JP2005033673A - Circuit and method for packet transfer control - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a packet transfer control circuit with a simple hardware configuration for performing band control on each of a plurality flows of packets, and realizing priority control simultaneously. <P>SOLUTION: The packet transfer control circuit comprises a class setting unit 133, an output queue unit 140, and an arrival rate update unit 150. The class setting unit 133 compares a flow setting information for a flow read from a flow setting information storage unit 120 with an arrival rate for the flow from a rate computing unit 132 based on the flow identified by a flow identifying unit 110, and sets up a class of the flow, to which a packet belongs, in unit of the packet. The output queue unit 140 controls output sequence for a plurality of the packets based on the class of the flow, to which the packets belong, established by the class setting unit 133. The arrival rate update unit 150 updates the arrival rate information for the flow with a predetermined timing, based on residual data amount from the output queue unit 140 and the packet arrival rate information on the flow setting information. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a packet transfer control circuit and a packet transfer control method for controlling the output order of a plurality of packets when a plurality of input packets are selectively output to an output line, and more particularly to a plurality of the plurality of packets. The present invention relates to a packet transfer control circuit and a packet transfer control method for guaranteeing bandwidth for each of the flows.

  In recent years, with the spread of ADSL (Asymmetric Digital Subscriber Line) and FTTH (Fiber To The Home), consumer-based always-on services have become commonplace, and broadband access networks are accelerating. In addition, with the progress of information home appliances and the spread of digital video distribution services, it is expected that demand for differentiating communication quality according to various communication services will increase. The current mainstream of the Internet is a best effort service that does not guarantee communication quality, and with the increase in traffic and the emergence of services that require different communication quality, there is a problem of deterioration in communication quality for user communication devices. Therefore, in the future, it is considered important that the user communication apparatus performs high-quality QoS (Quality of Services) control in consideration of the service type and bandwidth request for each packet flow.

  Further, in future access networks, it is necessary to accommodate a high-speed communication line such as a maximum of 100 Mbps to 1 Gbps on a large scale from the viewpoint of cost reduction of the communication system. When handling packet flows, for example, when QoS control is performed by scheduling with a queue for each packet flow, such as WRR (Weighted Round Robin), scalability is possible in terms of both the amount of hardware and the processing load of the scheduler. It becomes difficult to have.

  Further, Patent Literature 1 discloses a bandwidth control apparatus and method for performing bandwidth control for each user flow with a simple hardware configuration. In the technique disclosed in Patent Document 1, first, the traffic flow rate of each flow is measured by the rate measurement unit, and the measured input rate is stored in the flow information storage unit, while the received packet of each flow is output to the output line. The queue length of the buffer for monitoring is observed by the queue length monitoring unit.

  Then, the permission rate calculation unit calculates the permission rate of each flow from the observed queue length and the minimum guaranteed bandwidth of each flow stored in the flow information storage unit. Next, the measured input rate is compared with the calculated permitted rate at the discard control unit. If the input rate is less than the permitted rate, the packet of that flow is input to the buffer, and the input rate exceeds the permitted rate. In this case, control is performed so that the input rate to the buffer of each flow is always equal to or lower than the permitted rate by discarding the excess.

  According to this, since control is performed so that a plurality of flows to be accommodated share one FIFO (First In First Out) buffer, the amount of hardware is small even if the number of flows increases. In addition, by monitoring the input rate for each flow and discarding packets that exceed the permitted rate, the influence of the flow that violated the bandwidth (the flow whose input rate exceeds the permitted rate) is affected to other flows. prevent.

Thus, by using the technique disclosed in Patent Document 1, it is possible to guarantee bandwidth for a plurality of flows using a single queue. In addition, if surplus bandwidth (that satisfies all the minimum guaranteed bandwidth of each input flow and the remaining bandwidth up to the output link bandwidth) occurs, the permitted rate of each flow is proportional to the minimum guaranteed bandwidth of each flow. By increasing the number, it becomes possible to distribute the surplus bandwidth among the flows according to the minimum guaranteed bandwidth of each flow.
JP 2002-185459 A

  Incidentally, the bandwidth control device disclosed in Patent Literature 1 performs bandwidth control by storing all the flows in one queue. On the other hand, various types of packets are mixed in each flow input to the bandwidth control apparatus. For example, each flow contains different application packets, which are relatively tolerant to delays and fluctuations such as e-mail and Web access, and delays and fluctuations such as voice communication and video distribution. There are various things, such as those requiring real-time sensitivity sensitive to mission-critical things for mission-critical operations.

  As described above, when all the flows in which various types of packets are mixed are stored and managed by one queue, QoS control according to the communication quality required for each of the various types of packets in each flow. It is impossible to do.

  Further, the bandwidth control device disclosed in Patent Document 1 distributes surplus bandwidth in proportion to the minimum guaranteed bandwidth of each flow. However, depending on the user apparatus, the minimum guaranteed bandwidth may be small, but there is a demand for a large amount of transmission to the surplus bandwidth, that is, a so-called best effort area. In the bandwidth control device disclosed in Patent Document 1, it is impossible to answer such a request simply by distributing the surplus bandwidth in proportion to the minimum guaranteed bandwidth.

  The present invention has been made in view of such points, and a packet transfer control circuit capable of performing bandwidth control on each of a plurality of packet flows and simultaneously realizing priority control with a simple hardware configuration. It is another object of the present invention to provide a packet transfer control method.

  The present invention also provides a packet transfer control circuit capable of managing not only bandwidth control and priority control for each of a plurality of packet flows but also managing a plurality of packet flows as one group and performing bandwidth control for each group. It is another object of the present invention to provide a packet transfer control method.

  The invention according to claim 1 is flow identification means for identifying a plurality of flows to which a plurality of input packets belong, and class information indicating bandwidth information and priority set in advance for each of the plurality of flows. And flow setting information storage means for storing flow setting information having packet arrival rate information, rate measuring means for measuring the arrival rate of the packet as a data amount per predetermined unit time, and within the predetermined unit time Rate calculation means for calculating the arrival rate for the flow to which the packet belongs based on the total data amount of the packet for the flow to which the packet has arrived and the arrival rate for the packet; and The flow related to the flow read from the flow setting information storage means based on the identified flow Class setting means for comparing the row setting information with the arrival rate for the flow and setting the class of the flow to which the packet belongs in units of the packet, and to which the packet set by the class setting means belongs Output control means for controlling the output order of the plurality of packets based on the class of the flow, and at a predetermined timing based on the remaining data amount from the output control means and the packet arrival rate information of the flow setting information And an arrival rate updating means for updating the packet arrival rate information relating to the flow.

  According to this configuration, the flow to which the input packet belongs is identified, the packet setting is performed with reference to the flow setting information including the bandwidth information related to the flow, the class information indicating the priority, and the packet arrival rate information, Select a flow that is set to a class with high priority sequentially and output packets belonging to that flow in sequence, so priority control that selectively outputs flows belonging to a class with high priority on a packet-by-packet basis. This can be realized with a simple hardware configuration.

  The invention according to claim 2 is the invention according to claim 1, wherein the class setting means is configured such that the arrival rate of the flow to which the packet belongs is equal to or less than a value of minimum guaranteed bandwidth information of the flow setting information. In this case, the class of the flow to which the packet belongs is set in the reference priority class of the flow setting information, and the arrival rate for the flow to which the packet belongs is determined by the value of the minimum guaranteed bandwidth information in the flow setting information. When the value is not more than the value of the upper limit bandwidth information, the priority is lower than the reference priority class of the flow setting information, and the packet belongs to the upper limit priority class set in association with the reference priority class Use a configuration to set the flow class.

  According to this configuration, the flow to which the input packet belongs is identified, the packet setting is performed with reference to the flow setting information including the bandwidth information related to the flow, the class information indicating the priority, and the packet arrival rate information, Select a flow that is set to a class with high priority sequentially and output packets belonging to that flow in sequence, so priority control that selectively outputs flows belonging to a class with high priority on a packet-by-packet basis. This can be realized with a simple hardware configuration.

  The invention according to claim 3 is the invention according to claim 2, wherein the class setting means determines that the arrival rate of the flow to which the packet belongs is greater than the value of the upper limit bandwidth information of the flow setting information. In the case of being larger, the configuration is such that the priority is lower than the upper limit priority class and the flow class to which the packet belongs is set in the surplus priority class set in association with the reference priority class.

  According to this configuration, the flow to which the input packet belongs is identified, the packet setting is performed with reference to the flow setting information including the bandwidth information related to the flow, the class information indicating the priority, and the packet arrival rate information, Select a flow that is set to a class with high priority sequentially and output packets belonging to that flow in sequence, so priority control that selectively outputs flows belonging to a class with high priority on a packet-by-packet basis. This can be realized with a simple hardware configuration.

  The invention according to claim 4 is the invention according to claim 2 or 3, wherein the arrival rate of the flow to which the packet belongs is compared with the value of the upper limit bandwidth information of the flow setting information. A configuration is adopted in which packet discarding means for discarding the packet is adopted when the arrival rate of the flow to which the packet belongs is larger than the value of the upper limit bandwidth information of the flow setting information.

  According to this configuration, the flow to which the input packet belongs is identified, the packet setting is performed with reference to the flow setting information including the bandwidth information related to the flow, the class information indicating the priority, and the packet arrival rate information, Select a flow that is set to a class with high priority sequentially and output packets belonging to that flow in sequence, so priority control that selectively outputs flows belonging to a class with high priority on a packet-by-packet basis. This can be realized with a simple hardware configuration.

  The invention according to claim 5 is the flow set in advance for each of a plurality of groups in which a plurality of flows of packets are grouped in the invention according to any one of claims 1 to 4. Group setting information storage means for storing group setting information and group setting information having bandwidth information; and group rate calculation means for calculating an arrival rate related to the group to which the flow belongs based on an arrival rate of the packet. And the output control means is based on the group setting information identified by the flow identification means and read based on the flow group correspondence information in the group setting information storage means and the arrival rate related to the group. A configuration having means for controlling the output of a plurality of packets is adopted.

  According to this configuration, in addition to the effects of the invention according to any one of claims 1 to 4, it is possible to manage a plurality of flows of packets as one group and perform bandwidth control for each group.

  The invention according to claim 6 shows a flow identification step for identifying a plurality of flows to which a plurality of inputted packets belong, and band information and priority set in advance for each of the plurality of flows. A flow setting information storage step for storing flow setting information having class information and packet arrival rate information in the flow setting information storage means; a rate measuring step for measuring the arrival rate of the packet as a data amount per predetermined unit time; A rate calculation for calculating an arrival rate for the flow to which the packet belongs based on a total data amount of the packet for the flow to which the packet arrives within the predetermined unit time and the arrival rate for the packet And the flow based on the flow identified in the flow identification step A class setting step for setting the class of the flow to which the packet belongs in units of the packet by comparing the flow setting information related to the flow read from a fixed information storage unit and the arrival rate related to the flow; An output control step for controlling the output order of the plurality of packets based on the class of the flow to which the packet set in the class setting step belongs, the remaining data amount in the output control step, and the flow setting information An arrival rate update step of updating the packet arrival rate information related to the flow at a predetermined timing based on the packet arrival rate information.

  According to this method, the flow to which the input packet belongs is identified, the class setting of the packet is performed with reference to the flow setting information including the band information related to the flow, the class information indicating the priority, and the packet arrival rate information, Select a flow that is set to a class with high priority sequentially and output packets belonging to that flow in sequence, so priority control that selectively outputs flows belonging to a class with high priority on a packet-by-packet basis. This can be realized with a simple hardware configuration.

  The invention according to claim 7 is the invention according to claim 6, wherein the class setting step is configured such that the arrival rate of the flow to which the packet belongs is equal to or less than a value of minimum guaranteed bandwidth information of the flow setting information. In the case, the step of setting the class of the flow to which the packet belongs to the reference priority class of the flow setting information, and the arrival rate for the flow to which the packet belongs is the value of the minimum guaranteed bandwidth information of the flow setting information. When the value is lower than the value of the upper limit bandwidth information and lower than the reference priority class of the flow setting information, the packet is assigned to the upper limit priority class set in association with the reference priority class. And a step of setting a class of the flow to which it belongs.

  According to this method, the flow to which the input packet belongs is identified, the class setting of the packet is performed with reference to the flow setting information including the band information related to the flow, the class information indicating the priority, and the packet arrival rate information, Select a flow that is set to a class with high priority sequentially and output packets belonging to that flow in sequence, so priority control that selectively outputs flows belonging to a class with high priority on a packet-by-packet basis. This can be realized with a simple hardware configuration.

  The invention according to claim 8 is the invention according to claim 7, wherein the class setting step is configured such that the arrival rate of the flow to which the packet belongs is greater than the value of the upper limit bandwidth information of the flow setting information. If larger, the priority is lower than that of the upper limit priority class, and a step of setting the class of the flow to which the packet belongs to a surplus priority class set in association with the reference priority class is provided. I made it.

  According to this method, the flow to which the input packet belongs is identified, the class setting of the packet is performed with reference to the flow setting information including the band information related to the flow, the class information indicating the priority, and the packet arrival rate information, Select a flow that is set to a class with high priority sequentially and output packets belonging to that flow in sequence, so priority control that selectively outputs flows belonging to a class with high priority on a packet-by-packet basis. This can be realized with a simple hardware configuration.

  As described above, according to the present invention, the flow to which an input packet belongs is identified, the class of the packet is set by referring to the flow setting information related to the flow, and the flow set to the class with high priority. By sequentially selecting packets and sequentially outputting packets belonging to the flow, bandwidth control is performed and at the same time, classification is performed on a packet basis according to the bandwidth information of each flow. Priority control for selectively outputting a flow in packet units can be realized with a simple hardware configuration.

  The gist of the present invention is to identify the flow to which the input packet belongs, and to set the class of the packet with reference to the flow setting information having the band information related to the flow, the class information indicating the priority, and the packet arrival rate information, This is to sequentially select flows set in a class having a high priority and sequentially output packets belonging to the flows.

    Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(Embodiment 1)
FIG. 1 is a block diagram showing a configuration of a packet transfer control circuit according to Embodiment 1 of the present invention.

  As shown in FIG. 1, the packet transfer control circuit 100 includes a flow identification unit 110, a flow setting information storage unit 120, an arrival rate monitoring unit 130, an output queue unit 140, and an arrival rate update unit 150.

  For example, the flow identification unit 110 receives a packet transmitted from a communication terminal device accommodated in a predetermined communication network. The flow identification unit 110 identifies the flow to which the input packet belongs by referring to the header information of the input packet (input packet), and the flow identification information that is information related to the flow identification result is stored in the flow setting information storage unit 120 is notified.

  The flow setting information storage unit 120 stores flow setting information that is information regarding a plurality of flows of a plurality of packets. The flow setting information is set in advance. Then, the flow setting information storage unit 120 sends the flow setting information specified by the flow identification information notified from the flow identification unit 110 to the arrival rate monitoring unit 130.

  FIG. 2 is a diagram schematically illustrating an example of the flow setting information stored in the flow setting information storage unit 120 according to Embodiment 1 of the present invention. The flow setting information shown in FIG. 2 includes minimum guaranteed bandwidth information (MPR: Minimum Packet Rate) MPR1 to MPRn and upper limit bandwidth information (PPR: Peak Packet) of flows 1 to n (n is an integer of 1 or more). Rate) PPR1 to PPRn, and reference priority class information (ICL: Initial Class) ICL1 to ICLn to which the flow belongs when the packet arrival rate of each flow is equal to or less than the minimum guaranteed bandwidth information MPR, and packet arrival rate information (PAR: Packet Arrival Rate) PAR1 to PARn.

  Among the flow setting information, the minimum guaranteed bandwidth information MPR, the upper limit bandwidth information PPR, and the reference priority class information ICL have setting values stored in advance in each of a plurality of flows of a plurality of packets. This is used for packet discard processing or class setting processing in the monitoring unit 130. Further, as will be described later, the packet arrival rate information PAR is used for packet discard processing or class setting processing in the arrival rate monitoring unit 130, and further according to the result of packet input monitoring by the arrival rate monitoring unit 130. Stored values are updated sequentially. When a predetermined time for bandwidth monitoring has elapsed, all packet arrival rate information PAR is updated with the remaining data amount notified from the output queue unit 140 for each packet and flow.

  The arrival rate monitoring unit 130 receives the notification of the flow setting information from the flow setting information storage unit 120, is supplied with a packet via the flow identification unit 110, and performs a packet discarding process or a class setting process. The arrival rate monitoring unit 130 includes a rate measuring unit 131, a rate calculating unit 132, a class setting unit 133, and a packet discarding unit 134.

  The rate measuring unit 131 measures the arrival rate of packets supplied via the flow identifying unit 110. The rate calculation unit 132 calculates the packet arrival rate information PAR related to the flow to which the packet to be measured by the rate measurement unit 131 belongs. In addition, the class setting unit 133 compares the packet arrival rate information PAR calculated by the rate calculation unit 132 with the minimum guaranteed bandwidth information MPR and the upper limit bandwidth information PPR of the notified flow setting information, and the comparison result is In response, discard request information for instructing the discard of the packet and class setting information for instructing the class to which the packet belongs are output. When the packet discard unit 134 receives the discard request information from the class setting unit 133, the packet discard unit 134 discards the packet.

  Next, the operation of the arrival rate monitoring unit 130 will be described with reference to FIG. 3 together with FIG. FIG. 3 is a flowchart for explaining an example of the operation in the arrival rate monitoring unit 130 according to Embodiment 1 of the present invention.

  For example, when a packet of flow i arrives at the arrival rate monitoring unit 130, the rate measurement unit 131 measures the arrival rate of the packet (step ST301). The measured packet arrival rate is notified from the rate measuring unit 131 to the rate calculating unit 132.

  Moreover, the rate calculation part 132 acquires the flow setting information regarding the flow i to which the packet belongs from the flow setting information storage part 120 (step ST302). Rate calculation section 132 newly calculates packet arrival rate information PARi of flow i based on the measurement result of rate measurement section 131 and packet arrival rate information PARi of flow setting information (step ST303).

  The packet arrival rate information PARi is calculated by, for example, starting counting the supply data amount of packets belonging to the flow i at a predetermined reference timing and adding the supply data amounts of packets belonging to the same flow i. This is executed by calculating the data amount of the flow i supplied to the arrival rate monitoring unit 130 after a predetermined reference timing and resetting the count value when the predetermined reference timing is reached again.

  That is, by adding the measurement result of the rate measuring unit 131 and the PARi of the flow setting information, the data amount of the flow i can be calculated at a predetermined reference timing interval. As will be described later (step ST309), the calculation result (PAR) calculated by the rate calculation unit 132 is stored in the flow setting information and is referred to when calculating the data amount of the next flow i.

  Next, the class setting unit 133 determines whether PARi ≦ MPRi based on the PARi calculated by the rate calculation unit 132 and the minimum guaranteed bandwidth information MPRi and the upper limit bandwidth information PPRi of the flow setting information. (Step ST304).

  When PARi ≦ MPRi in step ST304, the class setting unit 133 has the arrived packet in the minimum guaranteed bandwidth information MPRi set for the flow i (that is, the flow i has not yet reached the minimum guaranteed bandwidth). And the packet is set to the class ICLi set in advance for the flow i (step ST306). At this time, the class setting unit 133 outputs information indicating that the packet is set to the class ICLi to the output queue unit 140 as class setting information.

  If PARi ≦ MPRi is not satisfied in step ST304, class setting section 133 determines whether or not MPRi <PARi ≦ PPRi in step ST305.

  If MPRi <PARi ≦ PPRi in step ST305, the class setting unit 133 uses the surplus bandwidth until the arrived packet satisfies the minimum guaranteed bandwidth information MPRi set for the flow i and reaches the upper limit bandwidth information PPRi. (That is, the flow i has reached the minimum guaranteed bandwidth but has not yet reached the upper limit bandwidth), and the packet is set to a class one lower than the class ICLi set in advance for the flow i. Set (step ST307). At this time, the class setting unit 133 outputs information indicating that the packet has been set to a class immediately below the class ICLi to the output queue unit 140 as class setting information.

  When MPRi <PARi ≦ PPRi is not satisfied in step ST305, the class setting unit 133 is in a state in which the arrived packet exceeds the upper limit bandwidth PPRi already set for the flow i, and all allowed surplus bandwidth is used up. The packet discarding process is executed by the packet discarding unit 134 (step ST308). In this case, the class setting unit 133 notifies the packet discard unit 134 of discard request information for requesting the packet to be discarded, and the packet discard unit 134 that has received the discard request information performs the packet discard processing.

  However, in order to effectively utilize the bandwidth of the output link, it is also possible to permit the output of a packet when there is a surplus bandwidth even if the upper limit bandwidth is exceeded. In this case, the class setting unit 133 sets a packet to a class two lower than the class ICLi set in advance for the flow i (step ST308). In addition, the class setting unit 133 outputs information indicating that the packet is set to a class two lower than the class ICLi to the output queue unit 140 as class setting information.

  If it is determined that the packet is PARi ≦ MPRi, or if it is determined that MPRi <PARi ≦ PPRi, the class setting unit 133 sets the flow i stored in the flow setting information storage unit 120. The packet arrival rate information PARi of the flow setting information is updated with new packet arrival rate information PARi (PARi calculated by the rate calculation unit 132) (step ST309).

  As described above, the packet discard process or the class setting process is performed in the arrival rate monitoring unit 130, and when the class setting process is performed, the arrival rate monitoring unit 130 sends the packet and its output queue unit 140 to the output queue unit 140. Class setting information related to the packet is supplied. The class setting information includes at least flow identification information that enables identification of a flow related to the packet and information indicating a class set for the flow related to the packet.

  Next, the output queue unit 140 of the packet transfer control circuit 100 according to the first embodiment of the present invention will be described with reference to the drawings.

  The output queue unit 140 includes an output order management unit 141, a packet selection unit 142, and a packet output unit 143. The output order management unit 141 stores packets supplied from the arrival rate monitoring unit 130, and manages the output order of flows by class. The output order management unit 141 has a plurality of buffer units 1410. The buffer unit 1410 is set to a class having the same priority for determining the order of operations. Note that the buffer unit 1410 may be associated with classes having different priorities for determining the order of operations. The packet supplied from the arrival rate monitoring unit 130 is stored in one of the plurality of buffer units 1410 according to the reference priority class information ICL of the flow setting information of the flow to which the packet belongs.

  Each of the plurality of buffer units 1410 has a plurality of FIFO queues 1411 to 1413. The plurality of FIFO queues 1411 are set to the reference priority class having the highest priority. The plurality of FIFO queues 1412 are set to the upper limit priority class having a lower priority than the reference priority class. The plurality of FIFO queues 1413 are set in a surplus priority class having a lower priority than the upper limit priority class.

  The output order management unit 141 stores the packets supplied from the arrival rate monitoring unit 130 in the FIFO queues 1411 to 1413 of the corresponding classes in the order of arrival, and manages the data amount of the stored packets for each flow and class. .

  Further, each of the plurality of buffer units 1410 has an upper limit priority class and a surplus in any of the FIFO queues 1411 to 1413 set corresponding to the reference priority class when a predetermined time for bandwidth monitoring has elapsed. Packets stored and stored in any of the FIFO queues 1411 to 1413 set in accordance with the priority class are re-stored in the order of the upper limit priority class and the surplus priority class, and the flow setting information storage unit 120 receives the flow. The remaining data amount in the FIFO queues 1411 to 1413 set corresponding to the upper limit priority class and the surplus priority class is notified every time.

  Further, the packet selection unit 142 refers to the output order of the packets managed by the output order management unit 141, selects the packet queued at the head of the highest class, and sends the packet output unit 143 to the packet output unit 143. Notify to output the packet. The packet output unit 143 reads out the packet selected by the packet selection unit 142 from the output order management unit 141 and outputs the packet to an external communication network.

  Next, the operation of the output queue unit 140 of the packet transfer control circuit 100 according to Embodiment 1 of the present invention will be described with reference to FIG. 4 together with FIG. FIG. 4 is a flowchart for explaining an example of the operation in the output queue unit 140 of the packet transfer control circuit 100 according to the first embodiment of the present invention.

  In step ST401, when the packet of the flow i and the class setting information are supplied from the arrival rate monitoring unit 130, the output order management unit 141 associates the packet with the class according to the information indicating the class in the class setting information. Stored in one of the FIFO queues 1411 to 1413 set in the above.

  Next, the packet selection unit 142 selects the packet to be output next according to the storage status of the packets stored in the output order management unit 141. Specifically, in step ST402, the packet selection unit 142 determines whether a packet exists in the FIFO queue 1411 of the reference priority class of the output order management unit 141. If there is a packet in the reference priority class FIFO queue 1411 of the output order management unit 141 in step ST402, the packet selection unit 142 next outputs queue identification information that can identify the reference priority class FIFO queue 1411. It is generated as information for identifying the queue storing the packet to be headed (step ST405).

  If there is no packet in the reference priority class FIFO queue 1411 in step ST402, the packet selection unit 142 determines whether there is a packet in the upper limit priority class FIFO queue 1412 having a lower priority than the reference priority class. Judgment is made (step ST403). If there is a packet in the upper-limit priority class FIFO queue 1412 in step ST403, the packet selection unit 142 stores the queue identification information that can identify the upper-limit priority class FIFO queue 1412 next to the packet to be output next. It is generated as information for identifying the queue that is currently in operation (step ST406).

  If there is no packet in the FIFO queue 1412 of the upper limit priority class in step ST403, the packet selection unit 142 sends a packet to the FIFO queue 1413 of the surplus priority class (lowest priority class) having a lower priority than the upper limit priority class. It is determined whether or not it exists (step ST404). In step ST404, when there is a packet in the FIFO queue 1413 of the surplus priority class (lowest priority class), the packet selection unit 142 next outputs queue identification information that can identify the FIFO queue 1413 of the lowest priority class. It is generated as information for identifying the queue storing the packet to be headed (step ST407).

  In step ST404, if there is no packet in the FIFO queue 1413 of the surplus priority class (lowest priority class), the packet selection unit 142 determines that there is no packet to be output, and the packet is output. I will not.

  When the packet selection unit 142 generates the queue identification information indicating the FIFO queue storing the packet to be output by any one of the steps ST405 to ST407, the packet selection unit 142 sends the FIFO queue to the packet output unit 143. The generated queue identification information is supplied to request output of the first packet of (step ST408). The packet output unit 143 selects the packet stored at the head in the FIFO queue indicated by the supplied queue identification information, and outputs it to the external output line (step ST409).

  The arrival rate updating unit 150 determines the arrival rate of the flow setting information related to the flow stored in the flow setting information storage unit 120 at a predetermined timing, the remaining data amount from the output order management unit 141 of the output queue unit 140, and the flow setting. Update based on information arrival rate. The arrival rate updating unit 150 updates the arrival rate held by the class setting unit 133 at the predetermined timing.

  As described above, according to the first embodiment of the present invention, the flow to which the input packet belongs is identified, the class setting of the packet is performed by referring to the flow setting information related to the flow, and the class having a high priority is set. By selecting a set flow sequentially and outputting packets belonging to that flow sequentially, bandwidth control is performed and classification is performed on a packet basis according to the bandwidth information of each flow. It is possible to perform priority control in which flows belonging to a higher class are selectively output in units of packets.

  Note that the types of flows to be identified by the flow identification unit 110 include, for example, classifications based on different applications, classifications based on transmission addresses, reception addresses, relay addresses, and the like.

  In Embodiment 1 of the present invention, the flow setting information storage unit 120 notifies the arrival rate monitoring unit 130 of the flow setting information identified by the flow identification information. The identification information may be notified from the flow identification unit 110 to the arrival rate monitoring unit 130, and the arrival rate monitoring unit 130 may read the flow setting information identified by the flow identification information.

(Embodiment 2)
Next, a second embodiment of the present invention will be described in detail with reference to the drawings.

  FIG. 5 is a block diagram showing a configuration of the packet transfer control circuit according to the second embodiment of the present invention. In the second embodiment of the present invention, the same components as those in the first embodiment of the present invention are denoted by the same reference numerals and description thereof is omitted.

  As shown in FIG. 5, the packet transfer control circuit 500 according to the second embodiment of the present invention is different from the packet transfer control circuit 100 according to the first embodiment of the present invention shown in FIG. A bandwidth control function is added. Specifically, the packet transfer control circuit 500 shown in FIG. 5 includes a group setting information storage unit 501 that stores information (group setting information) about each group of a plurality of flows of a plurality of packets in the packet transfer control circuit 100. And an arrival rate monitoring unit 530 instead of the arrival rate monitoring unit 130.

  The arrival rate monitoring unit 530 includes a rate measurement unit 131, a packet discard unit 134, a rate calculation unit 531, and a class setting unit 532. The rate calculation unit 531 and the class setting unit 532, in the rate calculation unit 132 and the class setting unit 133, receive a packet arrival rate (GPAR) and upper limit bandwidth information (GPPR) for each group of a plurality of flows of a plurality of packets. : Group Peak Packet Rate) is added.

  First, the group setting information storage unit 501 of the packet transfer control circuit 500 according to Embodiment 2 of the present invention will be described. The group setting information storage unit 501 stores flow group correspondence information indicating to which group each of a plurality of flows belongs, and information about each group (group setting information). When the flow identification information is notified from the flow identification unit 110, the group setting information storage unit 501 identifies the group with reference to the flow group correspondence information, and the group setting information related to the group identified by the flow identification information Is sent to the arrival rate monitoring unit 530.

  FIG. 6 is a diagram schematically showing an example of the flow group correspondence information stored in the group setting information storage unit 501 of the packet transfer control circuit 500 according to Embodiment 2 of the present invention. FIG. 7 is a diagram schematically illustrating an example of group setting information stored in the group setting information storage unit 501 of the packet transfer control circuit 500 according to Embodiment 2 of the present invention.

  The flow group correspondence information shown in FIG. 6 describes the correspondence between each group 1 to m (m is an integer of 1 or more) and each flow 1 to n (n is an integer of 1 or more). Yes. For example, in the example shown in FIG. 6, it can be seen that flows 1 to 5 belong to group 1 and flows 6 to 10 belong to group 2.

  Further, the group setting information shown in FIG. 7 includes upper limit band information GPPR1 to GPPRm for each group 1 to m and packet arrival rate information GPAR1 to GPARm for each group 1 to m. Of the group setting information, for the entry of the upper limit bandwidth information GPPR, a setting value is stored in advance for each group. Regarding the entry of the packet arrival rate information GPAR, values stored in accordance with the result of packet input monitoring by the arrival rate monitoring unit 530 are sequentially updated.

  The group setting information storage unit 501 receives the flow identification information from the flow identification unit 110 and first refers to the flow group correspondence information to determine the group to which the input packet belongs. Further, the group setting information storage unit 501 refers to the group setting information, acquires group setting information set for the determined group, and sends the group setting information of the group to the arrival rate monitoring unit 530. Notice.

  Next, the operation of the arrival rate monitoring unit 530 of the packet transfer control circuit 500 according to Embodiment 2 of the present invention will be described with reference to FIG. 8 together with FIG. FIG. 8 is a flowchart for explaining an example of the operation in the arrival rate monitoring unit 530 of the packet transfer control circuit 500 according to Embodiment 2 of the present invention.

  In step ST801, for example, when a packet of flow i arrives at the arrival rate monitoring unit 530, the rate measuring unit 131 first measures the arrival rate of the packet. The rate measuring unit 131 notifies the rate calculating unit 531 of the arrival rate of the measured packet.

  Further, the rate calculation unit 531 obtains the flow setting information related to the flow i to which the packet belongs from the flow setting information storage unit 120, and further sets the group setting information related to the group j to which the flow i of the packet belongs to group setting information. Obtained from the storage unit 501 (step ST802). Here, it is assumed that the flow i belongs to the group j.

  Then, the rate calculation unit 531 newly calculates the packet arrival rate information PARi of the flow i based on the measurement result of the rate measurement unit 131 and the packet arrival rate information PARi of the flow setting information. Based on the measurement result and the packet arrival rate information GPARj in the group setting information, the packet arrival rate information GPARj of group j is newly calculated (step ST803). The method for calculating the packet arrival rate information GPARj can be the same as the method for calculating the packet arrival rate PARi described above.

  Next, class setting section 532 determines whether or not GPARj ≦ GPPRj based on GPARj calculated by rate calculation section 531 and upper limit band information GPPRj in the group setting information (step ST804).

  When GPARj ≦ GPPRj in step ST804, the arrived packet has not yet reached the upper limit bandwidth information GPPRj set for the group j, and the arrived packet has the upper limit set for the entire group j. It is determined that it is within the band. That is, the packet does not violate the bandwidth set for the entire group j, and is permitted in terms of the bandwidth set for the entire group j. And about this packet, the process of above-mentioned step ST304-ST309 is performed based on flow setting information. Also, the class setting unit 532 converts the packet arrival rate information GPARj in the group setting information of the group j stored in the group setting information storage unit 501 into new packet arrival rate information GPARj (GPARj calculated by the rate calculation unit 531). ) (Step ST805).

  If GPARj ≦ GPPRj is not satisfied in step ST804, the class setting unit 532 is in a state where all of the surplus bandwidth allowed for the arrived packet exceeding the upper limit bandwidth GPPRj already set for the group j is exhausted. Judgment is made and the discard processing of the packet is executed (step ST806). In this case, the class setting unit 532 notifies the packet discard unit 134 of discard request information for requesting packet discard processing, and the packet discard unit 134 that has received the discard request information performs packet discard processing.

  The packet and the class setting information of the packet are supplied from the arrival rate monitoring unit 530 to the output queue unit 140 except when the above processing is performed by the arrival rate monitoring unit 530 and the packet discarding process is performed. Is done. The output queue unit 140 receives these pieces of information and selectively outputs packets by performing the same processing as in the first embodiment.

  As described above, according to the second embodiment of the present invention, by setting the flow and group and identifying the flow and group to which the input packet belongs, in addition to bandwidth control and priority control for each flow, Band control can be performed simultaneously for each group set for the flow.

  In the second embodiment of the present invention, as with the flow setting, the type and number of groups and the correspondence between flows and groups can be arbitrarily set as necessary. For example, the same link or the same A plurality of flows belonging to a VPN (Virtual Private Network) can be grouped.

  In Embodiment 2 of the present invention, in addition to the mode in which the group setting information storage unit 501 notifies the arrival rate monitoring unit 530 of the group setting information of the group identified from the flow identification information, for example, the flow The identification information may be notified from the flow identification unit 110 to the arrival rate monitoring unit 530, and the arrival rate monitoring unit 530 may read the group setting information related to a desired group by referring to the flow group correspondence information.

  Further, in the second embodiment of the present invention, as in the first embodiment, for the purpose of effectively utilizing the bandwidth of the output link, the packet is permitted to be output when there is a surplus bandwidth even if the upper limit bandwidth is exceeded. It is also possible to do.

  Further, in Embodiment 2 of the present invention, a plurality of flows are grouped to set one group group. Further, a plurality of groups belonging to these group groups are grouped, and the groups are grouped hierarchically. It is also possible to construct and perform bandwidth control processing. In the second embodiment of the present invention, it is also possible to group a plurality of flows by different modes (different divisions) to set a plurality of group groups, and to perform band control processing in parallel in each group group It is.

  In the block diagram showing the configuration of the packet transfer control circuit according to the first and second embodiments of the present invention, the buffer unit is classified into three (that is, identifiable classes are classified into three). However, the number of classes can be changed by the system. In Embodiments 1 and 2 of the present invention, the type of flow or group and the number of flows or groups can be arbitrarily set as necessary.

  The present invention can be applied to a device for transferring a packet.

1 is a block diagram showing a configuration of a packet transfer control circuit according to a first embodiment of the present invention. The figure which shows typically an example of the flow setting information stored in the flow setting information storage part of the packet transfer control circuit which concerns on Embodiment 1 of this invention. The flowchart for demonstrating an example of the operation | movement in the arrival rate monitoring part of the packet transfer control circuit which concerns on Embodiment 1 of this invention. The flowchart for demonstrating an example of the operation | movement in the output queue part of the packet transfer control circuit which concerns on Embodiment 1 of this invention. Block diagram showing a configuration of a packet transfer control circuit according to a second embodiment of the present invention The figure which shows typically an example of the flow group corresponding | compatible information stored in the group setting information storage part of the packet transfer control circuit which concerns on Embodiment 2 of this invention. The figure which shows typically an example of the group setting information stored in the group setting information storage part of the packet transfer control circuit which concerns on Embodiment 2 of this invention. The flowchart for demonstrating an example of the operation | movement in the arrival rate monitoring part of the packet transfer control circuit which concerns on Embodiment 2 of this invention.

Explanation of symbols

100, 500 Packet transfer control circuit 110 Flow identification unit 120 Flow setting information storage unit 130 Arrival rate monitoring unit 131 Rate measurement unit 132, 531 Rate calculation unit 133, 532 Class setting unit 134 Packet discard unit 140 Output queue unit 141 Output order management Unit 142 packet selection unit 143 packet output unit 1410 buffer unit 150 arrival rate update unit 501 group setting information storage unit

Claims (8)

  A flow having flow identification means for identifying a plurality of flows to which a plurality of input packets belong, bandwidth information preset for each of the plurality of flows, class information indicating priority, and packet arrival rate information Flow setting information storing means for storing setting information, rate measuring means for measuring the arrival rate of the packet as a data amount per predetermined unit time, and the flow to which the packet arriving within the predetermined unit time belongs. Rate calculating means for calculating the arrival rate of the flow to which the packet belongs based on the total data amount of the packet and the arrival rate of the packet, and based on the flow identified by the flow identifying means The flow setting information and the flow related to the flow read from the flow setting information storage means. Class setting means for setting the class of the flow to which the packet belongs in comparison with the arrival rate according to the packet, and based on the class of the flow to which the packet belongs set by the class setting means Output control means for controlling the output order of the plurality of packets, and the packets related to the flow at a predetermined timing based on the remaining data amount from the output control means and the packet arrival rate information of the flow setting information A packet transfer control circuit comprising: arrival rate update means for updating arrival rate information.   The class setting means, when the arrival rate of the flow to which the packet belongs is equal to or less than the value of the minimum guaranteed bandwidth information of the flow setting information, the class setting means of the flow to which the packet belongs to the reference priority class of the flow setting information A class is set, and the reference priority class of the flow setting information when the arrival rate for the flow to which the packet belongs is greater than the value of the minimum guaranteed bandwidth information of the flow setting information and less than or equal to the value of the upper limit bandwidth information 2. The packet transfer control circuit according to claim 1, wherein the class of the flow to which the packet belongs is set in an upper limit priority class that has a lower priority than that and is set in association with the reference priority class.   The class setting means has a lower priority than the upper limit priority class when the arrival rate related to the flow to which the packet belongs is larger than the value of the upper limit bandwidth information of the flow setting information, and the reference The packet transfer control circuit according to claim 2, wherein the class of the flow to which the packet belongs is set in a surplus priority class set in association with a priority class.   The arrival rate of the flow to which the packet belongs is compared with the value of the upper limit bandwidth information of the flow setting information, and the arrival rate of the flow to which the packet belongs is determined to be the upper limit bandwidth information of the flow setting information. 4. The packet transfer control circuit according to claim 2, further comprising packet discarding means for discarding the packet when the value is larger than the value of.   Group setting information storage means for storing flow group correspondence information and group setting information having bandwidth information set in advance for each of a plurality of groups in which a plurality of flows of packets are grouped, and an arrival rate of the packets Group rate calculation means for calculating an arrival rate for the group to which the flow belongs based on the flow group, and the output control means is identified by the flow identification means and the flow group of the group setting information storage means The packet transfer according to any one of claims 1 to 4, further comprising means for controlling output of the plurality of packets based on the group setting information read based on correspondence information and the arrival rate related to the group. Control circuit.   A flow having a flow identification step for identifying a plurality of flows to which a plurality of input packets belong, class information indicating priority, bandwidth information preset for each of the plurality of flows, and packet arrival rate information A flow setting information storing step for storing setting information in the flow setting information storage means; a rate measuring step for measuring the arrival rate of the packet as a data amount per predetermined unit time; and the arrival at the predetermined unit time A rate calculating step for calculating an arrival rate for the flow to which the packet belongs based on a total amount of data of the packet for the flow to which the packet belongs and an arrival rate for the packet; Read from the flow setting information storage means based on the flow A class setting step for setting the flow class to which the packet belongs in units of the packet by comparing the flow setting information related to the flow and the arrival rate related to the flow, and is set in the class setting step An output control step for controlling the output order of the plurality of packets based on the class of the flow to which the packet belongs, a residual data amount in the output control step and the packet arrival rate information of the flow setting information An arrival rate update step of updating the packet arrival rate information relating to the flow at a predetermined timing.   In the class setting step, when the arrival rate related to the flow to which the packet belongs is equal to or less than the value of the minimum guaranteed bandwidth information of the flow setting information, the flow of the flow to which the packet belongs to the reference priority class of the flow setting information Setting a class; and if the arrival rate for the flow to which the packet belongs is greater than the value of the minimum guaranteed bandwidth information of the flow setting information and less than or equal to the value of the upper limit bandwidth information, the reference of the flow setting information And a step of setting the class of the flow to which the packet belongs to an upper limit priority class that is lower in priority than a priority class and set in association with the reference priority class. Packet transfer control method.   The class setting step has a lower priority than the upper limit priority class when the arrival rate related to the flow to which the packet belongs is larger than the value of the upper limit bandwidth information of the flow setting information, and the reference The packet transfer control method according to claim 7, further comprising a step of setting the class of the flow to which the packet belongs in a surplus priority class set in association with a priority class.

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