port in order to ensure fairness immediately before the stop process, the history of transmitting the transmission stop message is referred to, and If a certain number of histories or time has not elapsed since the port sent a transmission stop message, the stop process can be performed on a specific port by reselecting the stop port except for the communication port. Concentration can be prevented and stoppage can be made fair.

1: Communication device 2 (2-1, 2-2): Transmission side communication node 3 (3-1, 3-2): Reception side communication node 11: Controller 12 (12-1, 12-2): Communication port (Input side communication port or receiving side communication port)
13 (13-1, 13-2): Communication port (output side communication port or transmission side communication port)
14: Distribution unit 15 (15-1, 15-2, 15-11, 15-12, 15-21, 15-22): Flow rate measurement unit 16 (16-11, 16-12, 16-21, 16- 22), 76 (76-11, 76-12, 76-22): output queue 17 (17-11, 17-12, 17-21, 17-22): queue length measuring unit 18 (18-1, 18) -2): Queue read unit 19 (19-1, 19-2): Distribution unit (by priority)
54: Sorting part (with flow measurement function)
64: Sorting part (with sorting destination measurement function)
79 (79-11, 79-12, 79-21, 79-22): Queue input / output time measuring unit

Claims (12)

A plurality of input side communication ports, a plurality of output side communication ports, a plurality of output queues, and a controller for controlling a flow, the frame received from the input side communication port according to the destination communication port and the priority A communication device that buffers the output queue, reads out the frame buffered in the output queue having a high priority first, and transmits the frame from the output communication port,
Initial stop means for selecting the input side communication port, specifying a priority corresponding to the priority of the output queue and transmitting a transmission stop message to stop frame transmission;
Stop effect determination means for determining the effectiveness of the initial stop performed by the initial stop means;
When it is determined by the determination of the stop effect determination means that there is an effect on the initial stop, a restart determination means for determining whether to cancel the frame transmission stop;
If it is determined by the stop effect determining means that the initial stop is not effective, the next communication stop port is selected from the input side communication ports that are not stop ports, and the priority of the output queue is set. An additional stop means for performing an additional stop to stop frame transmission by specifying a corresponding priority and transmitting a transmission stop message;
All-stop port resuming means for retransmitting a frame by sending a transmission resumption message by designating a priority that has been stopped for all the stop ports when it is determined to be resumed by the resumption judging means;
I have a,
The controller includes means for measuring a buffer amount (queue length) for each output queue, and means for measuring a flow rate of a frame input from the input side communication port.
The initial stop means waits for a predetermined normal standby time t0, measures the communication amount of each input side communication port, and communicates each input side communication in order of increasing flow rate at each normal standby time t0. Step S1b for sorting and storing ports, Step S1c for measuring the queue length qn of each output queue, Step S1d for determining the size of the queue length qn and a predetermined stop threshold value x0, and the queue length qn are stopped. If it is less than the threshold value x0, the process returns to step S1a. If the queue length qn is equal to or greater than the stop threshold value x0, the priority is set to the priority of the output queue from the port with the largest flow rate among the input side communication ports. Specify the priority, transmit a transmission stop message, execute the process consisting of step S1e to stop frame transmission from the port with the highest flow rate,
The stop effect determining means includes step S2a for storing the queue length qm of the output queue, step S2b for waiting for a predetermined redetermination time t1, step S2c for measuring the queue length qn of the output queue, When the queue length qn is compared with the queue length qm, the process proceeds to the processing by the additional stopping means when the queue length qn is equal to or greater than the queue length qm, and the queue length qn is less than the queue length qm. In step S2d, the process proceeds to the process by the restart determination means.
The restart determination means initializes the storage of the difference Δ between the queue length qn and the queue length qm, determines whether the queue length qn is a predetermined restart threshold value x1, and determines the queue length qn. If the queue length qn is equal to or greater than the restart threshold value x1, if the stop time for stopping the frame transmission has been designated in advance, the process is resumed. Executing a process consisting of step S3b, in which a stop instruction is given and the process proceeds to the process by the stop effect determining means,
The addition stop means 4 determines whether the queue length qn is larger or smaller than a predetermined additional stop threshold x2, and if the queue length qn is smaller than the additional stop threshold x2, the queue length difference (qn−qm) is calculated. Step S4b, which is stored as Δ, step S4c, in which the priority of stopping from the stop port is specified and a transmission restart message is transmitted, and the output queue from the port having the next largest flow rate after the previous stop port among the input side communication ports In step S4d in which a transmission stop message is transmitted by designating a priority corresponding to the priority of the frame and the frame transmission is stopped, and in step S4a, if the queue length qn is equal to or greater than the additional stop threshold x2, the queue length is determined in step S4a. Step S4e for determining whether or not the determination that qn is equal to or greater than the additional stop threshold value x2 is the second and subsequent times As a result of the determination in step S4e, if it is the first time, step S4f which designates the priority stopped from the stop port and transmits a transmission resumption message, and the output from the input side communication port where Δ is not 0 and the minimum As a result of the determination in step S4g in which a transmission stop message is transmitted by specifying a priority corresponding to the priority of the queue and frame transmission is stopped and the determination in step S4e is the second or later, Δ is 0 instead of a stop port. characterized in that to run the steps S4h to and stop minimum transmitted frames transmits a transmission stop message from the input-side communication port by specifying the priority corresponding to the priority of the output queue not consist processes A communication device. A plurality of input side communication ports, a plurality of output side communication ports, a plurality of output queues, and a controller for controlling a flow, the frame received from the input side communication port according to the destination communication port and the priority A flow control method by computer control in a communication device that buffers in an output queue and first reads out a frame buffered in a high priority output queue and transmits from a communication port on the output side,
An initial stop step S1 for selecting the input-side communication port, specifying a priority corresponding to the priority of the output queue and transmitting a transmission stop message to stop frame transmission;
Stop effect determination step S2 for determining the effectiveness of the initial stop performed in the initial stop step;
A restart determination step S3 for determining whether or not to cancel the frame transmission stop when it is determined by the determination of the stop effect determination step that the initial stop is effective;
If it is determined by the stop effect determination step that there is no effect on the initial stop, a port to stop transmission next is selected from the input side communication ports that are not stop ports, and the priority of the output queue is set. An additional stop step S4 for performing an additional stop for stopping the frame transmission by specifying a corresponding priority and transmitting a transmission stop message;
All-stop port restart step S5 in which when it is determined to restart in the restart determination step S3, a stop priority is specified for all stop ports, a transmission restart message is transmitted and frame transmission is restarted;
I have a,
The controller includes means for measuring a buffer amount (queue length) for each output queue, and means for measuring a flow rate of a frame input from the input side communication port.
The initial stop step S1 includes a step S1a for waiting for a predetermined normal standby time t0, and a communication amount of each input side communication port is measured, and each input side in order of increasing flow rate for each normal standby time t0. Step S1b for sorting and storing the communication ports, Step S1c for measuring the queue length qn of each output queue, Step S1d for determining the size of the queue length qn and a predetermined stop threshold value x0, and the queue length qn If it is less than the stop threshold value x0, the process returns to step S1a. If the queue length qn is greater than or equal to the stop threshold value x0, the priority is assigned to the output queue from the port with the highest flow rate among the input side communication ports. The transmission stop message is transmitted with the designated priority, and the frame transmission from the port with the maximum flow rate is stopped.
The stop effect determining step S2 includes a step S2a for storing the queue length qm of the output queue, a step S2b for waiting for a predetermined redetermination time t1, a step S2c for measuring the queue length qn of the output queue, The queue length qn and the queue length qm are determined. If the queue length qn is equal to or greater than the queue length qm, the process proceeds to the additional stop step S4. If the queue length qn is less than the queue length qm Consists of step S2d which proceeds to the restart determination step S3,
In the restart determination step S3, a step S3a for initializing the storage of the difference Δ between the queue length qn and the queue length qm, and a determination of the size of the queue length qn and a predetermined restart threshold value x1 are performed. If qn is smaller than the restart threshold x1, the process proceeds to the all-stop port restart step S5. If the queue length qn is equal to or greater than the restart threshold x1, if a stop time for stopping frame transmission has been designated in advance, Comprising a step S3b of giving a stop instruction and proceeding to the stop effect determining step S2.
The addition stop step S4 includes a step S4a for determining the size of the queue length qn and a predetermined addition stop threshold value x2, and a queue length difference (qn−qm) if the queue length qn is smaller than the additional stop threshold value x2. Step S4b, which is stored as Δ, step S4c, in which the priority of stopping from the stop port is specified and a transmission restart message is transmitted, and the output queue from the port having the next largest flow rate after the previous stop port among the input side communication ports In step S4d in which a transmission stop message is transmitted by designating a priority corresponding to the priority of the frame, and frame transmission is stopped. In step S4a, if the queue length qn is equal to or greater than the additional stop threshold x2, the queue length is determined in step S4a Step S for determining whether or not the determination that qn is equal to or greater than the additional stop threshold value x2 is the second and subsequent times. e, if the result of determination in step S4e is the first time, step S4f for transmitting the transmission restart message by designating the priority stopped from the stop port, and the input side communication port in which Δ is not 0 and the minimum From step S4g in which the priority corresponding to the priority of the output queue is designated to transmit a transmission stop message and frame transmission is stopped and the result of determination in step S4e is the second or later, it is not a stop port, communication, characterized in that Δ is Ru step S4h Tona stopping and transmit frames transmits a transmission stop message specifying the priority corresponding from and with minimal input-side communication ports not 0 to the priority of the output queue A flow control method by computer control in an apparatus. The flow control method by computer control in the communication apparatus according to claim 2 ,
The controller further comprises means for calculating and storing a token for each input communication port using a token bucket method from the flow rate of the frame,
The step S1b is changed to a step S1ba for observing the flow rate, calculating and sorting tokens of each input side communication port, and the step S1e is prioritized from the port having the smallest token among the input side communication ports. A transmission stop message is transmitted by designating a priority corresponding to each time, and the step S1ea is changed to stop frame transmission, and the step S4d is changed to step S4dc where the number of tokens stops next to the previous stop port. A flow control method by computer control in a communication apparatus. The flow control method by computer control in the communication apparatus according to claim 2 ,
The controller further includes means for measuring a flow rate for each priority of a frame input from the input side communication port,
The step S1b is changed to the step S1bb in which the input-side communication ports are sorted and stored in descending order of the flow rate, and the flow rate for each priority measured by the means for measuring the flow rate for each priority is changed to the step S1bb. Change the step S1eb to stop the frame transmission by sending a transmission stop message by designating the priority corresponding to the priority from the port having the highest flow rate corresponding to the priority of the output queue among the communication ports on the side. In step S4d, a transmission stop message is sent by designating a priority corresponding to the priority from a port whose flow rate corresponding to the priority of the output queue is next to the previous stop port among the input side communication ports. Step S4db for transmitting and stopping frame transmission is changed to flow control by computer control in the communication device Your method. The flow control method by computer control in the communication apparatus according to claim 4 ,
The controller further comprises means for calculating and storing a token for each priority for each input-side communication port from the flow rate using a token bucket method,
The step S1bb is changed to a step S1bc for observing the flow rate and calculating and sorting tokens for each priority of the input side communication ports, and the step S1eb is changed to the priority of the output queue in the input side communication ports. The port corresponding to the lowest priority token is assigned the priority corresponding to the priority, the transmission stop message is transmitted, and the step S1ec is changed to stop the frame transmission, and the step S4db is changed to the priority. A flow control method by computer control in a communication apparatus, wherein the number of corresponding tokens is changed to step S4dc in which the number of corresponding tokens stops next to the port stopped last time. The flow control method by computer control in the communication apparatus according to claim 2 ,
The controller further comprises means for measuring a flow rate of each destination output side communication port for each priority of a frame input from the input side communication port,
The step S1b is changed to the step S1bd for measuring the communication amount for each priority communication port and the communication port for each destination communication port, and sorting and storing the input communication ports in descending order of the flow rate, and the step S1e. In step S1ed, a transmission stop message is transmitted by designating a priority corresponding to the priority from the port having the highest priority flow rate to the output queue among the input side communication ports, and stopping frame transmission. If the queue length qn is smaller than the additional stop threshold x2 in step S4a, the process proceeds to step 2 as it is. If the queue length qn is equal to or greater than the additional stop threshold x2, step S4e is input. The priority flow from the port with the next highest priority flow rate to the output queue in the communication port Flow control computer controlled method in a communication apparatus characterized by sending a transmission stop message specifying the priority corresponding to change in step S4ed stopping the frame transmission. The flow control method by computer control in the communication device according to claim 6 ,
The controller includes: a unit for measuring a flow rate for each destination output side communication port for each priority of a frame input from the input side communication port; and a priority for each input side communication port from the flow rate using a token bucket method. Means for calculating and storing a token for each destination communication port on the output side,
The step S1bd is changed to a step S1be for observing the flow rate and calculating and sorting tokens for each destination port for each input communication port priority. The step S1ed is changed to the output queue of the output queue in the input communication port. The step corresponding to the priority and the priority corresponding to the priority are designated from the port having the smallest token of the destination port, the transmission stop message is transmitted, and the step S1ee is changed to stop the frame transmission, and the step S4ed Is changed to step S4ee in which the number of tokens corresponding to the priority and the destination port is the second less than the previous stop port, and the flow control method by computer control in the communication device. The flow control method by computer control in the communication apparatus according to claim 2 ,
The controller includes means for measuring and storing the buffer amount for each queue, and means for measuring the number of frames for each destination output side communication port for each priority of frames input from the input side communication port,
The step S1b is changed to step S1bf for measuring the number of distribution frames for each input communication port priority and for each destination communication port, and sorting and storing the input communication ports in descending order of the distribution number, In S1e, a transmission stop message is transmitted from the port with the highest priority distribution number to the output queue in the input side communication port by specifying a priority corresponding to the priority, and frame transmission is stopped. Change to step S1ef, and in step S4d, specify the priority corresponding to the priority from the ports whose distribution queue corresponding to the priority of the output queue is the second largest after the previous stop port among the input side communication ports In step S4df, a transmission stop message is transmitted and frame transmission is stopped. Flow control method by computer control. The flow control method by computer control in the communication apparatus according to claim 2 ,
The step S1b is not performed, and the step S1e is transmitted from the input side communication port-k by designating a priority corresponding to the priority of the output queue, and a transmission stop message is transmitted. Is changed to step S1eg, in which the procedure of transmitting a transmission restart message by designating and storing the difference Δk between the queue length at the time of restart and the queue length at the time of stop is performed for all the communication ports on the input side. From the result of S1eg, using the formula fk = (Δ1 + Δ2 +... + Δn− (n−1) Δk) / (n−1) (where n is the number of input side communication ports), The flow rate fk during the time dt to the queue is calculated, and the flow is changed to step S1fg for sorting and storing the flow rates of all the input side communication ports. A transmission stop message is transmitted by designating a priority corresponding to the priorities, and the step S1gg is changed to stop the frame transmission, and the step S4a is output from the non-stop port and the fk maximum input side communication port. A flow control method by computer control in a communication device, wherein the priority is changed to step S4ag in which a transmission stop message is transmitted by designating a priority corresponding to the priority of the queue and frame transmission is stopped. The flow control method by computer control in the communication apparatus according to claim 2 ,
The controller comprises queue input / output time measuring means for measuring and storing the frame input / output time for each output queue instead of means for measuring the buffer amount (queue length) for each output queue,
In step S1c, the elapsed time from the input to the queue being output using the queue input / output time measuring means is calculated, and the average queue stay time that is an average value over a certain number of frames is observed as tx. Step S1c is changed to step S1c, and step S1d is changed to step S1dh for determining the magnitude relationship between the average queue stay time tx and a predetermined stop threshold y0, and the step when the average queue stay time tx is equal to or greater than the stop threshold y0 To S1e, when the average queue stay time tx is less than the stop threshold y0, the process proceeds to Step S1a. After Step S1e, an average queue input time interval between predetermined redetermination times t1 is calculated and stored as tm. Step S2 for providing S1fh and observing the average queue stay time and storing the step S2a as tx and the step S2c is changed to step S2ch for calculating an average queue input time interval and storing it as tn, and the step S2d is changed from the average queue input time interval tn calculated in the step S2ch to the previous step S196. Is changed to step S2dh for determining the magnitude relationship of the average queue input time interval (previous average queue input time interval) tm calculated in step S2. If the average queue input time interval tn is larger than the previous average queue input time interval tm, the process proceeds to step S3. If the average queue input time interval tn is equal to or less than the previous average queue input time interval tm, the process proceeds to step S4, and the step S3a determines the magnitude relationship between the average queue stay time tx and a predetermined restart threshold y1. Change to step S3ah to determine, and the average queue stay time tx is If it is smaller than the open threshold value y1, the process proceeds to step S5, and if the average queue stay time tx is equal to or greater than the restart threshold value y1, the process proceeds to step S2. Further, the step S4a is additionally stopped in advance determined as the average queue stay time tx. It changes to step S4dh which determines the magnitude relationship of threshold value y2, and if average queue stay time tx is smaller than additional stop threshold value y2, it will transfer to step S2, and when average queue stay time tx is more than additional stop threshold value y2, said step S4e Specify the priority corresponding to the priority from the port with the highest priority flow rate to the output queue in the input side communication port next to the previous stop port, send a transmission stop message, and send the frame Is changed to step S4eh for stopping the communication by computer control in the communication device Low control method. In the flow control computer controlled method in a communication device according to claim 2 in any one of 10,
Means for storing a history of transmitting a transmission stop message from the input-side communication port;
When selecting the input side communication port as a stop port, refer to the history of transmitting a transmission stop message, and if a certain history number or time has not elapsed since the port transmitted a transmission stop message A flow control method by computer control in a communication device, wherein stop processing is not concentrated on a specific port by reselecting a stop port except for the communication port. The computer program for executing the steps of the flow control method according to any one of claims 2-11.

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