JP2010218455A - Switch, information processor, and data transfer control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a switch, an information processor and a data transfer control method for properly executing data transfer control. <P>SOLUTION: Switches 101 to 103 are configured to control data transfer between a plurality of devices, and each provided with: a port connectable to the device; a determination means for determining whether or not the transfer rate of traffic passing through the port is equal to or higher than a prescribed value; and a restricting means for restricting the traffic whose priority is low among the traffic passing through the port when it is determined that the transfer rate of the traffic is equal to or higher than a prescribed value by the determination means. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a switch for controlling data transfer between devices, an information processing apparatus, and a data transfer control method.

  In general, in an information processing apparatus such as a digital copying machine or a multifunction peripheral (MFP) that handles image data and other data, a PCI bus is used as an interface between devices. A multi-function peripheral (MFP) has multi-functions such as copy, printer, and FAX, and a scanner controller, plotter controller, optional device, and the like are connected to the PCI bus.

  In recent years, with the diversification of image data, the amount of data transferred within one line cycle has increased, and there has been a problem that data loss occurs unless the bus master is controlled efficiently. In order to prevent data loss, for example, an image forming apparatus according to Patent Document 1 includes a controller that manages a data transfer amount on a PCI bus. The controller counts various transfer data amounts and changes the PCI bus settings based on the counted data amounts. Thereby, data transfer can be performed without excess or deficiency.

  However, the parallel PCI bus has problems such as racing and skew. Therefore, the transfer rate of the PCI bus is too low to apply the parallel PCI bus to recent high-speed and high-quality image forming apparatuses. Recently, an interface called PCI Express (registered trademark), which is a successor to the PCI bus system, has also been proposed and is in the stage of practical use. Furthermore, in recent years, the Advanced Switching Interconnect standard, which is a high-speed serial switch fabric based on the PCI Express architecture, has been developed.

  Based on these technologies, we also propose printers and MFPs that are connected by switches that can use high-speed serial switch fabrics and can freely expand devices with different traffic characteristics to high-speed serial switch fabrics. (See Patent Document 2 and Patent Document 3).

  In a system in which devices are connected to a parallel PCI bus, all traffic passes through a common bus. Therefore, all traffic can be detected and managed by the traffic detection circuit connected on the bus.

  On the other hand, in a system in which a plurality of devices are connected via a high-speed serial switch fabric, data transfer is performed via a plurality of switches. In such a system, when excessive traffic is instantaneously generated at one output port of a certain switch, the traffic transfer capability of different output ports may be reduced due to the transfer of this traffic. Furthermore, the occurrence of traffic in one switch may affect the forwarding capacity of traffic in other switches. However, since data transfer is performed via a plurality of switches, there is a problem that the traffic of the entire system cannot be detected and managed in one place. In particular, even when there is traffic that wants to maintain the data transfer rate, it is difficult to maintain the data transfer rate of the predetermined traffic because the traffic of the entire system cannot be managed.

  The present invention has been made in view of the above, and an object of the present invention is to provide a switch, an information processing apparatus, and a data transfer control method capable of appropriately executing data transfer control.

  In order to solve the above-described problems and achieve the object, the present invention provides a switch capable of controlling data transfer between a plurality of devices, a port connectable to the device, and traffic passing through the port. A determination unit that determines whether or not the transfer rate is equal to or higher than a predetermined value; and when the determination unit determines that the transfer rate of the traffic is equal to or higher than a predetermined value, the priority among the traffic passing through the port And limiting means for limiting low traffic.

  According to another aspect of the present invention, there is provided an information processing apparatus capable of executing data transfer between a plurality of devices, the setting unit configured to set an operation mode of the information processing apparatus according to an input from the outside, A switch for controlling data transfer between a plurality of devices, wherein the switch includes a port connectable to the device and an operation mode in which a transfer rate of traffic passing through the port is set by the setting unit. And determining means for determining whether or not the traffic transfer rate is equal to or greater than a predetermined value by the determining means, and in the traffic passing through the port, Limiting means for limiting low-priority traffic corresponding to the operation mode set by the setting means,

  According to another aspect of the present invention, in a data transfer control method executed by a switch capable of controlling data transfer between a plurality of devices, whether or not a transfer rate of traffic passing through the port is a predetermined value or more. When the traffic transfer rate is determined to be equal to or higher than a predetermined value, traffic having a low priority is restricted among traffic passing through the port.

  According to another aspect of the present invention, in a data transfer control method executed by an information processing apparatus capable of controlling data transfer between a plurality of devices, an operation mode of the information processing apparatus is set according to an input from the outside. A switch having a port for connecting to the device determines whether or not a transfer rate of traffic passing through the port is equal to or higher than a predetermined value corresponding to the set operation mode; When it is determined that the rate is equal to or higher than a predetermined value, the switch limits low-priority traffic corresponding to the set operation mode among traffic passing through the port.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to provide the switch, information processing apparatus, and data transfer control method which can perform data transfer control appropriately.

1 is a diagram illustrating an example of a main configuration of a multifunction machine 1 including a switch system. 3 is a diagram schematically illustrating an example of a data configuration of a configuration information storage unit 105. FIG. 3 is a block diagram illustrating an example of a functional configuration of a third switch 103. FIG. It is a figure which shows an example of a data structure of configuration information typically. 10 is a flowchart illustrating an example of processing by the first port unit 110 of the third switch 103 of the multifunction machine 1. It is a flowchart which shows an example of a process when the 1st port unit 110 receives flow control information from another port. 6 is a diagram for explaining an example of traffic competition in the multifunction machine 1 when the flow control process is not performed. FIG. It is a figure for demonstrating an example of a flow control process. It is a figure for demonstrating an example of a flow control process. It is a figure for demonstrating an example of a flow control process. It is a figure for demonstrating an example of a flow control process. 6 is a diagram for explaining an example of traffic competition in the multi-function peripheral 1 when a flow control process is performed. FIG.

  Exemplary embodiments of a switch, an information processing apparatus, and a data transfer control method according to the present invention will be explained below in detail with reference to the accompanying drawings.

  FIG. 1 is a diagram illustrating an example of a main configuration of an information processing apparatus such as a multifunction machine 1 including a switch system according to an embodiment. The multifunction device 1 includes a scanner 200 as a device, a plotter 201, a network 202, a memory 203, a user interface (UI) 204, a first switch 101 that connects these devices, a second switch 102, And a third switch 103. The multifunction device 1 further includes an operation mode setting unit 104, a configuration information storage unit 105, and a configuration information setting unit 106.

  Each of the switches 101 to 103 is connected serially and performs data transfer between devices. Each switch has a plurality of ports, and each port connects to another device or switch. The first switch 101 has three ports, a first port, a second port, and a third port. The second switch 102 has four ports, a first to a fourth port. Similarly, the third switch 103 has four ports.

  The number and types of devices included in the multifunction device 1 are examples, and are not limited to the present embodiment. Further, the number of switches included in the multifunction device 1 and the number of ports included in each switch are examples, and are not limited to the present embodiment.

  A data flow for transferring an image input in the scanner 200 to the plotter 201 is referred to as a first traffic 301. A data flow for transferring the data input in the UI 204 to the memory 203 is referred to as second traffic 302. A data flow from the network 202 to the memory 203 is referred to as third traffic 303.

  The first traffic 301 is transmitted from the scanner 200 and transferred to the plotter 201 via the first switch 101, the second switch 102, and the third switch 103. More specifically, the first traffic 301 is input to the third port of the first switch 101 and output from the second port. The first traffic 301 is input to the first port of the second switch 102 and output from the fourth port. Further, the first traffic 301 is input from the second port of the third switch 103, output from the first port, and transferred to the plotter 201. The second traffic 302 is transmitted from the UI 204 and transferred to the memory 203 via the second switch 102 and the third switch 103. The third traffic 303 is transferred to the memory 203 via the third switch 103. Thus, data transfer between devices is performed via one or more switches. In the multi function device 1, a plurality of traffics are simultaneously transferred via a plurality of switches.

  The operation mode setting unit 104 sets an operation mode in the multifunction machine 1. Note that the operation mode includes FAX transmission, printing, copying, and the like. The configuration information storage unit 105 stores a plurality of pieces of configuration information. The configuration information is information indicating a condition for data transfer at each port of each switch. The configuration information will be described later. FIG. 2 is a diagram schematically illustrating an example of a data configuration of the configuration information storage unit 105. The configuration information storage unit 105 stores an operation mode and configuration information in the MFP 1 in association with each other. Each configuration information is set in advance by an administrator or the like. The administrator can set, as configuration information, flow control conditions in the switch system of the multifunction peripheral 1, such as a lower limit value to be maintained as a traffic transfer rate in each operation mode and traffic to be prioritized.

  When a predetermined operation mode is set by the operation mode setting unit 104, the configuration information setting unit 106 specifies configuration information associated with the set operation mode in the configuration information storage unit 105. Then, a configuration information change packet is transmitted to all switches, and the specified configuration information is set in all switches. The configuration information setting unit 106 is connected to the second switch 102, and the configuration information is transmitted to other switches via the second switch 102 and set in each switch.

  The configuration information setting unit 106 may be connected to a switch other than the second switch 102, or may be connected to all switches as another example. The configuration information setting unit 106 only needs to be able to set configuration information for all switches, and the physical connection relationship is not limited to this embodiment.

  Each of the switches 101 to 103 performs a flow control process, which is control for traffic passing through each of the switches 101 to 103, according to the configuration information set by the configuration information setting unit 106. Even when a plurality of traffic transfers occur and data concentrates on a predetermined switch, appropriate control can be performed by stopping or slowing down the appropriate traffic transfer according to the configuration information.

  FIG. 3 is a block diagram illustrating an example of a functional configuration of the third switch 103. The third switch 103 includes a first port unit 110 including a first port 111, a second port unit 120 including a second port 121, a third port unit 130 including a third port 131, and a fourth port 141. Including a fourth port unit 140. In addition to the first port 111, the first port unit 110 includes a first configuration register 112, a first traffic detection circuit 113, a first traffic determination circuit 114, a first transmission / reception circuit 115, and a first traffic restriction circuit. 116.

  The first configuration register 112 stores configuration information. The configuration information is set by the configuration information setting unit 106. The configuration information setting unit 106 sets the same configuration information in all configuration registers of all switches. That is, all the configuration registers store the same configuration information corresponding to the operation mode.

  FIG. 4 is a diagram schematically illustrating an example of a data configuration of configuration information. The configuration information includes control setting information, priority information, transfer rate information, restriction content information, timeout information, and plotter control information.

  The control setting information is information for setting whether or not each switch performs flow control processing. Specifically, the control setting information is information in which switch identification information for identifying a switch is associated with information indicating the presence or absence of control. For example, in the example illustrated in FIG. 4, the identification information “first switch” of the first switch 101 is associated with information indicating the presence or absence of control “no flow control”.

  The priority information is information indicating which traffic is preferentially executed when the traffic competes. The priority information is information in which traffic identification information for identifying the type of traffic is associated with a priority. The traffic identification information in the present embodiment is information for identifying the first traffic, the second traffic, and the third traffic. That is, different traffic identification information is given to traffic with different transfer paths. In the example illustrated in FIG. 4, traffic identification information “first traffic” for identifying the type of the first traffic is associated with a priority of “priority_high”. As described above, since the priority of traffic is set in the configuration information, the priority of traffic can be changed by rewriting the configuration information.

  The transfer rate information is information indicating a threshold of a transfer rate of traffic transferred through each port of each switch. The transfer rate information is information in which port identification information for identifying a switch port is associated with a threshold value. In the example illustrated in FIG. 4, port identification information “third switch third port” for identifying the third port of the third switch 103 is associated with a threshold value “threshold value 1_th”. As in the example shown in FIG. 4, the transfer rate threshold value is stored for a necessary port. As described above, since the threshold value of the transfer rate can be set for each port, a different value can be set for each port.

  The restriction content information is information indicating the restriction content to be executed when the traffic competes. Examples of the restriction contents include temporary suspension of transfer and reduction of transfer speed. The restriction content information further includes information indicating an execution time which is a time during which the restriction is continued. In the example shown in FIG. 4, “pause” is specified as the restriction content, and “execution time 1_T1” is stored as the execution time. This indicates a pause for T1 time.

  Furthermore, as shown in FIG. 4, a plurality of threshold values can be set for the same port in the transfer rate information, and a plurality of execution times can be set in the restriction content information. Thereby, for example, when the data transfer rate is larger than the threshold 1 and equal to or lower than the threshold 2, the execution time 1 is limited, and when the data transfer rate is larger than the threshold 2, the execution time 2 is limited. Two-stage restriction can also be performed. Note that three or more thresholds and execution times can be set for the same port, and three or more stages can be restricted. It is also possible to execute different restrictions depending on the stage, such as decelerating the restriction contents at a low threshold value and temporarily suspending the restriction contents at a high threshold value.

  The timeout information is information for determining the presence or absence of traffic. The timeout information is information in which traffic identification information is associated with a timeout time. If no traffic is detected during the timeout period, it is determined that no traffic is transferred. In the example shown in FIG. 4, traffic identification information “first traffic” for identifying the type of the first traffic is associated with “timeout time_τ1”. That is, when the first traffic is not detected for τ1 time, it is determined that the first traffic is not transferred.

  The plotter control information is information for performing control resulting from plot processing by the plotter 201. In the plotter 201, when data for one line is not transferred within a predetermined time, that is, when the transfer speed is slower than the printing speed, a problem such as missing data occurs. Thus, the plotter 201 has a problem of so-called line isochronism. Therefore, the plotter 201 needs to receive data at a transfer speed that is faster than the printing speed. The condition for this is plotter control information. The plotter control information is information in which traffic identification information is associated with a data amount. The plotter control information further includes one line cycle time.

  In the example shown in FIG. 4, the traffic identification information “first traffic” for identifying the type of the first traffic is associated with the data amount “D”. Furthermore, “τs” is stored as one line cycle time.

  For traffic other than the output from the plotter 201, there is no request for isochronism on the line. Therefore, as shown in FIG. 4, the configuration register 112 does not store the data amount of traffic other than the first traffic.

  Here, referring again to FIG. 3, the description returns to the block diagram illustrating an example of the functional configuration of the third switch 103. The first traffic detection circuit 113 detects the type of traffic passing through the first port 111 and the data transfer rate. Specifically, the first traffic detection circuit 113 acquires the traffic identification information for identifying the type of traffic and the payload size from the header part of the packet passing through the first port 111. Then, from the interval at which the packet passes through the first port 111 and the payload size, the port usage rate, the transfer rate for each traffic, and the amount of data passed are detected.

  The first traffic determination circuit 114 compares the set threshold value with the data transfer rate of traffic passing through the first port 111 when the threshold value of the first port 111 is set in the first configuration register 112. If the data transfer rate is larger than the threshold, a port other than the first port 111 through which the traffic passing through the first port 111 passes is specified.

  The first transmission / reception circuit 115 transmits flow control information indicating that the flow control processing is performed in the first port 111 to the port specified by the first traffic determination circuit 114. Further, the first transmission / reception circuit 115 receives traffic identification information of traffic being transferred through another port as a response to the flow control information from the other port, and passes it to the first traffic restriction circuit 116. The first transmission / reception circuit 115 also transmits traffic identification information of traffic passing through the first port 111 specified by the first traffic determination circuit 114 when flow control information is received from another port.

  The first traffic restriction circuit 116 is traffic that passes through the first port 111 and traffic that is identified by the traffic identification information received as a reply from the other ports by the first transmission / reception circuit 115, that is, all that passes through the first switch 103. The traffic for which the lowest priority is set in the priority information of the first configuration register 112 is identified from among the traffics. This traffic transfer is restricted.

  The configuration of the second port unit 120 to the fourth port unit 140 of the third switch 103 is the same as the configuration of the first port unit 110 of the third switch 103. The configuration of the second switch is the same as the configuration of the third switch. Furthermore, the first switch is different from the third switch only in the number of ports, and the other configuration is the same as that of the third switch.

  FIG. 5 is a flowchart illustrating an example of processing by the first port unit 110 of the third switch 103 of the multifunction machine 1. The other port units perform the same processing. First, when receiving configuration information from the configuration information setting unit 106 (step S100), the first transmission / reception circuit 115 sets configuration information in the first configuration register 112 (step S102). Next, the first traffic detection circuit 113 refers to the control setting information of the configuration information set in the first configuration register 112, and confirms whether or not the flow control processing for the switch including itself is instructed.

  In the control setting information, when “flow control_present” is set for the first switch (step S104, Yes), when traffic transfer is started (step S106, Yes), the flow control process is performed. Start. That is, the first traffic detection circuit 113 detects traffic passing through the first port 111 (step S110). Specifically, the first traffic detection circuit 113 detects traffic input to the third switch 103 via the first port 111 and traffic sent from the third switch 103 via the first port 111. The first traffic detection circuit 113 further detects the detected traffic type and data transfer rate.

  Next, the first traffic determination circuit 114 sets the total data transfer rate of all traffic passing through the first port 111 and the transfer rate information of the first configuration register 112 to the first port 111 of the third switch 103. The threshold value set for the comparison is compared. If the sum of the data transfer rates of all traffic passing through the first port 111 is equal to or less than the threshold value (Yes in step S112), the first traffic determination circuit 114 further sets the data amount in the plotter control information. The actual data transfer rate of traffic is compared with the data transfer rate D / τs obtained from the data amount “D” set in the plotter control information and the one-line cycle time “τs”. When the data transfer rate of traffic is equal to or higher than the data transfer rate D / τs (step S114, Yes), there is no problem of a decrease in data transfer rate due to traffic competition, and the speed of traffic transmitted to the plotter 201 is also high. The line is isochronous and there is no need to perform flow control. Therefore, if the data transfer is not completed (No at Step S116), the process returns to Step S110 again, and monitoring of the traffic of the first port 111 is continued by the flow control process. In step S116, if the data transfer is completed (step S116, Yes), the process ends.

  On the other hand, if the total transfer rate is larger than the threshold value in step S112 (step S112, No) and if the predetermined traffic transfer rate is larger than D / τs in step S114 (step S114, No), The first transmission / reception circuit 115 transmits flow control information to ports other than the first port 111 through which traffic passing through the first port 111 passes (step S120).

  When the first transmission / reception circuit 115 receives a response from the port to which the flow control information is transmitted (step S122, Yes), the first traffic restriction circuit 116 indicates that the traffic passing through the first port 111 and the first transmission / reception circuit 115 From the traffic identified by the traffic identification information received as a response, the traffic having the lowest priority set in the priority information of the configuration information is specified. And the restriction | limiting shown by the restriction | limiting content information of configuration information is performed with respect to this traffic (step S124). Then, during the execution time indicated in the restriction content information, the specified restriction such as stop or deceleration is performed, and when the execution time elapses (Yes in step S126), the flow returns to step S110 again to continue the flow control process.

  In step S104, if “no flow control” is set for the first switch in the control setting information of the configuration information (No in step S104), no processing is performed.

  As a result of the above processing, when traffic is concentrated on a predetermined port and the transfer rate is reduced, it is possible to restrict the transfer of the appropriate traffic, thereby suppressing the decrease in the transfer rate of the traffic whose speed is to be maintained. Also, for traffic that wants to maintain the data transfer rate, such as print data, it is possible to suppress a decrease in transfer rate by controlling the transfer of other traffic.

  FIG. 6 is a flowchart illustrating an example of processing when the first port unit 110 receives flow control information from another port. When the first transmission / reception circuit 115 receives the flow control information from another port (step S200, Yes), the traffic identification information of the traffic detected by the first port 111 is transmitted to the transmission source of the flow control information (step S202). . Further, the flow control information is transmitted to ports other than the first port 111 through which the traffic detected by the first port 111 passes and the source port of the flow control information (step S204). At this time, port identification information indicating the transmission source of the flow control information is transmitted together with the flow control information. When receiving the flow control information, the port unit of the port that has received the flow control information transmitted in step S204 transmits the traffic identification information of the traffic passing through the port unit to the first port unit 110. Send to.

  Hereinafter, specific processing in the third switch 103 according to the setting of the configuration information shown in FIG. 4 will be described. FIG. 7 is a diagram for explaining an example of traffic contention in the multifunction device 1 when the flow control process is not performed. The horizontal axis of the graph shown in FIG. 7 indicates time. The vertical axis of the graph indicates the traffic data transfer rate. In the section t1, the first traffic 301 and the second traffic 302 exist, and the third traffic 303 does not occur.

  Thereafter, it is assumed that the data transfer of the third traffic 303 has occurred from the network 202 as in the section t2. When the third traffic 303 is excessive traffic exceeding the capacity of the third port 131 that is an output port from the third switch 103 to the memory 203, the data transfer rate of the second traffic 302 transmitted from the UI 204 is It decreases compared to the t1 interval. Further, if the output of the second traffic 302 is delayed in the third switch 103, the first traffic that similarly flows from the second switch 102 to the third switch 103 due to the influence of the data of the second traffic 302 remaining in the third switch 103. The data transfer rate 301 is also reduced. Since the first traffic 301 is print data used by the plotter 201, when the amount of decrease in the first traffic 301 falls below the lower limit of the performance target of the first traffic 301, the plotter 201 receives print data. Abnormal data missing in part will be printed in time for printing the print data.

  Therefore, in the MFP 1 according to the present embodiment, the configuration information shown in FIG. 4 is set, and each port unit performs the processing described with reference to FIGS. 5 and 6 based on this configuration information. To perform flow control processing.

  In the configuration information shown in FIG. 4, the flow control in the third switch 103 is set to “Yes”. Therefore, in the multifunction device 1, the flow control process is executed in the third switch 103 among the first switch 101 to the third switch 103. That is, when the traffic transfer starts, each port unit 110 to 140 of the third switch 103 detects the type of traffic and the data transfer rate in the flow control process (step S110). In the transfer rate information of the configuration information, the threshold value of the third port 131 of the third switch 103 is set. Therefore, the third traffic detection circuit 133 compares the data transfer rate of the traffic passing through the third port 131 with a threshold value (step S112).

  In the t1 period when the transfer of the first traffic 301 and the second traffic 302 is performed, the transfer rate is equal to or less than the threshold (Yes in step S112). Therefore, if the first traffic 301 is transferred at a transfer rate equal to or higher than D / τs (step S114, Yes), the traffic transfer is continued. However, when the third traffic 303 is transferred while the first traffic 301 and the second traffic are being transferred as in the period t2, the total transfer rate of the traffic passing through the third port 131 is It becomes larger than the threshold value (step S112, No). Therefore, the third transmission / reception circuit 135 transmits flow control information (step S120). FIG. 8 is a diagram illustrating an example of a transmission destination of flow control information. In this case, since the transmission destination of the flow control information is the port through which the second traffic 302 passes and the port through which the third traffic 303 passes, they are the second port 121 and the fourth port 141.

  As shown in FIG. 9, in the second port unit 120 that has received the flow control information from the third port unit 130, the second transmission / reception circuit 125 performs traffic detected by the second traffic detection circuit 123, that is, first traffic. The traffic identification information 301 and the second traffic 302 are transmitted to the third port 131 as a response to the flow control information. Further, the second transmission / reception circuit 125 transfers the flow control information to the port through which the traffic passing through the second port 121 passes. As shown in FIG. 9, the first traffic 301 and the second traffic 302 pass through the second port 121. Therefore, the flow control information is transmitted to the first port 111 through which the first traffic 301 passes.

  On the other hand, in the fourth port unit 140, the fourth transmission / reception circuit 145 sends the traffic detected by the fourth traffic detection circuit 143, that is, the traffic identification information of the third traffic 303 to the third port 131 as a response to the flow control information. Send. Since the port through which the third traffic 303 passing through the fourth port 141 passes is the third port 131, the fourth transmission / reception circuit 145 does not transfer the flow control information. As shown in FIG. 10, in the first port unit 110, the first transmission / reception circuit 115 transmits the identification information of the first traffic 301 to the third port 131 as a response to the flow control information.

  In the third port unit 130, when the third transmission / reception circuit 135 receives replies from all ports through the above processing (step S122, Yes), the third traffic restriction circuit 136 determines the traffic to be restricted. . In this example, in addition to the second traffic 302 and the third traffic 303 detected by itself, the first traffic 301 passes through the third switch 103, and the second traffic 302 and the third traffic are transmitted through the third port 131. When 303 competes, the data transfer rate of the first traffic 301 decreases. Therefore, the third traffic restriction circuit 136 determines the second traffic 302 having the lowest priority as a restriction target in accordance with the priority information of the configuration information.

  The third traffic restriction circuit 136 further refers to the restriction content information of the configuration information and determines to perform control for temporarily stopping the transfer of the second traffic 302 for the time T1. Then, as shown in FIG. 11, the third traffic restriction circuit 136 sends a stop command 310 indicating that the transfer of the second traffic 302 is suspended for the time T1 to the second port upstream of the second traffic 302. Transmit to unit 120.

  In the second port unit 120, when the second transmission / reception circuit 125 receives the stop instruction 310, the second transmission / reception circuit 125 further transmits the stop instruction 310 to the fourth port of the second switch 102 upstream of the second traffic 302. The transmission / reception circuit of the fourth port further transmits a stop command 310 to the third port of the second switch 102. The third port of the second switch 102 transmits a stop command 310 to the UI 204. When the stop command 310 arrives at the UI 204 in this way, the UI 204 temporarily stops issuing the second traffic 302 for the time T1. When the time T1 elapses, the UI 204 resumes issuing the second traffic 302.

  When the third traffic 303 is generated by the above flow control processing, appropriate flow control is performed as a whole of the multifunction device 1 by temporarily stopping the second traffic 302 having a lower priority instead of the third traffic 303. be able to. FIG. 12 is a diagram for explaining an example of traffic contention in the multifunction device 1 when the flow control process is performed. The horizontal axis of the graph shown in FIG. 12 indicates time. The vertical axis of the graph indicates the traffic data transfer rate. As shown in FIG. 12, by temporarily stopping the transfer of the second traffic 302 by the flow control process, it is possible to minimize a decrease in the data transfer rate of the first traffic 301. A data transfer rate exceeding the limit can be maintained. That is, it is possible to prevent a decrease in the data transfer rate that is less than the performance limit as viewed from the scanner 200.

  As a first modification, the present embodiment has been described by taking an example in which the switch system is applied to a multifunction machine having at least two functions of a copy function, a printer function, a scanner function, and a facsimile function. The present invention can be applied to any image forming apparatus such as a printer, a printer, a scanner apparatus, and a facsimile apparatus. Furthermore, any system can be applied as long as it is a system in which a plurality of devices are connected by a switch. In a system that does not include a plotter, the plotter control information and the processing related to the plotter control information are not required.

  As a second modification, when the amount of data is set in the plotter control information and processing based on the plotter control information is performed, the priority of the target traffic may be variable. Specifically, when the data amount D for the first traffic is set, a higher priority is set as the remaining amount of untransferred data in the first traffic increases. For example, the priority when the remaining amount of data is D1 or more is “high”, the priority when the remaining amount of data is less than D1 D2 (D2 <D1) or more is “medium”, and the remaining amount of data is less than D2. In some cases, the priority is “low”. As described above, by changing the priority according to the remaining amount of data, when the remaining amount of data decreases, transfer of other more important traffic can be preferentially executed.

  As a third modification, the transfer rate information of the configuration information may include a threshold value for each traffic instead of the threshold value for each port. In this case, the flow control information is transmitted when the data transfer rate of the predetermined traffic becomes smaller than the threshold value. Further, the configuration information may include a priority, a threshold value, and a limit execution time according to the remaining data amount. In this case, each port unit can further detect the data remaining amount of each traffic and perform processing according to the data remaining amount.

  As a fourth modification example, the switch according to the present embodiment includes the same number of configuration registers, traffic detection circuits, traffic determination circuits, and traffic restriction circuits as the number of ports corresponding to each port. A configuration having one configuration register used by all the ports may be used. Similarly, each switch may have one traffic detection circuit, traffic determination circuit, and traffic restriction circuit, and each circuit may perform processing for all ports in the switch.

  As described above, a switch system for controlling data transfer between a plurality of devices, a plurality of switches having a plurality of ports for connecting to the device or the switch, port identification information for identifying each port, First storage means for storing the transfer rate threshold of data that can be transferred to each port in association with each other, and second storage means for storing the type and priority of the data passing through each port in association with each other Each of the plurality of switches includes a type specifying means for specifying a type of data passing through each port, a transfer rate calculating means for calculating a transfer rate of the data passing through each port, and a predetermined one of the plurality of ports. The transfer rate calculated by the transfer rate calculating unit for the predetermined data that has passed through the port identifies the predetermined port in the first storage unit A port in the switch having the predetermined port when the predetermined value is larger than the threshold value associated with the port identification information, and other ports other than the predetermined port through which the predetermined data passes The port specifying means for specifying the data and the second storage means restrict data transfer based on the priority associated with the predetermined data and data other than the predetermined data passing through the other port Data determining means for determining data to be determined, and limiting means for limiting the transfer of the data determined by the data determining means.

  Each of the plurality of switches includes a plurality of the type specifying unit, the transfer rate calculating unit, and the port specifying unit for each port, and the type specifying unit provided for the first port among the plurality of ports includes: The type of data passing through the first port is specified, and the transfer rate calculation means of the first port calculates the transfer rate of the data passing through the first port, and the port of the first port The specifying means, when the transfer rate for the data that has passed through the first port is greater than the threshold value associated with the port identification information for identifying the first port in the first storage means, The other port other than the first port in the same switch through which the data passes is specified.

  Each of the plurality of switches includes transmission means for transmitting flow control information indicating that data transfer is controlled to the other port specified by the port specification means, and reception means for receiving the flow control information. And when the receiving means of the second port receives the flow control information transmitted by the transmitting means of the first port, the port specifying means of the second port is The transmission means of the second port specifies the data identification information for identifying the data specified by the port specification means of the second port as the transmission source of the flow control information. When data is transmitted to one port and the receiving means of the first port receives the data identification information, the data determining means of the first port passes through the first port. From the data which the identified by the data and the data identification information received from said second port that determines data to be limiting.

  With the above configuration, the first register stores the port identification information for identifying each port in association with the threshold of the transfer rate of data that can be transferred to each port, and the second register passes through each port. Type and priority are stored in association with each other. Each port detects the type of data passing through the port and the transfer rate, and compares it with the value of the register to determine which data transfer is restricted. Therefore, there is an effect that appropriate data transfer control can be performed as the entire system.

DESCRIPTION OF SYMBOLS 1 MFP 101 1st switch 102 2nd switch 103 3rd switch 104 Operation mode setting part 105 Configuration information storage part 106 Configuration information setting part 110 1st port unit 111 1st port 112 1st configuration register 113 1st traffic detection Circuit 114 First traffic determination circuit 115 First transmission / reception circuit 116 First traffic restriction circuit 120 Second port unit 121 Second port 130 Third port unit 131 Third port 140 Fourth port unit 141 Fourth port 200 Scanner 201 Plotter 202 Network 203 Memory 204 UI
301 First traffic 302 Second traffic 303 Third traffic

JP 2006-18406 A JP 2007-65847 A JP 2005-354658 A

Claims (13)

A switch capable of controlling data transfer between a plurality of devices,
A port connectable to the device;
Determining means for determining whether a transfer rate of traffic passing through the port is a predetermined value or more;
Limiting means for limiting low priority traffic among traffic passing through the port when the determination means determines that the traffic transfer rate is equal to or greater than a predetermined value;
A switch comprising:   The switch according to claim 1, wherein the determination unit determines whether or not a total value of transfer rates of all traffic passing through the port is a predetermined value or more.   The switch according to claim 1, wherein the determination unit determines whether a transfer rate of specific traffic passing through the port is a predetermined value or more.   The limiting means specifies a port through which the traffic passes among ports of the switch other than the port, and limits traffic having a low priority among traffic passing through the specified port. The switch according to claim 1.   The switch according to claim 1, wherein the limiting unit stops or slows down forwarding of low priority traffic among traffic passing through the port. Information regarding the presence or absence of forwarding of traffic passing through the port, information indicating which traffic is prioritized among traffic passing through the port, information indicating the traffic forwarding rate, traffic restriction content Further comprising storage means for storing information indicating
The port allows the traffic to pass when the storage means is set to transfer the traffic;
The determination means makes a determination based on information indicating a transfer rate of the traffic stored in the storage means,
The limiting means converts low-priority traffic determined based on information indicating which traffic is to be preferentially executed among traffic passing through the port into information indicating the content of the traffic limitation. The switch according to claim 1, wherein the restriction is based on the switch.   The switch according to claim 6, wherein the storage unit is provided for each port of the switch. An information processing apparatus capable of transferring data between a plurality of devices,
Setting means for setting an operation mode of the information processing apparatus in response to an external input;
A switch for controlling data transfer between the plurality of devices;
Comprising
The switch is
A port connectable to the device;
Determining means for determining whether a transfer rate of traffic passing through the port is equal to or greater than a predetermined value corresponding to the operation mode set by the setting means;
When the determination unit determines that the traffic transfer rate is equal to or higher than a predetermined value, the traffic that passes through the port is restricted to low-priority traffic corresponding to the operation mode set by the setting unit. Limiting means to
An information processing apparatus comprising:   The information processing apparatus according to claim 8, wherein a priority associated with traffic transmitted to the plotter is higher than a priority associated with other traffic.   The traffic is print data, different priorities are associated with the plotter according to the amount of print data that has already been transmitted, and the less data remaining in the untransmitted data to be transmitted to the plotter The information processing apparatus according to claim 8, wherein a higher priority is associated with the information processing apparatus. Storage means for storing transfer rate information indicating the transfer rate of the traffic and priority information indicating which of the traffic passing through the port is to be transferred with priority in association with an operation mode;
Second setting means for setting the transfer rate information and the priority information stored in the storage means corresponding to the operation mode set by the setting means in the second storage means of the switch;
The information processing apparatus according to claim 8, further comprising: In a data transfer control method executed by a switch capable of controlling data transfer between a plurality of devices,
Determining whether a transfer rate of traffic passing through the port is a predetermined value or more;
A data transfer control method, wherein when it is determined that the traffic transfer rate is equal to or higher than a predetermined value, traffic having a low priority is restricted among traffic passing through the port. In a data transfer control method executed by an information processing apparatus capable of controlling data transfer between a plurality of devices,
Set the operation mode of the information processing device according to the input from the outside,
A switch having a port for connecting the device determines whether or not a transfer rate of traffic passing through the port is equal to or higher than a predetermined value corresponding to the set operation mode;
When it is determined that the traffic transfer rate is equal to or higher than a predetermined value, the switch limits low-priority traffic corresponding to the set operation mode among traffic passing through the port. Data transfer control method.

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