Method and equipment for realizing fair forwarding of multicast data message

Abstract

The invention provides a method and equipment for realizing fair forwarding of a multicast data message. The method applied to the multicast router comprises the following steps: generating a multicast routing table entry for a multicast group; setting an equivalent multipath group of the multicast group; recording an index of an equivalent multi-path table entry of the equivalent multi-path group in a multicast routing table entry; generating a copy chain table corresponding to each outbound interface of the multicast group, recording each outbound interface in the copy chain table corresponding to each other outbound interface, wherein each outbound interface is at different positions of different copy chain tables; recording the chain table index of each copy chain table in an equivalent multipath table item; and copying and forwarding each multicast data message of the multicast group through a copy chain table.

Description

Technical Field

[0001] This application relates to communication technologies, and more specifically, to a method and device for implementing fair forwarding of multicast data packets. Background Art

[0002] IGMP (Internet Group Management Protocol) is used to establish and maintain multicast group membership relationships between hosts and their directly adjacent multicast routers. As the DR (Designated Router) on the receiver side, the multicast router receives requests from the multicast router based on the IGMP Membership Report from the host and generates (*, G) or (S, G) multicast routing table entries.

[0003] PIM (Protocol Independent Multicast) runs between multicast routers in a PIM domain. Taking the PIM-SM domain as an example, the DR on the receiver side sends a PIM Join message to the RP (Rendezvous Point) of the multicast group, and the multicast routers passing through from the DR on the receiver side to the RP form an RPT (Shared Tree) and generate (*, G) table entries. The multicast data packets of the multicast source are encapsulated as PIM (Register) messages and sent to the RP. After the RP receives the first multicast data packet, it sends a (S, G) join PIM Join message in the direction of the multicast source. The multicast routers forwarding the PIM Join message to the multicast source create (S, G) table entries and establish an SPT branch. After the DR on the receiver side receives the first multicast data packet of the multicast group, it generates (S, G) multicast routing table entries, initiates an SPT switch, and sends a PIM Join message of (S, G) in the direction of the multicast source. The multicast routers forwarding the PIM Join message along the way generate (S, G) table entries, and then send a PIM Prune message through the RP to switch the RPT to the SPT. In this way, the multicast routers of this SPT tree and the DR on the receiver side generate (S, G) multicast routing table entries, and can forward multicast data packets by multicast replication chains. However, in the multicast replication linked list of the (S, G) multicast routing table entries, the delay of the multicast data packets sent from the three-layer interface of the head node is small, while the delay of the multicast data packets sent from the nodes in the later positions of the replication linked list, especially the three-layer interface of the tail node, is large. There is also a problem of different delays in the multicast data packets sent from the three-layer interfaces of the multicast replication chains of the multicast routing table entries in the PIM-DM domain. Summary of the Invention

[0004] The purpose of this application is to provide a method and device for realizing fair forwarding of multicast data packets, so that the transmission delays of multicast data packets on different outgoing interfaces of each multicast group on a multicast router are fair.

[0005] To achieve the above purpose, this application provides a method for realizing fair forwarding of multicast data packets. The method includes generating a multicast routing table entry for a multicast group; setting an equivalent multi-path group for the multicast group; recording the index of the equivalent multi-path table entry of the equivalent multi-path group in the multicast routing table entry; generating a replication linked list corresponding to each outgoing interface of the multicast group, recording each outgoing interface in the replication linked lists corresponding to other outgoing interfaces, and each outgoing interface is in different positions in different replication linked lists; recording the linked list index of each replication linked list in the equivalent multi-path table entry; and replicating and forwarding each multicast data packet of the multicast group through one replication linked list.

[0006] To achieve the above purpose, this application also provides a device for realizing fair forwarding of multicast data packets. The device includes a processor and a memory; the memory is used to store processor-executable instructions; wherein, the processor is configured to execute the following operations by running the processor-executable instructions in the memory: generating a multicast routing table entry for a multicast group; setting an equivalent multi-path group for the multicast group; recording the index of the equivalent multi-path table entry of the equivalent multi-path group in the multicast routing table entry; generating a replication linked list corresponding to each outgoing interface of the multicast group, recording each outgoing interface in the replication linked lists corresponding to other outgoing interfaces, and each outgoing interface is in different positions in different replication linked lists; recording the linked list index of each replication linked list in the equivalent multi-path table entry; and replicating and forwarding each multicast data packet of the multicast group through one replication linked list.

[0007] The beneficial effect of this application is that the multicast router replicates and forwards each multicast data packet of the multicast group through the same but differently sorted outgoing interfaces of each replication linked list, avoiding replicating and forwarding multicast data packets through the outgoing interfaces of the multicast group with a fixed sorting, and avoiding that a certain outgoing interface of each multicast group on the multicast router always preferentially sends the replicated multicast data packets or always sends the replicated multicast data packets at the end. In this way, the transmission delays of the multicast data packets on each outgoing interface of the multicast group on the multicast router are balanced, making the transmission delays of the outgoing interfaces of the multicast group on the multicast router fair. Description of the Drawings

[0008] Figure 1 It is a flowchart of an embodiment of a method for realizing fair forwarding of multicast data packets provided by this application;

[0009] Figures 2A-2D It is a schematic diagram of generating a fair multicast routing table entry provided by this application;

[0010] Figure 3This application provides a schematic diagram for deleting the outgoing interface leaving the multicast group from the fair multicast routing entry;

[0011] Figure 4 This application provides a schematic diagram of a device for realizing fair forwarding of multicast data packets. Detailed implementation

[0012] Multiple examples shown in multiple figures will be described in detail. In the following detailed description, multiple specific details are used to provide a comprehensive understanding of this application. Known methods, steps, components, and circuits are not described in detail in the examples to avoid making these examples difficult to understand.

[0013] Among the terms used, the term "including" means including but not limited to; the term "containing" means including but not limited to; the terms "above", "within", and "below" include the number itself; the terms "greater than" and "less than" do not include the number itself. The term "based on" means at least based on a part of it.

[0014] Figure 1 The following shows a flowchart of a method embodiment for realizing fair forwarding of multicast data packets; this method includes the following steps:

[0015] Step 101, generate a multicast routing entry for the multicast group;

[0016] Step 102, set the equal-cost multipath group of the multicast group;

[0017] Step 103, record the index of the equal-cost multipath entry of the equal-cost multipath group in the multicast routing entry;

[0018] Step 104, generate a replication linked list corresponding to each outgoing interface of the multicast group, record each outgoing interface in the replication linked lists corresponding to other each outgoing interface, and each outgoing interface is in different positions in different replication linked lists;

[0019] Step 105, record the linked list index of each replication linked list in the equal-cost multipath entry;

[0020] Step 106, copy and forward each multicast data packet of the multicast group through a replication linked list.

[0021] Figure 1The beneficial effects of the embodiments are as follows: The multicast router replicates and forwards the multicast data packets of the multicast group through the outgoing interfaces of each replication linked list with the same but different sorting, avoiding replicating and forwarding the multicast data packets through the outgoing interfaces of the multicast group with a fixed sorting, and avoiding that a certain outgoing interface of each multicast group on the multicast router always preferentially sends the replicated multicast data packets or always sends the replicated multicast data packets last. In this way, the transmission delay of the multicast data packets of each outgoing interface of the multicast group on the multicast router is balanced, making the transmission delays of the outgoing interfaces of the multicast group on the multicast router fair.

[0022] Figures 2A-2D This is a schematic diagram of generating a fair multicast routing table entry provided by this application. Figures 2A-2D The shown embodiments can be used in multicast routing devices, including the DR on the receiver side, RP, multicast source server, and other multicast routing devices within the PIM domain.

[0023] This application does not improve the way the multicast routing device is triggered to generate a multicast routing table entry and identify the outgoing interfaces of the multicast group; this application improves the generation, lookup, and forwarding of the Outgoing Interface List (OIL) in the multicast routing table, making the transmission delays of the multicast data packets sent by different outgoing interfaces fair during the process of each multicast router continuously forwarding the multicast data packets of the multicast group.

[0024] Figure 2A In [the figure], the multicast router adds the first outgoing interface (lif03x01, port a) for the multicast group with the multicast source IP address S1 and the multicast group IP address G1. In this application, the outgoing interface includes the three-layer interface lif03x01 and the physical port porta of this three-layer interface. In this application, the outgoing interface is the VLAN interface where the DR on the receiver side receives the IGMP packet; or it is the routing interface where other multicast routers receive the PIM Join packet.

[0025] The multicast routing device generates a multicast routing table entry 201 for the multicast group, sets the equal-cost multipath group of the multicast group; records the index of the equal-cost multipath table entry 202 of the equal-cost multipath group in the multicast routing table entry 201; generates a first replication linked list 203 for the first outgoing interface lif03x01 of the multicast group, and records the first outgoing interface (lif03x01, port a) in the first replication linked list; records the linked list index of the first replication linked list 203 in the equal-cost multipath table entry 202.

[0026] Figure 2BIn it, the multicast group joins by adding a second egress interface (lif03x02, port b) to the multicast router, and the multicast routing device adds the second egress interface (lif03x02, port b) of the multicast group to the end of the first replication linked list 203.

[0027] The multicast router generates a corresponding subsequent replication linked list 204 for the egress interface (lif03x02, port b), adds the second egress interface (lif03x02, port b) to the head of the subsequent replication linked list 204, and then adds the first egress interface (lif03x02, port b).

[0028] The multicast router records the linked list index 204 of the subsequent replication linked list corresponding to the egress interface (lif03x02, port b) in the equal-cost multi-path entry 202.

[0029] Figure 2C In it, the multicast group joins by adding a third egress interface (lif03x03, port c) to the multicast router, and the multicast routing device adds the third egress interface (lif03x03, port c) of the multicast group to the end of the first replication linked list 203.

[0030] The multicast router searches for the second egress interface in the subsequent replication linked list 204 and adds the third egress interface (lif03x03, port c) to the tail of the found second egress interface.

[0031] The multicast router generates a corresponding subsequent replication linked list 205 for egress interface 3 (lif03x03, port c), adds the third egress interface to the head, and then adds the first egress interface (lif03x01, port a) and the second egress interface (lif03x02, port b) in sequence;

[0032] The multicast router records the linked list index of the subsequent replication linked list 205 corresponding to the egress interface (lif03x02, port b) in the equal-cost multi-path entry 202.

[0033] Figure 2D In it, the multicast group joins by adding a fourth egress interface (lif03x03, port c) to the multicast router, and the multicast routing device adds the fourth egress interface (lif03x04, port d) of the multicast group to the end of the first replication linked list 203.

[0034] The multicast router searches for the third egress interface (lif03x03, port c) in the subsequent replication linked lists 204 and 205, and adds the fourth egress interface (lif03x04, port d) at the tail of the second egress interface (lif03x03, port c) found in the subsequent replication linked lists 204 and 205.

[0035] The multicast router generates a corresponding subsequent replication linked list 206 for the fourth egress interface (lif03x04, port d), adds the fourth egress interface (lif03x04, port d) at the head, and then adds the first egress interface (lif03x01, porta), the second egress interface (lif03x02, port b), and the third egress interface (lif03x03, port c) in sequence.

[0036] The multicast router records the linked list index of the subsequent replication linked list 206 corresponding to the fourth egress interface (lif03x04, port d) in the equal-cost multipath entry 202.

[0037] The multicast router continuously receives multicast data packets from the multicast source. Based on the multicast source IP address IP1 and the multicast group IP address G1 of each multicast data packet, it finds the entry identifier of the multicast routing entry 201, and reads the current forwarding linked list index in the equal-cost multipath entry 202 in the multicast routing table.

[0038] The multicast router obtains the replication linked list index REPL1 from the equal-cost multipath entry 202, and sequentially copies and sends the multicast data packets according to the sorting of the egress interfaces in the replication linked list 203; it increments the ECMP member pointer pointing to REPL1 by 1 to point to REPL2.

[0039] For the next multicast data packet, the multicast router selects the index REPL2 from the equal-cost multipath entry 202, and sequentially copies and sends the multicast data packets according to the sorting of the egress interfaces in the replication linked list 204; it increments the ECMP member pointer pointing to REPL2 by 1 to point to REPL3.

[0040] For the next multicast data packet, the multicast router selects the index REPL3 from the equal-cost multipath entry 202, and sequentially copies and sends the multicast data packets according to the sorting of the egress interfaces in the replication linked list 205; it increments the ECMP member pointer pointing to REPL3 by 1 to point to REPL4.

[0041] For the next multicast data packet, the multicast router selects index REPL4 from the equal-cost multipath entry 202, and sequentially copies and sends the multicast data packet according to the sorting of the outgoing interfaces in the replication linked list 206. Increment the ECMP member pointer pointing to REPL3 by 1, and jump back to REPL1 pointed to by the initial value. Subsequently, the multicast router copies and forwards the multicast data packets of the multicast group through a replication linked list in the above manner.

[0042] Figure 3 This is a schematic diagram provided by this application for deleting the outgoing interface that will leave the multicast group from the fair multicast routing entry;

[0043] When the (lif03x03, port c) of the multicast router receives an IGMP leave message or a PIM Prune message, and the multicast router deletes the outgoing interface (lif03x03, port c) from the multicast routing entry 201.

[0044] The multicast router deletes the corresponding replication linked list 205 of the outgoing interface (lif03x03, port c); deletes the deleted outgoing interface from the replication linked lists corresponding to other outgoing interfaces; deletes the deleted outgoing interface (lif03x03, port c) from the replication linked lists 203, 204, and 206 corresponding to other outgoing interfaces; deletes the index of the replication linked list 205 in the equal-cost multipath entry 202. The multicast router continuously receives multicast data packets from the multicast source. Based on the multicast source IP address IP1 and the multicast group IP address G1 of each multicast data packet, it finds the entry identifier (S1, G1) of the multicast routing entry 201, and reads the index of the equal-cost multipath entry 202 from the multicast routing entry.

[0045] Read the current forwarding linked list index in the multicast routing entry from the equal-cost multipath entry 202.

[0046] The multicast router obtains the replication linked list index REPL1 from the equal-cost multipath entry 202, and sequentially copies and sends the multicast data packet according to the sorting of the outgoing interfaces in the replication linked list 203; increment the ECMP member pointer pointing to REPL1 by 1 to point to REPL2.

[0047] For the next multicast data packet, the multicast router selects index REPL2 from the equal-cost multipath entry 202, and sequentially copies and sends the multicast data packet according to the sorting of the outgoing interfaces in the replication linked list 204. Increment the ECMP member pointer pointing to REPL2 by 1, and when pointing to REPL3, jump to the pointer pointing to REPL4.

[0048] For the next multicast data packet, the multicast router selects index REPL4 from the equal-cost multipath entry 202, copies and sends the multicast data packet in sequence according to the sorting of the outgoing interfaces in the copy linked list 206, increments the ECMP member pointer pointing to REPL3 by 1, and jumps back to REPL1 pointed to by the initial value. Subsequently, the multicast router copies and forwards each multicast data packet of the multicast group through a copy linked list in the above manner.

[0049] Figures 2A-2D 、 Figure 3 In Figure 3 , the multicast router forwards each multicast data packet of the multicast group through a copy linked list of the multicast group by per-packet load sharing; for other implementations that can achieve per-packet load sharing and can also be used in this application, forwarding each multicast data packet of the multicast group through a copy linked list of the multicast group is not limited in this application.

[0050] Figure 4 FIG. is a schematic diagram of a device for implementing fair forwarding of multicast data packets provided by this application. The device 40 can be used for multicast routing devices; the device 40 includes a processor 41, a memory 42, a switching chip 43, and a network interface 44. The switching chip 43 includes at least an entry storage module 431 and a multicast forwarding module 432. The processor 41 executes the multicast protocol module 421 by running processor-executable instructions in the memory 42.

[0051] The multicast protocol module 421 is used to generate multicast routing entries for the multicast group; set the equal-cost multipath group of the multicast group; record the index of the equal-cost multipath entry of the equal-cost multipath group in the multicast routing entry; generate a copy linked list corresponding to each outgoing interface of the multicast group, record each outgoing interface in the copy linked list corresponding to each other outgoing interface, and each outgoing interface is in a different position in different copy linked lists; record the linked list index of each copy linked list in the equal-cost multipath entry;

[0052] The entry storage module 431 is used to record multicast routing entries, equal-cost multipath entries, and each copy linked list;

[0053] The multicast forwarding module 432 receives each multicast data packet of the multicast group through the upstream interface of the multicast group, and copies and forwards each multicast group data packet through a copy linked list.

[0054] The multicast protocol module 421 generates a copy linked list corresponding to each outgoing interface of the multicast group, records each outgoing interface in the copy linked list corresponding to each other outgoing interface, and each outgoing interface is in a different position in different copy linked lists, including: generating a first copy linked list for the first outgoing interface of the multicast group; recording the first outgoing interface in the first copy linked list; recording the linked list index of the first copy linked list in the equal-cost multipath entry.

[0055] The multicast protocol module 421 generates a replication linked list corresponding to each outgoing interface of the multicast group, records each outgoing interface in the replication linked lists corresponding to each other outgoing interface, and each outgoing interface is at different positions in different replication linked lists, including: adding the Nth outgoing interface of the multicast group to the end of the first replication linked list; searching for the (N - 1)th outgoing interface in each subsequent replication linked list other than the first replication linked list, and adding the Nth outgoing interface to the tail of each found (N - 1)th outgoing interface; generating a corresponding subsequent replication linked list for the Nth outgoing interface, adding the Nth outgoing interface to the head, and then adding the first outgoing interface to the (N - 1)th outgoing interface in sequence; recording the linked list index of the subsequent replication linked list corresponding to the Nth outgoing interface in the equal-cost multi-path entry; N is an integer greater than 2.

[0056] The multicast protocol module 421 is further configured to delete the replication linked list corresponding to the deleted outgoing interface of the multicast group; delete the deleted outgoing interface from the replication linked lists corresponding to other outgoing interfaces; and delete the linked list index corresponding to the deleted outgoing interface from the equal-cost multi-path entry.

[0057] The multicast forwarding module 432 replicates and forwards each multicast data packet of the multicast group through a replication linked list, including: based on each multicast data packet of the multicast group, finding a multicast routing entry in the multicast routing table; based on the index of the equal-cost multi-path entry recorded in the multicast routing entry, finding the equal-cost multi-path entry; selecting the current forwarding linked list index in the multicast routing entry; and replicating and sending in sequence based on the sorting of each outgoing interface of the replication linked list pointed to by the selected linked list index.

[0058] In this application, the machine-readable storage medium can be any electronic, magnetic, optical, or other physical storage device used to store or contain information (such as executable instructions, data, etc.). For example, any machine-readable storage medium herein can be any type of random access memory (RAM), volatile memory, non-volatile memory, flash memory, storage drive (such as a hard disk drive), solid-state drive, any type of storage optical disc (such as a CD, DVD, etc.), and similar devices, or a combination thereof. In addition, any machine-readable storage medium described herein can be a non-transitory machine-readable storage medium.

[0059] The above are only the preferred embodiments of this application and are not intended to limit this application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of this application shall be included within the scope of protection of this application.

Claims

1. A method for realizing fair forwarding of multicast data packets, characterized in that: The method comprises, Generate multicast routing table entries for multicast groups; Setting an equal-cost multipath group for the multicast group; Recording the index of the equal-cost multi-path entry of the equal-cost multi-path group in the multicast routing table entry; Generate a replication chain list corresponding to each outbound interface of the multicast group, record each outbound interface in the replication chain list corresponding to each other outbound interface, and each outbound interface is at a different position in different replication chain lists; Recording the linked list index of each of the duplicate linked lists in the equal-cost multi-path table entry; Each multicast data message of the multicast group is copied and forwarded through the copy chain list.

2. The method according to claim 1, characterized in that Generating a replication chain list corresponding to each outbound interface of the multicast group, recording each outbound interface in a replication chain list corresponding to each other outbound interface and each outbound interface in a different position in different replication chain lists, including: Generating a first replication linked list for a first outbound interface of the multicast group; Record the first outgoing interface in the first copy-copy linked list; The linked list index of the first copy linked list is recorded in the equal-cost multi-path table entry.

3. The method according to claim 2, characterized in that Generating a replication chain list corresponding to each outbound interface of the multicast group, recording each outbound interface in a replication chain list corresponding to each other outbound interface and each outbound interface in a different position in different replication chain lists, including: Adding the Nth outbound interface of the multicast group to the end of the first replication linked list; Searching for the N-1th outgoing interface in each subsequent copy chain list other than the first copy chain list, and adding the Nth outgoing interface to the end of each found N-1th outgoing interface; Generate a corresponding subsequent copy linked list for the output interface N, add the Nth output interface at the head, and then add the first output interface to the N-1th output interface in sequence; The linked list index of the subsequent copy linked list corresponding to the output interface N is recorded in the equal-cost multi-path table entry; N is an integer greater than 2.

4. The method according to claim 3, characterized in that The method further comprises: Deleting the copy linked list corresponding to the deleted outbound interface of the multicast group; Deleting the deleted outbound interface from the copy linked lists corresponding to other outbound interfaces; The linked list index corresponding to the deleted outbound interface is deleted from the equal-cost multi-path table entry.

5. The method according to claim 1, characterized in that Sending each multicast data message of the multicast group through one of the replication linked lists comprises: Based on each multicast data message of the multicast group, searching the multicast routing table entry in the multicast routing table; Find the equal-cost multi-path entry based on the index of the equal-cost multi-path entry recorded in the multicast routing entry; Selecting a current forwarding list index in the multicast routing table entry; The output interfaces of the copy list pointed to by the selected list index are copied and sent in sequence.

6. A device for realizing fair forwarding of multicast data packets, characterized in that: The device comprises: A multicast protocol module is used to generate a multicast routing table entry for a multicast group; set an equal-cost multipath group for the multicast group; record the index of the equal-cost multipath table entry of the equal-cost multipath group in the multicast routing table entry; generate a replication chain list corresponding to each output interface of the multicast group, record each output interface in the replication chain list corresponding to each other output interface and each output interface in a different position of different replication chain lists; record the chain list index of each replication chain list in the equal-cost multipath table entry; An entry storage module, used for recording the multicast routing entry, the equal-cost multi-path entry and the replication linked lists; The multicast forwarding module receives each multicast data message of the multicast group through the upstream interface of the multicast group, and copies and forwards each multicast group data message through one of the copy linked lists.

7. The device according to claim 6, characterized in that The multicast protocol module generates a replication chain list corresponding to each outbound interface of the multicast group, and records each of the outbound interfaces in a replication chain list corresponding to each other outbound interface, and each of the outbound interfaces is at a different position in different replication chain lists, including: Generating a first replication linked list for a first outbound interface of the multicast group; Record the first outgoing interface in the first copy-copy linked list; The linked list index of the first copy linked list is recorded in the equal-cost multi-path table entry.

8. The device according to claim 7, characterized in that The multicast protocol module generates a replication chain list corresponding to each outbound interface of the multicast group, and records each outbound interface in a replication chain list corresponding to each other outbound interface and each outbound interface is at a different position in different replication chain lists, including: Adding the Nth outbound interface of the multicast group to the end of the first replication linked list; Searching for the N-1th outgoing interface in each subsequent copy chain list other than the first copy chain list, and adding the Nth outgoing interface to the end of each found N-1th outgoing interface; Generate a corresponding subsequent copy linked list for the output interface N, add the Nth output interface at the head, and then add the first output interface to the N-1th output interface in sequence; The linked list index of the subsequent copy linked list corresponding to the output interface N is recorded in the equal-cost multi-path table entry; N is an integer greater than 2.

9. The device according to claim 8, characterized in that The multicast protocol module is also used to delete the copy linked list corresponding to the deleted outbound interface of the multicast group; delete the deleted outbound interface from the copy linked list corresponding to other outbound interfaces; and delete the linked list index corresponding to the deleted outbound interface from the equal-cost multipath table entry.

10. The device according to claim 6, characterized in that The multicast forwarding module, replicating and forwarding each multicast data message of the multicast group through the replication chain table, comprises searching the multicast routing table entry in the multicast routing table based on each multicast data message of the multicast group; Find the equal-cost multi-path entry based on the index of the equal-cost multi-path entry recorded in the multicast routing entry; Selecting a current forwarding list index in the multicast routing table entry; The output interfaces of the copy list pointed to by the selected list index are copied and sent in sequence.

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