Multicast source discovery method and communication device

Abstract

Embodiments of the present application provide a multicast source discovery method and a communication device. The method can be applied to a last-hop multicast router, and comprises: in response to the local addition of a multicast group, generating a request packet, and flooding the request packet within a multicast domain, wherein the request packet is used for requesting multicast source information corresponding to the multicast group; and receiving a response packet from a first-hop multicast router in the multicast domain, and obtaining the multicast source information on the basis of the response packet, wherein the response packet is a feedback packet generated by the first-hop multicast router for the request packet, and the response packet comprises the multicast source information.

Description

Multicast source discovery method and communication device

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to a Chinese patent application filed with the Patent Office of China on January 12, 2024, with application number 202410052213.2 and invention name “Multicast Source Discovery Method and Communication Device”. The entire contents of the Chinese patent application are incorporated herein by reference. Technical Field

[0003] The present application relates to the field of multicast technology in the field of communications, and in particular to a multicast source discovery method and communication equipment. Background Art

[0004] In the related art, the multicast source discovery mechanism involves the first-hop multicast router connected to the multicast source periodically flooding PIM Flooding Mechanism (PFM) protocol messages carrying multicast source information. These PFM protocol messages are then flooded hop-by-hop throughout the entire Protocol Independent Multicast (PIM) domain. Each router that receives these PFM protocol messages learns the multicast group and corresponding multicast source information. However, this method requires periodic (by default, 60 seconds) flooding of a large number of PFM protocol messages, resulting in high network overhead.

[0005] Summary of the Invention

[0006] The purpose of the embodiments of the present application is to provide a multicast source discovery method and a communication device, which can solve the problem of high network overhead of the multicast source discovery method.

[0007] In a first aspect, an embodiment of the present application provides a multicast source discovery method, which is applied to a last-hop multicast router, comprising: generating a request message in response to a local join of a multicast group, and flooding the request message within a multicast domain; wherein the request message is used to request multicast source information corresponding to the multicast group; receiving a response message from a first-hop multicast router within the multicast domain, and obtaining the multicast source information based on the response message, wherein the response message is a feedback message generated by the first-hop multicast router in response to the request message, and the response message includes the multicast source information.

[0008] In a second aspect, an embodiment of the present application provides a multicast source discovery method, which is applied to a first-hop multicast router, including: receiving a request message, where the request message is generated by the last-hop multicast router in a multicast domain in response to a local join of a multicast group and flooded within the multicast domain, and the request message is used to request multicast source information corresponding to the multicast group; in response to the request message, generating a response message and sending the response message, where the response message includes the multicast source information.

[0009] In a third aspect, an embodiment of the present application provides a communication device, such as a last-hop multicast router, comprising the following modules: a communication module, configured to generate a request message in response to a local join of a multicast group, and flood the request message within the multicast domain; wherein the request message is used to request multicast source information corresponding to the multicast group; and a communication module, further configured to receive a response message from a first-hop multicast router within the multicast domain, and obtain the multicast source information based on the response message, wherein the response message is a feedback message generated by the first-hop multicast router for the request message, and the response message includes the multicast source information.

[0010] In a fourth aspect, an embodiment of the present application provides a communication device, such as a first-hop multicast router, comprising the following modules: a communication module for receiving a request message, wherein the request message is generated by the last-hop multicast router in the multicast domain in response to local joining of the multicast group and is flooded within the multicast domain, and the request message is used to request multicast source information corresponding to the multicast group; the communication module is also used to generate a response message in response to the request message and send the response message, wherein the response message includes the multicast source information.

[0011] In a fifth aspect, an embodiment of the present application provides a communication device, comprising: a memory, a processor, and computer-executable instructions stored on the memory and executable on the processor, wherein the computer-executable instructions, when executed by the processor, implement the steps of the method described in the first aspect or the second aspect.

[0012] In a sixth aspect, an embodiment of the present application provides a computer-readable storage medium, which is used to store computer-executable instructions. When the computer-executable instructions are executed by a processor, the steps of the method described in the first aspect or the second aspect are implemented. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments recorded in this application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0014] FIG1 is a schematic diagram showing a flow chart of a multicast source discovery method according to an embodiment of the present application;

[0015] FIG2 shows a schematic diagram of the structure of a multicast group and multicast source request TLV provided in an embodiment of the present application;

[0016] FIG3 shows a schematic diagram of the structure of a multicast group and multicast source PIM protocol response message provided in an embodiment of the present application;

[0017] FIG4 shows a schematic diagram of the structure of a multicast group and multicast source announcement TLV provided in another embodiment of the present application;

[0018] FIG5 shows a flow chart of a multicast source discovery method provided by another embodiment of the present application;

[0019] FIG6 shows a schematic structural diagram of a last-hop multicast router provided in an embodiment of the present application;

[0020] FIG7 shows a schematic structural diagram of a first-hop multicast router provided in an embodiment of the present application;

[0021] FIG8 is a schematic diagram of the hardware structure of a communication device that executes the multicast source discovery method provided in an embodiment of the present application. DETAILED DESCRIPTION

[0022] In order to enable those skilled in the art to better understand the technical solutions in this application, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of this application.

[0023] To address the high network overhead associated with periodic flooding of PFM protocol messages by a first-hop multicast router, an embodiment of the present application provides a multicast source discovery method in which the last-hop multicast router connected to a receiver requests multicast source information, which is responded to by the first-hop multicast router. This reduces the network overhead associated with periodic flooding of protocol messages and also reduces the storage overhead associated with processing and storing large amounts of information by non-related routers.

[0024] Figure 1 shows a flow chart of a multicast source discovery method provided by an embodiment of the present application. The method can be executed by a last-hop multicast router. In other words, the method can be executed by software or hardware installed on the last-hop multicast router. As shown in Figure 1, the method can include the following steps.

[0025] S102: In response to a local joining of a multicast group, a request message is generated and flooded in the multicast domain; wherein the request message is used to request multicast source information corresponding to the multicast group.

[0026] The embodiments of the present application can be applied in Protocol Independent Multicast-Sparse Mode (PIM-SM). The last-hop multicast router directly connected to the receiver can generate a request message when joining the multicast group locally and flood the request message in the multicast domain.

[0027] In one embodiment, the last-hop multicast router may locally join the multicast group received from the Internet Group Management Protocol (IGMP) or Multicast Listener Discovery (MLD), generate and send a request message.

[0028] In one embodiment, the request message may be a PFM protocol message including a multicast group and a multicast source request (Group Source Request, GSReq) type length value (Type Length Value, TLV).

[0029] In one embodiment, the request message is sent by hop-by-hop flooding according to a first time interval and a first number of transmission times, so that the multicast source information can be learned quickly.

[0030] In one embodiment, the request message carries at least one of the multicast groups, and the request message is used to request the multicast source information corresponding to each of the carried multicast groups; or, the multicast group field in the request message is a specific value, and the specific value is used to indicate the request for the multicast source information corresponding to all multicast groups in the first-hop multicast router.

[0031] In one embodiment, the request message includes an originator address field, where the originator address field represents a routable address of the last-hop multicast router, and the routable address is used to instruct the first-hop multicast router to determine a destination address of the response message.

[0032] As shown in FIG. 2 , FIG. 2 is a schematic diagram of a structure of a multicast group and multicast source request TLV. The request message may carry the multicast group and multicast source request TLV in a PFM message, see Group Source Request TLV in FIG. 2 .

[0033] The T field is the transferable flag and is set to 1 in the multicast group and multicast source request TLVs, indicating that the router must continue to forward the TLV even if it does not support it.

[0034] The Type field indicates that the TLV is a multicast group and multicast source request TLV, and its value is to be defined.

[0035] The length field is the total length of the multicast group address field.

[0036] The multicast group address (Group Address) field is used to indicate the multicast group information for requesting multicast source information.

[0037] In this embodiment, upon receiving a local join request for a multicast group from IGMP or MLD, the last-hop multicast router generates a PFM protocol message carrying the Multicast Group and Multicast Source Request TLV, as shown in Figure 2. The Multicast Group and Multicast Source Request TLV can carry one or more multicast groups, indicating the multicast source information for each multicast group carried in the request. It is worth noting that when the multicast group address is the specific value 0, it indicates a request for multicast source information corresponding to all multicast groups in the first-hop multicast router.

[0038] In this embodiment, the last-hop multicast router can set a first time interval and a first number of transmissions for sending PFM protocol messages carrying multicast group and multicast source request TLVs to enable rapid learning of multicast source information. In one example, when generating a local join entry for a multicast group, PFM protocol messages carrying multicast group and multicast source request TLVs are sent in pulses. Within each pulse, two PFM protocol messages are sent continuously at intervals of three seconds, and three pulses are sent at intervals of ten seconds. Furthermore, a premature stop condition can be set such that transmission stops after a certain amount of multicast source information has been learned, thereby reducing network overhead.

[0039] The originator address field in the PFM protocol message carrying the multicast group and multicast source request TLVs is filled with the address of the last-hop multicast router within a domain that is reachable. This address will be used as the destination address of the response message.

[0040] S104: Receive a response message from a first-hop multicast router in the multicast domain, and obtain the multicast source information according to the response message, wherein the response message is a feedback message generated by the first-hop multicast router in response to the request message, and the response message includes the multicast source information.

[0041] In one embodiment, the response message is a unicast PIM protocol reply message; or the response message is a PFM notification message.

[0042] In this embodiment, a request message (such as a PFM protocol message carrying a multicast group and multicast source request TLV) can be flooded hop by hop to the entire PIM domain. When the first-hop multicast router receives the PFM protocol message carrying the multicast group and multicast source request TLV, it generates a response message based on the multicast group carried in the PFM protocol message. The response message can be a PIM protocol message including a multicast group and a Group Source Reply (GSRep) message, which notifies the multicast source information of a specific multicast group or all multicast groups.

[0043] As shown in FIG3 , FIG3 is a schematic diagram of the structure of a multicast group and a multicast source PIM protocol response message, and FIG3 is an example of a response message.

[0044] The Type field indicates that the PIM protocol message type is a multicast group and multicast source reply message type, and its value is to be defined.

[0045] The multicast group count field indicates the number of multicast groups and multicast groups carried in the multicast source response message.

[0046] Each multicast group is followed by a record of its associated multicast source. This multicast source is the directly connected source of the first-hop multicast router. It can also include multicast source information learned from the Multicast Source Discovery Protocol (MSDP) or Multicast VPN Active Source Automatic Discovery Routing (MVPN Source Active AD) based on local policies.

[0047] In this embodiment, upon receiving a PFM protocol message containing a multicast group and multicast source request TLV, the first-hop multicast router responds with a PIM protocol message containing a multicast group and multicast source reply message. The PIM protocol message containing a multicast group and multicast source reply message can be a unicast message, with the source IP address of the message being the outbound interface address of the first-hop multicast router, and the destination IP address being the address indicated by the originator address field in the received PFM message containing the multicast group and multicast source request TLV. The first-hop multicast router unicasts the PIM protocol message to the last-hop multicast router. Intermediate nodes, other than unicast forwarding, do not need to process or learn the multicast group and multicast source information in the PIM protocol message. The last-hop multicast router learns the multicast group and multicast source information locally, and the learned information does not age or become deleted over time.

[0048] The multicast source discovery method provided by the embodiment of the present application is as follows: the last-hop multicast router generates a request message in response to the local joining of the multicast group, and floods the request message in the multicast domain. The request message is used to request the multicast source information corresponding to the multicast group; the first-hop multicast router responds to the request message and sends a response message including the multicast source information. In this way, the last-hop multicast router can obtain the multicast source information based on the response message. The embodiment of the present application only needs to flood the request message and the response message when the multicast group is locally joined. There is no need for the first-hop multicast router to flood periodically, which reduces the frequency of PIM protocol message flooding in the network, thereby reducing the bandwidth occupied by the periodic flooding of PIM protocol messages in the network, and reducing the CPU resources occupied by the device's periodic learning and updating, which is convenient for saving network overhead.

[0049] The embodiments of the present application can also reduce the number of protocol messages that non-network edge devices need to process, and can achieve that newly connected receivers can quickly learn multicast source information without requiring each multicast router in the network to store a large amount of multicast group and multicast source information.

[0050] The embodiments of the present application can be applied to any scenario where PIM-SM multicast is applied.

[0051] In one embodiment, based on any one of the above embodiments, the method further includes the following steps: receiving a notification message from the first-hop multicast router, the notification message being used to indicate an update message of a target multicast source, the update message of the target multicast source being generated by the first-hop multicast router in at least one of the cases where a new multicast source is added or an existing multicast source is invalid, for example, in at least one of the cases where a new (multicast source, multicast group) entry appears or an existing (multicast source, multicast group) entry is deleted and invalidated, the target multicast source including the new multicast source or the invalid existing multicast source; and updating local multicast source information according to the notification message.

[0052] In one embodiment, the notification message is sent according to the second time interval and the second number of times of sending, so that the multicast source information can be learned quickly.

[0053] In one embodiment, the announcement message includes a type field, and the indication information of the type field is used to instruct the last-hop multicast router to process the announcement message, and the intermediate multicast router only forwards the announcement message, thereby reducing the processing and storage overhead of the intermediate routers.

[0054] In one embodiment, the notification message includes a retention time field, and updating the local multicast source information according to the notification message includes: when the retention time field is a first value, determining that the target multicast source is a new multicast source and adding the target multicast source locally; or, when the retention time field is a second value, determining that the target multicast source is invalid and deleting the target multicast source.

[0055] In this embodiment, when a new multicast source appears on the first-hop multicast router, a notification message is generated and sent. The notification message can be a PFM protocol message carrying a multicast group and multicast source announcement (Group Source Advertisement (GS AD)) TLV, wherein the retention time field can have two valid values: a first value (such as a maximum value) and a second value (such as 0). The maximum value indicates that a new multicast source appears and never times out, and the value 0 indicates that the multicast source is invalid and needs to be deleted immediately.

[0056] FIG4 is a schematic diagram of a structure of a multicast group and multicast source advertisement TLV. The advertisement message may carry the multicast group and multicast source advertisement TLV in a PFM message, as shown in the Group Source Advertisement TLV in FIG4 .

[0057] The structures of the multicast group and multicast source announcement TLVs are similar to those of the multicast group and multicast source holdtime TLVs defined in RFC8364, but the processing is different.

[0058] The Type field indicates that the TLV is a multicast group and source announcement TLV. When a new multicast source appears, the first-hop multicast router sends a PFM protocol message with the multicast group and source announcement TLVs and sets the Src Holdtime field to 0xFFFF, indicating the emergence of a new multicast source. When the original multicast source fails, the first-hop multicast router sends a PFM protocol message with the multicast group and source announcement TLVs, but sets the Src Holdtime field to 0. The first-hop multicast router can set the time interval and number of times to send PFM protocol messages with the multicast group and source announcement TLVs so that the last-hop multicast router can quickly learn the newly emerged multicast source. In one embodiment, when a new multicast source is discovered, PFM protocol messages carrying the multicast group and source announcement TLVs are sent in pulses. Within a pulse, two PFM protocol messages are sent continuously at a 5-second interval, and three pulses are sent every 30 seconds.

[0059] By default, only the last-hop multicast router processes this TLV. Intermediate routers only forward it but do not process or learn it. When the last-hop multicast router receives a PFM protocol message with the Src Holdtime set to 0xFFFF in the Multicast Group and Multicast Source Advertisement TLV or a PIM protocol message with the Multicast Group and Multicast Source Reply TLV, it learns the multicast group and multicast source information carried in the protocol message and does not age out or delete this information. The corresponding multicast group and multicast source information is deleted only when the last-hop multicast router receives a PFM protocol message with the Src Holdtime set to 0 in the Multicast Group and Multicast Source Advertisement TLV.

[0060] It is worth noting that in another implementation, the multicast group and multicast source reply messages (PIM) can be omitted. Instead, PFM messages with the multicast group and multicast source announcement TLVs are used as both responses when the first-hop multicast router receives PFM messages with the multicast group and multicast source request TLVs and as flood notifications when new multicast sources appear.

[0061] Alternatively, another implementation method is to appropriately expand the existing Multicast Group and Multicast Source Hold Time TLV in RFC8364 and combine it with the Multicast Group and Multicast Source Request TLV newly added in this application. The first-hop multicast router sets the Src Holdtime in the Multicast Group and Multicast Source Hold Time TLV to 0xFFFF and floods the message every 18724 seconds by default. Upon receiving a PFM with the Multicast Group and Multicast Source Request TLV from the last-hop multicast router, it immediately floods the message. This can partially reduce flooding while allowing the receiver to quickly learn multicast source information.

[0062] The multicast source discovery method according to an embodiment of the present application is described in detail above with reference to FIG1 . A multicast source discovery method according to another embodiment of the present application will be described in detail below with reference to FIG5 . It will be appreciated that the interaction between the first-hop multicast router and the last-hop multicast router described from the perspective of the first-hop multicast router is identical or corresponding to the description of the last-hop multicast router in the method shown in FIG1 . To avoid repetition, the relevant description is omitted as appropriate.

[0063] FIG5 is a schematic diagram of a multicast source discovery method according to an embodiment of the present invention, which can be applied to a first-hop multicast router. As shown in FIG5 , the method 500 includes the following steps.

[0064] S502: Receive a request message, where the request message is generated by the last-hop multicast router in the multicast domain in response to a local join of a multicast group and is flooded in the multicast domain. The request message is used to request multicast source information corresponding to the multicast group.

[0065] As shown in FIG. 2 , FIG. 2 is a schematic diagram of a structure of a multicast group and multicast source request TLV. The request message may carry the multicast group and multicast source request TLV in a PFM message, see Group Source Request TLV in FIG. 2 .

[0066] S504: In response to the request message, generate a response message and send the response message, where the response message includes the multicast source information.

[0067] As shown in FIG3 , FIG3 is a schematic diagram of the structure of a multicast group and a multicast source PIM protocol response message, and FIG3 is an example of a response message.

[0068] In the embodiment of the present application, the request message and the response message need to be flooded only when the multicast group is locally joined. There is no need for the first-hop multicast router to flood periodically, which reduces the frequency of PIM protocol message flooding in the network and saves network overhead.

[0069] As an embodiment, the request message carries at least one of the multicast groups, and the request message is used to request the multicast source information corresponding to each of the carried multicast groups; or the multicast group field in the request message is a specific value, and the specific value is used to indicate the request for the multicast source information corresponding to all multicast groups in the first-hop multicast router.

[0070] As an embodiment, the response message is a unicast PIM protocol reply message; or the response message is a PFM notification message.

[0071] As an embodiment, the response message is a PIM protocol reply message. Before sending the response message, the method further includes: determining the destination address of the PIM protocol reply message based on the originator address field in the request message; wherein the originator address field represents the routable address of the last-hop multicast router.

[0072] As an embodiment, the method also includes: sending a notification message, wherein the notification message is used to indicate an update message of the target multicast source, wherein the update message of the target multicast source is generated by the first-hop multicast router when at least one of the new multicast source and the original multicast source fails, and the target multicast source includes the new multicast source or the failed original multicast source.

[0073] FIG4 is a schematic diagram of a structure of a multicast group and multicast source advertisement TLV. The advertisement message may carry the multicast group and multicast source advertisement TLV in a PFM message, as shown in the Group Source Advertisement TLV in FIG4 .

[0074] As an embodiment, the notification message includes a holding time field. Before sending the notification message, the method also includes: when the target multicast source is a newly added multicast source, setting the holding time field to a first value; or, when the target multicast source fails, setting the holding time field to a second value.

[0075] FIG6 shows a schematic structural diagram of a last-hop multicast router 600 provided in an embodiment of the present application. The last-hop multicast router 600 includes the following modules.

[0076] The communication module 602 is configured to generate a request message in response to a local joining of a multicast group, and flood the request message in the multicast domain; wherein the request message is used to request multicast source information corresponding to the multicast group.

[0077] The communication module 602 is also used to receive a response message from the first-hop multicast router in the multicast domain, and obtain the multicast source information based on the response message, wherein the response message is a feedback message generated by the first-hop multicast router in response to the request message, and the response message includes the multicast source information.

[0078] In one embodiment, the last-hop multicast router 600 further includes a processing module, etc.

[0079] In the embodiment of the present application, the request message and the response message need to be flooded only when the multicast group is locally joined. There is no need for the first-hop multicast router to flood periodically, which reduces the frequency of PIM protocol message flooding in the network and saves network overhead.

[0080] As an embodiment, the request message carries at least one of the multicast groups, and the request message is used to request the multicast source information corresponding to each of the carried multicast groups; or the multicast group field in the request message is a specific value, and the specific value is used to indicate the request for the multicast source information corresponding to all multicast groups in the first-hop multicast router.

[0081] As an embodiment, the response message is a unicast PIM protocol reply message; or the response message is a PIM flooding mechanism PFM notification message.

[0082] As an embodiment, the request message includes an originator address field, where the originator address field represents a routable address of the last-hop multicast router, and the routable address is used to instruct the first-hop multicast router to determine a destination address of the response message.

[0083] As an embodiment, the communication module 602 is also used to receive a notification message from the first-hop multicast router, where the notification message is used to indicate an update message of the target multicast source. The update message of the target multicast source is generated by the first-hop multicast router when at least one of the new multicast source and the original multicast source fails. The target multicast source includes the new multicast source or the failed original multicast source; and the local multicast source information is updated according to the notification message.

[0084] As an embodiment, the notification message includes a holding time field, and the communication module 602 can be used to: when the holding time field is a first value, determine that the target multicast source is a new multicast source and add the target multicast source locally; or, when the holding time field is a second value, determine that the target multicast source is invalid and delete the target multicast source.

[0085] The last-hop multicast router 600 provided in the embodiment of the present application can execute the methods described in the above method embodiments and achieve the functions and beneficial effects of the methods described in the above method embodiments, which will not be described in detail here.

[0086] FIG7 shows a schematic structural diagram of a first-hop multicast router 700 provided in an embodiment of the present application. The first-hop multicast router 700 includes the following modules.

[0087] The communication module 702 is used to receive a request message, which is generated by the last hop multicast router in the multicast domain in response to a local join of the multicast group and flooded in the multicast domain. The request message is used to request multicast source information corresponding to the multicast group.

[0088] The communication module 702 is further configured to generate a response message in response to the request message and send the response message, where the response message includes the multicast source information.

[0089] In one embodiment, the first-hop multicast router 700 further includes a processing module, etc.

[0090] In the embodiment of the present application, the request message and the response message need to be flooded only when the multicast group is locally joined. There is no need for the first-hop multicast router to flood periodically, which reduces the frequency of PIM protocol message flooding in the network and saves network overhead.

[0091] As an embodiment, the request message carries at least one of the multicast groups, and the request message is used to request the multicast source information corresponding to each of the carried multicast groups; or the multicast group field in the request message is a specific value, and the specific value is used to indicate the request for the multicast source information corresponding to all multicast groups in the first-hop multicast router.

[0092] As an embodiment, the response message is a unicast PIM protocol reply message; or the response message is a PFM notification message.

[0093] As an embodiment, the response message is a PIM protocol reply message, and the communication module 702 is further used to determine the destination address of the PIM protocol reply message based on the originator address field in the request message; wherein the originator address field represents the routable address of the last-hop multicast router.

[0094] As an embodiment, the communication module 702 is also used to send a notification message, wherein the notification message is used to indicate an update message of the target multicast source. The update message of the target multicast source is generated by the first-hop multicast router when at least one of the new multicast source and the original multicast source fails. The target multicast source includes the new multicast source or the failed original multicast source.

[0095] As an embodiment, the notification message includes a holding time field, and the communication module 702 is also used to set the holding time field to a first value when the target multicast source is a newly added multicast source; or to set the holding time field to a second value when the target multicast source fails.

[0096] The first-hop multicast router 700 provided in the embodiment of the present application can execute the methods described in the above method embodiments and achieve the functions and beneficial effects of the methods described in the above method embodiments, which will not be repeated here.

[0097] FIG8 shows a schematic diagram of the hardware structure of a communication device provided by an embodiment of the present application. Referring to the figure, at the hardware level, the communication device includes a processor, and may also include an internal bus, a network interface, and a memory. Among them, the memory may include a memory, such as a high-speed random access memory (RAM), and may also include a non-volatile memory (non-volatile memory), such as at least one disk storage. Of course, the communication device may also include hardware required for other services.

[0098] The processor, network interface, and memory can be interconnected via an internal bus, such as an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, or an Extended Industry Standard Architecture (EISA) bus. These buses can be classified as address buses, data buses, and control buses. For ease of illustration, the figure uses only one bidirectional arrow, but this does not imply that there is only one bus or only one type of bus.

[0099] The memory is used to store programs. The programs may include program code, which includes computer operating instructions. The memory may include internal memory and non-volatile memory, and provides instructions and data to the processor.

[0100] The processor reads the corresponding computer program from the non-volatile memory into the internal memory and then runs it, forming a device for locating the target user at a logical level. The processor executes the program stored in the memory and is used to perform the methods disclosed in the embodiments shown in Figures 1-5 and to achieve the functions and benefits of the various methods described in the method embodiments above, which will not be repeated here.

[0101] The methods disclosed in the embodiments shown in Figures 1-5 of the present application can be applied to a processor or implemented by a processor. The processor may be an integrated circuit chip with signal processing capabilities. During implementation, each step of the above method can be completed by hardware integrated logic circuits in the processor or software instructions. The above processor can be a general-purpose processor, including a central processing unit (CPU), a network processor (NP), etc.; it can also be a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components. The various methods, steps, and logic block diagrams disclosed in the embodiments of the present application can be implemented or executed. The general-purpose processor can be a microprocessor or any conventional processor. The steps of the methods disclosed in the embodiments of the present application can be directly embodied as being executed by a hardware decoding processor, or can be executed by a combination of hardware and software modules in the decoding processor. The software module can be located in a storage medium well-known in the art, such as random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, registers, etc. The storage medium is located in the memory, and the processor reads the information in the memory and, in conjunction with its hardware, completes the steps of the above method.

[0102] The communication device can also execute the methods described in the above method embodiments and realize the functions and beneficial effects of the methods described in the above method embodiments, which will not be repeated here.

[0103] Of course, in addition to software implementation, the communication device of this application does not exclude other implementation methods, such as logic devices or a combination of software and hardware, etc. That is to say, the execution subject of the following processing flow is not limited to each logic unit, but can also be hardware or logic devices.

[0104] An embodiment of the present application also proposes a computer-readable storage medium, which stores one or more programs. When the one or more programs are executed by a communication device including multiple application programs, the communication device executes the method disclosed in the embodiments shown in Figures 1-5 and realizes the functions and beneficial effects of the various methods described in the previous method embodiments, which will not be repeated here.

[0105] The computer-readable storage medium includes a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, etc.

[0106] Furthermore, an embodiment of the present application also provides a computer program product, which includes a computer program stored on a non-transitory computer-readable storage medium, and the computer program includes program instructions. When the program instructions are executed by a computer, the following process is implemented: the method disclosed in the embodiment shown in Figures 1-5 and the functions and beneficial effects of the various methods described in the previous method embodiments are implemented, which will not be repeated here.

[0107] In short, the above description is only a preferred embodiment of the present application and is not intended to limit the scope of protection of the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application shall be included in the scope of protection of the present application.

[0108] The systems, devices, modules, or units described in the above embodiments may be implemented by a computer chip or entity, or by a product having a certain function. A typical implementation device is a computer. The computer may be, for example, a personal computer, a laptop computer, a cellular phone, a camera phone, a smartphone, a personal digital assistant, a media player, a navigation device, an email device, a game console, a tablet computer, a wearable device, or a combination of any of these devices.

[0109] Computer-readable media includes permanent and non-permanent, removable and non-removable media that can be implemented by any method or technology to store information. The information can be computer-readable instructions, data structures, program modules or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, compact disc read-only memory (CD-ROM), digital versatile disc (DVD) or other optical storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices or any other non-transmission media that can be used to store information that can be accessed by a computing device. As defined herein, computer-readable media does not include transitory computer-readable media (transitory media), such as modulated data signals and carrier waves.

[0110] It should also be noted that the terms "comprises," "includes," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, commodity, or apparatus that includes a series of elements includes not only those elements but also other elements not explicitly listed, or includes elements inherent to such process, method, commodity, or apparatus. In the absence of further limitations, an element defined by the phrase "comprises a ..." does not exclude the presence of other identical elements in the process, method, commodity, or apparatus that includes the element.

[0111] The various embodiments in this specification are described in a progressive manner. Similar parts between the various embodiments can be referred to in conjunction with each other. Each embodiment focuses on the differences between the other embodiments. In particular, the system embodiments are generally similar to the method embodiments, so the description is relatively simple. For relevant parts, refer to the description of the method embodiments.

Claims

1. A multicast source discovery method applied to the last-hop multicast router, comprising: responding to a local join of a multicast group, generating a request message, and flooding the request message within the multicast domain; wherein, the request message is used to request multicast source information corresponding to the multicast group; receiving a response message from the first-hop multicast router within the multicast domain, and obtaining the multicast source information according to the response message, wherein, the response message is a feedback message generated by the first-hop multicast router for the request message, and the response message includes the multicast source information.

2. The method according to claim 1, wherein, the request message carries at least one of the multicast groups, and the request message is used to request multicast source information corresponding to each of the carried multicast groups; or the multicast group field in the request message is a specific value, and the specific value is used to indicate requesting multicast source information corresponding to all multicast groups in the first-hop multicast router.

3. The method according to claim 1, wherein, the response message is a unicast Protocol Independent Multicast (PIM) protocol reply message; or the response message is a PIM Flooding Mechanism (PFM) advertisement message.

4. The method according to claim 1, wherein The request message includes an originator address field, and the originator address field represents the reachable address of the last-hop multicast router's route, and the reachable address is used to indicate the first-hop multicast router to determine the destination address of the response message.

5. The method according to claim 1, wherein, The method further comprises: receiving an advertisement message from the first-hop multicast router, the advertisement message being used to indicate an update message of a target multicast source, and the update message of the target multicast source being generated by the first-hop multicast router in at least one of the cases of adding a new multicast source or an original multicast source failing, and the target multicast source including the new multicast source or the failed original multicast source; updating the local multicast source information according to the advertisement message.

6. The method according to claim 5, wherein The advertisement message includes a hold time field, and updating the local multicast source information according to the advertisement message includes: when the hold time field is a first value, determining that the target multicast source is a new multicast source and adding the target multicast source locally; or, when the hold time field is a second value, determining that the target multicast source has failed and deleting the target multicast source.

7. A multicast source discovery method applied to the first-hop multicast router, comprising: receiving a request message, the request message being generated by the last-hop multicast router within the multicast domain in response to a local join of a multicast group and flooded within the multicast domain, and the request message being used to request multicast source information corresponding to the multicast group; responding to the request message, generating a response message and sending the response message, the response message including the multicast source information.

8. The method according to claim 7, wherein, the request message carries at least one of the multicast groups, and the request message is used to request multicast source information corresponding to each of the carried multicast groups; or the multicast group field in the request message is a specific value, and the specific value is used to indicate requesting multicast source information corresponding to all multicast groups in the first-hop multicast router.

9. The method according to claim 7, wherein, the response message is a unicast PIM protocol response message; or the response message is a PFM advertisement message.

10. The method according to claim 7, wherein The response message is a PIM protocol response message. Before sending the response message, the method further includes: determining the destination address of the PIM protocol response message based on the originator address field in the request message; wherein, the originator address field represents the reachable address of the last-hop multicast router.

11. The method according to claim 7, wherein, The method further includes: sending an advertisement message, the advertisement message being used to indicate an update message of a target multicast source, the update message of the target multicast source being generated by the first-hop multicast router when at least one of a new multicast source is added or an original multicast source fails, and the target multicast source including the new multicast source or the failed original multicast source.

12. The method according to claim 11, wherein, The advertisement message includes a hold time field. Before sending the advertisement message, the method further includes: when the target multicast source is a new multicast source, setting the hold time field to a first value; or, when the target multicast source fails, setting the hold time field to a second value.

13. A communication device, comprising: a processor; and a memory arranged to store computer-executable instructions, the executable instructions when executed using the processor to perform the steps of the method according to any one of claims 1-12.

14. A computer-readable medium, the computer-readable medium storing one or more programs, the one or more programs when executed by a communication device including a plurality of application programs, causing the communication device to perform the steps of the method according to any one of claims 1-12.

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