CN117097580A

CN117097580A - Multicast communication method and related device

Info

Publication number: CN117097580A
Application number: CN202210983137.8A
Authority: CN
Inventors: 庞东磊; 盛成; 王海波; 段方红; 闫刚; 庄顺万
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2022-05-13
Filing date: 2022-08-16
Publication date: 2023-11-21

Abstract

A multicast communication method is applied to a software defined wide area network SD-WAN. In the multicast communication method, bit index explicit replication (Bit Index Explicit Replication, BIER) capability is deployed on site equipment on an SD-WAN, and a BIER header in a multicast message is used for indicating the site equipment through which the multicast message needs to pass, so that a multicast distribution tree is not required to be constructed; and the multicast message is forwarded through the SD-WAN tunnel between the site devices, and the intermediate node does not need to sense the multicast service, so that the multicast list items of the network device are fewer and the convergence speed of the multicast list items is higher, and the normal operation of the multicast service is ensured.

Description

Multicast communication method and related device

Priority is claimed in chinese patent application No. 202210523662.1, entitled "method and apparatus for BIER (public network mode) via BGP over SD-WAN," having application date 2022, month 05 and 13.

Technical Field

The present application relates to the internet technologies, and in particular, to a multicast communication method and related devices.

Background

A Software Defined wide area network (SD-WAN) is a network formed by applying Software Defined network (Software Defined Network, SDN) technology to a wide area network scenario. Specifically, on the basis of carrier networks such as an operator network and a private line network, an SD-WAN constructed by a POP and a logical link between POPs can be obtained by adding a Point-of-Presence (POP) and abstracting a link between POPs across the carrier network into a logical link.

Typically, a plurality of customer premise equipment (Customer Premise Equipment, CPE) are included in the SD-WAN. The CPE is an edge device of the user network, and is used for bearing the service flow of the user and accessing the network through the POP.

Currently, the multicast service is implemented in SD-WAN by deploying a protocol independent multicast (Protocol Independent Multicast, PIM) protocol on each CPE, and creating a multicast distribution tree of PIM for each multicast traffic in the network through the CPE. Along with the large-scale deployment of the multicast service, the number of multicast distribution trees to be maintained is increased sharply, and each node device on the multicast distribution tree needs to store a large number of multicast stream states, namely, more multicast table entries in the node device, so that the multicast table entries on the node device converge slowly when the network changes, and the normal operation of the multicast service is affected.

Disclosure of Invention

The application provides a multicast communication method and a related device, which can ensure that the multicast list items of network equipment are fewer and the convergence speed of the multicast list items is higher, thereby ensuring the normal operation of multicast service.

The application provides a multicast communication method which is applied to an SD-WAN. The multicast communication method comprises the following steps: a first station device in the SD-WAN receives a first message, wherein the first message includes a first (Bit Index Explicit Replication, BIER) header and multicast data, the first BIER header being for indicating a set of destination nodes for the multicast data.

The first station device generates a second message according to the first message, wherein the second message comprises a first SD-WAN tunnel encapsulation header, a second BIER header and multicast data. The destination address of the encapsulation header of the first SD-WAN tunnel is the IP address of the second site device, and the IP address of the second site device is the exit address of the first SD-WAN tunnel between the first site device and the second site device. The first SD-WAN tunnel encapsulation header is used to instruct other network devices between the first site device and the second site device to forward the second message to the second site device. In addition, the second BIERv6 header is used to indicate a set of destination nodes for the multicast data.

After the second message is generated, the first station device sends the second message to the second station device through the first SD-WAN tunnel.

In the scheme, BIER capability is deployed on site equipment on an SD-WAN, and the site equipment through which a multicast message needs to pass is indicated through a BIER header in the multicast message, so that a multicast distribution tree is not required to be constructed; and the multicast message is forwarded through the SD-WAN tunnel between the site devices, and the intermediate node does not need to sense the multicast service, so that the multicast list items of the network device are fewer and the convergence speed of the multicast list items is higher, and the normal operation of the multicast service is ensured.

In one possible implementation, an extended generic routing encapsulation (Generic Routing Encapsulation, GRE) header is also encapsulated between the first SD-WAN tunneling header and the second BIER header, and a protocol type field in the extended GRE header is used to indicate that the next header (next header) of the extended GRE header is the BIER header.

In the scheme, the extended GRE header is encapsulated between the SD-WAN tunnel header and the BIER header, and the next header is indicated to be the BIER header by the extended GRE header, so that the modification to the prior art can be reduced as much as possible on the basis of realizing the coupling of the SD-WAN tunnel and the BIER forwarding, and the feasibility of the scheme is improved.

In one possible implementation, the method further includes: the first station equipment determines that the next-hop station is a first station according to the bit string in the first BIER header and the BIER forwarding table, and the target station equipment is positioned at the first station; and the first station equipment determines to send a second message to the second station equipment through the first SD-WAN tunnel according to the first station.

In the scheme, under the condition that the station equipment has BIER capability, the station equipment firstly determines the next-hop station based on the BIER forwarding table, and then determines the SD-WAN tunnel for forwarding the multicast message based on the mapping relation between the next-hop station and the SD-WAN tunnel, so that the coupling between the SD-WAN tunnel and BIER multicast is realized, the intermediate node is ensured to be free from sensing multicast service, and the deployment complexity of the multicast service is reduced.

In one possible implementation, the method further includes: the first station apparatus transmits first BIER information to the third station apparatus, the first BIER information including at least one of: BIER forwarding router identification (Bit-Forwarding Router Identity, BFR-ID) of the first site device and Prefix (BFR-Prefix) of the BIER forwarding router of the first site device; the first station device receives second BIER information advertised by the destination station device, the second BIER information including one or more of: BFR-ID of target site equipment and BFR-Prefix of target site equipment.

In the scheme, the first site equipment sends the BIER information to other site equipment and receives the BIER information advertised by other site equipment, so that each site equipment can generate a BIER forwarding table for guiding the BIER message forwarding, and the multicast forwarding is completed in the SD-WAN network.

In one possible implementation, the first BIER information or the second BIER information is carried in border gateway protocol (Border Gateway Protocol, BGP) messages.

In one possible implementation, BGP messages include BGP shortest path first (shortest path first, SPF) address family messages, BGP Link State (LS) address family messages, or BGP SD-WAN address family messages.

In one possible implementation, the first BIER information or the second BIER information is carried in a Prefix network layer reachability information (Prefix Network Layer Reachability Information, prefix NLRI) field in a BGP SPF address family message or BGP LS address family message. In practical application, the BIER information can be carried by expanding on BGP SPF address family message or other TLVs in BGP LS address family message,

in one possible implementation, the first BIER information or the second BIER information may also be carried in an extended SD-WAN NLRI attribute field in a BGP SD-WAN address family message.

In the scheme, the BIER information is carried by expanding the BGP message, so that the BIER information can be mutually announced between site equipment in the SD-WAN network, the realizability of BIER multicast forwarding can be ensured, and the modification to the prior art is reduced as much as possible.

In one possible implementation, the method further includes: the first station equipment generates a third message according to the first message, wherein the third message comprises a second SD-WAN tunnel encapsulation head, a third BIER head and multicast data, the destination address of the second SD-WAN tunnel encapsulation head is the IP address of the third station equipment, the IP address of the third station equipment is the exit address of a second SD-WAN tunnel between the first station equipment and the third station equipment, and the third BIER head is used for indicating the set of destination nodes of the multicast data; and the first site equipment sends a third message to the third site equipment through the second SD-WAN tunnel.

In the scheme, after the first station device receives the first message, the multicast forwarding path of the multicast data can be determined according to the indication of the first BIER header in the first message, so that the multicast data is copied and forwarded to the corresponding station device, and the normal operation of the multicast service is ensured.

In one possible implementation, the first station device is a customer edge device CPE or a network access point POP station device.

A second aspect of the present application provides a multicast communication method applied to an SD-WAN. The method specifically comprises the following steps: the second site equipment receives a first message sent by the first site equipment through a first SD-WAN tunnel, wherein the first message comprises a first SD-WAN tunnel encapsulation head, a first BIER head and multicast data, the destination address of the first SD-WAN tunnel encapsulation head is the IP address of the second site equipment, the IP address of the second site equipment is the exit address of the first SD-WAN tunnel between the first site equipment and the second site equipment, and the second BIERv6 head is used for indicating a set of destination nodes of the multicast data; the second site equipment generates a second message according to the first message, wherein the second message comprises multicast data; and the second station equipment forwards the second message.

In the scheme, BIER capability is deployed on site equipment on an SD-WAN, and the site equipment through which a multicast message needs to pass is indicated through a BIER header in the multicast message, so that a multicast distribution tree is not required to be constructed; and the station equipment receives and forwards the multicast data through the SD-WAN tunnel, and the intermediate node does not need to perceive the multicast service, so that the multicast list items of the network equipment are fewer and the convergence speed of the multicast list items is higher, and the normal operation of the multicast service is ensured.

In one possible implementation, an extended GRE header is further encapsulated between the first SD-WAN tunnel header and the first BIER header, and a protocol type field in the extended GRE header is used to indicate that the next header of the extended GRE header is the BIER header.

In one possible implementation manner, the second packet includes a second SD-WAN tunnel encapsulation header, a second BIER header, and multicast data, where a destination address of the second SD-WAN tunnel encapsulation header is an IP address of a third site device, and an IP address of the third site device is an exit address of the second SD-WAN tunnel between the second site device and the third site device, and the second BIER header is used to indicate a set of destination nodes of the multicast data; the second station device forwards a second message, including: and the second station equipment sends a second message to the third station equipment through the second SD-WAN tunnel.

A third aspect of the present application provides a multicast communication method, which is applied to an SD-WAN. The method comprises the following steps: the method comprises the steps that first station equipment sends a first BGP message to second station equipment, wherein the first BGP message carries first BIER information, and the first BIER information comprises a BIER forwarding router identifier BFR-ID of the first station equipment; the first station equipment receives a second BGP message advertised by the second station equipment, wherein the second BGP message carries second BIER information, and the second BIER information comprises BFR-ID of the second station equipment; the first station equipment generates a first BIER forwarding table item according to the second BGP message, and the first BIER forwarding table item records the mapping relation between the BFR-ID of the second station equipment and the next hop station, wherein the BFR-ID in the first BIER forwarding table item indicates the destination equipment for BIER forwarding.

Specifically, the destination device is represented by the BFR-ID of the second site device, and the next-hop site is calculated based on the topology of the SD-WAN with the second site device as the destination address. For the station devices in the SD-WAN, each station device will notify the other station devices of the SD-WAN tunnel information established by itself and other station devices. Therefore, after receiving the SD-WAN tunnel information advertised by other station devices, the first station device can obtain the tunnel connection relationship between the station devices in the SD-WAN, i.e. obtain the topology of the whole SD-WAN. In this way, when the first station apparatus uses the second station apparatus as a destination address, the first station apparatus can calculate the next hop station to the second station apparatus based on the topology of the SD-WAN.

In one possible implementation, the method further includes: the second station equipment generates a second BIER forwarding table item according to the first BGP message, and the second BIER forwarding table item records the mapping relation between the BFR-ID of the first station equipment and the next hop station, wherein the BFR-ID in the second BIER forwarding table item indicates the destination equipment for BIER forwarding.

In one possible implementation, the method further includes: the first station device determines a next hop station reaching the second station device according to the topology of the SD-WAN.

In one possible implementation, the method further includes: the first site equipment receives first SD-WAN tunnel information advertised by third site equipment, wherein the first SD-WAN tunnel information comprises an IP address of the third site equipment and site information of the third site equipment; the first station equipment establishes a first SD-WAN tunnel between the first station equipment and the third station equipment according to the first SD-WAN tunnel information, and stores a first mapping relation between a next-hop station and the first SD-WAN tunnel, wherein the next-hop station in the first mapping relation is a station to which the third station equipment belongs.

That is, in the case where the first SD-WAN tunnel is established between the first site device and the third site device, when the next-hop site of the first site device is the third site device, the outgoing interface of the first site device may be the first SD-WAN tunnel pointing between the first site device and the third site device, that is, through the first SD-WAN tunnel, forwarding the packet to the corresponding next-hop site can be achieved.

In one possible implementation, the method further includes: the third site equipment receives second SD-WAN tunnel information advertised by the second site equipment, wherein the second SD-WAN tunnel information comprises an IP address of the second site equipment and site information of the second site equipment; and the third station equipment establishes a second SD-WAN tunnel between the third station equipment and the second station equipment according to the second SD-WAN tunnel information, and stores a second mapping relation between the next-hop station and the second SD-WAN tunnel, wherein the next-hop station in the second mapping relation is the station to which the second station equipment belongs.

That is, a second SD-WAN tunnel is also established between the third site device and the second site device, and the third site device may establish a second mapping relationship between the next-hop site and the second SD-WAN tunnel, so as to send the message through the second SD-WAN tunnel when the next-hop site of the message is the second site device.

In one possible implementation, the method further includes: the first site equipment receives third SD-WAN tunnel information advertised by the second site equipment, wherein the third SD-WAN tunnel information comprises an IP address of the second site equipment and site information of the second site equipment; the first station device establishes a third SD-WAN tunnel between the first station device and the second station device according to the third SD-WAN tunnel information, and stores a third mapping relation between a next-hop station and the third SD-WAN tunnel, wherein the next-hop station in the third mapping relation is the station to which the second station device belongs.

In one possible implementation, the method further includes: the first station equipment receives a first BIER message, wherein the first BIER message comprises a first BIER header and multicast data, and the first BIER header is used for indicating a set of destination nodes of the multicast data; and the first station equipment determines to forward the multicast data through the first SD-WAN tunnel according to the first BIER head, the first BIER forwarding table item and the first mapping relation.

In one possible implementation, the method further includes: the first station equipment receives a first BIER message, wherein the first BIER message comprises a first BIER header and multicast data, and the first BIER header is used for indicating a set of destination nodes of the multicast data; and the first station equipment determines to forward the multicast data through the third SD-WAN tunnel according to the first BIER head, the first BIER forwarding table item and the third mapping relation.

A fourth aspect of the present application provides a communication apparatus pertaining to a first station device in an SD-WAN, comprising: the receiving module is used for receiving a first message, wherein the first message comprises a first bit index explicit copy BIER header and multicast data, and the first BIER header is used for indicating a set of destination nodes of the multicast data; the processing module is used for generating a second message according to the first message, wherein the second message comprises a first SD-WAN tunnel encapsulation head, a second BIER head and multicast data, the destination address of the first SD-WAN tunnel encapsulation head is the IP address of second site equipment, the IP address of the second site equipment is the exit address of the first SD-WAN tunnel between the first site equipment and the second site equipment, and the second BIER head is used for indicating the set of destination nodes of the multicast data; and the sending module is used for sending the second message to the second site equipment through the first SD-WAN tunnel.

In one possible implementation, an extended generic routing encapsulation GRE header is further encapsulated between the first SD-WAN tunnel header and the second BIER header, and a protocol type field in the extended GRE header is used to indicate that the next header of the extended GRE header is the BIER header.

In one possible implementation, the processing module is further configured to: determining a next-hop site as a first site according to the bit string in the first BIER header and the BIER forwarding table, wherein target site equipment is located at the first site; and according to the first station, determining to send a second message to second station equipment through the first SD-WAN tunnel.

In one possible implementation, the sending module is further configured to send first BIER information to the third station apparatus, where the first BIER information includes at least one of the following information: the BIER forwarding router of the first site equipment identifies BFR-ID and issues a Prefix BFR-Prefix; the receiving module is further configured to receive second BIER information advertised by the target site device, where the second BIER information includes one or more of the following information: BFR-ID of target site equipment and BFR-Prefix of target site equipment.

In one possible implementation, the first BIER information or the second BIER information is carried in BGP messages.

In one possible implementation, the BGP message includes a BGP shortest path first SPF address family message, a BGP link state LS address family message, or a BGP SD-WAN address family message.

In one possible implementation, the first BIER information or the second BIER information is carried in a Prefix network layer reachability information, prefix NLRI, field in a BGP SPF address family message or a BGP LS address family message.

In a possible implementation manner, the processing module is further configured to generate a third packet according to the first packet, where the third packet includes a second SD-WAN tunnel encapsulation header, a third BIER header, and multicast data, a destination address of the second SD-WAN tunnel encapsulation header is an IP address of a third site device, the IP address of the third site device is an exit address of a second SD-WAN tunnel between the first site device and the third site device, and the third BIER header is used to indicate a set of destination nodes of the multicast data; and the sending module is also used for sending a third message to the third site equipment through the second SD-WAN tunnel.

In one possible implementation, the first site device is a CPE or POP site device.

A fifth aspect of the present application provides a communications apparatus pertaining to a second site device in an SD-WAN. The communication device includes: a receiving module, configured to receive, through a first SD-WAN tunnel, a first packet sent by a first site device, where the first packet includes a first SD-WAN tunnel encapsulation header, a first BIER header, and multicast data, a destination address of the first SD-WAN tunnel encapsulation header is an IP address of a second site device, an IP address of the second site device is an exit address of the first SD-WAN tunnel between the first site device and the second site device, and the second BIER 6 header is used to indicate a set of destination nodes of the multicast data; the processing module is used for generating a second message according to the first message, wherein the second message comprises the multicast data; and the sending module is used for forwarding the second message.

In one possible implementation manner, an extended GRE header is further encapsulated between the first SD-WAN tunnel header and the first BIER header, and a protocol type field in the extended GRE header is used to indicate that a next header of the extended GRE header is a BIER header.

In one possible implementation manner, the second packet includes a second SD-WAN tunnel encapsulation header, a second BIER header, and the multicast data, where a destination address of the second SD-WAN tunnel encapsulation header is an IP address of a third site device, and the IP address of the third site device is an exit address of a second SD-WAN tunnel between the second site device and the third site device, and the second BIER header is used to indicate a set of destination nodes of the multicast data; and the sending module is further configured to send the second packet to the third site device through the second SD-WAN tunnel.

A sixth aspect of the present application provides a communication apparatus pertaining to a first station device in an SD-WAN, comprising: the sending module is used for sending a first BGP message to the second site equipment, wherein the first BGP message carries first BIER information, and the first BIER information comprises a BIER forwarding router identifier BFR-ID of the first site equipment; the receiving module is used for receiving a second BGP message advertised by second station equipment, wherein the second BGP message carries second BIER information, and the second BIER information comprises BFR-ID of the second station equipment; the processing module is configured to generate a first BIER forwarding table entry according to the second BGP packet, where the first BIER forwarding table entry records a mapping relationship between a BFR-ID of the second site device and a next-hop site, and the BFR-ID in the first BIER forwarding table entry indicates a destination device for BIER forwarding.

In a possible implementation manner, the processing module is further configured to determine a next hop station reaching the second station device according to the topology of the SD-WAN.

In one possible implementation manner, the receiving module is further configured to receive first SD-WAN tunnel information advertised by the third site device, where the first SD-WAN tunnel information includes an IP address of the third site device and site information to which the third site device belongs; the processing module is further configured to establish a first SD-WAN tunnel between the first site device and the third site device according to the first SD-WAN tunnel information, and store a first mapping relationship between a next-hop site and the first SD-WAN tunnel, where the next-hop site in the first mapping relationship is a site to which the third site device belongs.

In one possible implementation manner, the receiving module is further configured to receive third SD-WAN tunnel information advertised by the second site device, where the third SD-WAN tunnel information includes an IP address of the second site device and site information to which the second site device belongs; the processing module is further configured to establish a third SD-WAN tunnel between the first site device and the second site device according to the third SD-WAN tunnel information, and store a third mapping relationship between a next-hop site and the third SD-WAN tunnel, where the next-hop site in the third mapping relationship is a site to which the second site device belongs.

In one possible implementation manner, the receiving module is further configured to receive a first BIER packet, where the first BIER packet includes a first BIER header and multicast data, and the first BIER header is used to indicate a set of destination nodes of the multicast data; and the processing module is also used for determining to forward the multicast data through the first SD-WAN tunnel according to the first BIER head, the first BIER forwarding table item and the first mapping relation.

In one possible implementation manner, the receiving module is further configured to receive a first BIER packet, where the first BIER packet includes a first BIER header and multicast data, and the first BIER header is used to indicate a set of destination nodes of the multicast data; and the processing module is further used for determining to forward the multicast data through the third SD-WAN tunnel according to the first BIER head, the first BIER forwarding table item and the third mapping relation.

A seventh aspect of the present application provides a communication apparatus, including a receiving module, a processing module, and a transmitting module; the receiving module is configured to perform a receiving operation in any implementation manner of the first aspect, the second aspect or the third aspect, the processing module is configured to perform a processing operation in any implementation manner of the first aspect, the second aspect or the third aspect, and the transmitting module is configured to perform a transmitting operation in any implementation manner of the first aspect, the second aspect or the third aspect.

Alternatively, the receiving module is configured to perform the operations performed by the receiving module in any implementation manner of the fourth aspect, the fifth aspect or the sixth aspect, the processing module is configured to perform the operations performed by the processing module in any implementation manner of the fourth aspect, the fifth aspect or the sixth aspect, and the sending module is configured to perform the operations performed by the sending module in any implementation manner of the fourth aspect, the fifth aspect or the sixth aspect.

In one possible implementation, the communication apparatus belongs to a site device in an SD-WAN.

The communication device of the fourth aspect to the seventh aspect may be a processor or a chip system in a station apparatus, configured to perform the receiving operation, the processing operation, and the transmitting operation of the fourth aspect to the seventh aspect; the communication apparatus of the fourth to seventh aspects may be a site device, for example, a network device such as a switch, a gateway, a router, a hub, or the like, and the present application is not limited to the specific form of the communication apparatus.

An eighth aspect of the present application provides a communication system including a first communication device and a second communication device; the first communication means is for performing the operations performed by the first station apparatus in the first aspect or the third aspect, and the second communication means is for performing the operations performed by the second station apparatus in the second aspect

A ninth aspect of the application provides a computer readable storage medium storing instructions which, when executed on a processor, implement a method as in any of the embodiments of the first to third aspects.

A tenth aspect of the application provides a computer program product which, when run on a processor, implements a method as any of the embodiments of the first to third aspects.

An eleventh aspect of the application provides a chip comprising one or more processors. Some or all of the processor is configured to read and execute computer instructions stored in the memory to perform the method of any of the possible implementations of any of the aspects described above. Optionally, the chip further comprises a memory. Optionally, the chip further comprises a communication interface, and the processor is connected with the communication interface. The communication interface is used for receiving data and/or information to be processed, and the processor acquires the data and/or information from the communication interface, processes the data and/or information and outputs a processing result through the communication interface. Optionally, the communication interface is an input-output interface or a bus interface. The method provided by the application is realized by one chip or a plurality of chips in a cooperative manner.

The solutions provided in the second aspect to the eleventh aspect are used to implement or cooperate to implement the method provided in the first aspect, so that the same or corresponding beneficial effects as those in the first aspect can be achieved, which are not described herein.

Drawings

Fig. 1 is a schematic diagram of an SD-WAN network according to an embodiment of the present application;

fig. 2 is a schematic diagram of implementing data multicasting in BIER network according to an embodiment of the present application;

fig. 3 is a schematic diagram of searching a BIER forwarding table in a BIER network to implement forwarding of a multicast message according to an embodiment of the present application;

FIG. 4 is a schematic diagram of an SD-WAN network according to an embodiment of the present application;

fig. 5 is a schematic diagram of a station device generating a forwarding table in an SD-WAN network according to an embodiment of the present application;

FIG. 6 is a schematic diagram of a station device generating a BIER forwarding table in an SD-WAN network according to an embodiment of the present application;

fig. 7 is a schematic diagram of a BGP SPF address family packet extended carrying BIER information according to an embodiment of the present application;

fig. 8 is a flow chart of a multicast communication method 800 according to an embodiment of the present application;

FIG. 9 is a schematic diagram of determining a next hop station based on a bit string and a BIER forwarding table according to an embodiment of the present application;

Fig. 10 is a schematic diagram of a format of a multicast packet according to an embodiment of the present application;

FIG. 11 is a schematic diagram of a BIER header format according to an embodiment of the present application;

fig. 12 is a flowchart of a multicast communication method 1200 according to an embodiment of the present application;

fig. 13 is a schematic flow chart of a multicast communication method 1300 according to an embodiment of the present application;

fig. 14 is a schematic structural diagram of a network device 1400 according to an embodiment of the present application;

fig. 15 is a schematic structural diagram of a network device 1500 according to an embodiment of the present application;

fig. 16 is a schematic structural diagram of a network device 1600 according to an embodiment of the present application;

fig. 17 is a schematic structural diagram of a network device 1700 according to an embodiment of the present application.

Detailed Description

In order to make the objects, technical solutions and advantages of the present application more apparent, embodiments of the present application will be described below with reference to the accompanying drawings. It will be apparent that the described embodiments are merely some, but not all embodiments of the application. As a person skilled in the art can know, with the appearance of a new application scenario, the technical scheme provided by the embodiment of the application is also applicable to similar technical problems.

The terms first, second and the like in the description and in the claims and in the above-described figures, are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the description so used is interchangeable under appropriate circumstances such that the embodiments are capable of operation in other sequences than those illustrated or otherwise described herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or modules is not necessarily limited to those steps or modules that are expressly listed or inherent to such process, method, article, or apparatus. The naming or numbering of the steps in the present application does not mean that the steps in the method flow must be executed according to the time/logic sequence indicated by the naming or numbering, and the execution sequence of the steps in the flow that are named or numbered may be changed according to the technical purpose to be achieved, so long as the same or similar technical effects can be achieved. The division of the units in the present application is a logical division, and may be implemented in another manner in practical application, for example, a plurality of units may be combined or integrated in another system, or some features may be omitted or not implemented, and in addition, coupling or direct coupling or communication connection between the units shown or discussed may be through some interfaces, and indirect coupling or communication connection between the units may be electrical or other similar manners, which are not limited in the present application. The units or sub-units described as separate components may be physically separated or not, may be physical units or not, or may be distributed in a plurality of circuit units, and some or all of the units may be selected according to actual needs to achieve the purpose of the present application.

In order to facilitate understanding, some of the techniques according to embodiments of the present application are described below.

(1)SD-WAN

SD-WAN is a network formed by applying SDN technology to a wide area network scenario. The SD-WAN aims to reduce the expense of the wide area network and improve the flexibility of network connection, and provides safe and reliable interconnection services for enterprise networks, data center networks and the like scattered in a wide geographic range.

Referring to fig. 1, fig. 1 is a schematic diagram of an SD-WAN network according to an embodiment of the present application. As shown in fig. 1, the SD-WAN network includes a site device 1-a site device 5, and both the site device 1-the site device 5 are connected to the transmission network 1 and the transmission network 2. The station device 1 and the station device 3-station device 5 can be connected through the transmission network 1 and the transmission network 2, and the station device 2 and the station device 3-station device 5 can also be connected through the transmission network 1 and the transmission network 2. Wherein the site device 1 and the site device 2 are, for example, headquarter site devices, and the site device 3-site device 5 is, for example, branch site devices. Station apparatus 1 and station apparatus 2 as headquarter station apparatuses may distribute data to station apparatus 3-station apparatus 5 as branch station apparatuses; alternatively, station apparatus 1 and station apparatus 2 serve as intermediate nodes for forwarding data transmitted between branch station apparatuses to each other.

Wherein station apparatus 1-station apparatus 5 may be CPE or POP station apparatus. The transport network 1 and the transport network 2 are wide area access networks provided by operators for enabling interconnection between site equipments. Illustratively, the transmission network 1 and the transmission network 2 may be public networks including an operator private line network and the Internet (Internet), etc.

By using transport network 1 and transport network 2 as bearer networks, SD-WAN tunnels can be deployed between different site devices. The SD-WAN tunnel refers to a logical channel between two site devices, and data transmission between the two site devices can be realized through the SD-WAN tunnel. In general, the physical outbound interface of the SD-WAN tunnel is a wide area network interface on the site device. That is, the outgoing interfaces at the two ends of the SD-WAN tunnel are wide area network interfaces on the two site devices, respectively, and the wide area network interfaces on the two site devices can be interconnected through the bearer network.

(2) Bit index explicit replication (Bit Index Explicit Replication, BIER)

The BIER is a novel multicast forwarding technology, and the destination node set to be reached by the multicast message is packaged in a Bit String (BS) manner at the message header for sending, so that the network intermediate node does not need to sense the multicast service and maintain the multicast stream state, the problems existing in the traditional multicast technology can be well solved, and good multicast service expansibility is provided.

In the BIER network, based on a bit index forwarding table (Bit Index Forwarding Table, BIFT) established by BIER technology on a bit forwarding router (Bit Forwarding Router, BFR), the BFR only needs to copy and forward the message according to the bit string, so that the multicast of the message can be realized.

Referring to fig. 2, fig. 2 is a schematic diagram illustrating implementation of data multicasting in BIER network according to an embodiment of the present application. As shown in fig. 2, the BIER network includes network devices 1-8, where each of the network devices 1-8 has BIER capability. The network equipment 1 is connected with a multicast source and the network equipment 2; the network device 2 is also connected with the network device 3 and the network device 4; the network device 3 is also connected to the network device 5 and the network device 6; the network device 4 is also connected to a network device 7 and a network device 8. And, the network device 5-the network device 8 are connected to the reception device 1-the reception device 4, respectively.

In the BIER network shown in fig. 2, the multicast source needs to transmit multicast data to the reception apparatus 1 to the reception apparatus 4 through the BIER network. Firstly, the multicast source sends a multicast message 0 to the network device 1, where the multicast message 0 carries multicast data. The network device 1 obtains the BS corresponding to the multicast data by searching the multicast forwarding table, where the BS is used to indicate the set of destination nodes of the multicast data, that is, the destination nodes of the multicast data are the network devices 5-8. Then, the network device 1 transmits a multicast message 1 encapsulating the BS and the multicast data to the network device 2 to indicate that the destination node of the multicast data is the network device 5-network device 8.

After receiving the multicast message 1, the network device 2 determines that the next-hop devices are the network device 3 and the network device 4 respectively based on the BS in the multicast message 1. Therefore, the network device 2 sends the multicast message 2 to the network device 3, the multicast message 2 carries multicast data, and the BS in the multicast message 2 is used to indicate that the destination nodes of the multicast data are the network device 5 and the network device 6. In addition, the network device 2 generates the multicast message 3 by copying the multicast data, and transmits the multicast message 3 to the network device 4. Multicast data is carried in multicast message 3, and BS in multicast message 3 is used to indicate that destination nodes of multicast data are network device 7 and network device 8.

After receiving the multicast message 2, the network device 3 determines that the next-hop devices are the network device 5 and the network device 6 respectively based on the BS in the multicast message 2. Similar to the forwarding procedure of the network device 2, the network device 3 sends a multicast message 4 to the network device 5 indicating that the destination node is the network device 5, and sends a multicast message 5 to the network device 6 indicating that the destination node is the network device 6.

Similar to the forwarding process of the network device 3, the network device 4, after receiving the multicast message 3, sends a multicast message 6 to the network device 7 indicating that the destination node is the network device 7, and sends a multicast message 7 to the network device 8 indicating that the destination node is the network device 8.

Finally, the network device 5-8 respectively transmits the multicast data to the receiving device 1-4 based on the received multicast message, thereby realizing the multicast of the data.

Referring to fig. 3, fig. 3 is a schematic diagram of searching a BIER forwarding table in a BIER network to implement forwarding of a multicast message according to an embodiment of the present application. As shown in fig. 3, the BS represents different network devices with bits at different positions, and when a bit at the BS is set to 1, the network device corresponding to the bit belongs to a set of destination nodes of multicast data. In fig. 3, the BS has five bits, and the five bits in the BS represent the network device 1, the network device 5, the network device 6, the network device 7, and the network device 8, respectively, in order from right to left. For example, BS with value 00001 represents that the destination node is network device 1; a BS with a value of 00110 represents that the destination node is the network device 5 and the network device 6.

As shown in fig. 3, the BIER forwarding table of network device 2 includes BIER forwarding router identification (Bit-Forwarding Router Identity, BFR-id), bitmask, and BFR neighbors. The BFR-id is used for indicating the identification of the destination node, the bit mask is used for indicating the mask corresponding to the destination node, and the BFR neighbor is used for indicating the destination address as the next hop neighbor of the multicast message of the destination node. When network device 2 receives BS with value 11110, network device 2 performs bit and operation on the received BS and bitmask in the BIER forwarding table. After the BS with the value 11110 performs the bit mask execution in the 2 nd forwarding table entry and the 4 th forwarding table entry in the BIER forwarding table, the bit and the result with the value not being 0 can be obtained. Thus, the network device 2 transmits a BS with a value of 00110 (i.e., a BS with a value of 11110 and a bit mask 00110's location result) to the network device 3 indicated by the 2 nd forwarding entry and transmits a BS with a value of 11000 (i.e., a BS with a value of 11110 and a bit mask 11000's location result) to the network device 4 indicated by the 4 th forwarding entry according to the result of performing the location operation.

Similarly, upon network device 3 receiving BS with value 00110, network device 3 performs a locate operation on BS with bitmask in BIER forwarding table. In the network device 3, after the BS with the value 00110 performs the bit mask execution in the 2 nd forwarding table entry and the 3 rd forwarding table entry in the BIER forwarding table, the bit and the result with the value not being 0 can be obtained. Thus, the network device 3 transmits a BS with a value of 00010 (i.e., a BS with a value of 00110 and a bit mask 00010's location result) to the network device 5 indicated by the 2 nd forwarding entry, and transmits a BS with a value of 00100 (i.e., a BS with a value of 00110 and a bit mask 00100's location result) to the network device 4 indicated by the 4 th forwarding entry, according to the result of performing the location operation.

Currently, the multicast service is implemented in SD-WAN by deploying PIM protocols on each CPE, and building a multicast distribution tree of PIM for each multicast traffic in the network through the CPE. Along with the large-scale deployment of the multicast service, the number of multicast distribution trees to be maintained is increased sharply, and each node device on the multicast distribution tree needs to store a large number of multicast stream states, namely, more multicast table entries in the node device, so that the multicast table entries on the node device converge slowly when the network changes, and the normal operation of the multicast service is affected.

In view of this, the embodiment of the present application provides a multicast communication method, in which BIER capability is deployed on a site device on an SD-WAN, and a destination node of a multicast packet is indicated by a BIER header in the multicast packet, without constructing a multicast distribution tree; and the multicast message is forwarded through the SD-WAN tunnel between the site devices, and the intermediate node does not need to sense the multicast service, so that the multicast list items of the network device are fewer and the convergence speed of the multicast list items is higher, and the normal operation of the multicast service is ensured.

Specifically, the multicast communication method provided by the embodiment of the application can be applied to the SD-WAN network shown in fig. 1, and is used for realizing multicast service in the SD-WAN network.

In order to facilitate understanding of the multicast communication method provided by the embodiment of the present application, the following describes a process of deploying an SD-WAN tunnel between site devices in an SD-WAN network and deploying a BIER forwarding table on the site devices.

Referring to fig. 4, fig. 4 is a schematic diagram of an SD-WAN network according to an embodiment of the present application. As shown in fig. 4, the SD-WAN network includes a station apparatus 1 to a station apparatus 7, a Route Reflector (RR), and a controller. Station apparatus 1-station apparatus 4 are connected to transmission network 1 and transmission network 2, i.e. interconnection between station apparatus 1-station apparatus 4 can be realized through transmission network 1 and transmission network 2. Furthermore, both the station apparatus 3 to the station apparatus 6 access the transmission network 3 and the transmission network 4, i.e. the interconnection between the station apparatus 3 to the station apparatus 6 can be realized by the transmission network 3 and the transmission network 4. Station apparatus 1-station apparatus 6 is also connected to an RR for realizing notification of information between station apparatuses through the RR.

In addition, the controller is connected to the RR in the SD-WAN network and to the respective station apparatuses (only the controller is shown in fig. 4 to be connected to the RR, the station apparatus 1, and the station apparatus 3 in order to avoid the complexity of the drawing).

Illustratively, in fig. 4, the SD-WAN network contains three types of channels, a management channel, a control channel, and a data channel. Specifically, detailed information of three channels in the SD-WAN network is shown in table 1.

TABLE 1

The various channels in the SD-WAN network will be described in detail below in conjunction with table 1.

The network configuration protocol (Network Configuration Protocol, netcon f) manages channels.

The netcon f management channel refers to a connection channel between the controller and the site device and the network devices such as RR. The controller can issue configuration, such as network basic configuration, VPN service parameters, routing policies, etc., to the site device and the network device, such as RR, etc., through the netcon f management channel. The network basic configuration includes a site device and a System IP (System IP) of the RR. In addition, in the case of having a plurality of RRs in the SD-WAN network, the controller can also allocate the associated RR to the station apparatus.

The site equipment, RR and other network equipment can report network operation and maintenance information to the controller through the NETCONF management channel, such as alarm information, equipment log, network traffic and other performance acquisition information of the equipment.

2, packet transport layer security protocol (Datagram Transport Layer Security, DTLS) manages channels.

The DTLS management channel is a connection channel between the RR and the site equipment for interactive transport of network port (Transport network point, TNP) information. The TNP information may include information such as an IP address of a port of the network device, an identifier of an operator network to which the port on the network device is connected, an identifier of a private network to which the network device is connected, and an identifier of a site where the site device is located. In general, TNP information can indicate information of a transport network to which RR/site equipment has access, as well as information of ports on RR/site equipment that have access to the transport network.

Based on the DTLS management channel, RR can notify the site equipment of own TNP information; the site appliance can also announce its own TNP information to the RRs.

Border gateway protocol (Border Gateway Protocol, BGP) control channels.

After the RR and each site device interact TNP information, the RR and each site device establish a BGP control channel between the RR and the site device according to the TNP information learned by each other. After establishing the BGP control channel between the RR and the site appliance, the site appliance announces TNP information to the RR to cause the RR to reflect the TNP information to other site appliances.

And 4, a data channel.

And under the condition that the station equipment receives TNP information of other station equipment reflected by the RR, the station equipment establishes an SD-WAN tunnel reaching the opposite station equipment based on the received TNP information so as to realize the transmission of the data message through the SD-WAN tunnel.

In addition, in the SD-WAN network, when receiving the routing information issued by other network devices, the station device may advertise the routing information to other station devices through the RR, so that a forwarding table for guiding packet forwarding can be generated on each station device, and a forwarding path indicated in the forwarding table is related to the SD-WAN tunnel between the station devices.

Fig. 5 is a schematic diagram illustrating generation of a forwarding table by a station device in an SD-WAN network according to an embodiment of the present application. As shown in fig. 5, station apparatus 1 and station apparatus 2 are at station 1, station apparatus 3 and station apparatus 4 are at station 2, station apparatus 5 is at station 3, and station apparatus 6 is at station 4.

After the site apparatus 1, the site apparatus 5, and the site apparatus 6 notify the site apparatus 3 of TNP information and route information through RR, the site apparatus 3 can generate a forwarding table. The TNP information may include a site identifier of a site where the site equipment is located and related information required for creating the SD-WAN tunnel. For example, the TNP information includes the site to which the site apparatus belongs and the IP address of the site apparatus. Thus, the station apparatus 3 can generate a mapping relationship between the SD-WAN tunnel and the counterpart station of the SD-WAN tunnel based on the received TNP information.

As shown in fig. 5, the mapping relationship among the destination address, the egress interface and the opposite end station identifier is recorded in the forwarding table. For example, in the first forwarding table entry of the forwarding table, the destination address is IP address 1, where IP address 1 is the IP address of station apparatus 1 or the IP address in the routing information sent by station apparatus 1 to station apparatus 3; the outgoing interface corresponding to the IP address 1 points to the SD-WAN tunnel 1, namely the SD-WAN tunnel between the site equipment 3 and the site equipment 1; the opposite site is identified as site 1, i.e., the opposite site of SD-WAN tunnel 1 is site 1.

In the second forwarding table entry of the forwarding table, the destination address is IP address 2, where the IP address 2 is the IP address of the station device 5 or the IP address in the routing information sent by the station device 5 to the station device 3; the outgoing interface corresponding to the IP address 2 points to the SD-WAN tunnel 2, namely the SD-WAN tunnel between the site equipment 3 and the site equipment 5; the opposite site is identified as site 3, i.e., the opposite site of SD-WAN tunnel 2 is site 3.

Similarly, in the third forwarding table entry of the forwarding table, the destination address is IP address 3, where IP address 3 is the IP address of station device 6 or the IP address in the routing information sent by station device 6 to station device 3; the outgoing interface corresponding to the IP address 3 points to the SD-WAN tunnel 3, namely the SD-WAN tunnel between the site equipment 3 and the site equipment 6; the opposite site is identified as site 4, i.e., the opposite site of SD-WAN tunnel 3 is site 4.

As can be seen from fig. 5, the mapping relationship between the SD-WAN tunnel and the opposite end station identifier of the SD-WAN tunnel when the outbound interface points to the SD-WAN tunnel is recorded in the forwarding table associated with the SD-WAN tunnel.

Alternatively, in some embodiments, the mapping relationship between the SD-WAN tunnel and the peer station identifier of the SD-WAN tunnel may be directly recorded in the station device, for example, a mapping table for recording the mapping relationship between the SD-WAN tunnel and the peer station identifier of the SD-WAN tunnel is generated.

In general, in the case that the site device establishes a mapping relationship between the SD-WAN tunnel and the opposite site identifier of the SD-WAN tunnel, the site device can determine, through the mapping relationship, that the interface is the SD-WAN tunnel corresponding to the next-hop site identifier, in the case that the next-hop site identifier is determined.

In the process of generating a BIER forwarding table by the station device, the station device advertises BIER information to other station devices through the RR, wherein the BIER information comprises, for example, the BFR-ID of the station device and the BIER forwarding router release Prefix (BFR-Prefix) of the station device.

After the station device receives BIER information advertised by other station devices, the station device can generate a BIER forwarding table according to the received BIER information and topology of the SD-WAN. The BIER forwarding table is used for recording the mapping relation between the BFR-ID and the next hop station.

Further, the site device may obtain the topology of the SD-WAN by receiving SD-WAN tunnel information advertised by other site devices. Specifically, for the station devices in the SD-WAN, each station device will advertise the SD-WAN tunnel information established by itself and other station devices to other station devices. Therefore, after receiving the SD-WAN tunnel information advertised by other station devices, any station device can obtain the tunnel connection relationship between the station devices in the SD-WAN, i.e. obtain the topology of the whole SD-WAN. The topology of the SD-WAN is used for describing the connection relation of the SD-WAN tunnel established between all site devices in the SD-WAN. In this way, when the station apparatus uses another station apparatus as a destination address, the station apparatus can calculate the next hop station to the other station apparatus based on the topology of the SD-WAN.

For example, suppose that the SD-WAN includes station device a-station device E, station device a receives SD-WAN tunnel information advertised by station device B-station device E. The SD-WAN tunnel information advertised by the site equipment B is as follows: the station equipment B establishes an SD-WAN tunnel with the station equipment A and the station equipment C; the SD-WAN tunnel information advertised by station device C is: the station equipment C and the station equipment B establish an SD-WAN tunnel; the SD-WAN tunnel information advertised by station device D is: the station equipment D and the station equipment A and the station equipment E establish an SD-WAN tunnel; the SD-WAN tunnel information advertised by station device E is: site device E establishes an SD-WAN tunnel with site device D and site device C.

Then, station device a may obtain the topology of the SD-WAN according to the SD-WAN tunnel information advertised by station device B-station device E. Specifically, the topology of the SD-WAN is: the station equipment A establishes an SD-WAN tunnel with the station equipment B and the station equipment D, and the station equipment B also establishes an SD-WAN tunnel with the station equipment C; site device C also establishes a tunnel with site device E and site device D also establishes an SD-WAN tunnel with site device E. That is, the SD-WAN topology may describe the SD-WAN tunnel connection relationship of the individual site devices as: [ A-B-C ] and [ A-D-E-C ].

Illustratively, when the station device a takes the station device C as a destination address, the station device a may calculate, through a shortest path algorithm, that a station of a next hop destined for the station device C is the station device B on the topology of the SD-WAN.

Fig. 6 is a schematic diagram illustrating generation of a BIER forwarding table by a station device in an SD-WAN network according to an embodiment of the present application. As shown in fig. 6, in the SD-WAN network, each site device is configured with a unique BFR-Prefix and BFR-ID.

In fig. 6, each station device announces its BIER information to other station devices through RR, where the BIER information may include BFR-Prefix and BFR-ID of the station device. Based on BIER information obtained from other site devices, each site device is able to generate a corresponding BIER forwarding table.

As shown in fig. 6, for the station apparatus 1, the station apparatus 1 generates a BIER forwarding table on the station apparatus 1 from BIER information acquired from the station apparatus 2-the station apparatus 7. The BIER forwarding table on the station device 1 records the BFR-ID of the station device, the End-BIER of the next hop, and the mapping relationship between the stations of the next hop. For example, in the BIER forwarding table, the BFR-ID in the first forwarding entry is 3 and the next hop site is site 2. That is, in the station apparatus 1, for a message addressed to the station apparatus 3 having the BFR-ID of 3, the next hop station is the station 2. For another example, in the BIER forwarding table, the BFR-ID in the third forwarding entry is 5 and the next hop site is site 2. That is, in the station apparatus 1, for a message destined for the station apparatus 5 having the BFR-ID of 5, the next hop station is the station 2; that is, the station device 1 sends the message to the station device 5 to the station device 3, so that the station device 3 continues to forward the message to the station device 5.

Similarly, for site device 3, site device 3 generates a BIER forwarding table on site device 3 based on BIER information obtained from site devices 1, 2, 4-7. The BIER forwarding table on the station device 3 also records the BFR-ID of the station device, the next hop End-BIER, and the mapping relationship between the next hop stations.

Optionally, a bitmask for performing a locate operation with the BS may be further included in the BIER forwarding table generated by the station apparatus, that is, the same BIER forwarding table entry includes the BFR-ID, the bitmask, and the mapping relationship between the next hop stations.

As can be seen from fig. 5 and 6, in the case where the station apparatus determines the next hop station based on the BIER forwarding table shown in fig. 6, the station apparatus can determine the SD-WAN tunnel for performing packet forwarding based on the mapping relationship between the station identification and the SD-WAN tunnel shown in fig. 5, thereby enabling BIER multicast forwarding through the SD-WAN tunnel.

The above describes the procedure in which the station apparatus generates the BIER forwarding table based on BIER information advertised by other station apparatuses. It should be understood that BIER information is only advertised to each other between site devices of the SD-WAN network in this embodiment, and not to all network devices in the network. Therefore, in this embodiment, the existing protocol packet is extended to realize that BIER information is only advertised between the site devices of the SD-WAN network.

Specifically, the station device may advertise BGP messages to other station devices, where BIER information is carried in the BGP messages. The BGP message may include, for example, a BGP shortest path first (shortest path first, SPF) address family message, a BGP Link State (LS) address family message, or a BGP SD-WAN address family message.

In one possible implementation, BIER information is carried by extending the Prefix network layer reachability information (Prefix Network Layer Reachability Information, prefix NLRI) field in BGP SPF address family messages or BGP LS address family messages.

Referring to fig. 7, fig. 7 is a schematic diagram illustrating that a BGP SPF address family packet extension carries BIER information according to an embodiment of the present application. As shown in fig. 7, the BGP SPF address family message includes the following fields: protocol identification (Protocol-ID), identifier (Identifier), local node descriptor (Local Node Descriptors), and prefix descriptor (Local Node Descriptors). Wherein Local Node Descriptors is a type-length-value (TLV) field, and Local Node Descriptors is the Prefix NLRI described above. By extending Local Node Descriptors field, a Sub-TLV (Sub-TLV) is obtained. The Sub-TLV is 32 in type, and BIER information carried in the Sub-TLV comprises the following components: subdomain identification (Subdomain-ID), BFR-ID. In addition, two Sub-TLVs may be extended in the Sub-TLV. The BIER information carried by the first Sub-TLV includes: a MAX set identifier (Maximum Set Identifier, MAX SI), a bit string length (Bit String Length, BSL), and a BIER forwarding table identification (bit index forwarding table identifier, BIFT-ID), wherein MAX SI is used to indicate the maximum length of the BS; BSL is used to indicate the bit string length in BIER encapsulation. The BIER information carried by the second Sub-TLV includes End-BIER.

It will be appreciated that the above example of fig. 7 extends over this TLV Local Node Descriptors to implement a specific way of carrying BIER information. In practical applications, the BIER information may be extended and carried on a BGP SPF address group packet or other TLVs in a BGP LS address group packet, which is not limited in this embodiment.

In another possible implementation, BIER information is carried by extending the SD-WAN NLRI attribute field in BGP SD-WAN address family messages.

The specific manner of carrying BIER information by expanding the existing BGP address family message is described above, and in practical application, BIER information may also be carried by other protocol messages, which is not specifically limited in this embodiment. In addition, instead of carrying BIER information by expanding an existing protocol message, BIER information may be carried by adding a new protocol message, for example, adding a BGP address family message.

The above describes the process of carrying BIER information by extending protocol messages, so as to realize the notification of BIER information between site devices, so that the site devices can generate BIER forwarding tables conveniently. After the site equipment generates the mapping relation between the SD-WAN and the site identification and the BIER forwarding table, the site equipment can forward the BIER message based on the SD-WAN tunnel.

However, for the first station device that acquires multicast data (e.g., a station device connected to a multicast source or a station device that is a multicast source), the station device needs to generate a BS according to the multicast group of the multicast data to instruct other station devices to forward the multicast data. Wherein, the multicast group refers to the destination address of the multicast data. For network devices that need to receive multicast data, the network devices need to join the multicast group in advance. That is, the first station device that acquires the multicast data needs to know the multicast group information in the SD-WAN network in order to generate a corresponding BS based on the multicast group corresponding to the multicast data when the multicast data is acquired.

In this embodiment, when receiving the Multicast group joining request information sent by the receiving device of the Multicast data, the station device notifies the receiving device of the joining Multicast information to other station devices through BGP Multicast VPN (MVPN) address family messages, so that the other station devices can generate corresponding Multicast group information.

Illustratively, taking the site device 5 in fig. 6 as an example, the site device 5 is also connected to a receiving device. The receiving device transmits multicast group joining request information to the station device 5 to instruct the receiving device to request joining to a specific multicast group. For example, the multicast group addition request information includes (G) addition information or (S, G) addition information. Wherein, the key information of the (G) joining information is (RD, source AS, RP, G, origin IP), RD refers to the Routing Domain of the receiving device; source AS refers to Source domain (Source Autonomous System); RP refers to a multicast distribution point (rendezvous point); g refers to a multicast group; the origin IP refers to the source IP address of the access device. The key information of the (S, G) joining information is (RD, source AS, S, G, origin IP), which refers to a multicast Source. After acquiring the multicast group joining request information sent by the receiving device, the station device 5 may notify other station devices (for example, station devices 1-4) of the information that the receiving device joins the multicast through the RR, where the information that the receiving device joins the multicast may include the above-mentioned (x, G) joining information or (S, G) joining information. After receiving the information of joining the multicast by the receiving device advertised by the station device 5, the other station devices can determine the multicast group joined by the receiving device, and further determine the destination node set of the multicast message based on the multicast group.

The above describes the deployment procedure of creating an SD-WAN tunnel on a site device of the SD-WAN network, generating a BIER forwarding table, and generating multicast group information, and how the site device in the SD-WAN network implements BIER multicast based on the above deployment procedure will be described below.

Referring to fig. 8, fig. 8 is a flowchart of a multicast communication method 800 according to an embodiment of the present application. As shown in fig. 8, the multicast communication method 800 includes the following steps 801-808.

In step 801, the multicast source sends a multicast packet 0 to the station apparatus 1.

In this embodiment, the multicast source is a sender of multicast data and is responsible for sending the multicast data to each device joining in the multicast group. The multicast message 0 includes multicast data, and the multicast message 0 is further used for indicating a multicast group corresponding to the multicast data.

In step 802, the station apparatus 1 generates a multicast packet 1 according to the multicast packet 0.

Since multicast message 0 indicates a multicast group corresponding to the multicast data, station device 1 may determine the BIER forwarding table and the bit string by querying the multicast forwarding table based on the multicast group corresponding to the multicast data. Station apparatus 1 determines the next hop station of the multicast data as station apparatus 3 by performing bit and operation on the bit string and the bit mask in the BIER forwarding table. Then, based on the next-hop station being station 3, station apparatus 1 determines SD-WAN tunnel 1 for forwarding the multicast data by querying the mapping relationship between the next-hop station and the SD-WAN tunnel. Next, the station apparatus 1 encapsulates a first BIER header in an outer layer of the multicast data, wherein the first BIER header includes therein a bit string for indicating a destination node set of the multicast data. In addition, the station device 1 encapsulates the SD-WAN tunnel encapsulation header on the outer layer of the first BIER header based on the information of the SD-WAN tunnel 1, thereby obtaining the multicast message 1.

In step 803, the station apparatus 1 sends the multicast message 1 to the station apparatus 3 through the SD-WAN tunnel 1.

Wherein, station apparatus 1 and station apparatus 3 are two endpoints of SD-WAN tunnel 1.

In step 804, the station device 3 generates a multicast message 2 and a multicast message 3 according to the multicast message 1.

After receiving the multicast message 1 through the SD-WAN tunnel 1, since the site device 3 is an endpoint of the SD-WAN tunnel 1, the site device 3 decapsulates the SD-WAN tunnel encapsulation header in the multicast message 1, to obtain the first BIER header and multicast data.

Then, the station device 3 determines that the next hop station is the station 3 and the station 4 according to the bit string in the first BIER header and the BIER forwarding table in the station device 3. Referring to fig. 9, fig. 9 is a schematic diagram illustrating determining a next hop station based on a bit string and a BIER forwarding table according to an embodiment of the present application. As shown in fig. 9, the bit string in the first BIER header of the multicast packet 1 sent by the station apparatus 1 to the station apparatus 3 is 0111, where bits in the bit string indicate from left to right, station 1, station 2, station 3, and station 4, respectively. Thus, a bit string of 0111 in the first BIER header indicates that the set of destination nodes of the multicast data are site 2, site 3 and site 4. Station device 3 determines that forwarding entries with bitmasks of 0010 and 0001, respectively, match the bit string by performing a bitstring of 0111 with a bitmask in the BIER forwarding table, thus determining that the next hop stations are station 3 and station 4, respectively.

Further, based on the next-hop stations being station 3 and station 4, respectively, the station device 3 determines that the outgoing interface points to the SD-WAN tunnel 1 when the next-hop station is station 3 and determines that the outgoing interface points to the SD-WAN tunnel 3 when the next-hop station is station 4 based on the mapping relationship on the station device 3.

Alternatively, when the station device 3 determines the SD-WAN tunnel corresponding to the next-hop station based on the mapping relationship between the next-hop station and the SD-WAN tunnel, the same next-hop station may correspond to one or more SD-WAN tunnels, and the station device 3 may select one of the multiple SD-WAN tunnels to forward the message. Illustratively, when the station apparatus 3 determines, for the station 1, an SD-WAN tunnel corresponding to the next-hop station based on the next-hop station, the station apparatus 3 may determine that the SD-WAN tunnel includes the SD-WAN tunnel between the station apparatus 3 and the station apparatus 1 and the SD-WAN tunnel between the station apparatus 3 and the station apparatus 2, so that the station apparatus 3 may select one of the SD-WAN tunnels as a path for forwarding the message. Specifically, the station apparatus 3 may select the SD-WAN tunnel for forwarding the packet based on a preset load balancing policy or the link quality of the tunnel, which is not limited in this embodiment.

Based on the information obtained by searching the BIER forwarding table and the mapping relation, the station device 3 encapsulates the multicast data with a header to obtain a multicast message 2 and a multicast message 3. Specifically, the station apparatus 3 encapsulates the second BIER header on the outer layer of the multicast data, where the format of the second BIER header is the same as the format of the first BIER header. Then, the station device 3 encapsulates the first SD-WAN tunnel encapsulation header on the outer layer of the second BIER header, to obtain the multicast message 2. The destination address of the first SD-WAN tunnel encapsulation header is the destination address of the peer device of SD-WAN tunnel 1 (i.e. the destination address of site device 5: IP address 2). That is, multicast message 2 includes a first SD-WAN tunnel encapsulation header, a second BIER header, and multicast data.

Similarly, the station apparatus 3 copies the multicast data and encapsulates a third BIER header in an outer layer of the copied multicast data, wherein the format of the third BIER header is the same as the format of the first BIER header. Then, the station device 3 encapsulates the second SD-WAN tunnel encapsulation header on the outer layer of the third BIER header, to obtain the multicast message 3. Wherein the destination address of the second SD-WAN tunnel encapsulation header is the destination address of the peer device of SD-WAN tunnel 2 (i.e. the destination address of station device 6: IP address 3). That is, the multicast message 3 includes the second SD-WAN tunnel encapsulation header, the third BIER header, and the multicast data.

Fig. 10 is a schematic diagram illustrating a format of a multicast packet according to an embodiment of the present application. As shown in fig. 10, in this embodiment, the multicast message based on the SD-WAN tunnel is obtained by expanding the original SD-WAN message. The original SD-WAN message comprises an outer Ethernet header, an IPv4 header, a general routing encapsulation (Generic Routing Encapsulation, GRE) header and multicast data. The multicast message (e.g., the multicast message 2 and the multicast message 3 described above) generated by the station device in this embodiment includes an outer ethernet header, an IPv4 header, a GRE header, a BIER header, and multicast data. Wherein the outer Ethernet header and the IPv4 header form an SD-WAN tunnel encapsulation header. And, a Protocol (Protocol) field in the IPv4 header is used to indicate that the next header is a GRE header; a Protocol Type (Protocol Type) field in the GRE header is used to indicate that the next header is a BIER header.

In the SD-WAN tunnel encapsulation header of the multicast message, the destination Address (DEST Address) in the IPv4 header is the IP Address of the opposite site equipment of the SD-WAN tunnel, namely the exit Address of the SD-WAN tunnel. For example, in the multicast packet 2 described above, the destination address of the first SD-WAN tunnel encapsulation header is the destination address of the peer device (station device 5) of the SD-WAN tunnel 1.

Referring to fig. 11, fig. 11 is a schematic diagram of a format of a BIER header according to an embodiment of the present application. As shown in fig. 11, the following key fields are included in the BIER header of the multicast message.

BIFT-id: an identifier for identifying a BIER forwarding table.

Traffic Class (TC): for indicating the quality of service of the communication.

S: and (5) marking the label stack bottom.

Time To Live (TTL): indicating the hop count of the message after BIER forwarding.

Nibble: legal value is 0101. If the field of the BIER message received by the station apparatus is not 0101, the message is discarded.

Ver: for indicating the version number of the BIER message.

Bit String Length (BSL): the values are 1-7 to represent different bit string lengths.

Entropy: for making a path selection when an equivalent path exists. Specifically, messages with the same Bit String and entry values select the same path.

Rsv: the reserved bit, default to 0.

Differential service code point (Differentiated Services Code Point, DSCP): the priority of the message itself determines the priority of message transmission.

Proto: the next layer of protocol identification is used for identifying the Payload type behind the BIERv6 message header.

Bit forwarding ingress router (Bit Forwarding Ingress Router identity, BFIR-ID): the identity of the ingress device that the multicast message entered the BIER domain.

Bit String (Bit String): and a bit string, wherein each bit corresponds to the BIER equipment in one BFER domain, and the bit is set to 1, so that the message is forwarded to the corresponding BIER equipment.

In step 805, the station apparatus 3 transmits the multicast message 2 to the station apparatus 5 through the SD-WAN tunnel 2.

After obtaining the multicast message 2, the station device 3 sends the multicast message 2 to the station device 5 through the SD-WAN tunnel 2. The site device 3 and the site device 5 may be directly connected, and other network devices may be connected between the site device 3 and the site device 5. In case that another network device is connected between the station device 3 and the station device 5, the other network device forwards the multicast message 2 based on the destination address in the first SD-WAN tunnel encapsulation header of the multicast message 2 (i.e. the IP address of the station device 5).

In step 806, the station apparatus 3 sends the multicast message 3 to the station apparatus 6 through the SD-WAN tunnel 3.

In this embodiment, step 806 is similar to step 805, and please refer to step 805 described above, and further description is omitted herein.

In step 807, the station apparatus 5 transmits the multicast data in the multicast message 2 to the reception apparatus 1.

After the station device 5 receives the multicast message 2, the station device 5 decapsulates the first SD-WAN tunnel header in the multicast message 2. Because the destination address in the second BIERv6 header in multicast packet 2 is the SID of station apparatus 5, station apparatus 5 queries the BIER forwarding table based on the bit string in the second BIERv6 header. In the process that the station device 5 queries the BIER forwarding table based on the bit string, the BIER forwarding table in the station device 5 does not have a forwarding table item matched with the bit string, so that the station device 5 can determine that the station device itself is the destination of BIER forwarding, the station device 5 decapsulates the second BIERv6 header in the multicast message 2, and sends multicast data to the receiving device 1 according to the indication of the multicast data.

In step 808, the station apparatus 6 transmits the multicast data in the multicast packet 3 to the receiving apparatus 2.

In this embodiment, step 808 is similar to step 807, and please refer to step 807 described above, and will not be repeated here.

Referring to fig. 12, fig. 12 is a flowchart of a multicast communication method 1200 according to an embodiment of the present application. As shown in fig. 12, the multicast communication method 1200 includes the following steps 1201-1203.

Step 1201, a first station device receives a first packet, where the first packet includes a first BIER header and multicast data, where the first BIER header is used to indicate a set of destination nodes of the multicast data.

In this embodiment, the multicast communication method 1200 is used to implement the method 800 of the above embodiment. When the multicast communication method 1300 is used to implement the method 800, the first station device may be the station device 3 in the method 800, and the first packet may be the multicast packet 1 in the method 800.

Optionally, the first site device is a CPE or POP site device.

Step 1202, the first site device generates a second message according to the first message, where the second message includes a first SD-WAN tunnel encapsulation header, a second BIER header, and multicast data, a destination address of the first SD-WAN tunnel encapsulation header is an IP address of the second site device, and the IP address of the second site device is an exit address of the first SD-WAN tunnel between the first site device and the second site device, where the second BIER header is used to indicate a set of destination nodes of the multicast data.

Correspondingly, the second packet may be the multicast packet 2 in the method 800, and the second station device may be the station device 5 in the method 800.

In step 1203, the first station device sends a second message to the second station device through the first SD-WAN tunnel.

Correspondingly, the first SD-WAN tunnel may be SD-WAN tunnel 2 between station device 3 and station device 5 in method 800 described above.

Optionally, an extended GRE header is further encapsulated between the first SD-WAN tunneling header and the second BIER header, and a protocol type field in the extended GRE header is used to indicate that the next header of the extended GRE header is the BIER header.

Optionally, the first site device is a CPE or POP site device.

Optionally, the first station device determines that the next-hop station is the first station according to the bit string in the first BIER header and the BIER forwarding table, and the target station device is located at the first station; and the first station equipment determines to send a second message to the second station equipment through the first SD-WAN tunnel according to the first station.

Optionally, the first station device sends first BIER information to the third station device, where the first BIER information includes at least one of the following information: BFR-ID of the first site device and BFR-Prefix of the first site device; the first station device receives second BIER information advertised by the destination station device, the second BIER information including one or more of: BFR-ID of target site equipment and BFR-Prefix of target site equipment.

Optionally, the first BIER information or the second BIER information is carried in BGP messages.

Optionally, the BGP message includes a BGP shortest path first SPF address family message, a BGP link state LS address family message, or a BGP SD-WAN address family message.

Optionally, the first BIER information or the second BIER information is carried in a Prefix network layer reachability information Prefix NLRI field in a BGP SPF address family message or a BGP LS address family message.

Specifically, the carrying manner of the first BIER information and the second BIER information may refer to the description of the corresponding embodiments of fig. 6 and fig. 7, and are not repeated herein.

Optionally, the first site device generates a third message according to the first message, where the third message includes a second SD-WAN tunnel encapsulation header, a third BIER header, and multicast data, a destination address of the second SD-WAN tunnel encapsulation header is an IP address of the third site device, the IP address of the third site device is an exit address of the second SD-WAN tunnel between the first site device and the third site device, and the third BIER header is used to indicate a set of destination nodes of the multicast data; and the first site equipment sends a third message to the third site equipment through the second SD-WAN tunnel.

Illustratively, when the multicast communication method 1200 is used to implement the method 800, the third station device may be the station device 6 in the method 800, and the third packet may be the multicast packet 3 in the method 800.

Referring to fig. 13, fig. 13 is a flowchart of a multicast communication method 1300 according to an embodiment of the present application. As shown in fig. 13, the multicast communication method 1300 provided by the embodiment of the present application includes the following steps 1301 to 1302.

In step 1301, the first station device sends a first BGP message to the second station device, where the first BGP message carries first BIER information, and the first BIER information includes a BIER forwarding router identifier BFR-ID of the first station device.

In step 1302, the first site device receives a second BGP message advertised by a second site device, where the second BGP message carries second BIER information, and the second BIER information includes a BFR-ID of the second site device.

In this embodiment, the multicast communication method 1300 is used to implement the above embodiment corresponding to fig. 6. When the multicast communication method 1300 is used to implement the embodiment corresponding to fig. 6, the first site device may be the site device 3, and the second site device may be the site device 1 or the site device 5.

Optionally, the first station device generates a first BIER forwarding table item according to the second BGP message, where the first BIER forwarding table item records a mapping relationship between a BFR-ID of the second station device and a next hop station, where the BFR-ID in the first BIER forwarding table item indicates a destination device for BIER forwarding.

Specifically, the first site device may be the site device 3 in the embodiment corresponding to fig. 6, and the process of generating the BIER forwarding table entry by the first site device according to the second BGP message may refer to the process of generating the BIER forwarding table entry by the site device 3 in the embodiment corresponding to fig. 6, which is not described herein.

Optionally, the method 1300 further includes: the second station equipment generates a second BIER forwarding table item according to the first BGP message, and the second BIER forwarding table item records the mapping relation between the BFR-ID of the first station equipment and the next hop station, wherein the BFR-ID in the second BIER forwarding table item indicates the destination equipment for BIER forwarding.

Specifically, the first site device may be the site device 3 in the embodiment corresponding to fig. 5, the second site device may be the site device 5 in the embodiment corresponding to fig. 5, and the process of establishing the SD-WAN tunnel and storing the mapping relationship between the next hop site and the SD-WAN tunnel by the first site device may refer to the process of generating the forwarding table by the site device 3 in the embodiment corresponding to fig. 5, which is not described herein.

Optionally, the method 1300 further includes: the first station device determines a next hop station reaching the second station device according to the topology of the SD-WAN.

Optionally, the method 1300 further includes: the first site equipment receives first SD-WAN tunnel information advertised by third site equipment, wherein the first SD-WAN tunnel information comprises an IP address of the third site equipment and site information of the third site equipment; the first station equipment establishes a first SD-WAN tunnel between the first station equipment and the third station equipment according to the first SD-WAN tunnel information, and stores a first mapping relation between a next-hop station and the first SD-WAN tunnel, wherein the next-hop station in the first mapping relation is a station to which the third station equipment belongs.

Specifically, the first site device may be the site device 1 in the embodiment corresponding to fig. 5, the third site device may be the site device 3 in the embodiment corresponding to fig. 5, the second site device may be the site device 5 in the embodiment corresponding to fig. 5, and the processes of establishing the SD-WAN tunnel and storing the mapping relationship between the next hop site and the SD-WAN tunnel by the first site device, the second site device and the third site device may refer to the process of generating the forwarding table by the site device in the embodiment corresponding to fig. 5, which is not described herein.

Optionally, the method 1300 further includes: the third site equipment receives second SD-WAN tunnel information advertised by the second site equipment, wherein the second SD-WAN tunnel information comprises an IP address of the second site equipment and site information of the second site equipment; and the third station equipment establishes a second SD-WAN tunnel between the third station equipment and the second station equipment according to the second SD-WAN tunnel information, and stores a second mapping relation between the next-hop station and the second SD-WAN tunnel, wherein the next-hop station in the second mapping relation is the station to which the second station equipment belongs.

Optionally, the method 1300 further includes: the first site equipment receives third SD-WAN tunnel information advertised by the second site equipment, wherein the third SD-WAN tunnel information comprises an IP address of the second site equipment and site information of the second site equipment; the first station device establishes a third SD-WAN tunnel between the first station device and the second station device according to the third SD-WAN tunnel information, and stores a third mapping relation between a next-hop station and the third SD-WAN tunnel, wherein the next-hop station in the third mapping relation is the station to which the second station device belongs.

Optionally, the method 1300 further includes: the first station equipment receives a first BIER message, wherein the first BIER message comprises a first BIER header and multicast data, and the first BIER header is used for indicating a set of destination nodes of the multicast data; and the first station equipment determines to forward the multicast data through the first SD-WAN tunnel according to the first BIER head, the first BIER forwarding table item and the first mapping relation.

Optionally, the method 1300 further includes: the first station equipment receives a first BIER message, wherein the first BIER message comprises a first BIER header and multicast data, and the first BIER header is used for indicating a set of destination nodes of the multicast data; and the first station equipment determines to forward the multicast data through the third SD-WAN tunnel according to the first BIER head, the first BIER forwarding table item and the third mapping relation.

In order to implement the above embodiment, the present application further provides a communication device. Referring to fig. 14, fig. 14 is a schematic structural diagram of a communication device 1400 according to an embodiment of the application. The communication device 1400 shown in fig. 14 belongs to, for example, the station apparatus 3 in the method 800 or the first station apparatus in the method 1200 in the embodiment corresponding to fig. 5 or fig. 6.

As shown in fig. 14, the communication apparatus 1400 belongs to a first site device in an SD-WAN, and the communication apparatus 1400 includes: a receiving module 1401, configured to receive a first packet, where the first packet includes a first bit index explicit replication BIER header and multicast data, and the first BIER header is used to indicate a set of destination nodes of the multicast data; a processing module 1402, configured to generate a second packet according to the first packet, where the second packet includes a first SD-WAN tunnel encapsulation header, a second BIER header, and multicast data, a destination address of the first SD-WAN tunnel encapsulation header is an IP address of a second site device, and an IP address of the second site device is an exit address of the first SD-WAN tunnel between the first site device and the second site device, where the second BIER header is used to indicate a set of destination nodes of the multicast data; a sending module 1403 is configured to send the second packet to the second site device through the first SD-WAN tunnel.

In one possible implementation, the processing module 1402 is further configured to: determining a next-hop site as a first site according to the bit string in the first BIER header and the BIER forwarding table, wherein target site equipment is located at the first site; and according to the first station, determining to send a second message to second station equipment through the first SD-WAN tunnel.

In one possible implementation, the sending module 1403 is further configured to send first BIER information to the third station apparatus, where the first BIER information includes at least one of the following information: the BIER forwarding router of the first site equipment identifies BFR-ID and issues a Prefix BFR-Prefix; the receiving module 1401 is further configured to receive second BIER information advertised by the target site device, where the second BIER information includes one or more of the following information: BFR-ID of target site equipment and BFR-Prefix of target site equipment.

In a possible implementation manner, the processing module 1402 is further configured to generate a third packet according to the first packet, where the third packet includes a second SD-WAN tunnel encapsulation header, a third BIER header, and multicast data, a destination address of the second SD-WAN tunnel encapsulation header is an IP address of a third site device, the IP address of the third site device is an exit address of a second SD-WAN tunnel between the first site device and the third site device, and the third BIER header is used to indicate a set of destination nodes of the multicast data; the sending module 1403 is further configured to send a third packet to a third site device through the second SD-WAN tunnel.

In another possible embodiment, the communication apparatus 1400 may belong to a second site device in the SD-WAN. In the communication apparatus 1400, a receiving module 1401 is configured to receive, through a first SD-WAN tunnel, a first packet sent by a first site device, where the first packet includes a first SD-WAN tunnel encapsulation header, a first BIER header, and multicast data, a destination address of the first SD-WAN tunnel encapsulation header is an IP address of a second site device, an IP address of the second site device is an exit address of the first SD-WAN tunnel between the first site device and the second site device, and the second BIER 6 header is used to indicate a set of destination nodes of the multicast data; a processing module 1402, configured to generate a second packet according to the first packet, where the second packet includes the multicast data; a sending module 1403 is configured to forward the second packet.

Referring to fig. 15, fig. 15 is a schematic structural diagram of a communication device 1500 according to an embodiment of the present application. The communication apparatus 1500 shown in fig. 15 is, for example, the station apparatus 3 in the embodiment corresponding to fig. 5 or fig. 6, or the first station apparatus in the method 1300.

As shown in fig. 15, the communication apparatus 1500 is a first station device in an SD-WAN, and the communication apparatus 1500 includes: a sending module 1501, configured to send a first BGP packet to a second site device, where the first BGP packet carries first BIER information, and the first BIER information includes a BIER forwarding router identifier BFR-ID of the first site device; a receiving module 1502, configured to receive a second BGP message advertised by a second site device, where the second BGP message carries second BIER information, and the second BIER information includes a BFR-ID of the second site device; a processing module 1503, configured to generate a first BIER forwarding table entry according to the second BGP packet, where the first BIER forwarding table entry records a mapping relationship between a BFR-ID of the second site device and a next-hop site, where the BFR-ID in the first BIER forwarding table entry indicates a destination device for BIER forwarding.

In a possible implementation, the processing module 1503 is further configured to determine a next hop station reaching the second station device according to the topology of the SD-WAN.

In a possible implementation manner, the receiving module 1502 is further configured to receive first SD-WAN tunnel information advertised by the third site device, where the first SD-WAN tunnel information includes an IP address of the third site device and site information to which the third site device belongs; the processing module 1503 is further configured to establish a first SD-WAN tunnel between the first site device and the third site device according to the first SD-WAN tunnel information, and store a first mapping relationship between a next-hop site and the first SD-WAN tunnel, where the next-hop site in the first mapping relationship is a site to which the third site device belongs.

In a possible implementation manner, the receiving module 1502 is further configured to receive third SD-WAN tunnel information advertised by the second site device, where the third SD-WAN tunnel information includes an IP address of the second site device and site information to which the second site device belongs; the processing module 1503 is further configured to establish a third SD-WAN tunnel between the first site device and the second site device according to the third SD-WAN tunnel information, and store a third mapping relationship between a next-hop site and the third SD-WAN tunnel, where the next-hop site in the third mapping relationship is a site to which the second site device belongs.

In one possible implementation, the receiving module 1502 is further configured to receive a first BIER packet, where the first BIER packet includes a first BIER header and multicast data, and the first BIER header is configured to indicate a set of destination nodes of the multicast data; the processing module 1503 is further configured to determine to forward the multicast data through the first SD-WAN tunnel according to the first BIER header, the first BIER forwarding table entry, and the first mapping relationship.

In one possible implementation, the receiving module 1502 is further configured to receive a first BIER packet, where the first BIER packet includes a first BIER header and multicast data, and the first BIER header is configured to indicate a set of destination nodes of the multicast data; the processing module 1503 is further configured to determine to forward the multicast data through the third SD-WAN tunnel according to the first BIER header, the first BIER forwarding table entry, and the third mapping relationship.

Referring to fig. 16, fig. 16 is a schematic structural diagram of a communication device 1600 according to an embodiment of the application. The communication apparatus 1600 shown in fig. 16 may be used to perform the steps performed by the first station device described in the foregoing embodiments. While certain specific features are shown in fig. 16, those skilled in the art will appreciate from the present examples that various other features are not shown in fig. 16 for the sake of brevity so as not to obscure more pertinent aspects of the disclosed embodiments of the present application. To this end, as an example, in some implementations, the communication device 1600 includes one or more processors (e.g., CPUs) 1601, a network interface 1602, a programming interface 1603, a memory 1604, and one or more communication buses 1605 for interconnecting the various components. In other implementations, the communications device 1600 may also omit or add portions of functional components or units to the examples described above.

In some implementations, the network interface 1602 is used to connect with one or more other communication devices/servers in a network system. In some implementations, the communication bus 1605 includes circuitry that interconnects and controls communications between system components. The memory 1604 may include a nonvolatile memory such as a read-only memory (ROM), a Programmable ROM (PROM), an Erasable Programmable ROM (EPROM), an electrically erasable programmable EPROM (EEPROM), or a flash memory. The memory 1604 may also include volatile memory, which may be random access memory (random access memory, RAM) used as external cache memory.

In some implementations, the non-transitory computer readable storage medium of the memory 1604 stores the following programs, modules, and data structures, or a subset thereof, including, for example, an acquisition unit (not shown in the figures), a transmission unit (not shown in the figures), and a processing unit 16041.

In one possible embodiment, the communication apparatus 1600 may have any of the functions of the station device in the method embodiments described above with respect to fig. 12-14.

It should be understood that the communication apparatus 1600 corresponds to the first station device in the above method embodiment, and each module in the communication apparatus 1600 and the other operations and/or functions described above are respectively implemented for implementing various steps and methods implemented by the first communication apparatus in the above method embodiment, and specific details may be referred to the method embodiment corresponding to fig. 12 to 14, which are not repeated herein for brevity.

It should be understood that the present application may be implemented by the network interface 1602 on the communication device 1600, or the processor may invoke the program code in the memory and implement the functions of the transceiver unit in conjunction with the network interface 1602 when needed.

In various implementations, the communication device 1600 is configured to perform the multicast communication method provided by the embodiments of the present application, for example, the multicast communication method corresponding to the embodiments shown in fig. 12-13.

The specific structure of the communication device shown in fig. 16 of the present application may be as shown in fig. 17.

Fig. 17 is a schematic structural diagram of a communication device 1700 according to an embodiment of the present application. The communication apparatus 1700 shown in fig. 17 may be used to perform the steps performed by any one of the first station device, the second station device, the transmitting side device, and the receiving side device described in the above embodiments. The communication apparatus 1700 includes: a master board 1710 and an interface board 1730.

The main control board 1710 is also called a main processing unit (main processing unit, MPU) or a route processor (route processor), and the main control board 1710 is used for controlling and managing each component in the communication apparatus 1700, including route calculation, device management, device maintenance, and protocol processing functions. The main control board 1710 includes: a central processing unit 1711 and a memory 1712.

The interface board 1730 is also referred to as a line processing unit (line processing unit, LPU), line card, or service board. The interface board 1730 is used to provide various service interfaces and to enable forwarding of data packets. Traffic interfaces include, but are not limited to, ethernet interfaces, POS (Packet over SONET/SDH) interfaces, and the like. Interface board 1730 includes: a central processor 1731, a network processor 1732, a physical interface card (physical interface card, PIC) 1733, and a forwarding table entry memory 1734.

The central processor 1731 on the interface board 1730 is used to control and manage the interface board 1730 and communicate with the central processor 1711 on the master control board 1710.

The network processor 1732 is configured to implement forwarding processing of the packet. The network processor 1732 may be in the form of a forwarding chip.

The physical interface card 1733 is used to implement the docking function of the physical layer, from which the original traffic enters the interface board 1730, and from which the processed messages are sent out from the physical interface card 1733. The physical interface card 1733 includes at least one physical interface, also referred to as a physical interface, which may be a flexible ethernet (Flexible Ethernet, flexE) physical interface. In some embodiments, the central processor 1731 of the interface board 1730 may also perform the functions of the network processor 1732, such as implementing software forwarding based on a general purpose CPU, so that the network processor 1732 is not required in the interface board 1730.

Optionally, communication device 1700 includes a plurality of interface boards, for example communication device 1700 further includes an interface board 1740, interface board 1740 including: central processor 1741, network processor 1742, physical interface card 1743, and forwarding table entry memory 1744.

Optionally, communication apparatus 1700 further comprises a switch fabric 1720. Switch fabric 1720 may also be referred to as a switch fabric unit (switch fabric unit, SFU). Where the communication device has multiple interface boards 1730, switch fabric 1720 is used for data exchange between the interface boards. For example, interface board 1730 and interface board 1740 may communicate with each other through switch board 1720.

The master plate 1710 is coupled with an interface plate. For example, the master 1710, interface 1730, and interface 1740 boards, and the switch fabric 1720 are interconnected by a system bus and/or a system backplane to achieve interworking. In one possible implementation, an inter-process communication protocol (inter-process communication, IPC) channel is established between the master board 1710 and the interface board 1730, with communication between the master board 1710 and the interface board 1730 being via the IPC channel.

Logically, the communication device 1700 comprises a control plane comprising a main control board 1710 and a central processor 1731, and a forwarding plane comprising various components performing forwarding, such as a forwarding table entry memory 1734, a physical interface card 1733, and a network processor 1732. The control plane performs functions such as issuing a route, generating a forwarding table, processing signaling and protocol messages, configuring and maintaining a state of the device, and the like, and issues the generated forwarding table to the forwarding plane, where the network processor 1732 performs table lookup forwarding on the message received by the physical interface card 1733 based on the forwarding table issued by the control plane. The forwarding table issued by the control plane may be stored in forwarding table entry memory 1734. In some embodiments, the control plane and the forwarding plane may be completely separate and not on the same device.

It should be appreciated that the operations on interface board 1740 are consistent with the operations of interface board 1730 in embodiments of the present application and are not repeated for brevity. It should be understood that the communication device 1700 of the present embodiment may correspond to the first communication device in the above-mentioned method embodiments, and the main control board 1710, the interface board 1730 and/or the interface board 1740 in the communication device 1700 may implement the functions and/or the various steps implemented by the first communication device in the above-mentioned method embodiments, which are not repeated herein for brevity.

It should be noted that the main control board may have one or more blocks, and the main control board and the standby main control board may be included when there are multiple blocks. The interface board may have one or more pieces, the more data processing capabilities the communication device is, the more interface boards are provided. The physical interface card on the interface board may also have one or more pieces. The switching network board may not be provided, or may be provided with one or more blocks, and load sharing redundancy backup can be jointly realized when the switching network board is provided with the plurality of blocks. Under the centralized forwarding architecture, the communication device does not need to exchange network boards, and the interface board bears the processing function of the service data of the whole system. Under the distributed forwarding architecture, the communication device may have at least one switching network board, through which data exchange between multiple interface boards is implemented, providing high-capacity data exchange and processing capability. Alternatively, the communication device may be in the form of only one board card, i.e. there is no switching network board, the functions of the interface board and the main control board are integrated on the one board card, and at this time, the central processor on the interface board and the central processor on the main control board may be combined into one central processor on the one board card, so as to execute the functions after the two are overlapped. The specific architecture employed is not limited solely herein, depending on the particular networking deployment scenario.

It should be understood that the communication devices in the above various product forms have any function of the first station device in the above method embodiment, which is not described herein.

Further, embodiments of the present application also provide a computer program product, which when run on a network device, causes the network device to perform the method performed by any one of the above-described network device embodiments of the method corresponding to fig. 12-13.

The embodiment of the application also provides a chip system which comprises a processor and an interface circuit, wherein the interface circuit is used for receiving the instruction and transmitting the instruction to the processor. Wherein the processor is configured to implement the method in any of the method embodiments described above.

Optionally, the system on chip further includes a memory, and the processor in the system on chip may be one or more. The processor may be implemented in hardware or in software. When implemented in hardware, the processor may be a logic circuit, an integrated circuit, or the like. When implemented in software, the processor may be a general purpose processor, with the method of any of the method embodiments described above being implemented by reading software code stored in a memory.

Alternatively, the memory in the system-on-chip may be one or more. The memory may be integral with the processor or separate from the processor, and the application is not limited. The memory may be a non-transitory processor, such as a ROM, which may be integrated on the same chip as the processor, or may be separately provided on different chips, and the type of memory and the manner of providing the memory and the processor are not particularly limited in the present application.

The above embodiments of the present application are described in detail, and steps in the method of the embodiments of the present application may be sequentially scheduled, combined or pruned according to actual needs; the modules in the device of the embodiment of the application can be divided, combined or deleted according to actual needs.

It will be clear to those skilled in the art that, for convenience and brevity of description, specific working procedures of the above-described systems, apparatuses and units may refer to corresponding procedures in the foregoing method embodiments, which are not repeated herein.

The term "and/or" is herein merely an association relationship describing an associated object, meaning that there may be three relationships, e.g., a and/or B, may represent: a exists alone, A and B exist together, and B exists alone. In addition, the character "/" herein generally indicates that the front and rear associated objects are an "or" relationship.

It should be understood that in embodiments of the present application, "B corresponding to a" means that B is associated with a, from which B may be determined. It should also be understood that determining B from a does not mean determining B from a alone, but may also determine B from a and/or other information.

In the several embodiments provided in the present application, it should be understood that the disclosed systems, devices, and methods may be implemented in other manners. For example, the apparatus embodiments described above are merely illustrative, e.g., the division of elements is merely a logical functional division, and there may be additional divisions of actual implementation, e.g., multiple elements or components may be combined or integrated into another system, or some features may be omitted, or not performed. Alternatively, the coupling or direct coupling or communication connection shown or discussed with each other may be an indirect coupling or communication connection via some interfaces, devices or units, which may be in electrical, mechanical or other form.

The units described as separate units may or may not be physically separate, and units shown as units may or may not be physical units, may be located in one place, or may be distributed over a plurality of network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

In addition, each functional unit in the embodiments of the present application may be integrated in one processing unit, or each unit may exist alone physically, or two or more units may be integrated in one unit. The integrated units may be implemented in hardware or in software functional units.

Claims

1. A method of multicast communication, the method comprising:

the method comprises the steps that first station equipment receives a first message, wherein the first message comprises a first bit index explicit copy BIER header and multicast data, and the first BIER header is used for indicating a set of destination nodes of the multicast data;

the first station device generates a second message according to the first message, wherein the second message comprises a first software defined wide area network (SD-WAN) tunnel encapsulation header, a second BIER header and the multicast data, a destination address of the first SD-WAN tunnel encapsulation header is an IP address of second station device, the IP address of the second station device is an outlet address of a first SD-WAN tunnel between the first station device and the second station device, and the second BIER header is used for indicating a set of destination nodes of the multicast data;

And the first station equipment sends the second message to the second station equipment through the first SD-WAN tunnel.

2. The method of claim 1, wherein an extended generic routing encapsulation GRE header is further encapsulated between the first SD-WAN tunnel header and the second BIER header, and wherein a protocol type field in the extended GRE header is used to indicate that a next header of the extended GRE header is a BIER header.

3. The method according to claim 1 or 2, characterized in that the method further comprises:

the first station equipment determines a next-hop station as a first station according to the bit string in the first BIER header and a BIER forwarding table, and the target station equipment is positioned at the first station;

and the first station equipment determines to send the second message to the second station equipment through the first SD-WAN tunnel according to the first station.

4. A method according to any one of claims 1-3, characterized in that the method further comprises:

the first station device sends first BIER information to a third station device, the first BIER information including at least one of: the BIER forwarding router of the first site equipment identifies BFR-ID and issues a Prefix BFR-Prefix;

The first station device receives second BIER information advertised by the target station device, the second BIER information including one or more of: BFR-ID of the target site device and BFR-Prefix of the target site device.

5. The method of claim 4, wherein the first BIER information or the second BIER information is carried in a border gateway protocol BGP message.

6. The method of claim 5, wherein the BGP message comprises a BGP shortest path first, SPF, address family message, a BGP link state, LS, address family message, or a BGP psd-WAN, address family message.

7. The method of claim 6, wherein the first BIER information or the second BIER information is carried in a Prefix network layer reachability information, prefix NLRI, field in a BGPSPF address family message or a BGP LS address family message.

8. The method according to any one of claims 1-7, further comprising:

the first station device generates a third message according to the first message, wherein the third message comprises a second SD-WAN tunnel encapsulation head, a third BIER head and the multicast data, the destination address of the second SD-WAN tunnel encapsulation head is the IP address of the third station device, the IP address of the third station device is the exit address of a second SD-WAN tunnel between the first station device and the third station device, and the third BIER head is used for indicating the set of destination nodes of the multicast data;

And the first station device sends the third message to the third station device through the second SD-WAN tunnel.

9. A method as claimed in any one of claims 1 to 8, wherein the first station device is a customer edge device CPE or a network access point POP station device.

10. A method of multicast communication, comprising:

the second station equipment receives a first message sent by the first station equipment through a first SD-WAN tunnel, wherein the first message comprises a first SD-WAN tunnel encapsulation head, a first BIER head and multicast data, the destination address of the first SD-WAN tunnel encapsulation head is the IP address of the second station equipment, the IP address of the second station equipment is the exit address of the first SD-WAN tunnel between the first station equipment and the second station equipment, and the second BIERv6 head is used for indicating the set of destination nodes of the multicast data;

the second site equipment generates a second message according to the first message, wherein the second message comprises the multicast data;

and the second station equipment forwards the second message.

11. The method of claim 10 wherein an extended GRE header is further encapsulated between the first SD-WAN tunneling header and the first BIER header, a protocol type field in the extended GRE header being used to indicate that a next header of the extended GRE header is a BIER header.

12. The method according to claim 10 or 11, wherein the second message comprises a second SD-WAN tunnel encapsulation header, a second BIER header and the multicast data, the destination address of the second SD-WAN tunnel encapsulation header being the IP address of a third site device, the IP address of the third site device being the exit address of a second SD-WAN tunnel between the second site device and the third site device, the second BIER header being used to indicate the set of destination nodes of the multicast data;

the second station device forwards the second message, including:

and the second station equipment sends the second message to the third station equipment through the second SD-WAN tunnel.

13. A method of multicast communication, comprising:

the method comprises the steps that first station equipment sends a first BGP message to second station equipment, wherein the first BGP message carries first BIER information, and the first BIER information comprises a BIER forwarding router identifier BFR-ID of the first station equipment;

the first station equipment receives a second BGP message advertised by the second station equipment, wherein the second BGP message carries second BIER information, and the second BIER information comprises BFR-ID of the second station equipment;

And the first station equipment generates a first BIER forwarding table item according to the second BGP message, and the first BIER forwarding table item records the mapping relation between the BFR-ID of the second station equipment and the next-hop station, wherein the BFR-ID in the first BIER forwarding table item indicates the destination equipment for BIER forwarding.

14. The method of claim 13, wherein the method further comprises:

and the second station equipment generates a second BIER forwarding table item according to the first BGP message, and the second BIER forwarding table item records the mapping relation between the BFR-ID of the first station equipment and the next-hop station, wherein the BFR-ID in the second BIER forwarding table item indicates the destination equipment for BIER forwarding.

15. The method of claim 13, wherein the method further comprises:

and the first station equipment determines the next-hop station reaching the second station equipment according to the topology of the SD-WAN.

16. The method of claim 15, wherein the method further comprises:

the first site equipment receives first SD-WAN tunnel information advertised by the third site equipment, wherein the first SD-WAN tunnel information comprises an IP address of the third site equipment and site information of the third site equipment;

The first station device establishes a first SD-WAN tunnel between the first station device and the third station device according to the first SD-WAN tunnel information, and stores a first mapping relation between a next-hop station and the first SD-WAN tunnel, wherein the next-hop station in the first mapping relation is the station to which the third station device belongs.

17. The method of claim 16, wherein the method further comprises:

the third site equipment receives second SD-WAN tunnel information advertised by the second site equipment, wherein the second SD-WAN tunnel information comprises an IP address of the second site equipment and site information of the second site equipment;

and the third station equipment establishes a second SD-WAN tunnel between the third station equipment and the second station equipment according to the second SD-WAN tunnel information, and stores a second mapping relation between a next-hop station and the second SD-WAN tunnel, wherein the next-hop station in the second mapping relation is the station to which the second station equipment belongs.

18. The method of claim 15, wherein the method further comprises:

The first site device receives third SD-WAN tunnel information advertised by the second site device, wherein the third SD-WAN tunnel information comprises an IP address of the second site device and site information of the second site device;

and the first station equipment establishes a third SD-WAN tunnel between the first station equipment and the second station equipment according to the third SD-WAN tunnel information, and stores a third mapping relation between a next-hop station and the third SD-WAN tunnel, wherein the next-hop station in the third mapping relation is the station to which the second station equipment belongs.

19. The method according to claim 16 or 17, characterized in that the method further comprises:

the first station equipment receives a first BIER message, wherein the first BIER message comprises a first BIER header and multicast data, and the first BIER header is used for indicating a set of destination nodes of the multicast data;

and the first station device determines to forward the multicast data through the first SD-WAN tunnel according to the first BIER header, the first BIER forwarding table entry and the first mapping relation.

20. The method of claim 18, wherein the method further comprises:

and the first site equipment determines to forward the multicast data through the third SD-WAN tunnel according to the first BIER head, the first BIER forwarding table item and the third mapping relation.

21. A communication device, comprising: the device comprises a receiving module, a processing module and a sending module;

the receiving module is configured to perform the receiving operation performed by the first station apparatus in the method of any one of claims 1 to 9 and 13 to 20, the processing module is configured to perform the processing operation performed by the first station apparatus in the method of any one of claims 1 to 9 and 13 to 20, and the transmitting module is configured to perform the transmitting operation performed by the first station apparatus in the method of any one of claims 1 to 9 and 13 to 20.

22. A communication device, comprising: the device comprises a receiving module, a processing module and a sending module;

the receiving module is configured to perform the receiving operation performed by the second station apparatus in the method of any one of claims 10-12 and 13-20, the processing module is configured to perform the processing operation performed by the second station apparatus in the method of any one of claims 10-12 and 13-20, and the transmitting module is configured to perform the transmitting operation performed by the second station apparatus in the method of any one of claims 10-12 and 13-20.

23. A communication system comprising a first communication device and a second communication device;

the first communication means is arranged to perform the operations performed by the first station apparatus in the method of any of claims 1-9, 13-20, and the second communication means is arranged to perform the operations performed by the second station apparatus in the method of any of claims 10-12, 13-20.

24. The communication system of claim 23, wherein the system further comprises a third communication device;

the third communication means being for performing the operations performed by the third station apparatus in the method of any one of claims 13-20.

25. A computer readable storage medium storing instructions which, when executed on a processor, implement the method of any one of claims 1-20.

26. A computer program product, characterized in that it stores instructions that, when executed by a processor, implement the method of any one of claims 1 to 20.