JP2019165371A - Communication control device, communication control method and control program - Google Patents

Abstract

To reduce, when optimizing a traffic amount which flows through a transmission line in a communication control device, frame transmission to stop or restrict an output, and to reduce an influence upon other processing which uses a storage unit to be used for the extension of a transmission buffer.SOLUTION: A communication control device 1 includes: a control unit 1a; a communication unit 1b which includes a transmission buffer 1d for storing frame data to be transmitted to transmit and receive a frame; and a storage unit 1c which can store data to be stored into the transmission buffer 1d. The control unit 1a monitors a data traffic amount transmitted through the transmission buffer 1d, and based on the above traffic amount, determines an extension capacity which is a capacity which uses the storage unit 1c as an extension buffer of the transmission buffer 1d.SELECTED DRAWING: Figure 1

Description

  The present disclosure relates to a communication control device, a communication control method, and a control program.

  Patent Documents 1-4 propose a flow control technique for suppressing frame overflow in an Ethernet (registered trademark; hereinafter the same) frame transmission path. In the flow control described in Patent Literatures 1-4, when traffic amount data exceeding the reception allowable amount of the transmission destination flows, a PAUSE frame is transmitted from the transmission destination to the layer 2 switch (L2SW) serving as the transmission source. The output from the L2SW is stopped or limited. The limitation of output here means lowering the transmission rate.

Japanese Patent Laid-Open No. 2006-0666835 JP 2013-093761 A JP 2002-223223 A JP 2002-152255 A

  However, in the flow control described in Patent Literatures 1-4, if a shared memory used for extending the transmission buffer and the receiving buffer is provided, if the PAUSE frame is frequently transmitted to the L2SW, transmission is performed. While it is stopped, the shared memory capacity is limited. As a result, in this flow control, there is a possibility that the Ethernet frame cannot be transmitted / received not only from the port but also from all ports of the L2SW. Therefore, in this flow control, when a PAUSE frame is used, precise desktop calculation is required, and the processing becomes complicated.

  On the other hand, in an Ethernet frame transmission path that does not use a PAUSE frame, when data with a traffic amount exceeding the reception allowable amount of the transmission destination flows, the overflowed Ethernet frame is discarded.

  Therefore, in the communication control apparatus, the transmission of a frame that stops or restricts output, such as a PAUSE frame, is reduced, and the amount of traffic flowing through the transmission path is optimized (for example, discarded in response to an increase in the amount of traffic) To reduce the number of frames). At the same time, in the communication control device, when adjusting the capacity of the storage unit used for expansion of the transmission buffer in order to optimize the amount of traffic flowing through the transmission path, the influence on other processing using the storage unit Is required to be reduced. Examples of the other processing include communication at another port, that is, communication via another communication buffer.

  The objective of this indication is providing the communication control apparatus, the communication control method, and control program which solve the subject mentioned above. In the communication control apparatus, when the amount of traffic flowing through the transmission path is optimized, the above-described problem is another process that uses a storage unit that reduces the transmission of a frame that stops or restricts output and that is used to expand a transmission buffer. The effect on the environment cannot be reduced.

A communication control device according to the first aspect of the present disclosure is provided.
A communication unit having a transmission buffer for storing data of a frame to be transmitted, and transmitting and receiving a frame;
A storage unit capable of storing data to be stored in the transmission buffer;
A control unit that monitors a traffic amount of data transmitted via the transmission buffer, and determines an expansion capacity that is a capacity to use the storage unit as an expansion buffer of the transmission buffer based on the traffic amount;
It is equipped with.

The communication control method according to the second aspect of the present disclosure includes:
Communication executed by a communication control device having a transmission buffer that stores data of a frame to be transmitted, and a communication unit that transmits and receives frames and a storage unit that can store data to be stored in the transmission buffer A control method,
Monitoring the traffic volume of data transmitted via the transmission buffer;
Determining an expansion capacity, which is a capacity to use the storage unit as an expansion buffer of the transmission buffer, based on the traffic volume;
It is what has.

The control program according to the third aspect of the present disclosure is:
A communication control device having a transmission buffer that stores data of a frame to be transmitted, and having a communication unit that transmits and receives frames and a storage unit that can store data to be stored in the transmission buffer. A control program,
In the communication control device,
Monitoring the traffic volume of data transmitted via the transmission buffer;
Determining an expansion capacity, which is a capacity to use the storage unit as an expansion buffer of the transmission buffer, based on the traffic volume;
Is a control program for executing

  According to the present disclosure, it is possible to provide a communication control device, a communication control method, and a control program that solve the above-described problems. That is, according to the present disclosure, in the communication control device, when optimizing the amount of traffic flowing through the transmission path, the storage unit used for extending the transmission buffer and reducing the transmission of frames for stopping or limiting the output is provided. The influence on other processing to be used can be reduced.

1 is a block diagram illustrating a configuration example of a communication control apparatus according to a first embodiment. It is a block diagram which shows the example of 1 structure of the communication system provided with the communication control apparatus which concerns on Embodiment 2. FIG. It is a block diagram which shows one structural example of the control part in the communication system of FIG. It is a flowchart for demonstrating the communication control using the PAUSE frame in L2SW which concerns on a comparative example. It is a flowchart for demonstrating an example of the communication control method in the control part of FIG. FIG. 10 is a diagram for describing a setting example in a communication control apparatus according to a third embodiment. FIG. 10 is a block diagram illustrating a configuration example of a control unit in a communication control apparatus according to a fourth embodiment. It is a figure which shows an example of the hardware constitutions of a communication control apparatus.

  Hereinafter, embodiments will be described with reference to the drawings. In the embodiment, the same or equivalent elements are denoted by the same reference numerals, and redundant description is omitted.

<Embodiment 1>
FIG. 1 is a block diagram illustrating a configuration example of a communication control apparatus according to the first embodiment.
As shown in FIG. 1, the communication control apparatus 1 according to the present embodiment includes a control unit 1a, a communication unit 1b, and a storage unit 1c. The communication control device 1 is a device that can relay communication between devices connected to the communication control device 1 by wire or wirelessly, and can also be referred to as a relay device or a communication device.

  The control unit 1a can be realized by, for example, a CPU (Central Processing Unit), a working memory, and a nonvolatile storage device that stores a control program. Moreover, the control part 1a is also realizable with an integrated circuit (Integrated Circuit), for example. The control in the control unit 1a will be described later.

  The communication unit 1b transmits and receives frames. The communication unit 1 b can be configured to receive a frame from a device connected to the communication control device 1 and transmit the frame to another device connected to the communication control device 1. This frame can be a frame based on the Ethernet standard, for example, but is not limited to this.

  The communication unit 1b includes a transmission buffer 1d that stores data of a frame to be transmitted (sometimes referred to as packet data). The buffer such as the transmission buffer 1d can also be referred to as a buffer memory. Further, the communication unit 1b can include a reception buffer (not shown) that stores data of a received frame. Both the transmission buffer 1d and the reception buffer can be realized by a storage device such as a semiconductor memory, and this storage device may be volatile or nonvolatile as long as data can be temporarily stored. The communication unit 1b can include a transmission port having a transmission buffer 1d and a reception port having a reception buffer. The number of transmission ports and the number of reception ports are not limited.

  The storage unit 1c is a device capable of storing data to be stored in the transmission buffer 1d. The storage unit 1c can be realized by a storage device such as a semiconductor memory. The memory | storage part 1c should just be able to store data temporarily, even if it is volatile or non-volatile. The storage unit 1c can be provided inside the communication unit 1b as shown in FIG. 1, but can also be provided outside the communication unit 1b. In addition, the storage unit 1c can be a shared storage unit for the transmission buffer 1d and the reception buffer, that is, can store data to be stored in the reception buffer. Further, although the buffer such as the transmission buffer 1d is described as being different from the storage unit 1c, the storage area of each buffer may be a predetermined area of the storage unit 1c originally.

  The control unit 1a monitors the traffic amount (data amount) of data transmitted via the transmission buffer 1d. Then, based on the traffic volume, the control unit 1a determines an expansion capacity (capacity of the expansion buffer) that is a capacity for using the storage unit 1c as the expansion buffer of the transmission buffer 1d.

  As described above, in the communication control apparatus 1 according to the present embodiment, the flow capacity as described above is not used (without limiting the traffic volume on the transmission side by flow control), and the expansion capacity is determined by monitoring the traffic volume. The transmission buffer has been expanded. Therefore, according to the communication control device 1, when optimizing the amount of traffic flowing through the transmission path, the transmission of frames for stopping or limiting the output is reduced, and the storage unit used for expansion of the transmission buffer is used. The influence on the processing can be reduced. Further, since the transmission buffer can be appropriately expanded by the above optimization, it is possible to cope with an increase in traffic volume and to reduce the number of discarded frames.

  Here, examples of the other process include communication at another port, that is, communication via another communication buffer. Supplementing the above effects, in the present embodiment, when adjusting the traffic volume, the free capacity of the storage unit 1c is taken into consideration, so that communication to other ports that may use the storage unit 1c is used. It becomes possible to suppress the influence of.

  The case where the communication control apparatus 1 is an apparatus functioning as an L2SW having a transmission port will be described as an example. In this embodiment, the traffic volume is monitored on the transmission side of the L2SW and the transmission buffer is expanded by the storage unit. And adjust the traffic volume. Therefore, according to the present embodiment, when optimizing the amount of traffic flowing through the transmission path, it is possible to reduce the transmission of the PAUSE frame and suppress the influence of the L2SW other than the transmission port.

  Furthermore, as another effect, according to the present embodiment, since the traffic volume is monitored, debugging in an actual operation environment (for example, correction of various setting values of L2SW, etc.) can be easily performed.

<Embodiment 2>
The second embodiment will be described with reference to FIGS. 2 to 5 while focusing on the differences from the first embodiment, but various examples described in the first embodiment can be applied. FIG. 2 is a block diagram illustrating a configuration example of a communication system including the communication control apparatus according to the second embodiment, and FIG. 3 is a block diagram illustrating a configuration example of a control unit in the communication system of FIG.

  As shown in FIG. 2, the communication system according to the present embodiment includes a communication control device 10, a transmission source device A (31), a transmission source device B (32), and a transmission destination device connected to the communication control device 10. C (41). This communication system includes these components and can constitute a LAN (Local Area Network), and can also be referred to as a network system.

  Each device 31, 32, 41 is a device that can communicate with the communication control device 10, and only needs to have a communication unit. Each device 31, 32, 41 is a communicable electronic device such as, for example, a relay device similar to the communication control device 10, another relay device, a PC (Personal Computer), a mobile phone (including a smartphone). It can be a device.

  The communication control apparatus 10 according to the present embodiment includes an L2SW (11) as an example of the communication unit 1b and a control unit 12 as an example of the control unit 1a.

  The L2SW (11) determines a relay destination based on a MAC (Media Access Control) address included as destination information in the frame, and performs a relay operation. The L2SW (11) includes a reception port A (11a), a reception port B (11b), and a transmission port C (11c).

  In the communication system shown in FIG. 2, the reception port A (11a), the reception port B (11b), and the transmission port C (11c) are respectively the transmission source device A (31), the transmission source device B (32), and the transmission destination. It is connected to the device C (41). In this communication system, it is assumed that the communication control apparatus 10 is connected to the devices 31, 32, and 41 in this way to construct a transmission path for the Ethernet frame. That is, in this communication system, the transmission source device A (31) and the transmission source device B (32) can transmit an Ethernet frame to the transmission destination device C (41) via the L2SW (11).

  The L2SW (11) includes a reception buffer A (26) on the reception port A (11a) side, a reception buffer B (27) on the reception port B (11b) side, and a transmission buffer on the transmission port C (11c) side. C (23). For example, as shown in FIG. 2, the reception port A (11a) has a reception buffer A (26), the reception port B (11b) has a reception buffer B (27), and the transmission port C (11c) has A transmission buffer C (23) can be included.

  The reception buffer A (26), the reception buffer B (27), and the transmission buffer C (23) temporarily store an Ethernet frame to be transmitted to the transmission destination device C (41), for example, when a transmission wait occurs ( Storage).

  Thus, the L2SW (11) can have a plurality of communication ports, and one of them corresponds to the transmission port C (11c) having the transmission buffer C (23). Each communication port may have a communication buffer (transmission buffer or reception buffer) that stores data of frames to be communicated. For convenience of explanation, the number of communication ports (connection ports) is three, but there is no need to limit the number of connection ports of the L2SW (11), and the number of devices actually connected is also limited. There is no need to provide it. That is, although this embodiment is described based on a network configuration as shown in FIG. 2, this embodiment is not limited to such a network configuration.

  Further, the L2SW (11) can include a shared memory 21 as an example of the storage unit 1c. The shared memory 21 is a memory having a predetermined capacity. The shared memory 21 can share the storage area with the reception buffer A (26), the reception buffer B (27), and the transmission buffer C (23). Therefore, although not shown in FIG. 2 for convenience, when such sharing is performed, the reception buffer A (26) and the shared memory 21 are connected, and the reception buffer B (27) and the shared memory 21 are also connected. Become. It is assumed that the capacity of each buffer 23, 26, 27 can be freely determined by the transmission line designer and can be made variable.

  Thus, the shared memory 21 can store data to be stored in the communication buffer corresponding to each communication port provided in the L2SW (11). Thus, the shared memory 21 can be shared by each communication port, that is, can be a storage unit for expansion shared by each communication buffer.

  In addition to the transmission buffer C (23), the transmission port C (11c) can have a packet number counter 24 and a bit number counter 25 as general functions. The control unit 12 can monitor the traffic amount of the transmission buffer C (23) by reading these count values.

  Furthermore, it is preferable that the control unit 12 restricts the flow rate of data transmitted through the transmission buffer C (23) based on the traffic amount obtained by monitoring. Here, the data flow rate can be the amount of data flowing per unit time as in the case of a general traffic amount.

  For this purpose, the shaping port 22 is provided in the transmission port C (11c). The shaping unit 22 has a function of limiting the flow rate (traffic amount) of data transmitted from the L2SW (11) to the transmission destination device C (41). That is, the control unit 12 operates not only the capacity expansion function of the transmission buffer C (23) but also the shaping function by the shaping unit 22 based on the calculation result by the calculation unit 12a, and the transmission destination device C from the L2SW (11). The flow rate up to (41) is controlled. Thereby, the communication control apparatus 10 can perform control more appropriately so as not to exceed the reception allowable amount of the transmission destination device C (41).

  In the communication system shown in FIG. 2, the Ethernet frame can be simultaneously transmitted from the transmission source device A (31) and the transmission source device B (32) to the transmission destination device C (41) by the configuration as described above. The Ethernet frames transmitted simultaneously from the transmission source device A (31) and the transmission source device B (32) stay in the transmission buffer C (23) via the reception buffer A (26) and the reception buffer B (27), respectively. Are sequentially transmitted to the destination device C (41).

  The control by L2SW which concerns on a comparative example in such a scene is demonstrated. The L2SW according to the comparative example performs flow control. In this flow control, when the amount of traffic from the transmission port of the L2SW according to the comparative example increases and exceeds the allowable reception amount of the transmission destination device, the transmission destination device issues a PAUSE frame to the L2SW according to the comparative example. The output from the transmission port C is temporarily stopped. Communication control using a PAUSE frame in the L2SW according to the comparative example will be described with reference to the flowchart of FIG. When the L2SW according to the comparative example receives the PAUSE frame (step S101), the L2SW stops the transmission or cancels the transmission stop for the time specified according to the PAUSE setting time stored in the PAUSE frame. (Step S102).

However, in the comparative example, if the PAUSE frame is frequently transmitted to the L2SW, the capacity of the shared memory (corresponding to the shared memory 21) is limited while the transmission is stopped, and not only in the port but also in other ports. There is a risk that frames cannot be sent or received.
Further, in the L2SW according to another comparative example used in an environment that does not use the PAUSE frame, the Ethernet frame whose processing cannot keep up within the transmission destination device is discarded.

  On the other hand, in the communication control apparatus 10 according to the present embodiment, the control unit 12 performs the following control. That is, the control unit 12 monitors the traffic volume of data transmitted via the transmission buffer C (23), and uses the shared memory 21 as an expansion buffer of the transmission buffer C (23) based on the traffic volume. Determine the capacity (expanded capacity) to be used. Such an expansion of the transmission buffer C (23) can reduce the number of discarded frames.

  In particular, the control unit 12 in the present embodiment changes the expansion capacity when the traffic volume exceeds a predetermined threshold. Thus, the expansion capacity can be determined based on whether or not the traffic volume exceeds the threshold value.

  In addition, the control unit 12 preferably increases (increases) the expansion capacity when the traffic volume exceeds the threshold. As a result, not only the number of discarded frames can be reduced, but also the capacity of the shared memory 21 can be used as much as necessary, and the communication at other ports (reception ports A and B) can be prevented from being hindered. it can.

  The extended capacity can be stored in a changeable state as the set value of the L2SW (11). For example, this set value can be stored in a memory in the control unit 12 (not shown), or can be stored in the shared memory 21 if a non-volatile memory is adopted as the shared memory 21. Also, this set value can be stored in a separately provided memory in the L2SW (11).

  As a more specific example, the control unit 12 includes a calculation unit 12a as shown in FIG. 3, and can perform the following Ethernet frame transmission control.

  First, the calculation unit 12a reads the value of the counter (count value) from at least one of the packet number counter 24 and the bit number counter 25 periodically (for example, every 1 second), and calculates the traffic volume per unit time.

  When the calculation unit 12a detects a traffic amount exceeding a preset threshold, the calculation unit 12a calculates a traffic amount per unit time from the read packet count value 12b or the bit count value 12c. The threshold value can be stored as a part of the set value, for example. Further, the calculation unit 12a reads the free capacity 12d of the shared memory 21 at the time of such detection. Then, the calculation unit 12a calculates the amount of memory to be allocated to the expansion of the buffer amount of the transmission buffer C (23) from the calculated traffic amount per unit time and the free capacity 12d of the shared memory 21.

  Here, the threshold value is preferably set to a value smaller than the reception allowable amount of the transmission destination device C (41). Accordingly, the control unit 12 can activate the expansion of the transmission buffer C (23) before exceeding the reception allowable amount on the transmission destination device C (41) side, and can perform transmission control at an appropriate timing. The communication control apparatus 10 may include an operation unit that receives a user operation for changing the threshold value, or may be configured to receive such a user operation from a device such as a PC connected to the outside.

  Further, the threshold value for operating the capacity expansion function and the threshold value for operating the shaping function may be different values.

  Further, the control unit 12 expands the capacity of another communication port, for example, the reception port A (11a), or the reception port A (11a) and the reception port B (based on the traffic volume of the transmission buffer C (23). The expansion capacity for 11b) may also be determined.

  Further, the control unit 12 can determine the expansion capacity to be a capacity within the free capacity of the shared memory 21. However, the free capacity of the shared memory 21 varies depending on the amount of data to be received, the amount of data to be transmitted in another transmission buffer (not shown), and other transmission / reception can be limited. Therefore, the control unit 12 can also determine the extended capacity as a value exceeding the free capacity of the shared memory 21 (of course, a value equal to or less than the total capacity of the shared memory 21).

  The control unit 12 can also be configured to monitor the traffic amount (the traffic amount of data communicated via each communication buffer) of each communication port (ports 11a to 11c in this example). Then, the control unit 12 may determine the expansion capacity for the transmission port C (11c) based on the traffic amount for each communication buffer. Alternatively, the control unit 12 may determine the expansion capacity for the transmission port C (11c) and other ports based on the traffic amount for each communication buffer. The other port in the example of FIG. 2 may be at least one of the reception port A (11a) and the reception port B (11b).

  For example, the control unit 12 collectively monitors the traffic volume of all ports included in the L2SW (11), and determines the expansion buffer volume of each port based on the traffic volume and the free capacity of the shared memory 21. can do. In addition, the control unit 12 can perform control so that a port that does not use the shared memory 21 for expansion is released to another port accordingly.

  Next, an example of a communication control method in the control unit 12 will be described with reference to FIG. FIG. 5 is a flowchart for explaining an example of the communication control method in the control unit 12.

  The control unit 12 periodically reads the values of various counters (the count value 12b from the packet number counter 24 and the count value 12c from the bit number counter 25 in the example of FIG. 3) (step S1). Next, the calculation unit 12a of the control unit 12 determines (confirms) whether or not a preset traffic volume threshold is exceeded (step S2).

  If the calculation unit 12a determines that the threshold value has been exceeded (YES in step S2), the calculation unit 12a subsequently checks the free capacity of the shared memory 21 (step S3 and step S4). Specifically, the calculation unit 12a checks the free capacity 12d of the shared memory 21 (step S3) and determines whether there is a free capacity (step S4).

  When there is free space (YES in step S4), the calculation unit 12a calculates the amount of expansion of the transmission buffer C (23) and the amount of bandwidth for shaping (the maximum amount of data that can be transmitted per unit time) The set value of L2SW (11) is changed (step S5).

  If there is no free space in the shared memory 21 (NO in step S4), the calculation unit 12a notifies the transmission source device of the necessity of bandwidth limitation (step S7). In step S7, notification can be performed by a method such as transmitting a PAUSE frame from the L2SW (11) to the transmission source device A (31) and the transmission source device B (32), for example. After the processes in steps S5 and S7, the process returns to the start time (step S1) and the process is continued.

  Thus, even after the traffic volume is limited by changing the setting value of the L2SW (11) in step S5, reading of various counters (step S1) is continued. Thereafter, when the traffic amount is equal to or less than the threshold value (NO in step S2), the calculating unit 12a cancels the expansion and shaping of the transmission buffer C (23) (step S6). That is, when the threshold value is exceeded, the transmission buffer may be expanded, or when it falls below the threshold value, it may be reduced and restored. As described above, it is preferable that the control unit 12 restores the expanded capacity to the original value (returns to the original value) when the traffic amount exceeds the threshold value and then becomes the threshold value or less.

  As another example of processing, when NO is determined in step S2 (when the calculation unit 12a determines that the threshold value is not exceeded), the control unit 12 can return to step S1 and continue reading the counter.

  According to the communication control apparatus 10 according to the present embodiment described above, the following effects can be obtained in the same manner as the effects of the communication control apparatus 1 according to the first embodiment. That is, the communication control apparatus 10 monitors the traffic volume on the transmission side of the L2SW, expands the transmission buffer C (23) with the shared memory 21, and adjusts the traffic volume. Therefore, according to this embodiment, when optimizing the amount of traffic flowing through the transmission path, the transmission of PAUSE frames is reduced, and the influence of the L2SW (11) other than the transmission port C (11c) is suppressed. Will be able to. Supplementing the latter effect, in this embodiment, since the free capacity of the shared memory 21 is taken into account when adjusting the traffic volume, the transmission port C (11c) that may use the shared memory 21 may be used. It becomes possible to suppress the influence on other than.

  Furthermore, according to the communication control apparatus 10 according to the present embodiment, in addition to such effects, the following effects are also achieved. That is, the communication control apparatus 10 monitors the amount of traffic flowing in the transmission path instead of using the PAUSE frame in the L2SW (11) arranged in the Ethernet frame transmission path, and buffers the buffer when a predetermined threshold is exceeded. Dynamic expansion of quantity. Thereby, according to the communication control apparatus 10, it is possible to optimize the amount of traffic flowing through the Ethernet frame transmission path without stopping or restricting frame transmission / reception more than necessary. Further, in the communication control apparatus 10, when the above threshold value is exceeded, the flow amount is dynamically limited (shaping), so that the amount of traffic flowing in the Ethernet frame transmission path can be further optimized.

  In addition, since the communication control apparatus 10 according to the present embodiment monitors the traffic volume, the threshold corresponding to the traffic volume can be adjusted, and optimization of the expansion buffer setting can be easily realized. .

  As described above, the communication control apparatus 10 according to the present embodiment can perform threshold adjustment corresponding to the traffic volume. Therefore, according to the communication control apparatus 10, even in a case where the traffic volume of the Ethernet frame transmission path increases, for example, when the traffic capacity that can be transmitted increases due to the improvement of the processing capability of the transmission source device and the transmission destination device, the setting optimization is performed. Can be easily done. In fact, since there are many Ethernet frame transmission paths in which there is no constant traffic volume and the traffic volume varies greatly, it can be said that such an effect is great.

<Embodiment 3>
The third embodiment will be described with reference to FIG. 6 with a focus on differences from the second embodiment including the effects thereof. Various examples described in the first and second embodiments can be applied to the third embodiment. FIG. 6 is a diagram for explaining a setting example in the communication control apparatus according to the third embodiment.

  In the example of the communication control method described with reference to FIG. 5, processing is performed based on one threshold value. However, several threshold values may be provided according to the traffic amount. In the present embodiment, an example of processing for changing the set value of the L2SW (11) using a plurality of threshold values will be described with reference to the matrix 60 shown in FIG.

  In the matrix 60, the vertical axis indicates a setting example of a plurality of threshold values. In the matrix 60, an example is shown in which three thresholds 1 to 3 are set. As shown in this example, the threshold value can be prepared in a plurality of stages according to the traffic volume, and the specific value of each threshold value is determined by the traffic volume of the Ethernet frame transmission path in which the communication control device 10 is incorporated. Can do.

  In the matrix 60, the horizontal axis indicates the size of the free capacity of the shared memory 21. In the matrix 60, an example is shown in which three capacities, small, medium, and large, are set. In practice, specific thresholds can be set as these three capacities.

  In the values shown in two stages in the matrix 60, the upper part indicates the buffer expansion amount and the lower part indicates the shaping amount. Actually, these values can also be set in advance. These buffer expansion amount and shaping amount correspond to the values in step S5 in FIG.

  As described above, by making it possible to set a plurality of threshold values (traffic amount threshold values), buffer expansion amounts, and shaping amounts, it is possible to control traffic volume more precisely.

<Embodiment 4>
The fourth embodiment will be described with reference to FIG. 7 with a focus on differences from the second embodiment including the effects thereof. Various examples described in Embodiment 1-3 can be applied to Embodiment 4. FIG. 7 is a block diagram illustrating a configuration example of a control unit in the communication control apparatus according to the fourth embodiment.

  In the communication control apparatus 10 according to the present embodiment, the control unit 70 corresponding to the control unit 12 has at least the transmission port C (() based on the number of communication ports whose traffic volume obtained by monitoring exceeds a predetermined threshold. Determine the expansion capacity for 11c). Further, the control unit 70 determines the expansion capacity for other communication ports, for example, the reception port A (11a) or the expansion capacity for the reception port A (11a) and the reception port B (11b) based on the above number. It may be determined.

  In the present embodiment, besides the number of such communication ports, it can be used to determine the expansion capacity. That is, the control unit 70 in the present embodiment can calculate the setting change value of the L2SW (11) using elements other than the counter provided in the transmission port C (11c) described in the second embodiment. This setting change value includes at least the buffer expansion amount described above, and preferably includes the shaping amount.

  More specifically, the control unit 70 includes a calculation unit 71 corresponding to the calculation unit 12a. The calculation unit 71 uses information other than the count value 72 and the count value 73 acquired from the packet number counter 24 and the bit number counter 25 in the transmission port C (11c), respectively, for calculation of the setting change value.

  For example, the calculation unit 71 obtains information (reception port state 75) such as the number 74 of communication ports exceeding the threshold, the number of error occurrences at the reception port of the destination device C (41), the number of overflow occurrences, and the number of packet discard occurrences. , And can be used to calculate a setting change value. Further, the calculation unit 71 can calculate the setting change value by taking in the value of the packet number counter (count value 76) in the transmission destination device C (41) and other elements 77. Of course, the calculation unit 71 can also calculate the setting change value by using a part of the information.

  The reception port state 75 and the count value 76 can be included in a frame transmitted from the transmission destination device C (41), for example, and the calculation unit 71 can extract the frame from the frame. The receiving port state 75 and count value 76 of the destination device C (41) may lack real-time properties and are not suitable for dynamic changes. However, since these values are useful for debugging the Ethernet frame transmission path, it is preferable to incorporate them as values used for calculation.

<Other embodiments>
[A]
In the first embodiment, the functions of the control unit 1a, the communication unit 1b, and the storage unit 1c of the communication control device 1 illustrated in FIG. 1 have been described, but it is sufficient that these functions can be realized as the communication control device 1. Similarly, in Embodiment 2-4, the function of each component in the communication control apparatus 10 illustrated in FIGS. 2 and 3 has been described, but it is only necessary to realize these functions as the communication control apparatus.

[B]
The communication control apparatuses 1 and 10 according to Embodiment 1-4 may have the following hardware configuration. FIG. 8 is a diagram illustrating an example of a hardware configuration of the communication control apparatuses 1 and 10. The same applies to the other embodiment [a].

  The communication control device 80 illustrated in FIG. 8 includes a processor 81 and a memory 82. The functions of the control units 1a, 12, and 70 in the communication control apparatuses 1 and 10 described in the embodiment 1-4 are realized by the processor 81 reading and executing the control program stored in the memory 82. This control program can be a program for causing the processor 81 to function as the control unit 1 a or the control unit 12.

  In the above example, the control program can be stored and supplied to a computer using various types of non-transitory computer readable media. Non-transitory computer readable media include various types of tangible storage media. Examples of non-transitory computer readable media include magnetic recording media (eg, flexible disks, magnetic tapes, hard disk drives), magneto-optical recording media (eg, magneto-optical disks). Further, this example includes a CD-ROM (Read Only Memory), a CD-R, and a CD-R / W. Further, this example includes a semiconductor memory (for example, mask ROM, PROM (Programmable ROM), EPROM (Erasable PROM), flash ROM, RAM (Random Access Memory)). The program may also be supplied to the computer by various types of transitory computer readable media. Examples of transitory computer readable media include electrical signals, optical signals, and electromagnetic waves. The temporary computer-readable medium can supply the program to the computer via a wired communication path such as an electric wire and an optical fiber, or a wireless communication path.

[C]
Further, in the above-described embodiment, as exemplified in the procedure of the communication control method in the communication control apparatus, the present disclosure can also take a form as the communication control method. This communication control method includes a transmission buffer that stores data of a frame to be transmitted, and includes a communication unit that transmits and receives a frame, and a storage unit that can store data to be stored in the transmission buffer. A method performed by an apparatus. And this communication control method has the following monitoring steps and determination steps. The monitoring step monitors the traffic volume of data transmitted via the transmission buffer. The determining step determines an expansion capacity that is a capacity for using the storage unit as an expansion buffer of the transmission buffer based on the traffic volume. Other examples are as described in the various embodiments described above. Further, it can be said that the control program is a program for causing the communication control device to execute the monitoring step and the determination step described above.

  In addition, this indication is not restricted to the said embodiment, It can change suitably in the range which does not deviate from the meaning. In addition, the present disclosure may be implemented by appropriately combining the embodiments.

1, 10, 80 Communication control devices 1a, 12, 70 Control unit 1b Communication unit 1c Storage unit 1d Transmission buffer 11 L2SW
12a calculation unit 12b, 72 packet count value 12c, 73 bit count value 12d shared memory free capacity 21 shared memory 22 shaping unit 23 transmission buffer C
24 packet counter 25 bit counter 26 receive buffer A
27 Receive buffer B
31 Source device A
32 Source device B
41 Destination device C
60 Matrix 71 Calculation Unit 74 Number of Ports Exceeding Threshold 75 Receive Port Status 76 of Destination Device Count of Packet Count of Destination Device 77 Other Elements 81 Processor 82 Memory

Claims (10)

A communication unit having a transmission buffer for storing data of a frame to be transmitted, and transmitting and receiving a frame;
A storage unit capable of storing data to be stored in the transmission buffer;
A control unit that monitors a traffic amount of data transmitted via the transmission buffer, and determines an expansion capacity that is a capacity to use the storage unit as an expansion buffer of the transmission buffer based on the traffic amount;
A communication control device comprising: The control unit changes the expansion capacity when the traffic volume exceeds a predetermined threshold.
The communication control apparatus according to claim 1. The control unit increases the expansion capacity when the traffic volume exceeds the threshold.
The communication control apparatus according to claim 2. The control unit restores the expanded capacity when the traffic amount exceeds the threshold and then becomes the threshold or less.
The communication control apparatus according to claim 3. The control unit determines the expansion capacity to be a capacity within a free capacity of the storage unit,
The communication control apparatus of any one of Claims 1-4. The communication unit has a plurality of communication ports,
Each communication port has a communication buffer for storing data of frames to be communicated,
One of the plurality of communication ports is a transmission port having the transmission buffer;
The storage unit can store data to be stored in a communication buffer corresponding to each communication port,
The control unit monitors the traffic volume of data communicated via each communication buffer, and determines at least the expansion capacity for the transmission port based on the traffic volume for each communication buffer.
The communication control apparatus of any one of Claims 1-5. The control unit determines an expansion capacity for at least the transmission port based on the number of the communication ports in which the traffic volume exceeds a predetermined threshold.
The communication control apparatus according to claim 6. The control unit limits a flow rate of data to be transmitted through the transmission buffer based on the traffic amount.
The communication control apparatus of any one of Claims 1-7. Communication executed by a communication control device having a transmission buffer that stores data of a frame to be transmitted, and a communication unit that transmits and receives frames and a storage unit that can store data to be stored in the transmission buffer A control method,
Monitoring the traffic volume of data transmitted via the transmission buffer;
Determining an expansion capacity, which is a capacity to use the storage unit as an expansion buffer of the transmission buffer, based on the traffic volume;
A communication control method. A communication control device having a transmission buffer that stores data of a frame to be transmitted, and having a communication unit that transmits and receives frames and a storage unit that can store data to be stored in the transmission buffer. A control program,
In the communication control device,
Monitoring the traffic volume of data transmitted via the transmission buffer;
Determining an expansion capacity, which is a capacity to use the storage unit as an expansion buffer of the transmission buffer, based on the traffic volume;
A control program to execute.

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