JP2012175130A - Distribution system, distribution method, distribution scheme control device, and program therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a multicast distribution technique for increasing the number of accommodating groups without deteriorating a traffic reduction effect.SOLUTION: A distribution system includes: a node for transferring a received packet to a transfer destination by applying either of a transfer table-multicast scheme and a source-routing multicast scheme; and a distribution scheme control device 1 for instructing the node to apply either of the transfer table-multicast scheme and source-routing multicast scheme, as a multicast distribution scheme for each multicast group, so that the data volume of a transfer table stored by the node does not exceed the upper-limit space.

Description

  The present invention relates to a technique for multicast distribution of data packets.

  Multicast distribution is a technique for efficiently transmitting data packets to a plurality of recipients and reducing traffic in a packet communication network. The source device does not send data packets directly to all recipients, but builds a tree-like route with the sender as the root and the recipient as the leaf, and the node devices (routers) on that route need it By duplicating data packets, traffic is greatly reduced.

  A conventional forwarding table multicast distribution method is shown in FIG. In the forwarding table multicast distribution method described in Non-Patent Document 1, the node device stores an entry including the ID of the group to be multicast and the ID of the output destination port in the forwarding table, and is written in the header of the data packet when the data packet arrives. The entry corresponding to the group ID is searched from the forwarding table to determine the output port of the data packet. The advantage of this method is that data packets can be efficiently transferred to a large number of recipients, and the effect of reducing traffic is great.

  A prior art source routing multicast distribution scheme is shown in FIG. In the source routing multicast distribution method described in Non-Patent Document 2, the IDs of the ports constituting the distribution tree (distribution route) are encoded into the header of the data packet by a method called a Bloom filter described in Non-Patent Document 3, for example. If the node ID of the node device is included in the header of the data packet, the node device outputs the data packet from that port. When the number of recipients increases and the header becomes excessive, the header is divided (divided into a plurality of distribution path trees) and distributed. The advantage of this method is that the node device can accommodate a large number of groups because it does not have a forwarding table.

Stephen Deering, “Host extensions for IP multicasting”, IETF Request for Comments 1112, August 1989. S. Ratnasamy, A .; Ermolinsky, and S.M. Shenker, “Revising IP multicast”, Proc. of SIGCOMM, 2006. Michael Mitzenmacher and Eli Upfal, “Probability and Calculation—Randomization Algorithm and Probabilistic Analysis”, Kyoritsu Shuppan, pp. 150-154, 2009.

  However, in the forwarding table multicast distribution method described in Non-Patent Document 1, there is a problem in that a large number of groups cannot be accommodated in the node device because the forwarding table increases in proportion to an increase in the number of groups. In the source routing multicast distribution method described in Non-Patent Document 2, when the number of recipients increases, there is a problem that the header of the data packet increases and the effect of reducing traffic decreases. Although the problem can be improved by dividing it into a plurality of distribution path trees, it is inevitable that the traffic reduction effect will be reduced.

  Therefore, in order to solve the above-described problems, an object of the present invention is to provide a multicast distribution technique that increases the number of groups accommodated without deteriorating the traffic reduction effect.

  In order to achieve the above-mentioned purpose, it was decided to deliver to the group with a small number of recipients using the source routing multicast delivery method, and deliver to the group with a large number of recipients using the forwarding table multicast delivery method. .

  Specifically, the present invention stores a forwarding table in which a group identifier and a forwarding port identifier are associated with each multicast group, and receives the group identifier written in the received packet based on the forwarding table to be stored. A forwarding table multicast distribution method for determining the forwarding destination port of the received packet, or a source routing multicast delivery method for determining the forwarding destination port of the received packet based on the forwarding port identifier written in the received packet. As a multicast distribution method for each multicast group, the forwarding is performed so that the data capacity of the node that forwards the received packet to the forwarding destination and the data capacity of the forwarding table stored in the node does not exceed the upper limit data capacity. Table multicast distribution method and source routing malware A distribution system controller of indicating either a cast distribution method to the node, a distribution system, characterized in that it comprises a.

  Further, the present invention stores a forwarding table in which a group identifier and a forwarding port identifier are associated with each multicast group, and based on the group identifier written in the received packet and the forwarding table to be stored, Apply either the forwarding table multicast delivery method that determines the forwarding port or the source routing multicast delivery method that determines the forwarding port of the received packet based on the forwarding port identifier written in the received packet Then, in a node that forwards the received packet to the forwarding destination, the delivery method control device uses the forwarding as a multicast delivery method for each multicast group so that the data capacity of the forwarding table to be stored does not exceed the upper limit data capacity. Table multicast distribution method and source route A distribution method instruction step for instructing one of the multicast distribution methods to the node, and packet transfer in which the node applies the multicast distribution method for each designated multicast group to transfer the received packet to a transfer destination. And a step in order.

  In the present invention, the node stores a forwarding table in which a group identifier and a forwarding port identifier are associated with each multicast group, and the group identifier written in the received packet and the forwarding table stored are received. In a transfer table multicast distribution method for determining a transfer destination port of a packet, a data capacity measuring unit that measures the data capacity of the stored transfer table, and a data capacity of the transfer table measured by the data capacity measuring unit is upper limit data As the multicast distribution method for each multicast group, the forwarding port of the received packet is determined based on the forwarding table multicast distribution method and the forwarding port identifier written in the packet received by the node so as not to exceed the capacity Source routing multicast distribution method A distribution method instruction unit for instructing whether Re to the node, a distribution method control device, characterized in that it comprises a.

  According to this configuration, since the source routing multicast delivery method is used together, the data capacity of the forwarding table stored in the node does not become too large, and the forwarding table multicast delivery method is used together, so that the node is written in the packet received The traffic of the forwarding port identifier does not increase too much. Therefore, it is possible to provide a multicast distribution technique that increases the number of groups accommodated without deteriorating the traffic reduction effect.

  In addition, the present invention provides a configuration in which the number of recipients in another multicast group to which the source routing multicast distribution method is applied is larger than the number of recipients in one multicast group to which the forwarding table multicast distribution method is applied. The distribution method control device instructs the node to switch to the source routing multicast distribution method as the multicast distribution method of the one multicast group, and the forwarding table multicast as the multicast distribution method of the other multicast group. A distribution system that instructs the node to switch to a distribution method.

  In addition, according to the present invention, in the distribution method instructing step, the distribution method control device applies the source routing multicast distribution method based on the number of recipients of one multicast group to which the forwarding table multicast distribution method is applied. When the number of recipients of another multicast group becomes large, the node is instructed to switch to the source routing multicast distribution method as the multicast distribution method of the one multicast group, and multicast distribution of the other multicast group is performed. As a method, a distribution method is characterized by instructing the node to switch to the forwarding table multicast distribution method.

  In addition, the present invention provides a configuration in which the number of recipients in another multicast group to which the source routing multicast distribution method is applied is larger than the number of recipients in one multicast group to which the forwarding table multicast distribution method is applied. The distribution method instruction unit instructs the node to switch to the source routing multicast distribution method as the multicast distribution method of the one multicast group, and the forwarding table multicast as the multicast distribution method of the other multicast group. A delivery method control apparatus that instructs the node to switch to a delivery method.

  According to this configuration, switching to the source routing multicast distribution method is performed for a group with a small number of recipients, and switching to the forwarding table multicast distribution method is performed for a group with a large number of recipients. Do. Therefore, it is possible to provide a multicast distribution technique that increases the number of groups accommodated without deteriorating the traffic reduction effect.

  In the present invention, the distribution system control device fixes a multicast distribution system of a predetermined multicast group to either the forwarding table multicast distribution system or the source routing multicast distribution system. It is.

  In the distribution method instructing step, the distribution method control device fixes the multicast distribution method of the predetermined multicast group to either the forwarding table multicast distribution method or the source routing multicast distribution method. This is a distribution method characterized by this.

  In the present invention, the distribution method instruction unit fixes a multicast distribution method of a predetermined multicast group to either the forwarding table multicast distribution method or the source routing multicast distribution method. It is a control device.

  According to this configuration, even when the number of recipients of each multicast group changes, the multicast distribution method of the predetermined multicast group is fixed, so the service quality is maintained without switching the multicast distribution method. be able to.

  Specifically, the present invention is a program for causing a computer to function as the data capacity measurement unit and the distribution method instruction unit of a distribution method control device.

  According to this configuration, it is possible to provide a multicast distribution program that increases the number of groups accommodated without deteriorating the traffic reduction effect.

  The present invention can provide a multicast distribution technique for increasing the number of groups accommodated without deteriorating the traffic reduction effect.

It is a figure which shows the forwarding table multicast delivery system of a prior art. It is a figure which shows the source routing multicast delivery system of a prior art. It is a figure which shows the structure of the delivery system of this invention. It is a figure which shows the structure of the delivery system control apparatus of this invention. It is a figure which shows the structure of the node apparatus of this invention. It is a figure which shows the structure of the edge node apparatus of this invention. It is a figure which shows the structure of the transmission source apparatus of this invention. It is a figure which shows the initial setting state of the multicast delivery system of this invention. It is a figure which shows the 1st change state of the multicast delivery system of this invention. It is a figure which shows the 1st change state of the multicast delivery system of this invention. It is a figure which shows the 2nd change state of the multicast delivery system of this invention. It is a figure which shows the 2nd change state of the multicast delivery system of this invention. It is a figure which shows the initial setting method of the multicast delivery system of this invention. It is a figure which shows the initial setting method of the multicast delivery system of this invention. It is a figure which shows the 1st change method of the multicast delivery system of this invention. It is a figure which shows the 2nd change method of the multicast delivery system of this invention. It is a figure which shows the other structure of the edge node apparatus of this invention.

  Embodiments of the present invention will be described with reference to the accompanying drawings. The embodiments described below are examples of the present invention, and the present invention is not limited to the following embodiments.

  The configuration of the distribution system of the present invention is shown in FIG. The distribution system includes a distribution method control device 1, a node device 2, edge node devices 3-1, 3-2, a transmission source device 4, and reception devices 5-1, 5-2, 5-3. The transmission source device 4 transmits a packet to the node device 2 using the port PID1-1. The node device 2 transmits packets to the edge node devices 3-1 and 3-2 using the ports PID 2-1 and PID 2-2, respectively. The edge node device 3-1 transmits the packet to the receiving devices 5-1 and 5-2 using the ports PID 3-1 and PID 3-2, respectively. The edge node device 3-2 transmits a packet to the reception device 5-3 using the port PID4-1. The distribution method control apparatus 1 selects either the forwarding table multicast distribution method or the source routing multicast distribution method.

  An outline of the node device 2 and the edge node devices 3-1 and 3-2 will be described. A forwarding table in which a group identifier and a forwarding port identifier are associated with each multicast group is stored, and forwarding is performed to determine a forwarding port of the received packet based on the group identifier written in the received packet and the forwarding table to be stored. A table multicast distribution scheme can be applied. It is also possible to apply a source routing multicast distribution method that determines a transfer destination port of a received packet based on a transfer destination port identifier written in the received packet. In practice, either the forwarding table multicast delivery method or the source routing multicast delivery method is applied to forward the received packet to the forwarding destination.

  An outline of the distribution method control apparatus 1 will be described. As the multicast distribution method for each multicast group, either the forwarding table multicast distribution method or the source routing multicast distribution method is instructed to the node device 2 and the edge node devices 3-1, 3-2. Here, the data capacity of the transfer table stored in the node device 2 and the edge node devices 3-1 and 3-2 is prevented from exceeding the upper limit data capacity.

  As a first specific example, when the data capacity of the forwarding table exceeds the upper limit data capacity, the multicast distribution method is switched from the forwarding table multicast distribution method to the source routing multicast distribution method for the multicast group with a small number of recipients. As a second specific example, when the number of multicast groups to which the forwarding table multicast distribution method is applied falls below a certain value, a multicast group having a large number of recipients within a range in which the data capacity of the forwarding table does not exceed the upper limit data capacity The multicast distribution method is switched from the source routing multicast distribution method to the forwarding table multicast distribution method.

  That is, since the source routing multicast distribution method is used together, the data capacity of the forwarding table stored in the node device 2 and the edge node devices 3-1 and 3-2 does not become too large. Since the forwarding table multicast distribution method is used in combination, the traffic of the transfer destination port identifier written in the packet received by the node device 2 and the edge node devices 3-1 and 3-2 does not become too large. Therefore, it is possible to provide a multicast distribution technique that increases the number of groups accommodated without deteriorating the traffic reduction effect.

  The number of recipients in another multicast group to which the source routing multicast distribution method is applied may be larger than the number of recipients in one multicast group to which the forwarding table multicast distribution method is applied. Therefore, the node device 2 and the edge node devices 3-1 and 3-2 are instructed to switch to the source routing multicast distribution method as the multicast distribution method of the one multicast group. Then, it instructs the node device 2 and the edge node devices 3-1 and 3-2 to switch to the forwarding table multicast distribution method as the multicast distribution method of the other multicast group.

  That is, switching to the source routing multicast distribution method is performed for a group with a small number of recipients, and switching to a forwarding table multicast distribution method is performed for a group with a large number of recipients. Therefore, it is possible to provide a multicast distribution technique that increases the number of groups accommodated without deteriorating the traffic reduction effect.

  The multicast distribution method of the predetermined multicast group can be fixed to either the forwarding table multicast distribution method or the source routing multicast distribution method. Specifically, for each multicast group, information indicating whether the multicast distribution method is variable or fixed is stored, and information indicating which multicast distribution method is currently applied is stored.

  That is, even when the number of recipients of each multicast group changes, the multicast distribution method of the predetermined multicast group is fixed, so that the service quality can be maintained without switching the multicast distribution method. Even when the number of recipients of a predetermined multicast group is expected to fluctuate frequently, it is possible to prevent frequent switching of the multicast distribution method of the predetermined multicast group.

  FIG. 4 shows the configuration of the distribution method control apparatus of the present invention. The distribution method control device 1 includes a multicast distribution method selection unit 11, a distribution tree management table 12, and a communication unit 13.

  The multicast delivery method selection unit 11 includes a data capacity measurement unit (not shown) and a delivery method instruction unit (not shown) in selecting either the forwarding table multicast delivery method or the source routing multicast delivery method. The data capacity measuring unit measures the data capacity of the transfer table stored in the node device 2 and the edge node devices 3-1 and 3-2 in the transfer table multicast distribution method. The distribution method instruction unit instructs the node device 2 and the edge node devices 3-1 and 3-2 as one of the forwarding table multicast distribution method and the source routing multicast distribution method as the multicast distribution method for each multicast group.

  The distribution tree management table 12 is a storage area for storing distribution tree information of a part or all of a group distributed by the forwarding table multicast distribution method and the source routing multicast distribution method. The distribution tree management table 12 is also a storage area for storing conditions for selecting a multicast distribution method for a group in a fixed manner.

  The multicast distribution method selection unit 11 updates the distribution tree information stored in the distribution tree management table 12 based on the distribution tree update information received from the multicast distribution method control unit 35 of the edge node device 3 described later. The multicast distribution method selection unit 11 updates the multicast distribution method of some or all groups based on the distribution tree information stored in the distribution tree management table 12. Based on the result of this update, the multicast distribution method selection unit 11 sends to the multicast distribution method control unit 35 of the edge node device 3 described later (or the multicast distribution method control unit 45 of the transmission source device 4 described later) if necessary. An instruction is given to a multicast control unit 31 (or a multicast control unit 41, which will be described later).

  When there are a plurality of distribution method control devices 1 in a distribution system that performs multicast distribution, the multicast distribution method selection unit 11 included in the distribution method control device 1 of FIG. A part or all of the distribution tree information stored in the distribution tree management table 12 can be exchanged with the selection unit 11 by communication.

  The communication unit 13 performs communication with the distribution method control device 1. In addition, this invention can be implemented using the program which functions the delivery system control apparatus 1 as a data capacity measurement part and a delivery system instruction | indication part. The program can be recorded on a recording medium, and the program can be provided through a network.

  The configuration of the node device of the present invention is shown in FIG. The node device 2 includes a multicast control unit 21, a transfer unit 22, a transfer table 23, and a communication unit 24.

  The transfer table 23 is a storage area for storing a transfer table of the transfer table multicast distribution method. The transfer unit 22 transfers either the transfer table multicast distribution method or the source routing multicast distribution method. When forwarding in the forwarding table multicast distribution method, forwarding is performed based on the information stored in the forwarding table 23. When forwarding in the source routing multicast distribution method, forwarding is performed based on the header of the data packet.

  The multicast control unit 21 receives the control packet of the forwarding table multicast distribution method from the adjacent another node device 2 or the adjacent edge node device 3 or the adjacent transmission source device 4, updates the forwarding table 23, and is adjacent. The control packet of the forwarding table multicast distribution method is transmitted to another node device 2 or an adjacent edge node device 3 or an adjacent transmission source device 4. The communication unit 24 communicates with the node device 2.

  The configuration of the edge node device of the present invention is shown in FIG. The edge node device 3 includes a multicast control unit 31, a transfer unit 32, a transfer table 33, a communication unit 34, and a multicast distribution method control unit 35.

  The transfer table 33 is a storage area for storing a transfer table of the transfer table multicast distribution method. The transfer unit 32 transfers one of the transfer table multicast distribution method and the source routing multicast distribution method. When forwarding in the forwarding table multicast distribution method, forwarding is performed based on the information stored in the forwarding table 33. When forwarding in the source routing multicast distribution method, forwarding is performed based on the header of the data packet.

  The multicast control unit 31 receives a control packet of the forwarding table multicast distribution method from the multicast control unit 21 of the node device 2, transmits an update of distribution tree information to the multicast distribution method control unit 35, and a multicast distribution method control unit The control instruction from 35 is received, the forwarding table 33 is updated, and the forwarding table multicast distribution control packet is transmitted to the multicast control unit 21 of the node device 2.

  The multicast distribution method control unit 35 transmits distribution tree update information to the multicast distribution method selection unit 11 of the distribution method control device 1. The multicast distribution method control unit 35 instructs the multicast control unit 31 to update the transfer table 33 when the multicast distribution method selection unit 11 of the distribution method control device 1 is instructed to control the transfer table multicast distribution method. The communication unit 34 communicates with the node device 3.

  The configuration of the transmission source apparatus of the present invention is shown in FIG. The transmission source device 4 includes a multicast control unit 41, a transfer unit 42, a transfer table 43, a communication unit 44, a multicast distribution method control unit 45, and a header table 46.

  The transfer table 43 is a storage area for storing a transfer table of the transfer table multicast distribution method. The header table 46 is a storage area for storing a header table of the source routing multicast distribution method. The transfer unit 42 performs transfer (transmission) of either the transfer table multicast distribution method or the source routing multicast distribution method. When forwarding in the forwarding table multicast distribution method, forwarding is performed based on the information stored in the forwarding table 43. When forwarding in the source routing multicast distribution method, forwarding is performed based on the information in the header table 46.

  The multicast control unit 41 receives the control packet of the forwarding table multicast distribution method from the adjacent node device 2, receives the control instruction from the multicast distribution method control unit 45, updates the forwarding table 43, and the header table 46. And the transmission of the control packet of the forwarding table multicast distribution method to the adjacent node device 2 is performed.

  The multicast distribution method control unit 45 instructs the multicast control unit 41 to update the header table 46 when the multicast distribution method selection unit 11 of the distribution method control device 1 is instructed to control the source routing multicast distribution method. The multicast distribution method control unit 45 instructs the multicast control unit 41 to update the transfer table 43 when the multicast distribution method selection unit 11 of the distribution method control device 1 is instructed to control the transfer table multicast distribution method. The communication unit 44 performs communication with the transmission source device 4.

  FIG. 8 shows an initial setting state of the multicast distribution method of the present invention. The forwarding table multicast distribution method is applied to the group GID1, and the source routing multicast distribution method is applied to the group GID2. Therefore, the packet header of group GID2 is larger than the packet header of group GID1. Here, it is assumed that the transfer tables 43, 23, 33-1 and 33-2 have no free space.

  A first change state of the multicast distribution method of the present invention is shown in FIGS. FIG. 9 shows a state where the recipient of the group GID1 has left the group GID1 as the first stage. FIG. 10 shows a state where the multicast distribution method is changed as the second stage.

  In the state shown in FIG. 9, all the recipients of the group GID1 have left the group GID1, and the transfer tables 43, 23, 33-1 and 33-2 have free capacity. Therefore, in the state shown in FIG. 10, the multicast distribution method of group GID2 is changed from the source routing multicast distribution method to the forwarding table multicast distribution method in accordance with an instruction from the distribution method control device 1. Specifically, transfer tables 43, 23, and 33-1 are created for the group GID2, and the transfer table 33-2 and the header table 46 are deleted.

  In the state shown in FIG. 10, the packet header of the group GID2 is smaller than in the state shown in FIG.

  A second change state of the multicast distribution method of the present invention is shown in FIGS. FIG. 11 shows a state where the recipient of the group GID1 has left the group GID1 as the first stage. FIG. 12 shows a state where the multicast distribution method is changed as the second stage.

  In the state shown in FIG. 11, some of the recipients of the group GID1 have left the group GID1, and the number of recipients of the group GID1 is less than a certain number of recipients, for example, the number of recipients of the group GID2. . Therefore, in the state shown in FIG. 12, the multicast distribution method of the group GID1 is changed from the forwarding table multicast distribution method to the source routing multicast distribution method according to the instruction of the distribution method control device 1, and the multicast distribution of the group GID2 is performed. The method is changed from the source routing multicast distribution method to the forwarding table multicast distribution method. Specifically, the transfer tables 43, 23, and 33-1 are created for the group GID2, the header table 46 is created for the group GID1, and the transfer table 33-2 is deleted.

  In the state shown in FIG. 12, the packet header of the small group GID1 is larger than the state shown in FIG. 11, but the packet header of the large group GID2 is small. Get higher.

  FIG. 13 shows an initial setting method of the multicast distribution method of the present invention for determining the multicast distribution method of the group GID1 in the previous stage of the state shown in FIG. 13 and 11 surrounded by a round frame in FIG. 13 represent the multicast distribution method control unit 35 of the edge node device 3 and the multicast distribution method selection unit 11 of the distribution method control device 1, respectively.

  The state shown in FIG. 13 is a case where an entry of the forwarding table multicast delivery method can be added to all the node devices on the delivery tree of the group GID1 for which the recipient participation notification has been made, or the forwarding table multicast delivery. This is a case where the number of recipients of the group GID1 is larger than the number of recipients of other groups that are performing the method.

  The multicast distribution method control unit 35 of the edge node device 3 to which the recipient of the group GID1 relates notifies the multicast distribution method selection unit 11 of the distribution method control device 1 of the update of the distribution tree. The multicast distribution method selection unit 11 of the distribution method control device 1 determines the multicast distribution method of the group GID1 as the forwarding table multicast distribution method, and sends it to the multicast distribution method control unit 35 of the edge node device 3 to which the recipient of the group GID1 relates. Instructing the creation / update of a distribution tree for the forwarding table multicast distribution method.

  The multicast distribution method control unit 35 transmits an instruction to add an entry of the group GID1 to the forwarding table 33 of the edge node device 3 to the multicast control unit 31 of the edge node device 3. In response to this instruction, the multicast control unit 31 uses the same method (for example, Non-Patent Document 1) as the control method of the existing forwarding table multicast delivery method, and the forwarding table 33 of the edge node device 3 and the group GID1. An entry of group GID1 is added to the transfer table of the device upstream of the delivery route.

  FIG. 14 shows an initial setting method of the multicast distribution method of the present invention for determining the multicast distribution method of the group GID2 in the previous stage of the state shown in FIG. 14, 11, and 45 surrounded by a round frame in FIG. 14 are the multicast distribution method control unit 35 of the edge node device 3, the multicast distribution method selection unit 11 of the distribution method control device 1, and the multicast distribution method of the transmission source device 4, respectively. The control part 45 is represented.

  The state shown in FIG. 14 is a case where it is not possible to add an entry for the forwarding table multicast delivery method to at least one node device on the delivery tree of group GID2 for which the recipient participation notification has been made, and forwarding table multicast delivery. This is a case where the number of recipients of the group GID2 is smaller than the number of recipients of other groups that are performing the scheme.

  The multicast distribution method control unit 35 of the edge node device 3 to which the recipient of the group GID2 relates notifies the multicast distribution method selection unit 11 of the distribution method control device 1 of the update of the distribution tree. The multicast distribution method selection unit 11 of the distribution method control device 1 determines the multicast distribution method of the group GID2 as the source routing multicast distribution method, and the source routing multicast distribution to the multicast distribution method control unit 45 of the transmission source device 4 of the group GID2. Instructs the creation / update of a distribution tree of a method.

  The multicast distribution method control unit 45 transmits an instruction to add / update the distribution tree information of the group GID2 to the header table 46 of the transmission source device 4 to the multicast control unit 41 of the transmission source device 4. In response to this instruction, the multicast control unit 41 adds / updates the entry of the group GID 2 to the header table 46 of the transmission source device 4.

  FIG. 15 shows a first change method of the multicast distribution method of the present invention in the state shown in FIGS. The multicast distribution method control unit 35 of the edge node device 3 to which the recipient of the group GID1 has cut off the relationship notifies the multicast distribution method selection unit 11 of the distribution method control device 1 of the update of the distribution tree. The multicast distribution method selection unit 11 of the distribution method control device 1 changes the multicast distribution method of the group GID2 from the source routing multicast distribution method to the forwarding table multicast distribution method.

  Then, the multicast distribution method selection unit 11 transmits an instruction to add the entry of the group GID2 to the forwarding table 33 of the edge node device 3 to the edge node device 3 to which the recipient of the group GID2 relates. Further, after this operation is completed, the multicast delivery method selection unit 11 transmits an instruction to delete the entry of the group GID2 from the header table 46 of the transmission source device 4 to the transmission source device 4 of the group GID2.

  FIG. 16 shows a second modification method of the multicast distribution method of the present invention in the state shown in FIGS. The multicast distribution method control unit 35 of the edge node device 3 to which the recipient of the group GID1 has cut off the relationship notifies the multicast distribution method selection unit 11 of the distribution method control device 1 of the update of the distribution tree. The multicast distribution method selection unit 11 of the distribution method control device 1 changes the multicast distribution method of the group GID1 from the forwarding table multicast distribution method to the source routing multicast distribution method, and changes the multicast distribution method of the group GID2 to the source routing multicast distribution. Change from method to forwarding table multicast distribution method. Since the change of the group GID2 is almost the same in the state shown in FIGS. 15 and 16, the change of the group GID1 will be described.

  Then, the multicast distribution method selection unit 11 transmits an instruction to add the entry of the group GID1 to the header table 46 of the transmission source device 4 to the transmission source device 4 of the group GID1. Further, after this operation is completed, the multicast delivery method selection unit 11 instructs the edge node device 3 to which the recipient of the group GID1 is related to delete the entry of the group GID1 from the forwarding table 33 of the edge node device 3. Send.

  The number of distribution method control device 1, node device 2, edge node device 3, transmission source device 4, and reception device 5 is not limited to the number shown in the present embodiment, and there may be a plurality even if each is one. Also good. Further, the arrangement and connection relation of each device are not limited to those shown in the present embodiment. In addition, the functional blocks of various devices may be merged with the functional blocks of other types of devices. For example, the edge node device 3 of FIG. 17 merges the functional blocks of the distribution method control device 1 of FIG. 4 with the functional blocks of the edge node device 3 of FIG. Is an example of implementing

  The distribution system, distribution method, distribution method control apparatus, and program thereof according to the present invention can be applied to a distribution technique that aims to reduce traffic and increase the number of groups accommodated.

1: Distribution method control device 2: Node device 3: Edge node device 4: Transmission source device 5: Reception device 11: Multicast distribution method selection unit 12: Distribution tree management table 13: Communication unit 21: Multicast control unit 22: Transfer unit 23: Transfer table 24: Communication unit 31: Multicast control unit 32: Transfer unit 33: Transfer table 34: Communication unit 35: Multicast distribution method control unit 36: Multicast distribution method selection unit 37: Distribution tree management table 41: Multicast control unit 42: Transfer unit 43: Transfer table 44: Communication unit 45: Multicast distribution method control unit 46: Header table

Claims (10)

A forwarding table in which a group identifier and a forwarding port identifier are associated with each multicast group is stored, and a forwarding port of the received packet is determined based on the group identifier written in the received packet and the forwarding table to be stored. Packets received by applying either the forwarding table multicast delivery method or the source routing multicast delivery method that determines the forwarding port of the received packet based on the forwarding port identifier written in the received packet A node that forwards to the destination,
Either the forwarding table multicast distribution method or the source routing multicast distribution method is assigned to the node as a multicast distribution method for each multicast group so that the data capacity of the forwarding table stored in the node does not exceed the upper limit data capacity. A distribution method control device for instructing;
A distribution system comprising:   When the number of recipients of another multicast group to which the source routing multicast distribution method is applied becomes larger than the number of recipients of one multicast group to which the forwarding table multicast distribution method is applied, the distribution method control device Instructs the node to switch to the source routing multicast distribution method as the multicast distribution method of the one multicast group, and switches to the forwarding table multicast distribution method as the multicast distribution method of the other multicast group. The distribution system according to claim 1, wherein the node is instructed.   The distribution system control device fixes a multicast distribution system of a predetermined multicast group to either the forwarding table multicast distribution system or the source routing multicast distribution system, according to claim 1 or 2. Distribution system. A forwarding table in which a group identifier and a forwarding port identifier are associated with each multicast group is stored, and a forwarding port of the received packet is determined based on the group identifier written in the received packet and the forwarding table to be stored. Packets received by applying either the forwarding table multicast delivery method or the source routing multicast delivery method that determines the forwarding port of the received packet based on the forwarding port identifier written in the received packet In the node that transfers the packet to the transfer destination, the distribution method control device uses the transfer table multicast distribution method and the multicast table distribution method for each multicast group so that the data capacity of the transfer table to be stored does not exceed the upper limit data capacity. Source routing multicast A delivery method instruction step of instructing one of the delivery method to the node,
A packet forwarding step in which the node applies the multicast delivery method for each designated multicast group to forward the received packet to a forwarding destination;
In order.   In the distribution method instructing step, the distribution method control device receives the other multicast group to which the source routing multicast distribution method is applied, based on the number of recipients of the one multicast group to which the forwarding table multicast distribution method is applied. When the number of users increases, the node is instructed to switch to the source routing multicast distribution method as the multicast distribution method of the one multicast group, and the forwarding table as the multicast distribution method of the other multicast group 5. The distribution method according to claim 4, wherein the node is instructed to switch to a multicast distribution method.   The distribution method instructing step fixes the multicast distribution method of a predetermined multicast group to either the forwarding table multicast distribution method or the source routing multicast distribution method in the distribution method instruction step. Item 6. The delivery method according to Item 4 or 5. The node stores a forwarding table in which a group identifier and a forwarding port identifier are associated with each multicast group, and based on the group identifier written in the received packet and the forwarding table to be stored, the forwarding port of the received packet is determined. A data capacity measuring unit that measures the data capacity of the stored forwarding table in the forwarding table multicast distribution method to be determined;
As the multicast distribution method for each multicast group, written to the forwarding table multicast distribution method and the packet received by the node so that the data capacity of the transfer table measured by the data capacity measurement unit does not exceed the upper limit data capacity A distribution method instruction unit for instructing the node of any one of the source routing multicast distribution methods for determining the transfer destination port of the received packet based on the transfer destination port identifier;
A delivery method control apparatus comprising:   When the number of recipients of another multicast group to which the source routing multicast distribution method is applied is larger than the number of recipients of one multicast group to which the forwarding table multicast distribution method is applied, the distribution method instruction unit Instructs the node to switch to the source routing multicast distribution method as the multicast distribution method of the one multicast group, and switches to the forwarding table multicast distribution method as the multicast distribution method of the other multicast group. The distribution method control apparatus according to claim 7, wherein the node instructs the node.   9. The distribution method instructing unit according to claim 7 or 8, wherein the distribution method instruction unit fixes a multicast distribution method of a predetermined multicast group to either the forwarding table multicast distribution method or the source routing multicast distribution method. Distribution method control device.   A program for causing a computer to function as the data capacity measuring unit and the distribution method instruction unit of the distribution method control device according to any one of claims 7 to 9.

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