WO2012043142A1 - Routeur de multidiffusion et système réseau de multidiffusion - Google Patents

Routeur de multidiffusion et système réseau de multidiffusion Download PDF

Info

Publication number
WO2012043142A1
WO2012043142A1 PCT/JP2011/070054 JP2011070054W WO2012043142A1 WO 2012043142 A1 WO2012043142 A1 WO 2012043142A1 JP 2011070054 W JP2011070054 W JP 2011070054W WO 2012043142 A1 WO2012043142 A1 WO 2012043142A1
Authority
WO
WIPO (PCT)
Prior art keywords
data packet
transmission
retransmission
unit
packet
Prior art date
Application number
PCT/JP2011/070054
Other languages
English (en)
Japanese (ja)
Inventor
聡史 神谷
Original Assignee
日本電気株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 日本電気株式会社 filed Critical 日本電気株式会社
Publication of WO2012043142A1 publication Critical patent/WO2012043142A1/fr

Links

Images

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L12/00—Data switching networks
    • H04L12/02—Details
    • H04L12/16—Arrangements for providing special services to substations
    • H04L12/18—Arrangements for providing special services to substations for broadcast or conference, e.g. multicast
    • H04L12/1863—Arrangements for providing special services to substations for broadcast or conference, e.g. multicast comprising mechanisms for improved reliability, e.g. status reports
    • H04L12/1868—Measures taken after transmission, e.g. acknowledgments
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L45/00—Routing or path finding of packets in data switching networks
    • H04L45/16—Multipoint routing

Definitions

  • the present invention relates to a multicast network system and a multicast router.
  • Multicast communication in which the same data packet is transmitted (distributed) to a plurality of terminals in a network is known.
  • Typical multicast network systems that perform multicast communication are described in, for example, Patent Document 1 and Patent Document 2.
  • FIG. 1 shows a configuration of a typical multicast network system 100 that performs multicast communication in the IP layer.
  • a multicast network system 100 includes a plurality of multicast routers (MC routers) 200-1 to 200-3, a transmission server 300, and a plurality of receiving terminals 400-1 to 400-4.
  • the plurality of multicast routers 200-1 to 200-3 are arranged on the multicast network between the transmission server 300 and the reception terminals 400-1 to 400-4.
  • Each multicast router 200 duplicates the data packet received from the upstream side and forwards the data packet to each of a plurality of downstream destinations. Accordingly, the same data packet transmitted from the transmission server 300 is distributed to the plurality of receiving terminals 400-1 to 400-4 through the multicast routers 200-1 to 200-3.
  • the tree structure of the multicast network as shown in FIG. 1 is called a “multicast tree”.
  • Non-Patent Document 1 discloses a method using “ACK (ACK) acknowledgment”. Specifically, as shown in FIG. 1, when each of the receiving terminals 400-1 to 400-4 receives a data packet, it sends an ACK indicating normal reception to the transmitting server that is the transmission source of the received data packet. Reply to 300. With this ACK, the transmission server 300 recognizes that the transmitted data packet has reached the receiving terminal 400 safely. When the transmission server 300 retransmits the data packet as necessary, the reliability can be improved from the viewpoint of data delivery.
  • ACK ACK
  • ACKs from all receiving terminals 400 are concentrated on one transmission server 300.
  • a “response explosion” occurs in which a huge number of ACKs are transmitted to the transmission server 300 for each data packet.
  • Such a response explosion significantly increases the processing load on the transmission server 300, which is not preferable.
  • limiting the number of receiving terminals 400 means deterioration of scalability of the receiving terminal 400, which is not preferable.
  • One object of the present invention is to provide a technique capable of suppressing response explosion in a multicast network system.
  • a multicast router is provided.
  • the multicast router is arranged between the transmission device and the reception device in the multicast network system.
  • the multicast router includes a response generation unit, a packet transmission unit, and a retransmission management unit.
  • the response generation unit receives the data packet from the transmission source on the transmission device side
  • the response generation unit returns an acknowledgment to the transmission source.
  • the packet transmission unit duplicates the received data packet and transmits it to the transmission destination on the reception device side.
  • the retransmission management unit performs retransmission control on the data packet transmitted to the transmission destination.
  • the retransmission management unit stores the data packet transmitted to the transmission destination in a buffer.
  • the retransmission management unit When the acknowledgment for the data packet is received from the transmission destination, the retransmission management unit discards the received acknowledgment. When the acknowledgment for the data packet is received from all of the transmission destinations, the retransmission management unit deletes the data packet stored in the buffer. When a retransmission timeout occurs for the data packet stored in the buffer, the retransmission management unit outputs the data packet as a retransmission data packet to the packet transmission unit, and the packet transmission unit retransmits the retransmission data packet to the transmission destination.
  • a multicast network system in another aspect of the present invention, includes a transmission device, a plurality of reception devices, and a multicast router arranged on the multicast network between the transmission device and the plurality of reception devices.
  • the multicast router includes a response generation unit, a packet transmission unit, and a retransmission management unit.
  • the response generation unit receives the data packet from the transmission source on the transmission device side
  • the response generation unit returns an acknowledgment to the transmission source.
  • the packet transmission unit duplicates the received data packet and transmits it to the transmission destination on the reception device side.
  • the retransmission management unit performs retransmission control on the data packet transmitted to the transmission destination.
  • the retransmission management unit stores the data packet transmitted to the transmission destination in a buffer.
  • the retransmission management unit When the acknowledgment for the data packet is received from the transmission destination, the retransmission management unit discards the received acknowledgment. When the acknowledgment for the data packet is received from all of the transmission destinations, the retransmission management unit deletes the data packet stored in the buffer. When a retransmission timeout occurs for the data packet stored in the buffer, the retransmission management unit outputs the data packet as a retransmission data packet to the packet transmission unit, and the packet transmission unit retransmits the retransmission data packet to the transmission destination.
  • a program for causing a multicast router to realize a multicast router function is provided.
  • the multicast router is arranged between the transmission device and the reception device in the multicast network system.
  • the multicast router function includes a response generation function, a packet transmission function, and a retransmission management function.
  • the response generation function receives a data packet from the transmission source on the transmission device side
  • the response generation function returns an acknowledgment to the transmission source.
  • the packet transmission function duplicates the received data packet and transmits it to the transmission destination on the receiving device side.
  • the retransmission management function performs retransmission control regarding the data packet transmitted to the transmission destination.
  • the retransmission management function stores the data packet transmitted to the transmission destination in a buffer.
  • the retransmission management function discards the received acknowledgment.
  • the retransmission management function deletes the data packet stored in the buffer.
  • the retransmission management function outputs the data packet as a retransmission data packet to the packet transmission function, and the packet transmission function retransmits the retransmission data packet to the transmission destination.
  • response explosion can be suppressed in a multicast network system.
  • FIG. 1 is a block diagram showing a configuration of a typical multicast network system.
  • FIG. 2 is a block diagram showing a configuration of the multicast network system according to the embodiment of the present invention.
  • FIG. 3 is a block diagram schematically showing the configuration of the multicast router according to the embodiment of the present invention.
  • FIG. 4 is a conceptual diagram showing a data packet in the embodiment of the present invention.
  • FIG. 5 is a conceptual diagram showing header information in the embodiment of the present invention.
  • FIG. 6 is a conceptual diagram showing DAT reception information in the embodiment of the present invention.
  • FIG. 7 is a conceptual diagram showing ACK reception information in the embodiment of the present invention.
  • FIG. 8 is a conceptual diagram showing management information in the embodiment of the present invention.
  • FIG. 1 is a block diagram showing a configuration of a typical multicast network system.
  • FIG. 2 is a block diagram showing a configuration of the multicast network system according to the embodiment of the present invention.
  • FIG. 3 is a block diagram schematically
  • FIG. 9 is a conceptual diagram illustrating an example of an output port state and an ACK reception state in the management information.
  • FIG. 10 is a conceptual diagram showing multicast information in the embodiment of the present invention.
  • FIG. 11 is a block diagram showing the configuration of the multicast router in the embodiment of the present invention.
  • FIG. 12 is a block diagram showing the configuration of the data processing unit in the embodiment of the present invention.
  • FIG. 13 is a block diagram showing a configuration of the retransmission control receiving unit in the embodiment of the present invention.
  • FIG. 14 is a block diagram showing a configuration of a retransmission control transmission unit in the embodiment of the present invention.
  • FIG. 15 is a block diagram showing a configuration of the transmission server according to the embodiment of the present invention.
  • FIG. 10 is a conceptual diagram showing multicast information in the embodiment of the present invention.
  • FIG. 11 is a block diagram showing the configuration of the multicast router in the embodiment of the present invention.
  • FIG. 12 is a block diagram showing the configuration of
  • FIG. 16 is a block diagram showing a configuration of a receiving terminal in the embodiment of the present invention.
  • FIG. 17 is a flowchart showing an operation when receiving a data packet in the multicast router according to the embodiment of the present invention.
  • FIG. 18 is a flowchart showing an operation at the time of ACK reception in the multicast router according to the embodiment of the present invention.
  • FIG. 19 is a flowchart showing an operation when a retransmission timeout occurs in the multicast router according to the embodiment of the present invention.
  • FIG. 2 shows a configuration of a multicast network system 1 according to an embodiment of the present invention.
  • the multicast network system 1 includes a plurality of multicast routers (MC routers) 2-1 to 2-3, a transmission server 3, and a plurality of reception terminals 4-1 to 4-4.
  • the transmission server 3 transmits the data packet DAT to the multicast network.
  • the receiving terminal 4 receives the data packet DAT from the multicast network.
  • a plurality of multicast routers 2-1 to 2-3 are arranged on a multicast network between the transmission server 3 and the reception terminals 4-1 to 4-4.
  • Each multicast router 2 duplicates the data packet DAT received from the upstream side, and transfers the data packet DAT to each of a plurality of downstream destinations. Accordingly, the same data packet DAT transmitted from the transmission server 3 is distributed to the plurality of receiving terminals 4-1 to 4-4 through the multicast routers 2-1 to 2-3.
  • the tree structure of the multicast network as shown in FIG. 2 is called a “multicast tree”.
  • each multicast router 2 has a “packet retransmission control function”. That is, delivery confirmation using an acknowledgment (ACK) is performed between the transmission server 3 and the multicast router 2, between adjacent multicast routers 2, and between the multicast router 2 and the receiving terminal 4. More specifically, each multicast router 2 has the following functions.
  • FIG. 3 is a block diagram schematically showing the configuration of the multicast router 2 according to the present embodiment.
  • the multicast router 2 includes an ACK generation unit 41, a packet transmission unit 50, and a retransmission management unit 60.
  • the ACK generation unit 41 When receiving the data packet DAT from the upstream (transmission server 3 side), the ACK generation unit 41 generates an ACK for the data packet DAT. Then, the ACK generation unit 41 returns an ACK to the transmission source (the adjacent multicast router 2 or the transmission server 3) of the received data packet DAT.
  • the packet transmission unit 50 When the packet transmission unit 50 receives the data packet DAT from the upstream side (transmission server 3 side), the packet transmission unit 50 duplicates the data packet DAT. Then, the packet transmission unit 50 transmits the data packet DAT to a designated transmission destination (adjacent multicast router 2 or reception terminal 4) downstream (receiving device 4 side). Typically, the number of downstream transmission destinations is plural. The packet transmitter 50 also retransmits a data packet DAT, which will be described later.
  • the retransmission management unit 60 performs retransmission control related to the data packet DAT transmitted to the downstream transmission destination. Specifically, the retransmission management unit 60 has (1) a buffer function, (2) an ACK termination function, and (3) a retransmission timeout detection function.
  • the retransmission management unit 60 temporarily stores the data packet DAT transmitted to the downstream transmission destination in a buffer in preparation for the retransmission process.
  • the downstream transmission destination returns an ACK in response to the data packet DAT.
  • the retransmission management unit 60 terminates and discards the received ACK.
  • the retransmission management unit 60 deletes the data packet DAT stored in the buffer.
  • the retransmission management unit 60 determines that a retransmission timeout (out) has occurred. In this case, the retransmission management unit 60 reads the data packet DAT stored in the buffer, and outputs the data packet DAT to the packet transmission unit 50 as the retransmission data packet DAT.
  • the packet transmission unit 50 retransmits the retransmission data packet DAT to a designated downstream destination as in the case of the normal data packet DAT.
  • the packet transmission unit 50 may retransmit the retransmission data packet DAT using the same queue as that for the normal data packet DAT. That is, the packet transmission unit 50 may use the same queue for both transmission of the data packet DAT and retransmission of the retransmission data packet DAT. In this case, the necessary memory is reduced, which is preferable.
  • ACK is used between the transmission server 3 and the multicast router 2, between adjacent multicast routers 2, and between the multicast router 2 and the receiving terminal 4. Confirmed delivery is performed. Therefore, not only the reliability is improved from the viewpoint of data delivery, but also the explosion of the ACK response is prevented. As a result, an increase in processing load on the transmission server 3 is also prevented.
  • the multicast router 2 includes an arithmetic processing device (eg, CPU) and a storage device (eg, RAM, HDD).
  • the multicast router function described above is realized by the arithmetic processing device executing a program stored in the storage device.
  • the program may be recorded on a computer-readable recording medium.
  • FIG. 4 is a conceptual diagram showing the data packet DAT.
  • the data packet DAT includes a packet identification number 81 and a packet 82.
  • the packet 82 includes a header 83 and a payload 84.
  • the packet identification number 81 is a number for identifying the packet 82. An arbitrary number may be given as the packet identification number 81, or a number calculated from information included in the packet 82 (for example, a hash value calculated from a field value in the header 83) may be used. Good.
  • the ACK has the same format as the data packet DAT.
  • FIG. 5 is a conceptual diagram showing the header information 85.
  • the header information 85 is a subset of the data packet DAT, and includes a packet identification number 81 and a header 83.
  • FIG. 6 is a conceptual diagram showing DAT reception information 88 for notifying that the multicast router 2 has received the data packet DAT.
  • the DAT reception information 88 includes a packet identification number 81 and a header 83 of the received data packet DAT.
  • FIG. 7 is a conceptual diagram showing ACK reception information 89 for notifying that the multicast router 2 has received an ACK.
  • the ACK reception information 89 includes a packet identification number 81 and a header 83 of the received ACK.
  • FIG. 8 is a conceptual diagram showing management information 90 used for managing the data packet DAT.
  • the management information 90 includes a packet identification number 81, an output port state 91, a transmission time 92, and an ACK reception state 93.
  • the management information 90 is associated with the data packet DAT on a one-to-one basis through the packet identification number 81.
  • FIG. 9 shows an example of the output port state 91 and the ACK reception state 93.
  • the output port state 91 indicates an output port (that is, a transmission destination) to which the data packet DAT is to be output.
  • a plurality of output ports (2, 3, N) in the state “1” output the data packet DAT.
  • the ACK reception state 93 indicates the reception status of ACK for the data packet DAT from the transmission destination.
  • the state “1” means that ACK has not been received, and the state is changed from “1” to “0” in response to ACK reception.
  • FIG. 10 is a conceptual diagram showing the multicast information 99.
  • the multicast information 99 is a subset of the management information 90 and includes a packet identification number 81 and an output port state 91.
  • FIG. 11 is a block diagram showing a configuration of multicast router 2 in the present embodiment.
  • the multicast router 2 includes a switch unit 6 and a data processing unit 10.
  • the switch unit 6 receives the data packet DAT or ACK from the external network through the ports 7-1 to 7-N, and transfers the received data packet DAT or ACK to the data processing unit 10. Further, the switch unit 6 receives the data packet DAT and ACK from the data processing unit 10, and sends the received data packet DAT and ACK to the external network through the ports 7-1 to 7-N.
  • the data processing unit 10 performs various data processing in response to reception of the data packet DAT or ACK.
  • the data processing unit 10 identifies whether the received packet is DAT or ACK.
  • the data processing unit 10 When receiving the data packet DAT, the data processing unit 10 generates an ACK in response to the received data packet DAT, and returns the ACK through the switch unit 6. Further, the data processing unit 10 determines a multicast transmission destination of the received data packet DAT, and transmits a copy of the received data packet DAT to each multicast transmission destination through the switch unit 6. Further, the data processing unit 10 temporarily stores the received data packet DAT in a buffer for retransmission control. On the other hand, when receiving the ACK, the data processing unit 10 terminates and discards the received ACK.
  • the data processing unit 10 deletes the received data packet DAT stored in the buffer.
  • the data processing unit 10 detects a retransmission timeout for the data packet DAT stored in the buffer, the data processing unit 10 executes a retransmission process for the data packet DAT.
  • FIG. 12 is a block diagram showing a configuration of the data processing unit 10 in the present embodiment.
  • the data processing unit 10 includes a route management unit 20, a retransmission control reception unit 30, and a retransmission control transmission unit 40.
  • the route management unit 20 holds and manages information indicating the configuration of the multicast tree. Then, the route management unit 20 determines the output destination (output port state 91) of the received data packet DAT based on the multicast tree. More specifically, the path management unit 20 receives the header information 85 (see FIG. 5) of the received data packet DAT from the retransmission control reception unit 30. Then, the path management unit 20 identifies the multicast tree based on the header information 85 and determines the output destination (output port state 91) of the received data packet DAT. Further, the route management unit 20 creates multicast information 99 (see FIG. 10), and outputs the multicast information 99 to the retransmission control transmission unit 40.
  • the retransmission control receiving unit 30 receives the data packet DAT and ACK from the switch unit 6. First, the retransmission control receiver 30 identifies whether the received packet is DAT or ACK. When receiving the data packet DAT, the retransmission control receiving unit 30 extracts the header information 85 (see FIG. 5) from the received data packet DAT, and notifies the route management unit 20 of the header information 85. Further, the retransmission control receiving unit 30 sends the received data packet DAT and the DAT reception information 88 (see FIG. 6) to the retransmission control transmitting unit 40. On the other hand, when ACK is received, the retransmission control receiving unit 30 sends ACK reception information 89 (see FIG. 7) to the retransmission control transmitting unit 40. Further, the retransmission control receiving unit 30 terminates / discards the received ACK.
  • the retransmission control transmission unit 40 When receiving the DAT reception information 88 (see FIG. 6), the retransmission control transmission unit 40 generates an ACK based on the packet identification number 81 and the header 83 and sends back the ACK through the switch unit 6. Further, upon receiving the data packet DAT and the multicast information 99 (see FIG. 10), the retransmission control transmission unit 40 creates management information 90 (see FIGS. 8 and 9) regarding the data packet DAT. Then, the retransmission control transmission unit 40 refers to the management information 90 and performs duplication / transmission processing of the data packet DAT. In addition, when receiving the ACK reception information 89 (see FIG. 7), the retransmission control transmission unit 40 updates the ACK reception state 93 (see FIGS. 8 and 9) in the management information 90. Then, the retransmission control transmission unit 40 executes a retransmission control process based on the management information 90.
  • FIG. 13 is a block diagram showing a configuration of retransmission control receiving unit 30 in the present embodiment.
  • the retransmission control reception unit 30 includes a packet identification unit 31 and a header extraction unit 35.
  • the packet identification unit 31 identifies whether the received packet received from the switch unit 6 is DAT or ACK. In the case of a data packet DAT, the packet identification unit 31 transfers the received data packet DAT to the header extraction unit 35 and sends DAT reception information 88 (see FIG. 6) to the retransmission control transmission unit 40. On the other hand, in the case of ACK, the packet identification unit 31 discards the received ACK and sends ACK reception information 89 (see FIG. 7) to the retransmission control transmission unit 40.
  • the header extraction unit 35 extracts header information 85 (see FIG. 5) from the received data packet DAT, and notifies the route management unit 20 of the header information 85. In addition, the header extraction unit 35 sends the received data packet DAT to the retransmission control transmission unit 40. At this time, in order to ensure uniqueness, the header extraction unit 35 assigns the same packet identification number 81 to the header information 85 and the received data packet DAT.
  • FIG. 14 is a block diagram showing a configuration of retransmission control transmission section 40 in the present embodiment.
  • the retransmission control transmission unit 40 includes an ACK generation unit 41, a multiplexing unit 42, a packet transmission unit 50, and a retransmission management unit 60.
  • the ACK generation unit 41 receives the DAT reception information 88 (see FIG. 6) from the retransmission control reception unit 30. Based on the packet identification number 81 and the header 83 of the DAT reception information 88, the ACK generation unit 41 generates an ACK and outputs the ACK to the multiplexing unit.
  • the multiplexing unit 42 performs output arbitration between the ACK from the ACK generation unit 41 and the data packet DAT from the packet transmission unit 50. Then, the multiplexing unit 42 outputs the data packet DAT and ACK to the switch unit 6.
  • the packet transmission unit 50 receives the multicast information 99 (see FIG. 10) from the route management unit 20 and receives the data packet DAT from the retransmission control reception unit 30.
  • the packet transmitting unit 50 creates and manages management information 90 (see FIGS. 8 and 9) regarding the data packet DAT.
  • the retransmission control transmission unit 40 refers to the management information 90 and performs duplication / transmission processing of the data packet DAT.
  • the packet transmission unit 50 includes a management information FIFO 51, a transmission data FIFO 52, a transmission control unit 53, and a packet duplication unit 54.
  • Management information FIFO 51 is a FIFO for storing management information 90 (see FIGS. 8 and 9).
  • the transmission data FIFO 52 is a FIFO for storing the data packet DAT and the retransmission data packet DAT. Note that the “queue” in FIG. 3 already corresponds to the management information FIFO 51 and the transmission data FIFO 52.
  • the transmission control unit 53 reads the management information 90 from the head of the management information FIFO 51 and transfers the management information 90 to the packet duplication unit 54. Further, the transmission control unit 53 records the current time at the transmission time 92 of the read management information 90 and sends the management information 90 to the retransmission management unit 60. Further, the transmission control unit 53 reads the corresponding data packet DAT from the transmission data FIFO 52 and sends the data packet DAT to the packet duplication unit 54. In addition, the transmission control unit 53 sends the read data packet DAT to the retransmission management unit 60.
  • the packet replication unit 54 receives the management information 90 and the data packet DAT.
  • the packet replication unit 54 refers to the output port state 91 of the management information 90 and replicates the data packet DAT. Then, the packet duplicating unit 54 outputs the data packet DAT to which the routing information to each output port is added to the multiplexing unit 42.
  • the retransmission management unit 60 receives the data packet DAT and the management information 90 from the packet transmission unit 50, and temporarily stores them. Then, retransmission management section 60 executes retransmission control processing according to the reception status of ACK. More specifically, the retransmission management unit 60 includes a management information buffer 61, a retransmission data buffer 62, a retransmission management control unit 63, and a timer 64.
  • Management information buffer 61 is a buffer for temporarily storing management information 90 (see FIGS. 8 and 9).
  • the transmission time 92 in the management information 90 is set to the time transferred from the management information FIFO 51 to the management information buffer 61.
  • the retransmission data buffer 62 is a buffer for temporarily storing the data packet DAT.
  • the retransmission management control unit 63 receives the ACK reception information 89 (see FIG. 7) from the retransmission control reception unit 30, and updates the management information 90 stored in the management information buffer 61. Specifically, the retransmission management control unit 63 searches the management information buffer 61 for management information 90 having the same packet identification number 81 in the ACK reception information 89. Then, the retransmission management control unit 63 updates the ACK reception state 93 (see FIG. 9) in the corresponding management information 90 based on the header 83 and the like. When the ACK reception state 93 indicates that ACK has been received from all the transmission destinations, the retransmission management control unit 63 transmits the data packet DAT corresponding to the management information 90 to the management information buffer 61, respectively. And deleted from the retransmission data buffer 62.
  • the timer 64 notifies the retransmission management control unit 63 of time information.
  • the retransmission management control unit 63 detects the occurrence of a retransmission timeout by referring to the time information notified from the timer 64 and the transmission time 92 in the management information 90.
  • the retransmission management control unit 63 updates the output port state 91 in the corresponding management information 90 according to the current ACK reception status. Specifically, the retransmission management control unit 63 overwrites the output port state 91 in the corresponding management information 90 with the ACK reception state 93 (see FIG. 9).
  • the retransmission management control unit 63 transfers the management information 90 from the management information buffer 61 to the management information FIFO 51 of the packet transmission unit 50, and sends the corresponding data packet DAT (retransmission data packet DAT) from the retransmission data buffer 62.
  • the data is transferred to the transmission data FIFO 52 of the packet transmission unit 50.
  • the retransmission data packet DAT is retransmitted from the packet transmission unit 50 toward the transmission destination where ACK has not been received.
  • FIG. 15 is a block diagram showing a configuration of transmission server 3 in the present embodiment.
  • symbol is attached
  • the transmission server 3 includes an upper application 25 in addition to the route management unit 20, the retransmission control reception unit 30, and the retransmission control transmission unit 40.
  • the host application 25 is an application that holds data to be transmitted to the receiving terminal 4, and sends transmission data to the retransmission control receiving unit 30. That is, the retransmission control receiving unit 30 is supplied with data from the upper application 25 instead of from the outside.
  • the functions of the route management unit 20, the retransmission control receiving unit 30, and the retransmission control transmitting unit 40 are basically the same as the data processing unit 10 of the multicast router 2. However, since no data packet DAT is received from the adjacent multicast router 2, no ACK is returned. In the case of the transmission server 3, there is only one set of connection interface with the external network, and the retransmission control transmission unit 40 operates with the number of output ports set to 1. Therefore, the switch unit 6 is not necessary.
  • FIG. 16 is a block diagram showing a configuration of receiving terminal 4 in the present embodiment.
  • symbol is attached
  • the receiving terminal 4 includes an upper application 26, a packet identification unit 31, and an ACK generation unit 41.
  • the packet identification unit 31 receives the data packet DAT from the adjacent upstream multicast router 2.
  • the packet identification unit 31 transfers the received data packet DAT to the upper application 26. Further, the packet identification unit 31 outputs the DAT reception information 88 (see FIG. 6) to the ACK generation unit 41.
  • the ACK generation unit 41 receives the DAT reception information 88 (see FIG. 6) from the packet identification unit 31. Based on the packet identification number 81 and the header 83 of the DAT reception information 88, the ACK generation unit 41 generates an ACK and returns the ACK to the adjacent multicast router 2 upstream.
  • FIG. 17 is a flowchart showing an operation at the time of receiving the data packet DAT in the multicast router 2 according to the present embodiment.
  • a data packet DAT is input from the port 7-1 and the data packet DAT is multicast to the ports 7-2, 7-3, 7-N.
  • Step S1 Data packet DAT is input from upstream to port 7-1.
  • the data packet DAT is input to the retransmission control receiving unit 30 of the data processing unit 10.
  • Step S10 In response to the reception of the data packet DAT, “ACK return processing (step S10)” described below is performed.
  • Step S11 The packet identification unit 31 of the retransmission control receiving unit 30 notifies the retransmission control transmitting unit 40 of the DAT reception information 88 in response to the reception of the data packet DAT.
  • Step S12 In response to the DAT reception information 88, the ACK generation unit 41 of the retransmission control transmission unit 40 generates an ACK.
  • Step S13 The ACK generation unit 41 transmits an ACK to the multiplexing unit 42 so as to be output from the port 7-1 connected to the transmission source of the data packet DAT.
  • the multiplexing unit 42 outputs the ACK from the port 7-1 through the switch unit 6.
  • Step S20 On the other hand, in response to reception of the data packet DAT, “DAT transfer processing (step S20)” described below is also performed.
  • Step S21 The header extraction unit 35 of the retransmission control reception unit 30 extracts header information 85 from the data packet DAT and notifies the route management unit 20 of the header information 85.
  • the header extraction unit 35 transmits the data packet DAT to the retransmission control transmission unit 40. At this time, in order to ensure uniqueness, the header extraction unit 35 assigns the same packet identification number 81 to the header information 85 and the data packet DAT.
  • Step S22 The path management unit 20 identifies the multicast tree based on the header information 85 and determines the output destination (output port state 91) of the data packet DAT. Further, the route management unit 20 creates the multicast information 99 and outputs the multicast information 99 to the retransmission control transmission unit 40.
  • Step S23 The packet transmitter 50 of the retransmission control transmitter 40 accommodates the data packet DAT in the transmission data FIFO 52.
  • Step S24 Further, the packet transmission unit 50 creates management information 90 (see FIGS. 8 and 9) corresponding to the data packet DAT based on the multicast information 99 received from the route management unit 20. Specifically, the packet identification information 81 and the output port state 91 are the same as those of the multicast information 99. The sending time 92 is set to zero. The ACK reception state 93 is set to be the same as the output port state 91. The packet transmission unit 50 stores the created management information 90 in the management information FIFO 51.
  • Step S25 The transmission control unit 53 reads the management information 90 from the head of the management information FIFO 51 and transfers the management information 90 to the packet duplication unit 54. Also, the transmission control unit 53 records the current time at the transmission time 92 of the read management information 90 and stores the management information 90 in the management information buffer 61 in the retransmission management unit 60.
  • Step S26 Further, the transmission control unit 53 reads the data packet DAT having the same packet identification information 81 as that of the management information 90 from the transmission data FIFO 52, and sends the data packet DAT to the packet duplication unit 54. Further, the transmission control unit 53 stores the read data packet DAT in the retransmission data buffer 62 in the retransmission management unit 60.
  • Step S27 The packet replication unit 54 receives the management information 90 and the data packet DAT.
  • the packet replication unit 54 refers to the output port state 91 of the management information 90 and replicates the data packet DAT. Then, the packet duplicating unit 54 outputs the data packet DAT to which the routing information to each output port is added to the multiplexing unit 42. In this example, three data packets DAT are duplicated, and the same data packet DAT is transmitted from each of the ports 7-2, 7-3, 7-N.
  • FIG. 18 is a flowchart showing an operation at the time of ACK reception in the multicast router 2 according to the present embodiment. As an example, consider a case where ACK is input from a port 7-3 connected downstream.
  • Step S31 ACK is input from downstream to port 7-3.
  • the ACK is input to the retransmission control receiving unit 30 of the data processing unit 10.
  • Step S32 The packet identifying unit 31 of the retransmission control receiving unit 30 terminates / discards the received ACK.
  • Step S33 In addition, the packet identification unit 31 notifies the retransmission control transmission unit 40 of the ACK reception information 89 in response to the ACK reception.
  • Step S34 The retransmission management control unit 63 of the retransmission management unit 60 of the retransmission control transmission unit 40 receives the ACK reception information 89.
  • the retransmission management control unit 63 searches the management information buffer 61 for management information 90 having the same packet identification number 81 in the ACK reception information 89.
  • Step S35 The retransmission management control unit 63 updates the ACK reception state 93 in the corresponding management information 90.
  • Steps S36 and S37 When ACKs are received from all transmission destinations (step S36; Yes), all “states” in the ACK reception state 93 are “0”. In this case, the retransmission management control unit 63 deletes the data packet DAT corresponding to the management information 90 from the management information buffer 61 and the retransmission data buffer 62, respectively.
  • the retransmission management control unit 63 discards the ACK reception information 89.
  • FIG. 19 is a flowchart showing retransmission timeout processing in the multicast router 2 according to the present embodiment.
  • Step S41 The timer 64 notifies the retransmission management control unit 63 of time information.
  • the retransmission management control unit 63 detects the occurrence of a retransmission timeout by referring to the time information notified from the timer 64 and the transmission time 92 in the management information 90.
  • Step S42 If a retransmission timeout has occurred (step S41; Yes), the retransmission management control unit 63 updates the output port state 91 in the corresponding management information 90 according to the current ACK reception status. Specifically, the retransmission management control unit 63 overwrites the output port state 91 in the corresponding management information 90 with the ACK reception state 93 (see FIG. 9).
  • Step S43 The retransmission management control unit 63 transfers the updated management information 90 from the management information buffer 61 to the management information FIFO 51 of the packet transmission unit 50.
  • Step S44 The retransmission management control unit 63 transfers the data packet DAT (retransmission data packet DAT) having the same packet management number 81 as that of the management information 90 from the retransmission data buffer 62 to the transmission data FIFO 52 of the packet transmission unit 50. .
  • Step S45 As a result, the retransmission data packet DAT is retransmitted from the packet transmission unit 50 toward the transmission destination where ACK has not been received.
  • ACKs are transmitted between the transmission server 3 and the multicast router 2, between adjacent multicast routers 2, and between the multicast router 2 and the receiving terminal 4. Confirmed delivery is performed. Therefore, not only the reliability is improved from the viewpoint of data delivery, but also the explosion of the ACK response is prevented. As a result, an increase in processing load on the transmission server 3 is also prevented. Further, high scalability is realized for the receiving terminal 4.
  • the management information FIFO 51, the transmission data FIFO 52, the management information buffer 61, and the retransmission data buffer 62 in the retransmission control transmission unit 40 may be one type each. Therefore, the storage memory for the data packet DAT and the management information 90 is reduced, which is preferable.
  • a multicast router disposed between a transmission device and a reception device in a multicast network system, When a data packet is received from the transmission source on the transmission device side, a response generation unit that returns an acknowledgment to the transmission source; A packet transmission unit that replicates the received data packet and transmits it to the transmission destination on the receiving device side; A retransmission management unit that performs retransmission control on the data packet transmitted to the transmission destination, The retransmission management unit stores the data packet transmitted to the transmission destination in a buffer, When an acknowledgment for the data packet is received from the destination, the retransmission management unit discards the received acknowledgment, When an acknowledgment for the data packet is received from all of the transmission destinations, the retransmission management unit deletes the data packet stored in the buffer, When a retransmission timeout occurs with respect to the data packet stored in the buffer, the retransmission management unit outputs the data packet as a retransmission data packet to the packet transmission unit, and the packet transmission unit transmits the retransmission data
  • the multicast router according to attachment 2 wherein The same queue of the packet transmitter is A transmission data queue in which the data packets are stored; A management information queue in which management information about the data packet is stored; The management information indicates an identification number of the data packet and an output port from which the data packet is output.
  • the packet transmission unit refers to the management information stored in the management information queue, and transmits the data packet stored in the transmission data queue. Multicast router.
  • the retransmission management unit stores the management information together with the data packet in the buffer, The management information further indicates a transmission time of the data packet, The retransmission management unit detects occurrence of the retransmission timeout by referring to the transmission time and a timer. Multicast router.
  • a transmitting device A plurality of receiving devices; A multicast router disposed on a multicast network between the transmitting device and the plurality of receiving devices, The multicast router When a data packet is received from the transmission source on the transmission device side, a response generation unit that returns an acknowledgment to the transmission source; A packet transmission unit that replicates the received data packet and transmits it to the transmission destination on the receiving device side; A retransmission management unit that performs retransmission control on the data packet transmitted to the transmission destination, The retransmission management unit stores the data packet transmitted to the transmission destination in a buffer, When an acknowledgment for the data packet is received from the destination, the retransmission management unit discards the received acknowledgment, When an acknowledgment for the data packet is received from all of the transmission destinations, the retransmission management unit deletes the data packet stored in the buffer, When a retransmission timeout occurs with respect to the data packet stored in the buffer, the retransmission management unit outputs the data packet as a retransmission data packet to
  • a program for realizing a multicast router function in a multicast router arranged between a transmission device and a reception device in a multicast network system The multicast router function is When a data packet is received from a transmission source on the transmission device side, a response generation function for returning an acknowledgment to the transmission source; A packet transmission function for copying the received data packet and transmitting it to a transmission destination on the receiving device side; A retransmission management function for performing retransmission control on the data packet transmitted to the transmission destination, The retransmission management function stores the data packet transmitted to the transmission destination in a buffer, When an acknowledgment for the data packet is received from the transmission destination, the retransmission management function discards the received acknowledgment.
  • the retransmission management function When an acknowledgment for the data packet is received from all of the destinations, the retransmission management function deletes the data packet stored in the buffer, When a retransmission timeout occurs with respect to the data packet stored in the buffer, the retransmission management function outputs the data packet as a retransmission data packet to the packet transmission function, and the packet transmission function transmits the retransmission data packet A program for retransmitting a message to the destination.

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Data Exchanges In Wide-Area Networks (AREA)

Abstract

L'invention concerne un routeur de multidiffusion, placé entre un dispositif émetteur et un dispositif récepteur dans un réseau de multidiffusion. Le routeur de multidiffusion comprend une unité de génération de réponse, une unité de transmission de paquets et une unité de gestion de retransmission. Dès réception d'un paquet de données de la part du dispositif émetteur, l'unité de génération de réponse renvoie un accusé de réception à la source de transmission. L'unité de transmission de paquets duplique le paquet de données reçu et le transmet au dispositif récepteur. L'unité de gestion de retransmission mémorise dans un tampon le paquet de données transmis vers la destination de transmission. En cas de réception d'un accusé de réception depuis la destination de transmission, l'unité de gestion de retransmission ignore l'accusé de réception reçu. En cas de réception d'un accusé de réception depuis toutes les destinations de transmission, l'unité de gestion de retransmission supprime le paquet de données mémorisé dans le tampon. En cas de fin de temporisation de retransmission pour le paquet de données mémorisé dans le tampon, l'unité de gestion de retransmission envoie un paquet de données de retransmission à l'unité de transmission de paquets qui le retransmet.
PCT/JP2011/070054 2010-09-27 2011-09-02 Routeur de multidiffusion et système réseau de multidiffusion WO2012043142A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2010-215565 2010-09-27
JP2010215565 2010-09-27

Publications (1)

Publication Number Publication Date
WO2012043142A1 true WO2012043142A1 (fr) 2012-04-05

Family

ID=45892615

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2011/070054 WO2012043142A1 (fr) 2010-09-27 2011-09-02 Routeur de multidiffusion et système réseau de multidiffusion

Country Status (1)

Country Link
WO (1) WO2012043142A1 (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2022127306A1 (fr) * 2020-12-18 2022-06-23 深圳市微网力合信息技术有限公司 Procédé de traitement de perte de paquet de données, système et terminal

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH05276189A (ja) * 1992-03-27 1993-10-22 Hitachi Ltd 同報通信装置
JPH07273798A (ja) * 1994-03-22 1995-10-20 Internatl Business Mach Corp <Ibm> マルチキャスト通信のための方法、システム及びネットワーク
JP2008078843A (ja) * 2006-09-20 2008-04-03 Konami Digital Entertainment:Kk 無線ネットワークシステム、ゲーム機、および、プログラム

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH05276189A (ja) * 1992-03-27 1993-10-22 Hitachi Ltd 同報通信装置
JPH07273798A (ja) * 1994-03-22 1995-10-20 Internatl Business Mach Corp <Ibm> マルチキャスト通信のための方法、システム及びネットワーク
JP2008078843A (ja) * 2006-09-20 2008-04-03 Konami Digital Entertainment:Kk 無線ネットワークシステム、ゲーム機、および、プログラム

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2022127306A1 (fr) * 2020-12-18 2022-06-23 深圳市微网力合信息技术有限公司 Procédé de traitement de perte de paquet de données, système et terminal

Similar Documents

Publication Publication Date Title
TW419919B (en) TCP resegmentation
US7876751B2 (en) Reliable link layer packet retry
CN104025525B (zh) 用于发送分组的方法和设备以及交换机装置
JP4153502B2 (ja) 通信装置及び論理リンク異常検出方法
JP4851585B2 (ja) クライアント装置と複数のサーバ装置からなるシステムの通信方法、その通信プログラム、クライアント装置及びサーバ装置
JP4857261B2 (ja) コンピュータ・ネットワークを通しての障害回復力を有するデータ転送方法および装置
US9577791B2 (en) Notification by network element of packet drops
US11863370B2 (en) High availability using multiple network elements
EP2978171B1 (fr) Procédé de communication, dispositif de communication, et programme de communication
US20020054570A1 (en) Data communication system, data communication method, and recording medium with data communication program recorded thereon
US20090006641A1 (en) Reliable multicast transport protocol
US6760766B1 (en) Data transmission method and device
US7496038B2 (en) Method for faster detection and retransmission of lost TCP segments
US9292370B2 (en) Relay node, control method of relay node and network system
JP2009296084A (ja) マルチパス通信システム
JP5857135B2 (ja) 複数の受信機にメッセージを伝送する装置および方法
US9210067B1 (en) Method and apparatus for exchanging routing information
KR20050077760A (ko) 인터넷 프로토콜 패킷의 다수의 사본 전달 방법 및 장치
JP5672836B2 (ja) 通信装置、通信方法、および通信プログラム
JP6547973B2 (ja) ストリーム制御の方法およびシステム
WO2012043142A1 (fr) Routeur de multidiffusion et système réseau de multidiffusion
JP5062121B2 (ja) マルチキャスト通信におけるパケット再送制御方法及び装置
JP4626646B2 (ja) パケット通信装置及びパケット通信方法及びパケット通信プログラム
KR20140069274A (ko) 운영 체제의 고장 검출 방법
KR101405533B1 (ko) 고가용성 멀티캐스트 전송 기반의 메시지 전송 시스템

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 11828703

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 11828703

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: JP