JP2010177942A - Router - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a router that can equalize the line utilization rate in each physical link. <P>SOLUTION: The router 10 including a plurality of physical links L1 to L3 between itself and an adjacent router 20 in a packet communication network, includes a receiving unit 11 for receiving IP packets, a transmission order information providing unit 13 for determining an order of transmission in which the IP packets are transmitted to the adjacent router 20, a plurality of buffers 14a to 14c which correspond to the physical links L1 to L3, respectively and store the IP packets; a packet sorting unit 12 that selects one buffer which is less used than the other ones at a predetermined point of time, as a selected buffer, and causes the IP packets whose order of transmission has been determined to be stored in the selected buffer; and a packet transmission unit 15 that transmits the IP packets stored in the selected buffer to one corresponding physical link in the order of transmission determined by the transmission order information providing unit 13. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a router device in which a plurality of physical links are provided between adjacent router devices in a packet communication network for transmitting and receiving packets.

  In a packet communication network that transmits and receives IP packets, a plurality of router devices that are nodes are connected to each other. In such a packet communication network, as the amount of traffic increases, router devices are connected by a plurality of physical links.

JP 2006-262291 A

  By the way, between router devices connected by a plurality of physical links, a hash value is calculated from the source address Src and destination address Dest in the IP packet, and each physical link corresponding to the calculated hash value (use Each IP packet is distributed to (bandwidth). In such sorting by hash values, the flow of each IP packet is evenly distributed.

  However, in the distribution based on the hash value, when a large number of IP packets having the same source address Src and the same destination address Dest are transmitted, the IP packets are concentrated on a specific physical link among a plurality of physical links. In this case, the transmission status of a plurality of physical links is biased. As a result of such a biased transmission situation, the traffic amount (line usage rate) in the physical link varies in each physical link, and the physical link may not always be effectively utilized.

  The present invention has been made to solve the above problems, and an object of the present invention is to provide a router device capable of making the line usage rate for each physical link more uniform.

  To achieve the above object, a router device according to the present invention is a router device in which a plurality of physical links are provided between adjacent router devices in a packet communication network for transmitting and receiving packets, and the adjacent router devices A packet acquisition unit for acquiring a packet to be transmitted to the destination router device, a transmission order determination unit for determining a transmission order for transmitting the packet acquired by the packet acquisition unit to the destination router device, and a plurality of As a selection buffer, a plurality of buffers for storing packets acquired by the packet acquisition means and one buffer having a lower buffer usage rate at a predetermined time than other buffers among the plurality of buffers corresponding to each physical link In addition to selecting, the packet whose transmission order is determined by the transmission order determining means is stored in the selection buffer. Packet distribution means, and packet transmission means for transmitting the packets stored in the selection buffer by the packet distribution means to the corresponding one physical link in the transmission order determined by the transmission order determination means. Features.

  With this configuration, the packet distribution unit stores the packet whose transmission order is determined in the selection buffer that has a lower buffer usage rate at a predetermined time than the other buffers among the plurality of buffers, and the packet transmission unit selects the selected packet. Packets stored in the buffer are transmitted in the transmission order to one physical link corresponding to the selected buffer. Packets are sent from each buffer whose buffer usage rate is made more uniform, so that the packets are distributed so that the line usage rate for each physical link becomes more even and the adjacent destination routers Can be sent to the device. The "buffer usage rate" here means the ratio of the stored data capacity (buffer usage) to the total buffer capacity of each of the plurality of buffers, and when the total capacity of each of the plurality of buffers is the same. Can also use the buffer usage as the buffer usage rate.

  The transmission order determining means assigns transmission order information indicating the transmission order to the destination router apparatus to the packet acquired by the packet acquiring means, and the packet sending means is selected by the packet sorting means. The transmission order information may be removed from the packet when the packet input to is sent to the corresponding one physical link. With this configuration, it is possible to easily determine the transmission order of packets to the destination router device and to remove transmission order information before transmitting the packets, so that the present invention can be reliably implemented.

  The transmission order determining means assigns transmission order information indicating the transmission order to the destination router apparatus to the packet acquired by the packet acquiring means, and the packet sending means is configured to transmit the transmission order by the transmission order determining means. A packet to which information is added may be transmitted to one corresponding physical link. In this case, the transmission order information given by the router device can be used for transmission processing from the destination router device to a further destination router device or the like. Since there is no need to add information, packet transfer processing can be performed quickly.

  The packet obtaining means obtains the packet by receiving a packet to which transmission order information indicating the transmission order from the transmission source router apparatus to the router apparatus among the adjacent router apparatuses is received. You may make it determine the transmission order which transmits the packet acquired by the acquisition means to the router apparatus of a transmission destination according to the transmission order information provided to the packet. In this case, the transmission order information used in the transmission source router apparatus can be used for transmission processing from the router apparatus to the transmission destination router apparatus, and there is no need to add new transmission order information in the router apparatus. Thus, the packet transfer process can be performed quickly.

  In addition, it is preferable that the packet distribution unit selects, as a selection buffer, one buffer that has the lowest buffer usage rate at a predetermined time point compared to the other buffers. With this configuration, since the packet is transmitted using the buffer with the smallest buffer usage rate and the physical link corresponding to the buffer, the packets are distributed adjacent to each other so that the line usage rate for each physical link becomes more uniform. Can be sent to the router device.

  According to the present invention, a packet is preferentially input to a selection buffer having a lower buffer usage rate at a predetermined time than other buffers among a plurality of buffers, so that the line usage rate for each physical link is made more even. Packets can be distributed and transmitted.

It is a block diagram which shows the partial structure of the packet communication network containing the router apparatus which concerns on this embodiment. It is a figure which shows typically the transmission procedure of the IP packet in the router apparatus which concerns on this embodiment. It is a figure which shows the structure of an IP packet. It is a figure which shows the hardware constitutions of the router apparatus which concerns on this embodiment. It is a flowchart which shows the procedure of the distribution operation | movement of an IP packet. It is a flowchart which shows the procedure of the transmission operation | movement of an IP packet. It is a figure which shows the change of the buffer usage-amount in buffer management DB. It is a figure which shows the change of the transmission order number in transmission order management DB.

  A router device 10 according to an embodiment of the present invention will be described with reference to FIGS. 1 and 2. FIG. 1 is a block diagram illustrating a partial configuration of a packet communication network including a router device 10 according to the present embodiment. FIG. 2 schematically illustrates an IP packet transmission procedure in the router device 10 according to the present embodiment. FIG. If possible, the same parts are denoted by the same reference numerals, and redundant description is omitted.

  As shown in FIGS. 1 and 2, the router device 10 is connected to an adjacent router device 20 (destination router device) by a plurality of physical links L1, L2, and L3. IP packets can be transmitted to The physical links L1, L2, and L3 that connect both the router devices 10 and 20 are configured by, for example, optical fibers. A logical line is formed by these three physical links L1, L2, and L3, and each physical link L1, L2, and L3 is specified by line numbers # 1, # 2, and # 3. The adjacent router device 20 has the same configuration as the router device 10.

  The router device 10 includes a reception unit 11 (packet acquisition unit), a packet distribution unit 12 (packet distribution unit), a transmission order information addition unit 13 (transmission order determination unit), buffers 14a, 14b, and 14c, A packet sending unit 15 (packet sending means). The receiving unit 11 receives an IP packet from another router device (transmission source router device) (not shown) via the physical link L4, thereby acquiring an IP packet to be transmitted to the adjacent router device 20. It is. The receiving unit 11 outputs the received IP packet to the packet sorting unit 12. As the output IP packets, for example, as shown in FIG. 2, there are IP packets IP1, IP2, IP3, IP4, etc., and each of the IP packets IP1 to IP4 is the same as exemplified in the IP packet IP3 of FIG. Each having an IP header, a layer 4 header (TCP, UDP, etc.) and a data portion.

  The packet distribution unit 12 is a part that performs a distribution operation of selecting one buffer from the buffers 14a to 14c and storing the IP packet in the buffer, and a buffer management database that manages the buffer usage (buffer usage rate) (Hereinafter referred to as “buffer management DB”) and a transmission order management database (hereinafter referred to as “transmission order management DB”) for managing the transmission order of IP packets. When receiving the IP packet from the receiving unit 11, the packet sorting unit 12 searches for the packet length (data capacity) of the IP packet. Then, the packet distribution unit 12 sets the buffer usage that is the total data capacity of the IP packets stored in the buffers 14a to 14c immediately before storing the IP packet in the buffer (predetermined time) for each buffer. Search using. In this buffer management DB, for example, as shown in FIGS. 7A to 7C, the line numbers # 1 to # 3 and the buffers of the buffers 14a to 14c corresponding to the line numbers # 1 to # 3, respectively. Used amount is stored.

  The packet distribution unit 12 selects one buffer that has the smallest buffer usage as compared to other buffers as a selection buffer by searching for the buffer usage using the buffer management DB. Then, in the buffer management DB, the packet allocating unit 12 compares the buffer usage of the line number corresponding to the selected buffer with respect to the searched IP packet as indicated by the line number # 1 in FIG. The buffer usage is updated in the buffer management DB by adding the packet length.

  Further, the packet distribution unit 12 once transmits the IP packet to the transmission order information adding unit 13 described later in order to mark the transmission order of the IP packet, and transmits the transmission order number of the IP packet whose transmission order is marked. Store in the order management DB. In this transmission order management DB, for example, as shown in FIGS. 8A to 8C, the line numbers # 1 to # 3 and the buffers 14a to 14c corresponding to the line numbers # 1 to # 3, respectively. The transmission sequence number marked on the stored IP packet is stored. After appropriately updating the buffer usage amount in the buffer management DB and the transmission sequence number in the transmission order management DB, the packet distribution unit 12 stores the IP packet in the selection buffer. . The packet distribution unit 12 is bidirectionally connected to a packet transmission unit 15 to be described later so that the packet transmission unit 15 can access the buffer management DB and the transmission order management DB.

  The transmission order information adding unit 13 is a part that determines a transmission order for transmitting IP packets to the adjacent router device 20 in the order received by the receiving unit 11, and is the head of each IP packet transmitted from the packet distribution unit 12. The part is marked to give transmission order information indicating the transmission order as shown in FIG. 3 (for example, information indicating a transmission order number such as “196”). The transmission order information assigning unit 13 returns each IP packet whose transmission order is marked to the packet sorting unit 12.

  The buffers 14 a to 14 c are portions that temporarily store one or more IP packets IP <b> 1 to IP <b> 4 received by the receiving unit 11 in accordance with a sorting operation by the packet sorting unit 12. Each of the buffers 14a to 14c has the same total buffer capacity. For example, as shown in FIG. 2, when storing IP packets whose data capacity increases in the order of IP packets IP1, IP4, IP2, and IP3, By the sorting operation of the packet sorting unit 12, the IP packet IP1 and the IP packet IP4 are stored in the buffer 14a, the IP packet IP2 is stored in the buffer 14b, and the IP packet IP3 is stored in the buffer 14c. By such storage, the buffer usage of each of the buffers 14a to 14c, that is, the buffer usage rate is made more uniform. The buffer 14a corresponds to the physical link L1, the buffer 14b corresponds to the physical link L2, and the buffer 14c corresponds to the physical link L3. The stored IP packet can be transferred to the corresponding physical link.

  The packet sending unit 15 is a part for transmitting each IP packet IP1 to IP4 stored in the buffers 14a to 14c to the adjacent router device 20 through the physical links L1 to L3 based on the transmission order management DB. The packet sending unit 15 reads the transmission order information of the IP packets IP1 to IP4 stored in any of the buffers 14a to 14c by accessing the transmission order management DB of the packet sorting unit 12, and the number in the transmission order information is The IP packets associated with the transmission order information are transmitted in order from the smallest. Specifically, for example, as shown in FIG. 2, the IP packet IP1 stored first in the buffer 14a, the IP packet IP2 stored in the buffer 14b next, and then stored in the buffer 14c. The IP packets IP1 to IP4 are sent to the physical links L1 to L3 corresponding to the buffers 14a to 14c in the order of the IP packet IP3 and finally the IP packet IP4 stored in the buffer 14a.

  When an IP packet is sent out by the packet sending unit 15, the packet sending unit 15 accesses the buffer management DB and the transmission order management DB of the packet sorting unit 12 and sends them, for example, as shown in FIG. The packet length of the IP packet is subtracted from the buffer usage amount of the buffer management DB to update the buffer usage amount of the buffer management DB. For example, as shown in FIG. The transmission order number in the transmission order management DB is updated by deleting the transmission order number from the transmission order management DB. Note that when sending the IP packet to the physical links L1 to L3, the packet sending unit 15 removes the transmission order information from the IP packet and returns to the same configuration as the configuration of the IP packet received by the receiving unit 11.

  The functional configuration of the router device 10 according to the present embodiment has been described above. Subsequently, FIG. 4 shows a hardware configuration of the router device 10 according to the present embodiment. As illustrated in FIG. 4, the router device 10 includes hardware such as a CPU (Central Processing Unit) 101, a RAM (Random Access Memory) 102, a ROM (Read Only Memory) 103, a communication module 104, and an auxiliary storage device 105. Has been. These components are connected so that various signals can be input and output via a bus. The functions described above are exhibited by the operation of these components.

  Subsequently, an IP packet distribution operation in the packet distribution unit 12 in the router device 10 according to the present embodiment will be described with reference to FIGS. 5, 7, and 8. FIG. 5 is a flowchart showing a procedure of IP packet distribution operation, FIG. 7 is a diagram showing a change in buffer usage in the buffer management DB, and FIG. 8 is a diagram of transmission sequence numbers in the transmission sequence management DB. It is a figure which shows a change.

  First, as shown in FIG. 5, the packet distribution unit 12 receives an IP packet (S11). The packet sorting unit 12 searches for the IP packet length of the received IP packet (S12). Subsequently, the packet distribution unit 12 searches the buffer management DB for the buffer usage corresponding to the line numbers # 1, # 2, and # 3 that specify the physical links L1 to L3 (S13). As a search result of the buffer management DB in step S13, for example, as shown in FIG. 7A, the buffer usage of the line number # 1 is 0 bytes, the buffer usage of the line number # 2 is 155 bytes, and the line number # 3 buffer usage is 230 bytes.

  In step S13, after retrieving the buffer usage amount in each of the line numbers # 1 to # 3, the line number # 1 which is the minimum buffer usage amount is selected (S14). In this embodiment, when searching for the minimum buffer usage, if there are two or more lines with the same minimum buffer usage, the one with the smaller line number that identifies the physical links L1 to L3 is selected. To do. Then, the IP packet length of 80 bytes retrieved in step S12 is added to the buffer usage of the selected line number # 1 as shown in FIG. 7B (S15), and the buffer for the line number # 1 is added. The amount used is 80 bytes.

  Subsequently, in step S15, the IP packet with the IP packet length added to the buffer management DB is once sent to the transmission order information adding unit 13, the transmission order information is assigned to the IP packet, and the transmission order number is marked on the IP packet. (S16). After marking the transmission order number on the IP packet in step S16, the IP packet is returned to the packet sorting unit 12, and the transmission order management DB shown in FIG. The transmission order number 201 of the marked IP packet is added to the line number # 1 in the transmission order management DB. Thereafter, the IP packet is stored in a buffer corresponding to the line number # 1 selected by the packet distribution unit 12 (S17). Such a distribution operation is performed every time an IP packet is received (S18).

  Next, an IP packet sending operation in the packet sending unit 15 in the router device 10 according to the present embodiment will be described with reference to FIGS. 6, 7, and 8. FIG. 6 is a flowchart showing the procedure of the IP packet transmission operation.

  First, as shown in FIG. 6, the packet sending unit 15 monitors the transmission order management DB of each of the line numbers # 1 to # 3 (buffers 14a to 14c) (S21). By monitoring in step S21, the packet sending unit 15 searches the transmission order management DB for the minimum transmission order number among the line numbers # 1 to # 3 (S22). Then, as shown in FIG. 8B, the retrieved IP packet with the minimum transmission order number 196 is transferred from the buffer of the line number # 2 to the corresponding physical link (S23). Note that the transmission order information attached to the IP packet is removed before transfer.

  Subsequently, the packet sending unit 15 deletes the buffer usage 55 bytes of the IP packet transferred in step S23 from the buffer management DB as shown in FIG. 7C (S24). Further, the packet sending unit 15 deletes the transmission order number 196 of the transferred IP packet from the transmission order management DB as shown in FIG. 8C (S25). Such a sending operation is performed when there is an IP packet in the buffer (S26).

  According to the present embodiment, the packet distribution unit 12 of the router device 10 includes the IP whose transmission order is determined in the selected buffer that has a smaller buffer usage amount at a predetermined time than the other buffers among the plurality of buffers 14a to 14c. The packet is input, and the packet transmission unit 15 transmits the IP packet input to the selection buffer to one physical link corresponding to the selection buffer in the transmission order described above. Each IP packet IP is transmitted from each of the buffers 14a to 14c in which the buffer usage is made more uniform, so that the IP packet is made so that the line usage rate for each physical link L1 to L3 becomes more uniform. Can be distributed and transmitted to the adjacent router device 20. As a result, the transmission speed is increased and unnecessary line speedup can be suppressed.

  Further, according to the present embodiment, the transmission order information assigning unit 13 assigns transmission order information indicating the transmission order to the adjacent router device 20 to the received IP packet, and the packet sending unit 15 selects When the IP packet input to the buffer is transmitted to the corresponding physical link, the transmission order information is removed from the IP packet. For this reason, the transmission order to the adjacent router device 20 can be easily determined, and the transmission order information can be removed before transmission of the IP packet, so that packet communication can be reliably performed. Note that the transmission order of IP packets may be managed by associating the transmission order information with data or headers constituting the IP packet without directly assigning the transmission order information described above to the IP packet itself.

  As mentioned above, although this invention was concretely demonstrated based on the embodiment, this invention is not limited to the said embodiment. For example, in the above-described embodiment, the buffer having the smallest buffer usage amount among the buffers 14a to 14c is selected as the selection buffer, but at least a buffer having a buffer usage amount smaller than that of other buffers is selected as the selection buffer. By doing so, the line usage rate for each physical link can be made more even. In the above embodiment, three lines of physical links L1 to L3 are prepared. However, for example, five lines may be provided, and at least two lines may be provided.

  In the above-described embodiment, the case where the IP packet received from the transmission source router device is transmitted to the adjacent router device 20 has been described. However, the router device 10 itself connects to the IP packet newly generated or the router device 10. Of course, the present invention may be applied to the case where an IP packet acquired from another device is transmitted to the adjacent router device 20. Furthermore, in the above-described embodiment, the IP packets are transmitted to the adjacent router device 20 in the reception order of the reception unit 11, but the transmission order to the router device 20 is not necessarily limited to the reception order. May be transmitted to the adjacent router device 20 in accordance with the priority.

  Further, in the above embodiment, when an IP packet is transmitted from the packet sending unit 15 to the adjacent router device 20, the transmission order information attached to the IP packet is removed. Instead of removing, the IP packet to which the transmission order information is assigned may be transmitted to the adjacent router device 20 as it is. Then, the transmission order information assigning unit (not shown) of the router device 20 that has received the IP packet to which the transmission order information is assigned transmits the IP packet to a further destination router device (including the destination router device). The transmission order may be determined according to the transmission order information given to the IP packet. Here, the router device 20 and a further destination router device are adjacent to each other and are connected by a plurality of physical links. The router device 20 has the same configuration as the router device 10 described above except for the transmission order determination function. In this case, the transmission order information given by the router device 10 can be used for transmission processing from an adjacent router device 20 as a transmission destination to a router device at a further destination, and the adjacent router device 20. Thus, it is not necessary to add new transmission order information, so that packet transfer processing can be performed quickly.

  Also, it is arbitrarily set whether to remove the transmission order information when sending IP packets to the destination router device, or to use the transmission order information in the destination router device by sending IP packets without removing them. can do. For example, in a packet communication network in which a case where adjacent router devices are connected by a plurality of physical links and a case where they are connected by a single physical link are mixed, setting information regarding the removal of transmission order information or its use is provided. It can be given to IP packets in advance and uniformly performed. Further, information indicating whether or not to remove the transmission order information may be stored in advance in the router apparatuses 10 and 20 according to the destination router apparatus, and it may be determined whether or not to remove the transmission order information based on the information. .

  DESCRIPTION OF SYMBOLS 10 ... Router apparatus, 11 ... Reception part (packet acquisition means), 12 ... Packet distribution part (packet distribution means), 13 ... Transmission order information provision part (transmission order determination means), 14a-14c ... Buffer, 15 ... Packet sending unit (packet sending means), 20 ... adjacent router device (destination router device), 101 ... CPU, 102 ... RAM, 103 ... ROM, 104 ... communication module, 105 ... auxiliary storage device, IP1, IP2, IP3, IP4 ... IP packet, L1, L2, L3 ... physical link.

Claims (5)

A router device provided with a plurality of physical links between adjacent router devices in a packet communication network for transmitting and receiving packets,
Packet acquisition means for acquiring a packet for transmission to a destination router device among the adjacent router devices;
A transmission order determination means for determining a transmission order for transmitting the packet acquired by the packet acquisition means to the destination router device;
A plurality of buffers corresponding to each of the plurality of physical links and storing packets acquired by the packet acquisition unit;
One buffer having a lower buffer usage rate at a predetermined time than other buffers among the plurality of buffers is selected as a selection buffer, and a packet whose transmission order is determined by the transmission order determination unit is stored in the selection buffer. Packet distribution means for
A packet sending means for sending the packets stored in the selection buffer by the packet sorting means to the corresponding one physical link in the sending order determined by the sending order determining means. Router device. The transmission order determining means assigns transmission order information indicating a transmission order to the destination router device to the packet acquired by the packet acquisition means,
2. The packet sending means, when sending the packet input to the selection buffer by the packet sorting means to the corresponding physical link, removes the transmission order information from the packet. The router device described in 1. The transmission order determining means assigns transmission order information indicating a transmission order to the destination router device to the packet acquired by the packet acquisition means,
The router apparatus according to claim 1, wherein the packet sending unit sends the packet to which the transmission order information is given by the transmission order determining unit to the corresponding one physical link. The packet obtaining means obtains the packet by receiving a packet to which transmission order information indicating a transmission order from the router apparatus of the transmission source to the router apparatus is given among the adjacent router apparatuses,
The transmission order determining means determines a transmission order for transmitting the packets acquired by the packet acquisition means to the destination router device according to the transmission order information given to the packets. The router device according to any one of claims 1 to 3.   5. The packet distribution unit selects, as the selection buffer, one buffer that has the lowest buffer usage rate at a predetermined time point compared to other buffers among the plurality of buffers. The router device according to any one of the above.

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