JP4472687B2 - Packet relay method and packet relay apparatus - Google Patents

Description

  The present invention relates to a packet relay method and a packet relay device that relay packets, and more particularly to a packet relay method and a packet relay device that limit the amount of packets to be relayed.

  Conventionally, as a packet relay device that limits the amount of packets to be relayed, for example, received packets are queued in order of arrival for each flow, and a group 1 to which a flow whose packet transfer rate is less than the minimum guaranteed bandwidth belongs, and packet transfer The flow is classified into group 2 to which a flow whose rate is equal to or higher than the minimum guaranteed bandwidth and less than the maximum restricted bandwidth, and group 3 to which a flow whose packet transfer rate exceeds the maximum restricted bandwidth belongs, and received for the flow to which group 1 belongs. The packet received with respect to the flow belonging to group 2 is transferred in preference to the packet received with respect to the flow to which group 2 belongs, and the packet received with respect to the flow belonging to group 3 is transferred with priority. Some are queued in order (for example, patent literature) Reference).

  However, the packet relay device described in Patent Document 1 requires a buffer for queuing received packets and a control unit for controlling the buffer, and thus has a problem that the configuration of the device becomes complicated.

In order to solve this problem, for example, a plurality of flows are assigned to a group, and a first label is added to a packet received at a transfer rate equal to or lower than the minimum guaranteed bandwidth determined for each flow, and the minimum guaranteed bandwidth is exceeded. When a second label is added to the packet received at the transfer rate and the transfer rate of the packet to be relayed exceeds the limit bandwidth on the transmission side or exceeds the limit bandwidth determined for each group, the packet to be relayed There is a packet that discards any packet to which the second label is added so that the transfer rate does not exceed these limited bands (see, for example, Patent Document 2).
Japanese Patent Laid-Open No. 2002-237841 JP 2006-229432 A

  However, the conventional packet relay device described in Patent Document 2 has a state in which the transfer rate of packets to be relayed is limited by a limited bandwidth in a certain group, and close to 0 in another group, There was a problem that the transmission band could not be used effectively.

  As described in Japanese Patent Application Laid-Open No. 2004-228620, such a problem is a minimum guarantee for a packet relay device that can set two types of bandwidth control conditions of a minimum guaranteed bandwidth and a maximum restricted bandwidth for each flow or for each group. This can be solved by setting individual bandwidth control conditions so that the total bandwidth is equal to the limited bandwidth on the transmission side.

  However, if the number of flows or groups relayed by a single packet relay device is large, setting the total guaranteed minimum bandwidth to be equal to the limited bandwidth on the transmitting side is not possible. It was a burden for the manager of the device.

  Furthermore, when the bandwidth limit on the transmission side is changed or a new flow or group is added to the active packet relay device, the relative bandwidth control conditions between the existing flows or groups are maintained. For this purpose, the minimum guaranteed bandwidth of all existing flows or groups has to be changed, which is an additional burden on the device administrator.

  The present invention provides a packet relay method and a packet relay apparatus that can effectively use the limited bandwidth on the transmission side and reduce the work of setting and changing the bandwidth control conditions by the administrator as compared with the conventional one. The purpose is to do.

  The packet relay method according to the present invention is a packet relay method for identifying a received packet as a flow and controlling the bandwidth of a flow group that is a set of the flows to relay the packet, wherein the set of one or more flows And a first maximum allowable bandwidth corresponding to the first flow group and a second maximum allowable bandwidth corresponding to the second flow group, which is a set of one or more first flow groups. And when the sum of the first maximum allowable bands corresponding to the first flow groups belonging to the second flow group exceeds the second maximum allowable band, the second flow group Each time the number of the first flow groups belonging to or the set value of the first maximum permissible band or the second maximum permissible band is changed, the second maximum permissible band is changed to the first maximum permissible band. To allocate based on bandwidth ratio Thus, a minimum guaranteed bandwidth corresponding to each of the first flow groups is calculated, and bandwidth control is performed based on the minimum guaranteed bandwidth, the first maximum allowable bandwidth, and the second maximum allowable bandwidth. It is said.

  By this method, the minimum guaranteed bandwidth is calculated each time the number of first flow groups or the set value of the first or second maximum permissible bandwidth is changed, so compared with the case where the conventional method is used. Thus, the limited bandwidth on the transmission side is effectively utilized, and the work of setting or changing the bandwidth control condition by the administrator is reduced.

  In the packet relay method of the present invention, the number of flows belonging to the first flow group is dynamically detected, the minimum allocated bandwidth that is the minimum usable bandwidth for each flow, and the flow belongs to When the bandwidth that can be used by the first flow group is up to the first maximum allowable bandwidth, a maximum allocated bandwidth that is a bandwidth allocated to each flow is set to the minimum corresponding to the first flow group. Dynamically calculated based on the guaranteed bandwidth, the first maximum allowable bandwidth, and the number of flows, and the minimum allocated bandwidth, the maximum allocated bandwidth, the first maximum allowable bandwidth, and the second maximum for each flow. Band control may be performed based on the allowable band.

  According to this method, the minimum allocated bandwidth and the maximum allocated bandwidth are dynamically changed depending on the number of flows, so that the transmission bandwidth is effectively used as compared with the case where the conventional method is used.

  The packet relay method of the present invention operates by allocating the minimum guaranteed bandwidth and the first maximum allowable bandwidth according to the ratio of contracted bandwidths of each flow, respectively. May be calculated automatically.

  With this method, the bandwidth is distributed fairly for each flow.

  The packet relay apparatus (1) of the present invention is a packet relay apparatus that identifies a received packet as a flow, relays the packet by controlling a bandwidth of a flow group that is a set of the flows, A first maximum allowable band corresponding to a first flow group that is a set of the above flows, and a second maximum allowable band corresponding to a second flow group that is a set of one or more of the first flow groups. Band setting means (4) for setting a band, and the sum of the first maximum allowable bands corresponding to the first flow groups belonging to the second flow group is the second maximum allowable band. Each time the number of the first flow groups belonging to the second flow group or the set value of the first maximum allowable band or the second maximum allowable band is changed, the second flow group A maximum allowable bandwidth for each of the first maximum allowable bandwidths; A bandwidth calculating means (5) for calculating a minimum guaranteed bandwidth corresponding to each of the first flow groups by allocating based on a ratio; the minimum guaranteed bandwidth; the first maximum allowable bandwidth; and the second maximum bandwidth. Band control means (6a to 6f, 7a and 7b) for performing band control based on the allowable band is provided.

  With this configuration, the packet relay device of the present invention calculates the minimum guaranteed bandwidth every time the number of first flow groups or the setting value of the first or second maximum allowable bandwidth is changed. In comparison, the limited bandwidth on the transmission side can be used effectively, and the work of setting or changing the bandwidth control condition by the administrator can be reduced.

  The packet relay apparatus of the present invention further includes flow detection means (3) for dynamically detecting the number of flows belonging to the first flow group, and the bandwidth calculation means can be used at least for each flow. A minimum allocated bandwidth that is a specific bandwidth, and a maximum allocated bandwidth that is a bandwidth allocated to each flow when a bandwidth that can be used by the first flow group to which the flow belongs is up to the first maximum allowable bandwidth, Is dynamically calculated based on the minimum guaranteed bandwidth corresponding to the first flow group, the first maximum allowable bandwidth, and the number of flows, and the bandwidth control means Band control may be performed based on the bandwidth, the maximum allocated bandwidth, the first maximum allowable bandwidth, and the second maximum allowable bandwidth.

  With this configuration, the packet relay device of the present invention dynamically changes the minimum allocated bandwidth and the maximum allocated bandwidth according to the number of flows, and therefore can effectively use the transmission bandwidth compared to the conventional one.

  Further, the bandwidth calculating means dynamically allocates the minimum allocated bandwidth and the maximum allocated bandwidth, respectively, and distributes the minimum guaranteed bandwidth and the first maximum allowable bandwidth according to a contract bandwidth ratio of each flow. You may make it calculate.

  With this configuration, the packet relay apparatus of the present invention can distribute the bandwidth fairly for each flow.

  The present invention provides a packet relay method and a packet relay apparatus that can effectively use the limited bandwidth on the transmission side and reduce the work of setting and changing the bandwidth control conditions by the administrator as compared with the conventional one. can do.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a block diagram of a packet relay apparatus according to an embodiment of the present invention.

  The packet relay apparatus 1 includes a reception interface (hereinafter simply referred to as “IF”) 2 that receives a packet, a flow identification unit 3 that identifies a flow of the received packet, and a flow identification unit 3 that identifies the flow. The setting table to be referred to and the information such as the transfer rate of the packet to be relayed are set by the administrator of the packet relay apparatus 1 and the setting unit 4 for storing the set information and the bandwidth such as the minimum allocated bandwidth of each flow. The band setting unit 5 to be defined, the label applying units 6a to 6f, the first policers 7a and 7b and the second policer 8 for limiting the transfer rate, and the label applying units 6a to 6f to the first policers 7a and 7b. A switch 9 that switches packets to be transmitted, a packet transmission scheduler 10 that schedules packets to be transmitted, and a middle packet And a transmission to send to the earlier IF11.

  In FIG. 1, the packet relay device 1 includes six label attaching units 6 a to 6 f, but the number of label attaching units provided in the packet relay device according to the present invention is not limited. In addition, any one of the label applying units 6a to 6f is described as “label applying unit 6” below.

  In FIG. 1, the packet relay apparatus 1 includes two first policers 7a and 7b. However, the packet relay apparatus according to the present invention corresponds to each first flow group to which each flow is assigned. A first policer is provided. In addition, one of the first policers 7a and 7b is described as “first policer 7” below.

  Here, the first flow group refers to a collection of flows. For example, when an ISP (Internet Service Provider) provides an Internet connection service to a plurality of users or companies, an apartment house or company A group of packet flows transmitted and received from each of the devices constitutes a first flow group.

  The second flow group refers to the entire flow that passes through the packet relay device 1. For example, when the ISP provides an Internet connection service using a single line, a collection of flows via this line constitutes the second flow group.

  The setting unit 4 stores a setting table as shown in FIG. Each entry in the setting table includes the presence / absence of a flow, the contract bandwidth, the identifier of the label assigning unit 6 that is passed through, and the identifier of the first policer 7 that is passed through for the set of the destination IP address and the source IP address Represents.

  Here, among the items of each entry of the setting table, “destination IP address”, “source IP address”, “contract bandwidth”, and “first policer” are the contract status of the subscriber. Etc. are set in advance according to the above.

  The flow identification unit 3 constitutes a flow detection unit according to the present invention, identifies the flow of the packet received by the reception IF 2 based on the setting table stored in the setting unit 4, and displays “ The items “flow presence / absence” and “label assigning unit” are set.

  Specifically, the flow identification unit 3 registers a set of the destination IP address and the source IP address of the packet received by the reception IF 2 in the setting table, and sets the “flow presence / absence” of the corresponding entry in the setting table. When the item is set to “0”, the “flow presence / absence” item of the corresponding entry in the setting table is set to “1”, and the label assigning unit 6 to which no flow is assigned is detected. The detected identifier of the label assigning unit 6 is set in the item “label assigning unit”. In addition, the flow identification unit 3 sets the “flow presence / absence” item of the entry for the set of IP addresses for which no packet has been received within a predetermined time to “0”.

  Note that the setting table shown in FIG. 2 allows the flow identifying unit 3 to identify a packet based on the destination and transmission source IP addresses. For example, “10.0.0. *” Or “*” ". *. *. *" Is used to specify the destination or source IP address in a range, and packets are sent to the flow identification unit 3 based on whether the destination or source IP address is in the specified range. You may make it identify.

  Further, the setting table may cause the flow identifying unit 3 to identify the packet based on the source port number, the destination port number, and the like in addition to the destination and source IP addresses.

  As described above, in the present embodiment, the flow identifying unit 3 identifies a flow by a combination of a transmission-side terminal and a reception-side terminal, but a plurality of transmission-side terminals and a plurality of receptions. The flow may be identified by a combination with the terminal on the side, or the flow may be identified for each application on the transmission side or reception side.

  In addition, the flow identification unit 3 adds header information to the packet that identifies the flow. Here, as shown in FIG. 3, the header information includes a flow group identification number 30, a flow identification flag 31 indicating whether the packet is a flow registered in the setting table, and the packet is relayed with priority. A priority flag 32 indicating whether the packet is a packet to be transmitted (hereinafter simply referred to as “priority packet”) and whether the packet is received at a transfer rate exceeding the maximum allocated bandwidth determined for each flow. It includes a maximum allocated bandwidth determination flag 33 and a minimum allocated bandwidth determination flag 34 indicating whether or not the packet is received at a transfer rate exceeding the minimum allocated bandwidth determined for each flow.

  Specifically, when the flow of the packet received by the reception IF 2 can be identified, the flow identification unit 3 sets the flow identification flag 31 to “1” and sets the “first” of the corresponding entry in the setting table. The item “1 policer” is set to the flow group identification number 30. On the other hand, when the flow of the packet received by the reception IF 2 cannot be identified, the flow identification unit 3 sets the flow identification flag 31 to “0”.

  Further, the flow identification unit 3 determines whether the packet is a priority packet based on the priority packet information preset in the setting unit 4, and when determining that the packet is a priority packet, When the priority flag 32 is set to “1” and it is determined that the packet is not a priority packet, the priority flag 32 is set to “0”.

  Here, the priority packet information represents the characteristics of the priority packet such that the protocol number of the IP header represents UDP (User Datagram Protocol). Note that the priority packet information may represent a plurality of features. Further, the priority packet information may be determined for each first flow group or may be determined for each flow.

  In FIG. 1, the flow identification unit 3 outputs a packet with header information added to any one of the label assignment units 6 a to 6 f and the packet transmission scheduler 10 based on the setting table.

  For example, when the setting table shown in FIG. 2 is stored in the setting unit 4, the flow identification unit 3 has a destination IP address “10.0.0.1” and a source IP address “20.0.0.1”. Is output to the label attaching unit 6a identified by the identifier 6a, and the packet having the destination IP address “60.0.0.1” and the source IP address “70.0.0.1” is identified by the identifier 6d. To the unit 6d.

  Further, the flow identification unit 3 outputs to the packet transmission scheduler 10 a packet whose destination IP address and transmission source IP address do not correspond to any entry in the setting table (hereinafter simply referred to as “non-identification packet”). It is like that.

  In FIG. 1, the bandwidth setting unit 5 constitutes bandwidth calculation means in the present invention, the second maximum allowable bandwidth of the second flow group, the first maximum allowable bandwidth and the minimum guaranteed bandwidth of each first flow group. In addition, the maximum allocated bandwidth and the minimum allocated bandwidth of each flow are determined.

  Here, the first maximum allowable bandwidth is, for example, a bandwidth that can be used to the maximum set according to a contract that the ISP exchanges with a housing complex or a company. The second maximum allowable bandwidth is, for example, a bandwidth that can be physically and logically maximally used for one line used by an ISP to provide an Internet connection service. Each of the first maximum allowable bandwidth and the second maximum allowable bandwidth is fixedly set in advance via the setting unit 4 constituting the bandwidth setting means in the present invention.

  The maximum allocated bandwidth is the flow identified by the flow identifying unit 3 when the transfer rate of the first flow group exceeds the first maximum allowable bandwidth (hereinafter simply referred to as “identification flow”). It is a band that starts to be limited in the first flow group. The minimum allocated bandwidth is the minimum bandwidth that guarantees the identification flow.

  When the sum of the first maximum allowable bands is equal to or less than the second maximum allowable band, the band setting unit 5 determines each first maximum allowable band as the minimum guaranteed band. For example, when the second maximum allowable bandwidth is 100 Mbps and the first maximum allowable bandwidth is 10 Mbps, 30 Mbps, and 30 Mbps, respectively, the bandwidth setting unit 5 sets the minimum guaranteed bandwidth of the first flow group to 10 Mbps, Set to 30 Mbps and 30 Mbps.

  Further, when the sum of the first maximum permissible bands exceeds the second maximum permissible band, the band setting unit 5 distributes the second maximum permissible band in proportion to the first maximum permissible band. The minimum guaranteed bandwidth of the first flow group is determined. For example, when the second maximum allowable bandwidth is 56 Mbps and the first maximum allowable bandwidth is 10 Mbps, 30 Mbps, and 30 Mbps, respectively, the bandwidth setting unit 5 sets the minimum guaranteed bandwidth of the first flow group to 8 Mbps, Set to 24 Mbps and 24 Mbps.

  Further, the bandwidth setting unit 5 changes the number of first flow groups belonging to the second flow group, or the first maximum allowable bandwidth or the set value of the second maximum allowable bandwidth each time there is a change. Redefine the minimum guaranteed bandwidth for one flow group.

  In addition, the bandwidth setting unit 5 determines the maximum allocated bandwidth of each identification flow as a distribution of the first maximum allowable bandwidth of the first flow group by the ratio of the contracted bandwidth of the identification flow of the first flow group. It has become. The identification flow can be specified by referring to the “flow presence / absence” item in the setting table stored in the setting unit 4, and the contracted bandwidth refers to the “contracted bandwidth” item in the setting table. Can be specified by.

  For example, when the first maximum allowable bandwidth of the first flow group is 30 Mbps and the contract bandwidth of the identification flow is 30 Mbps, 20 Mbps, and 10 Mbps, respectively, the bandwidth setting unit 5 sets the maximum allocated bandwidth of the identification flow. Set to 15 Mbps, 10 Mbps, and 5 Mbps.

  In addition, the bandwidth setting unit 5 determines the minimum allocated bandwidth of each identification flow that is obtained by allocating the minimum guaranteed bandwidth of the first flow group at the contracted bandwidth ratio of the identification flow of the first flow group. . For example, when the minimum guaranteed bandwidth of the first flow group is 18 Mbps and the contract bandwidth of the identification flow is 30 Mbps, 20 Mbps, and 10 Mbps, respectively, the bandwidth setting unit 5 sets the minimum allocated bandwidth of the identification flow to 9 Mbps and 6 Mbps, respectively. Set to 3 Mbps. Furthermore, the bandwidth setting unit 5 redefines the maximum allocated bandwidth and the minimum allocated bandwidth for each identified flow every time the value of the “flow presence / absence” item in the setting table is changed by the flow identifying unit 3.

  As shown in FIG. 4, the label attaching unit 6 includes a priority packet discriminating unit 40 that discriminates whether or not the input packet is a priority packet, and the packet is input exceeding the maximum allocated bandwidth of the corresponding flow. A maximum allocated bandwidth discriminating unit 41 that discriminates whether or not the packet is received, a minimum allocated bandwidth discriminating unit 42 that discriminates whether or not the packet is input beyond the minimum allocated bandwidth of the corresponding flow, and a maximum allocated bandwidth discriminating unit. 41 and a header information setting unit 43 that sets the discrimination result by the minimum allocated bandwidth discrimination unit 42 to the header information added to the packet.

  The priority packet determination unit 40 determines whether or not the packet is a priority packet based on the priority flag 32 included in the header information added to the input packet.

  The maximum allocated bandwidth discriminating unit 41 corresponds to the maximum allocated bandwidth of the corresponding flow defined by the bandwidth setting unit 5 and the first credit storage unit 45 and the second credit storage unit 46 that store credits indicating the transfer rate. A credit addition unit 47 that adds credits to the credits stored in the first credit storage unit 45 and the second credit storage unit 46, and is stored in the first credit storage unit 45 and the second credit storage unit 46. A credit subtracting section 48 for subtracting the credit corresponding to the length of the packet from the credits.

  The credit adder 47 stores the credit stored in the first credit storage unit 45 until the credit stored in the first credit storage unit 45 reaches the threshold value corresponding to the bandwidth reserved for the priority packet. And credits corresponding to the maximum allocated bandwidth of the corresponding flow are added, and when the credit stored in the first credit storage unit 45 reaches the threshold value, the surplus credit exceeding the threshold value is added to the second credit. The credit is stored in the storage unit 46.

  When the input packet is determined to be a priority packet by the priority packet determination unit 40, the credit subtraction unit 48 stores the credit stored in the first credit storage unit 45 and the second credit storage unit 46. If the sum of the credits is equal to or longer than the credit for the length of the packet, the credits stored in the first credit storage unit 45 and the credits stored in the second credit storage unit 46 are ordered in this order. The credit corresponding to the length of the packet is subtracted, and a determination result indicating that the credit has been subtracted is output to the header information setting unit 43.

  When the input packet is determined to be a priority packet by the priority packet determination unit 40, the credit subtraction unit 48 uses the credit stored in the first credit storage unit 45 and the second credit storage unit 46. If the sum of the credits stored in the packet is less than the credit corresponding to the length of the packet, a determination result indicating that the credits could not be subtracted is output to the header information setting unit 43.

  On the other hand, when the input packet is determined not to be a priority packet by the priority packet determination unit 40, the credit subtraction unit 48 determines that the credit stored in the second credit storage unit 46 is equivalent to the length of the packet. In the case above, the credit corresponding to the length of the packet is subtracted from the credit stored in the second credit storage unit 46, and the determination result that the credit has been subtracted is output to the header information setting unit 43 It is supposed to be.

  When the input packet is determined not to be a priority packet by the priority packet determination unit 40, the credit subtraction unit 48 determines that the credit stored in the second credit storage unit 46 is equal to the length of the packet. If the credit is less than the credit, a determination result indicating that the credit could not be subtracted is output to the header information setting unit 43.

  The minimum allocated bandwidth discriminating unit 42 is configured by adding the credit according to the minimum allocated bandwidth of the corresponding flow determined by the bandwidth setting unit 5 in the credit adding unit 47 of the maximum allocated bandwidth discriminating unit 41. be able to. For this reason, detailed description of the minimum allocated bandwidth determination unit 42 is omitted.

  When the determination result that the credit can be subtracted is obtained from the maximum allocated bandwidth determining unit 41, the header information setting unit 43 sets the maximum allocated bandwidth determining flag 33 included in the header information added to the packet to “ When the determination result that the credit could not be subtracted is obtained from the maximum allocated bandwidth determination unit 41, the maximum allocated bandwidth determination flag 33 is set to “1” corresponding to the first label in the present invention. It is supposed to be set.

  Further, when a determination result indicating that the credit can be subtracted is obtained from the minimum allocation bandwidth determination unit 42, the header information setting unit 43 determines the minimum allocation bandwidth determination flag 34 included in the header information added to the packet. Is set to “0”, and when a determination result indicating that the credit cannot be subtracted is obtained from the minimum allocated bandwidth determining unit 42, the minimum allocated bandwidth determining flag 34 is set to “1” corresponding to the second label in the present invention. Is set to "."

  In FIG. 1, the switch 9 outputs the packet to the first policer 7a or 7b identified by the flow group identification number 30 of the header information added to the packet output from each of the label assignment units 6a to 6f. It has become.

  The first policer 7 constitutes the bandwidth control means in the present invention together with the second policer 8, and, as shown in FIG. 5, a rate measuring unit 70 that measures the transfer rate of the packet input from the switch 9, and the rate A bandwidth excess determination unit 71 that determines whether or not the transfer rate measured by the measurement unit 70 exceeds the first maximum allowable bandwidth of the first flow group determined by the bandwidth setting unit 5; A packet discard unit 72 that discards any packet in which “1” is set in the maximum allocated bandwidth determination flag 33 of the header information so as not to exceed the first maximum allowable bandwidth of the first flow group. Yes.

  The rate measuring unit 70 measures the transfer rate based on the input time difference between the packet input from the switch 9 and the packet input from the switch 9 immediately before this, and the size of each packet.

  As shown in FIG. 6, the second policer 8 includes a rate measuring unit 80 that measures the transfer rate of the packet input from the first policer 7, and the transfer rate measured by the rate measuring unit 80 is a band setting unit. The bandwidth excess determination unit 81 that determines whether or not the second maximum allowable bandwidth determined by 5 is exceeded, and the minimum allocation bandwidth determination flag 34 of the header information so that the transfer rate does not exceed the second maximum allowable bandwidth. A packet discard unit 82 that discards any packet for which “1” is set.

  The rate measuring unit 80 measures the transfer rate based on the input time difference between the packet input from the first policer 7 and the packet input from the first policer 7 immediately before this, and the size of each packet. It is like that.

  In FIG. 1, the packet transmission scheduler 10 permits transmission of a packet output from the second policer 8 and restricts transmission of a non-identification packet.

  Specifically, when the transfer rate of the second flow group is less than the second maximum allowable bandwidth determined by the bandwidth setting unit 5, the packet transmission scheduler 10 sets the transfer rate of the second flow group to the first flow rate. The transmission of the non-identification packet is permitted within a range not exceeding the maximum allowable bandwidth of 2, and the non-identification packet within the range where the transfer rate of the second flow group exceeds the second maximum allowable bandwidth is discarded.

  Further, the packet transmission scheduler 10 is configured to remove header information from a packet that is permitted to be transmitted.

  The operation of the packet relay apparatus 1 configured as described above will be described with reference to FIGS.

  First, when a packet is received by the reception IF 2, the flow of the received packet is identified based on the setting table by the flow identification unit 3 (S1).

  Here, when the flow is not identified, header information in which the flow identification flag 31 is set to “0” is added to the packet by the flow identification unit 3 (S2). Next, the packet transmission scheduler 10 determines whether or not the transfer rate of the second flow group exceeds the second maximum allowable bandwidth (S3).

  If it is determined that the transfer rate of the second flow group exceeds the second maximum allowable bandwidth, the packet transmission scheduler 10 discards the packet as shown in FIG. 8 (S4). On the other hand, when it is determined that the transfer rate of the second flow group does not exceed the second maximum allowable bandwidth, the header information is removed from the packet by the packet transmission scheduler 10 (S5), and the packet is transmitted. It is transmitted to the relay destination by IF11 (S6).

  Returning to FIG. 7, when the flow is identified in step S <b> 1, the label assigning unit 6 that is the output destination of the packet is determined by the flow identifying unit 3, and the flow group identification number 30 is the first policer. 7 and the header information with the flow identification flag 31 set to “1” is added to the packet by the flow identification unit 3 (S7).

  Next, whether or not the packet is a priority packet is determined by the flow identification unit 3 (S8). If it is determined that the packet is a priority packet, the priority flag 32 of the header information added to the packet is set to “1” by the flow identification unit 3 (S9), and the packet is not a priority packet. If it is determined, the priority flag 32 of the header information added to the packet is set to “0” by the flow identification unit 3 (S10).

  Next, in the label assigning unit 6 determined as the output destination by the flow identifying unit 3, it is determined whether or not the packet is input exceeding the maximum allocated bandwidth of the flow (S11).

  Here, when it is determined that the packet is input beyond the maximum allocated bandwidth of the flow, the maximum allocated bandwidth determination flag 33 of the header information added to the packet is displayed by the label attaching unit 6. 1 "is set (S12).

  On the other hand, when it is determined that the packet is not input exceeding the maximum allocated bandwidth of the flow, the maximum allocated bandwidth determination flag 33 of the header information added to the packet is set to “0” by the label assigning unit 6. "Is set (S13).

  Further, it is determined by the label assigning unit 6 whether or not the packet is input beyond the minimum allocated bandwidth of the flow (S14).

  Here, when it is determined that the packet is input beyond the minimum allocated bandwidth of the flow, the label allocation unit 6 sets the minimum allocated bandwidth determination flag 34 of the header information added to the packet. 1 "is set (S15).

  On the other hand, when it is determined that the packet is not input exceeding the minimum allocated bandwidth of the flow, the minimum allocated bandwidth determination flag 34 of the header information added to the packet is set to “0” by the label assigning unit 6. "Is set (S16).

  Next, as shown in FIG. 8, in the first policer 7 identified by the flow group identification number 30 of the header information added to the packet, the maximum allocated bandwidth determination flag 33 of the header information added to the packet. Is set to "1", and whether or not the transfer rate of the packet input to the first policer 7, that is, the transfer rate of the corresponding first flow group exceeds the first maximum allowable bandwidth. Is determined (S17).

  Here, it is determined that “1” is set in the maximum allocated bandwidth determination flag 33 of the header information added to the packet and that the transfer rate of the first flow group exceeds the first maximum allowable bandwidth. If this happens, the packet is discarded by the first policer 7 (S4).

  On the other hand, it is determined that “1” is not set in the maximum allocation bandwidth determination flag 33 of the header information added to the packet, or the transfer rate of the first flow group does not exceed the first maximum allowable bandwidth. In the case of the second policer 8, whether or not “1” is set in the minimum allocation bandwidth determination flag 34 of the header information added to the packet, and is input to the second policer 8. It is determined whether or not the packet transfer rate, that is, the transfer rate of the second flow group exceeds the second maximum allowable bandwidth (S18).

  Here, it is determined that “1” is set in the minimum allocation bandwidth determination flag 34 of the header information added to the packet and that the transfer rate of the second flow group exceeds the second maximum allowable bandwidth. If so, the packet is discarded by the second policer 8 (S4).

  On the other hand, it is determined that “1” is not set in the minimum allocation bandwidth determination flag 34 of the header information added to the packet, or the transfer rate of the second flow group does not exceed the second maximum allowable bandwidth. If the packet information is received, the header information is removed from the packet by the packet transmission scheduler 10 (S5), and the packet is transmitted to the relay destination by the transmission IF 11 (S6).

  Thus, the packet relay device 1 according to the present embodiment calculates the minimum guaranteed bandwidth every time the number of first flow groups or the setting value of the first or second maximum allowable bandwidth is changed. Compared with the above, it is possible to effectively use the limited bandwidth on the transmission side and reduce the work of setting or changing the bandwidth control condition by the administrator.

  In the present embodiment, the label attaching unit 6 adds header information to the packet, and the first policer 7, the second policer 8, the switch 9 and the packet transmission scheduler 10 add the header information added to the packet. Although the example which performs each process with reference was demonstrated, the label provision part 6 registers header information into flow DB which is not shown in figure, the 1st policer 7, the 2nd policer 8, the switch 9, and the packet transmission scheduler 10 are as follows. Each process may be performed with reference to header information registered in the flow DB.

  Also, instead of the first policer 7 and the second policer 8 in the present embodiment, the packets are queued, and the packets are transferred so that the packet transfer rate does not exceed the first and second maximum allowable bandwidths. The packet relay apparatus may be configured using the first and second shapers. In this case, the first and second shapers select packets to be transferred based on the maximum allocated bandwidth and the minimum allocated bandwidth determined for each flow.

It is a block diagram which shows the structure of the packet relay apparatus which concerns on one embodiment of this invention. It is a table | surface which shows the example of the setting table set to the setting part which comprises the packet relay apparatus which concerns on one embodiment of this invention. It is a conceptual diagram which shows the packet to which header information was added by the label provision part which comprises the packet relay apparatus which concerns on one embodiment of this invention. It is a block diagram which shows the structure of the label provision part which comprises the packet relay apparatus which concerns on one embodiment of this invention. It is a block diagram which shows the structure of the 1st policer which comprises the packet relay apparatus which concerns on one embodiment of this invention. It is a block diagram which shows the structure of the 2nd policer which comprises the packet relay apparatus which concerns on one embodiment of this invention. It is a flowchart which shows operation | movement of the packet relay apparatus which concerns on one embodiment of this invention. It is a flowchart following FIG.

Explanation of symbols

1 Packet relay device 2 Reception IF
DESCRIPTION OF SYMBOLS 3 Flow identification part 4 Setting part 5 Band setting part 6 Label provision part 7 1st policer 8 2nd policer 9 Switch 10 Packet transmission scheduler 11 Transmission IF
DESCRIPTION OF SYMBOLS 40 Priority packet discrimination | determination part 41 Maximum allocation bandwidth discrimination | determination part 42 Minimum allocation bandwidth discrimination | determination part 43 Header information setting part 45 1st credit memory | storage part 46 2nd credit memory | storage part 47 Credit addition part 48 Credit subtraction part 70, 80 Rate measurement part 71, 81 Band excess determination unit 72, 82 Packet discard unit

Claims (4)

A packet relay method for identifying a received packet as a flow and controlling the bandwidth of a flow group that is a set of the flows to relay the packet,
A first maximum allowable bandwidth corresponding to a first flow group that is a set of one or more flows, and a second corresponding to a second flow group that is a set of one or more of the first flow groups. The maximum allowable bandwidth is set,
When the sum of the first maximum permissible bands corresponding to the first flow groups belonging to the second flow group exceeds the second maximum permissible band, it belongs to the second flow group Each time the number of first flow groups or the set value of the first maximum allowable band or the second maximum allowable band is changed, the second maximum allowable band is set to the ratio of the first maximum allowable band. Calculating the minimum guaranteed bandwidth corresponding to each of the first flow groups by allocating based on
Dynamically detecting the number of flows belonging to the first flow group;
A minimum allocated bandwidth, which is a minimum usable bandwidth for each flow, and a bandwidth that can be used by the first flow group to which the flow belongs reaches the first maximum allowable bandwidth. A maximum allocated bandwidth that is a bandwidth to be generated is dynamically calculated based on the minimum guaranteed bandwidth corresponding to the first flow group, the first maximum allowable bandwidth, and the number of flows;
A packet relay method, wherein bandwidth control is performed based on a minimum allocation bandwidth, a maximum allocation bandwidth, a first maximum allowable bandwidth, and a second maximum allowable bandwidth for each flow . The minimum allocated bandwidth and the maximum allocated bandwidth are dynamically calculated by allocating the minimum guaranteed bandwidth and the first maximum allowable bandwidth in accordance with a contract bandwidth ratio of each flow, respectively. Item 2. The packet relay method according to Item 1 . A packet relay device that identifies a received packet as a flow, controls a bandwidth of a flow group that is a set of the flows, and relays the packet;
A first maximum allowable bandwidth corresponding to a first flow group that is a set of one or more flows, and a second corresponding to a second flow group that is a set of one or more of the first flow groups. Band setting means (4) for setting the maximum allowable band;
Flow detection means (3) for dynamically detecting the number of flows belonging to the first flow group;
When the sum of the first maximum permissible bands corresponding to the first flow groups belonging to the second flow group exceeds the second maximum permissible band, it belongs to the second flow group Each time the number of first flow groups or the set value of the first maximum allowable band or the second maximum allowable band is changed, the second maximum allowable band is set to the ratio of the first maximum allowable band. To calculate a minimum guaranteed bandwidth corresponding to each of the first flow groups , a minimum allocated bandwidth that is a minimum usable bandwidth for each flow, and the first to which the flow belongs. A maximum allocated bandwidth, which is a bandwidth allocated to each flow when a bandwidth that can be used by the flow group is up to the first maximum allowable bandwidth, and the minimum guaranteed bandwidth corresponding to the first flow group, First maximum tolerance Bandwidth calculation means for dynamically calculated based on the number of pass and the flow (5),
Band control means (6a to 6f, 7a and 7b) for performing band control based on the minimum allocated band, the maximum allocated band, the first maximum allowable band, and the second maximum allowable band for each flow. A packet relay device characterized by that. The bandwidth calculating means dynamically calculates the minimum allocated bandwidth and the maximum allocated bandwidth by allocating the minimum guaranteed bandwidth and the first maximum allowable bandwidth in accordance with a contract bandwidth ratio of each flow, respectively. The packet relay device according to claim 3 .

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