CN114079583A

CN114079583A - Method for sending multicast message, method and device for obtaining forwarding table item

Info

Publication number: CN114079583A
Application number: CN202011271120.7A
Authority: CN
Inventors: 刘淑英; 廖婷; 方伟; 古锐; 谢经荣; 耿雪松
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2020-08-13
Filing date: 2020-11-13
Publication date: 2022-02-22

Abstract

The method for sending the multicast message provided by the embodiment of the application comprises the following steps: a first network device obtains a first multicast message, wherein the first multicast message comprises a bit string and an identifier of a network fragment, the bit string corresponds to a second network device, and the network fragment corresponds to a multicast service of the second network device; the first network equipment acquires a first interface corresponding to the network fragment according to the bit string and the identifier of the network fragment; and the first network equipment sends the first multicast message to the second network equipment through the first interface. The method for obtaining the forwarding table entry provided by the embodiment of the application comprises the following steps: a first network device acquires an identifier of a network fragment, wherein the network fragment corresponds to a multicast service of a second network device; and the first network equipment obtains a first forwarding table entry according to the identifier of the network fragment, wherein the first forwarding table entry comprises the identifier of the network fragment and the identifier of a first interface communicated with the second network equipment.

Description

Method for sending multicast message, method and device for obtaining forwarding table item

The present application claims priority of the chinese patent application entitled "a method and apparatus for multicast slicing" filed by the national intellectual property office at 8/13/2020, application number 202010815027.1, the entire contents of which are incorporated herein by reference.

Technical Field

The present invention relates to the field of communications technologies, and in particular, to a method for sending a multicast packet, and a method and an apparatus for obtaining a forwarding table.

Background

Network fragmentation is the division of logical resources based on a common network such that a set of logical networks of shared or dedicated network resources is divided into a certain network fragment. A certain network segment is used for carrying specific services, such as mobile services, private line services, telemedicine and the like, which require network forwarding resources to be reserved. At present, the network fragmentation does not distinguish the multicast service from the unicast service with low priority, that is, the multicast service and the unicast service with low priority share the default network fragmentation. In the default network slice, the message of the multicast service and the unicast service with low priority realize the forwarding of the message through queue scheduling. When the multicast service packet and the low-priority unicast service packet share one queue, the transmission quality such as the transmission delay and the packet loss of the multicast service cannot be guaranteed.

Disclosure of Invention

The embodiment of the application provides a method for sending a multicast message, a method for obtaining a forwarding table entry and a device, which can ensure the transmission quality of a multicast service.

In a first aspect, a method for sending a multicast packet is provided, where the method includes: a first network device obtains a first multicast message, wherein the first multicast message comprises a bit string (bit string) and an identifier of a network fragment, the bit string corresponds to a second network device, and the network fragment corresponds to a multicast service of the second network device; the first network equipment acquires a first interface corresponding to the network fragment according to the bit string and the identifier of the network fragment; and the first network equipment sends the first multicast message to the second network equipment through the first interface.

In the method, the first network device can determine the first interface corresponding to the network fragment according to the identifier of the network fragment carried in the multicast message, and further can send the multicast message through the specific network fragment, thereby ensuring the transmission quality of the multicast service.

In a possible implementation manner, the acquiring, by the first network device, the first interface corresponding to the network segment according to the bit string and the identifier of the network segment includes: the first network equipment searches a first forwarding table item by using the bit string included in the first multicast message and the identifier of the network fragment, and acquires the identifier of a first interface, wherein the first forwarding table item comprises the bit string, the identifier of the network fragment and the identifier of the first interface.

In one possible implementation, before the first network device obtains the first multicast message, the method further includes: the first network device obtains an identifier of the network fragment and a bit forwarding router identifier (BFR-id) of the second network device; the first network equipment obtains the bit string according to the BFR-id; and the first network equipment acquires the first forwarding table item according to the bit string and the identifier of the network fragment.

In a possible implementation manner, the acquiring, by the first network device, the first interface corresponding to the network segment according to the bit string and the identifier of the network segment includes: the first network equipment searches a second forwarding table item by using the bit string included in the first multicast message, and acquires an identifier of a second interface communicated with the second network equipment, wherein the second forwarding table item comprises the bit string and the identifier of the second interface; and the first network device searches a first forwarding table entry by using the identifier of the second interface and the identifier of the network fragment included in the first multicast message, and obtains the identifier of the first interface, wherein the first forwarding table entry includes the identifier of the second interface, the identifier of the network fragment and the identifier of the first interface.

In one possible implementation, before the first network device obtains the first multicast message, the method further includes: the first network equipment acquires the identifier of the network fragment and the BFR-id of the second network equipment; the first network equipment obtains the bit string according to the BFR-id; the first network equipment obtains the second forwarding table item according to the bit string and the identifier of the second interface; the first network equipment acquires the identifier of the first interface corresponding to the identifier of the network fragment according to the identifier of the second interface; and the first network equipment obtains the first forwarding table entry according to the identifier of the second interface, the identifier of the first interface and the identifier of the network fragment.

In a possible implementation manner, the first network device is a Bit Forwarding Ingress Router (BFIR) or a Bit Forwarding Router (BFR).

In one possible implementation manner, the first network device is a BFIR, and the obtaining, by the first network device, the first multicast packet includes: the first network equipment receives a second multicast message from a multicast source, wherein the second multicast message comprises multicast source group information, and the multicast source group information corresponds to the second network equipment; the first network equipment acquires the bit string corresponding to the multicast source group information and the identifier of the network fragment according to the multicast source group information; and the first network equipment acquires the first multicast message according to the second multicast message, the bit string and the identifier of the network fragment, wherein the first multicast message also comprises the second multicast message. The multicast source group information includes the address of the multicast source and the address of the multicast group.

In a possible implementation manner, the first network device is an intermediate BFR, and the obtaining, by the first network device, the first multicast packet includes: and the first network equipment receives the first multicast message sent by BFIR.

In a possible implementation manner, the first multicast packet includes an internet Protocol version 6 (IPv 6) header, and the IPv6 header includes the identifier of the network slice.

In a possible implementation manner, a Destination Address (DA) field of the IPv6 header includes an identifier of the network fragment; or a Source Address (SA) field of the IPv6 header includes an identification of the network fragment. Wherein, 32bit in DA or SA carries the label of the network fragment. When the DA field is a Segment Identifier (SID) in a Segment Routing over IPv6, SRv6 based on IPv6, a Bit Index of the SID shows that a duplicate (Bit Index extension) node (end.

In one possible implementation manner, the first multicast packet includes an IPv6 extension header, and the IPv6 extension header includes an identifier of the network fragment.

In one possible implementation, the first multicast packet includes a hop-by-hop options header (hop-by-hop options header), and the hop-by-hop options header includes an identifier of the network segment.

In a possible implementation manner, the first multicast packet includes a destination options header (destination options header), and the destination options header includes an identifier of the network segment. Wherein, the BIER header in the destination option header includes the identifier of the network fragment.

In one possible implementation, the first interface is a logical interface associated with a second interface for communicating with the second network device. Wherein the first interface is a Flexible Ethernet (FlexE) interface or a sub-interface. The sub-interface may be a channelized sub-interface.

In a possible implementation manner, the network segment corresponds to one or more Multicast Virtual Private Network (MVPN) services, or the network segment corresponds to one or more Virtual Private Network (VPN) services.

In a second aspect, a method for obtaining a forwarding table entry is provided, where the method includes: a first network device acquires an identifier of a network fragment, wherein the network fragment corresponds to a multicast service of a second network device; and the first network equipment obtains a first forwarding table entry according to the identifier of the network fragment, wherein the first forwarding table entry comprises the identifier of the network fragment and the identifier of a first interface communicated with the second network equipment.

In the method, the corresponding relation is established between the identifier of the network fragment allocated to the multicast service and the first interface to form a forwarding table entry, so that when the identifier carrying the network fragment is forwarded, the first interface can be utilized to forward through the corresponding network fragment, and the transmission quality of the multicast service can be ensured.

In a possible implementation manner, the first forwarding entry further includes a bit string, where the bit string corresponds to the second network device, and the method further includes: the first network equipment receives BFR-id sent by the second network equipment; and the first network equipment obtains the bit string according to the BFR-id.

In a possible implementation manner, after obtaining the first forwarding table entry, the method further includes: the first network equipment acquires a first multicast message, wherein the first multicast message comprises the bit string and the identifier of the network fragment; the first network device searches the first forwarding table entry by using the bit string and the identifier of the network fragment included in the first multicast message, and acquires the identifier of the first interface; and the first network equipment sends the first multicast message to the second network equipment according to the identifier of the first interface.

In one possible implementation, the first forwarding table entry further includes an identification of a second interface that communicates with the second network device, and the method further includes: the first network equipment receives a bit forwarding router BFR-id sent by the second network equipment; the first network equipment obtains bit string according to the BFR-id, and the bit string corresponds to the second network equipment; and the first network equipment acquires a second forwarding table item according to the bit string and the identifier of the second interface, wherein the second forwarding table item comprises the bit string and the identifier of the second interface.

In a possible implementation manner, after obtaining the first forwarding table entry, the method further includes: the first network equipment acquires a first multicast message, wherein the first multicast message comprises the bit string and the identifier of the network fragment; the first network equipment searches the second forwarding table item by using the bit string included in the first multicast message to acquire the identifier of the second interface; and the first network equipment searches the first forwarding table entry by using the identifier of the second interface and the identifier of the network fragment included in the first multicast message to obtain the identifier of the first interface.

In a possible implementation manner, the carrying manner of the identifier of the network segment may refer to the corresponding content of the first aspect, which is not described herein again. The first multicast message comprises a sixth version of internet protocol (IPv) 6 header, and the IPv6 header comprises a label of the network fragment

In one possible implementation, the first interface is a logical interface associated with a second interface for communicating with the second network device. Wherein, the first interface is a Flexe interface or a subinterface.

In a possible implementation manner, the network slice corresponds to one or more MVPN services, or the network slice corresponds to one or more VPN services.

In the second aspect, the first network device is a BFIR or an intermediate BFR, and the second network device is a Bit Forwarding Egress Router (BFER).

In a third aspect, an apparatus for sending a multicast packet is provided, where the apparatus is provided in a first network device, and the apparatus includes a unit configured to implement the functions corresponding to the steps in the first aspect or a possible implementation manner of the first aspect.

In a fourth aspect, an apparatus for obtaining a forwarding table entry is provided, where the apparatus is disposed in a first network device, and the apparatus includes a unit configured to implement the function corresponding to the step in the second aspect or a possible implementation manner of the second aspect.

In a fifth aspect, a system is provided, where the system includes the apparatus for sending a multicast packet according to the third aspect or the third aspect, or the apparatus for obtaining a forwarding table entry according to the fourth aspect.

A sixth aspect provides a chip, where the chip includes a memory and a processor, where the memory is used to store a computer instruction, and the processor is used to call and execute the computer instruction from the memory, so as to execute the method for sending a multicast packet provided in the first aspect or any possible implementation manner of the first aspect, or execute the method for obtaining a forwarding table entry provided in the second aspect or any possible implementation manner of the second aspect.

A seventh aspect provides a computer program product, where the computer program product includes one or more computer program instructions, and when the computer program instructions are loaded and executed by a computer, the computer is enabled to execute the method for sending a multicast packet provided in the first aspect or any possible implementation manner of the first aspect, or execute the method for obtaining a forwarding table entry provided in the second aspect or any possible implementation manner of the second aspect.

An eighth aspect provides a computer-readable storage medium, where the computer-readable storage medium is configured to store an instruction, where the instruction includes a program designed to execute the method for sending a multicast packet provided in any one of the foregoing first aspects or any one of the foregoing possible implementation manners of the first aspect, or the instruction includes a program designed to execute the method for obtaining a forwarding table entry provided in any one of the foregoing second aspects or any one of the foregoing possible implementation manners of the second aspect.

In a ninth aspect, an apparatus for sending a multicast packet is provided, where the apparatus for sending a multicast packet includes a processor and a non-transitory computer-readable storage medium storing program instructions for the processor to execute, where the program instructions instruct the processor to execute the method for sending a multicast packet provided in the first aspect or any possible implementation manner of the first aspect.

In a tenth aspect, an apparatus for obtaining a forwarding table entry is provided, where the apparatus for obtaining a forwarding table entry includes a processor and a non-transitory computer-readable storage medium storing program instructions for the processor to execute, where the program instructions instruct the processor to perform the method for obtaining a forwarding table entry provided in the second aspect or any possible implementation manner of the second aspect.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below.

Fig. 1 is a schematic diagram of a network scenario provided in an embodiment of the present application.

Fig. 2 is a flowchart of a method for obtaining a forwarding entry according to an embodiment of the present application.

Fig. 3 is a flowchart of a method for forwarding a multicast packet according to a second embodiment of the present application.

Fig. 4 is a Bit-Index-based display Replication (Bit Index Replication IPv6 Encapsulation, BIERv6) message format in a sixth version of internet protocol network according to an embodiment of the present application.

Fig. 5 is another BIERv6 message format provided in this embodiment of the present application.

Fig. 6(a) shows another BIERv6 message format provided in this embodiment.

Fig. 6(b) is a still another BIERv6 message format provided in this embodiment.

Fig. 7 is a further BIERv6 message format provided in this embodiment of the present application.

Fig. 8 is a schematic structural diagram of an apparatus for sending a multicast packet according to an embodiment of the present application.

Fig. 9 is a schematic structural diagram of an apparatus for obtaining a forwarding entry according to an embodiment of the present application.

Fig. 10 is a schematic structural diagram of an apparatus for sending a multicast packet according to an embodiment of the present application.

Fig. 11 is a schematic structural diagram of an apparatus for obtaining a forwarding entry according to an embodiment of the present application.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention.

Fig. 1 is a schematic diagram of a network scenario provided in an embodiment of the present application. In the network scenario shown in fig. 1, the service carried by the network segment 1 belongs to a unicast service, that is, a packet of the service carried by the network segment 1 is transmitted in a unicast manner. The slice identity (slice ID)1 is used to identify the network slice 1. The service carried by the network segment 2 belongs to a first multicast service, that is, the message of the service carried by the network segment 2 is transmitted in a multicast mode. slice ID 2 is used to identify network slice 2. The service carried by the network segment 3 belongs to the second multicast service, that is, the message of the service carried by the network segment 3 is transmitted in a multicast mode. The multicast mode may be a method of transmitting and receiving a message through Bit Index Explicit Replication (BIER). The three arrows in fig. 1 are used to indicate the path of the physical link to which the different network slices belong. The physical link corresponding to network segment 1 may be represented as device 107- > device 106- > device 104- > device 101- > receiver 1, where receiver 1 may be either a multicast receiver or a user configured to receive a message sent in a unicast manner. The physical links corresponding to network slice 2 may be represented as device 107- > device 106- > device 105- > device 102 and device 103- > multicast receiver 2 and multicast receiver 3. The physical links corresponding to network slice 3 may be represented as device 107- > device 106- > device 105 and device 104- > device 102 and device 101- > multicast receiver 2 and receiver 1. The device 107 connecting S as a multicast source is an ingress node and in the BIER domain is a Bit Forwarding Ingress Router (BFIR). The devices 101, 102 and 103, which are connected to the multicast receiver, are egress (egress) nodes, and Bit Forwarding Egress Routers (BFERs) in the BIER domain. Device 101, device 102, and device 103 belong to the same BIER domain, the BFR-id of device 101 is 1, the BFR-id of device 102 is 2, and the BFR-id of device 103 is 3. When the value of the BFR-id exceeds the Bit String Length (BSL), it can be represented by a combination of Set Identifier (SI) and bit string. The embodiment of the application takes the case that the BFR-id does not exceed the range of the BSL as an example, and if the BFR-id exceeds the range of the BSL expression, SI can be introduced to perform effective differentiation. Device 106, device 105, and device 104 are intermediate nodes, and in the BIER domain are Bit Forwarding Routers (BFRs). Devices 107, 106, 104, and 101 may support both multicast and unicast traffic. The above-mentioned unicast service may be SRv 6-based unicast service, and the above-mentioned unicast service may also be access internet service, video-on-demand service, mobile data service, or the like. Any of the above mentioned multicast services may be multicast services based on BIERv6, including but not limited to interactive television (IPTV) live broadcast services, enterprise conference live broadcast services, video services for the enterprise headquarters to synchronize their head to their branches, and the like, which are carried in BIERv 6. Of course, the unicast service and the multicast service are only an example, and may also be other services, and are not illustrated in sequence here. The network scenario and the method provided by the embodiment of the application are described by taking the BIER network as an example.

Example one

Fig. 2 is a flowchart of a method for obtaining a forwarding entry according to an embodiment of the present application. In the method shown in fig. 2, receiver 1 and multicast receiver 2 in fig. 1 receive a message of a first multicast service from a multicast source. Multicast receivers 2 and 3 in fig. 1 receive messages of the second multicast service from the multicast source. BFIR, BFER and intermediate BFR in BIER domain can obtain forwarding table item through configuration of control plane. A method for obtaining a forwarding table entry according to an embodiment of the present application is described below with reference to fig. 1 and fig. 2.

S201, the device acting as BFER floods its BFR-id and address through IGP.

In the scenario shown in fig. 1, device 101 floods a BFR-id with a value of 1 and the address of device 101 (which may be denoted as a101) through IGP. Device 102 floods a BFR-id with a value of 2 and the address of device 102 (which may be denoted as a102) through IGP. Device 103 floods the BFR-id with a value of 3 and the address of device 103 (which may be denoted as a103) via IGP. The address of the device mentioned in the first embodiment of the present application may be an Internet Protocol version 4 (IPv 4) address or an Internet Protocol version 6 (IPv 6) address, and its specific expression is not limited to the form of the first embodiment of the present application. In other possible implementations, the address may be replaced by other forms of identification of the device serving as the BFER, and the other forms of identification of the device serving as the BFER may also be information that can be routed to the device, such as name, and this is not limited in this embodiment of the present application.

Optionally, a device acting as a BFER may also flood the identity of its assigned network slice with IGP. In the scenario shown in fig. 1, device 101 may also flood slice ID 1 and slice ID3 with IGP. The device 102 may also flood slice ID 2 and slice ID3 with IGP. The device 103 may also flood slice ID 2 with IGP.

The device acting as an intermediate BFR floods its address and BFR-id through IGP S202.

For example, a device acting as an intermediate BFR may flood through IGP with BFR-id's of the device acting as a BFER and the physical interface to receive the BFR-id. The device acting as an intermediate BFR is directly connected or indirectly connected to the device acting as a BFER. The device acting as an intermediate BFR issues its own device address via IGP and its acquired BFR-id via IGP flooding. In the scenario illustrated in FIG. 1, device 104 obtains a BFR-id with a value of 1 via IGP and records the physical interface (which may be denoted as physical interface 4-1) that receives the BFR-id with a value of 1. Device 104 floods the BFR-id with a value of 1 and the address of device 104 (which may be denoted as a104) via IGP. Device 105 obtains a BFR-id of value 3 and a BFR-id of value 2 via IGP and records the physical interface that received the BFR-id of value 2 (which may be represented as physical interface 5-1) and the BFR-id physical interface that received the BFR-id of value 3 (which may be represented as physical interface 5-2). Device 105 may also obtain a BFR-id with a value of 1 via IGP and record the physical interface (which may be denoted as physical interface 5-3) that received the BFR-id with a value of 1, which physical interface 5-3 communicates with device 106. Device 105 floods with an IGP a BFR-id having a value of 2, a BFR-id having a value of 3, and the address of device 105 (which may be denoted as a 105). Device 106 obtains a BFR-id with a value of 3, a BFR-id with a value of 2, and a BFR-id with a value of 1 via IGP. Device 106 records the physical interface that receives the BFR-id with a value of 1 (which may be denoted as physical interface 6-1), and the physical interface that receives the BFR-ids with values of 2 and 3 (which may be denoted as physical interface 6-2). The device 106 floods the BFR-id with a value of 3, the BFR-id with a value of 2, the BFR-id with a value of 1 and the address of the device 106 (which may be denoted as a106) via IGP. The device 107 obtains a BFR-id with a value of 3, a BFR-id with a value of 2 and a BFR-id with a value of 1 by IGP. Device 107 records the physical interfaces (which may be denoted as physical interface 7-1) that receive values of 1, 2, and 3 BFR-ids. The BFR-id may be expressed in the form of a bit string (bit string) or in the form of a natural number. If the representation of BFR-id is in the form of bit string, then the BFR-id with value 1 for device 101 or device 104 flooded by IGP is denoted 0001, the BFR-id with value 2 for device 102 flooded by IGP is denoted 0010, the BFR-id with value 3 for device 103 flooded by IGP is denoted 0100, the BFR-id with values 2 and 3 for device 105 flooded by IGP is denoted 0110, and the BFR-id with values 1, 2 and 3 for device 106 flooded by IGP is denoted 0111. If the expression form of the BFR-id is a natural number form, the equipment in the BIER domain acquiring the BFR-id can convert the expression form into the bit string form, and the conversion process is not described again here.

Optionally, a device that is an intermediate BFR may also flood the identity of its assigned network slice with IGP. In the scenario shown in fig. 1, the device 104 may also flood slice ID 1 and slice ID3 with IGP. Device 105 may also flood slice ID 2 and slice ID3 with IGP. The device 106 may also flood slice ID 1, slice ID 2, and slice ID3 with IGP.

S203, the device serving as the intermediate BFR acquires a first forwarding table entry, wherein the first forwarding table entry comprises the identifier of the network fragment.

For example, in the first embodiment of the present application, the control plane of the device serving as the intermediate BFR may perform network fragmentation division on the multicast service in advance, that is, configure the identifier of the network fragmentation and the sub-interface related to the physical interface for the multicast service required by the multicast receiver. If the physical interface of the device serving as the intermediate BFR supports Flexible Ethernet (FlexE), the sub-interface related to the physical interface of the device serving as the intermediate BFR is a FlexE interface. If the physical interface of the device of the intermediate BFR does not support Flexible Ethernet (FlexE), the sub-interface related to the physical interface of the device as the intermediate BFR is a channelized sub-interface. In the embodiment of the present application, a FlexE interface or a channelized sub-interface is denoted by a sub-interface. The equipment serving as the intermediate BFR acquires a first forwarding table item according to the BFR-id acquired by IGP flooding, the identifier of the network fragment and the sub-interface related to the physical interface; or the device serving as the intermediate BFR acquires a first forwarding table entry corresponding to the BFR-id according to the identifier of the network fragment and the sub-interface related to the physical interface. In the scenario shown in fig. 1, taking a multicast service as an example, the device 105 and the device 106 serving as the intermediate BFR may be configured to transmit packets of the multicast service corresponding to the network slice 2 and the network slice 3, and both the device 105 and the device 106 are assigned with slice ID 2 and slice ID 3. The device 104 serving as the intermediate BFR is configured to transmit a packet of the multicast service corresponding to the network segment 3, and the device 104 is allocated with slice 3. A first sub-interface associated with physical interface 4-1 of device 104, which may be denoted as sub-interface 4-1-1, corresponds to slice ID 3. The physical interface 5-1 associated sub-interfaces of the device 105 include a first sub-interface (which may be denoted as sub-interface 5-1-1) and a second sub-interface (5-1-2). The first sub-interface (which may be denoted as sub-interface 5-1-1) corresponds to slice ID 2. The second sub-interface (which may be denoted as sub-interface 5-1-2) corresponds to slice ID 3. The sub-interface associated with physical interface 5-2 of device 105 includes a third sub-interface (which may be denoted as sub-interface 5-2-1). The third sub-interface (which may be denoted as sub-interface 5-2-1) corresponds to slice ID 2. The subinterface associated with the physical interface (6-1) of the device 106 includes a first subinterface (which may be referred to as subinterface 6-1-1) that corresponds to slice ID 3. The subinterface associated with physical interface (6-2) of device 106 includes a second subinterface (which may be referred to as subinterface 6-2-1) that corresponds to slice ID 2. The subinterface associated with physical interface (6-2) of device 106 includes a third subinterface (which may be referred to as subinterface 6-2-2) that corresponds to slice ID 3. In the scenario shown in fig. 1, the device 104 and the device 101 may further be configured to transmit a packet of a unicast service corresponding to the network segment 1, and the device 104 may further be assigned with a slice ID 1. The sub-interface associated with the physical interface 4-1 of the device 104 is the sub-interface 4-1-2, and is used to transmit the unicast service packet corresponding to the network segment 1. The sub-interface associated with physical interface 5-3 of device 105 comprises a fourth sub-interface (which may be denoted as sub-interface 5-3-1). The fourth sub-interface (which may be denoted as sub-interface 5-3-1) corresponds to slice ID 1. The identifier of the network segment in the embodiment of the present application may be obtained through IGP flooding or obtained through configuration, which is not limited in the embodiment of the present application.

In a first implementation, the first forwarding table entry includes a BFR-id, an identifier of the network fragment, and a sub-interface associated with the physical interface. In the scenario illustrated in FIG. 1, the device 104 obtaining the first forwarding table entry may be represented as Table 2-1. And the bit string in the BFR-id field is used for matching the bit string included in the received BIER multicast message. And the identification in the slice ID field is used for matching the slice ID included in the received BIER multicast message. The subinterface is used for forwarding the BIER multicast message.

TABLE 2-1

BFR-id	slice ID	Sub-interface
			0011	1	Sub-interface 4-1-2
0011	3	Sub-interface 4-1

The first forwarding table entry obtained by the device 105 may be represented as table 2-2. The meanings of the BFR-ID field, the slice ID field, and the subinterface field in table 2-2 are the same as those of the corresponding fields in table 2-1, and are not described herein again.

Tables 2 to 2

BFR-id	slice ID	Sub-interface
			0011	3	Sub-interface 5-1-2
0011	3	Sub-interface 5-3-1
			0110	2	Sub-interface 5-1
0110	2	Sub-interface 5-2-1

The first forwarding table entry obtained by the device 106 may be represented as tables 2-3. The meanings of the BFR-ID field, the slice ID field, and the subinterface field in table 2-3 are the same as those of the corresponding fields in table 2-1, and are not described herein again.

Tables 2 to 3

BFR-id	slice ID	Sub-interface
			0011	3	Sub-interface 6-1
0011	3	Sub-interface 6-2-1
			0110	2	Sub-interface 6-2

In a second implementation, the first forwarding table entry includes an identifier of the network fragment and a sub-interface associated with the physical interface. The corresponding physical interface may be located according to the sub-interface. Optionally, the first forwarding table entry further includes a physical interface. The device acting as the intermediate BFR also obtains the BIFT entry. In the scenario illustrated in FIG. 1, the first forwarding table entry obtained by the device 104 may be represented as tables 2-4, and the BIFT table entries obtained by the device 104 may be represented as tables 2-5. The BIFT table entry includes BFR-id as a sequence number, forwarding bit-string mask (F-BM), and Neighbor (NBR) as a next hop. The F-BM in tables 2-5 is used to operate with the bit string in the received BIER multicast packet, determine the bit string in the BIER multicast packet sent to the next hop and whether to continue the table lookup operation.

Tables 2 to 4

Physical interface (optional)	slice ID	Sub-interface
			Physical interface 4-1	3	Sub-interface 4-1

Tables 2 to 5

BFR-id	F-BM	NBR
			1	0001	Physical interface 4-1

The device 105 may obtain the first forwarding table entry as tables 2-6 and the obtained BIFT table entries as tables 2-7.

Tables 2 to 6

Physical interface (optional)	slice ID	Sub-interface
			Physical interface 5-1	2	Sub-interface 5-1
Physical interface 5-1	3	Sub-interface 5-1-2
			Physical interface 5-2	2	Sub-interface 5-2-1

Tables 2 to 7

BFR-id	F-BM	NBR
			1	0001	Physical interface 5-3
2	0010	Physical interface 5-1
			3	0100	Physical interface 5-2

The device 106 may obtain the first forwarding table entry as tables 2-8 and the obtained BIFT table entries as tables 2-9.

Tables 2 to 8

Physical interface (optional)	slice ID	Sub-interface
			Physical interface 6-1	3	Sub-interface 6-1
Physical interface 6-2	3	Sub-jointMouth 6-2-1
			Physical interface 6-2	2	Sub-interface 6-2

Tables 2 to 9

BFR-id	F-BM	NBR
			1	0001	Physical interface 6-1
2	0110	Physical interface 6-2
			3	0110	Physical interface 6-2

And S204, the BFIR equipment acquires a second forwarding table item, wherein the second forwarding table item comprises the network fragment identifier.

For example, the device serving as the BFIR may also be configured with network fragmentation and obtain the second forwarding table entry by using the method of S203. For details, reference may be made to corresponding contents of S203, which are not described herein again.

In the scenario shown in fig. 1, a device 107 serving as a BFIR may be configured to transmit a multicast service packet corresponding to a network segment 2 and a network segment 3, and the device 107 is assigned with a slice ID 2, a slice ID3, and a slice ID 1. The subinterface associated with physical interface 7-1 of device 107 includes a first subinterface (which may be referred to as subinterface 7-1-1) that corresponds to slice ID 2. The sub-interface associated with physical interface 7-1 of device 107 includes a second sub-interface (which may be referred to as sub-interface 7-1-2) corresponding to slice ID 3. Because the network slice with the slice ID of 1 corresponds to the unicast service, the table entry related to the multicast service does not include the parameter related to the slice ID 1.

In a first implementation manner, the second forwarding table entry includes a BFR-id, an identifier of the network fragment, and a sub-interface related to the physical interface. In the scenario illustrated in fig. 1, the obtaining of the second forwarding entry by the device 107 may be represented as tables 2-10.

Tables 2 to 10

BFR-id	slice ID	Sub-interface
			0011	3	Sub-interface 7-1-2
0110	2	Sub-interface 7-1

In a second implementation manner, the second forwarding entry includes an identifier of the network fragment and a sub-interface related to the physical interface.

The corresponding sub-interfaces can be located according to the physical interfaces and the fragment identifiers. The device 107 acting as a BFIR also obtains a BIFT entry. In the scenario shown in fig. 1, the device 107 obtains the second forwarding table entry may be represented as tables 2 to 11, and the device 107 obtains the BIFT table entry may be represented as tables 2 to 12. The BIFT table entry includes BFR-id, F-BM and NBR as sequence numbers.

Tables 2 to 11

Physical interface (optional)	slice ID	Sub-interface
			Physical interface 7-1	2	Sub-interface 7-1
Physical interface 7-1	3	Sub-interface 7-1-2

Tables 2 to 12

BFR-id	F-BM	NBR
			1	0111	Physical interface 7-1
2	0111	Physical interface 7-1

A header portion included in any one of tables 2-1 to 2-12 may be omitted, and the forwarding table entry and the BIFT table entry in the embodiment of the present application may exist in a form of a corresponding relationship or a mapping relationship, and the embodiment of the present application does not limit a specific expression form thereof.

The foregoing division of network segments may divide multicast services of a Virtual Private Network (VPN) into one network segment, or divide different multicast services of a VPN into different network segments, or divide multicast services of multiple VPNs into one network segment. In other possible implementation manners, multicast services of different Multicast Virtual Private Networks (MVPNs) are divided into different network segments, or multicast services of multiple MVPNs are divided into the same network segment. The embodiment of the present application does not limit the possible form of the network segment division.

The method for acquiring the forwarding table entry provided in the embodiment of the present application may generate the forwarding table entry related to the network fragment through the parameter acquired by IGP flooding, so that when the multicast packet is subsequently forwarded, the multicast packet can be sent by using the network fragment, so as to ensure a Service Level Agreement (SLA) requirement of the multicast Service.

Example two

Fig. 3 is a flowchart of a method for forwarding a multicast packet according to a second embodiment of the present application. The method provided in the second embodiment of the present application takes the example of sending the multicast packet of the multicast service corresponding to the network segment 2 through the network segment 2 as an example. The device in the scenario of fig. 1 may use the method provided in the second embodiment of the present application to send the multicast packet of the multicast service corresponding to the network segment 3 through the network segment 3, which is not described in this embodiment of the present application. Next, a method for forwarding a multicast packet according to the second embodiment of the present application is described with reference to fig. 3, fig. 2, and fig. 1.

S301, the device 107 obtains a first BIER multicast packet according to the multicast packet from the multicast source.

For example, the first BIER multicast packet includes a bit string (bit string) and a slice ID. The bit in bit string corresponding to device 102 and device 103 is set to 1, i.e. bit string may be denoted as 0000 … 00000110 or as 0110. In the scene with a BSL of 256 bits, for the first representation … omits 244 bits with a value of 0; for the second representation, 252 bits with a value of 0 are omitted. slice ID is slice ID 2

In one implementation, the obtaining, by the device 107, the first BIER multicast packet according to the multicast packet from the multicast source includes: receiving a multicast message of a multicast source by a device serving as a BFIR, wherein the multicast message comprises multicast source group information; the device serving as the BFIR obtains information of at least one BFER and a slice ID according to a configured corresponding relationship and multicast source group information included in the multicast message, wherein the corresponding relationship comprises the multicast source group information, the slice ID and the information of at least one BFER; the equipment as the BFIR obtains bit string according to the information of at least one BFER; and the equipment as the BFIR acquires the first multicast message according to the slice ID, the bit string and the multicast message. In another implementation, obtaining the first multicast message as a BFIR includes: receiving a multicast message of a multicast source by a device serving as a BFIR, wherein the multicast message comprises multicast source group information; the equipment serving as the BFIR obtains bit string and slice ID according to the configured corresponding relation and the multicast source group information included in the multicast message, wherein the corresponding relation includes the multicast source group information, the slice ID and the bit string; and the equipment as the BFIR acquires the first multicast message according to the slice ID, the bit string and the multicast message. The multicast source group information includes an address of a multicast source and an address of a multicast group. The information of the at least one BFER may be a BFR-id of the at least one BFER. Optionally, the first multicast packet further includes an SI to which the bit string belongs. The combination of SI and bit sting may also be used to identify one or more BFERs, in other words, the combination of SI and bit sting is used to determine one or more BFR-ids, any of which is used to identify a BFER.

In the scenario shown in fig. 1, the device 107 receives a multicast packet sent by a multicast source, and obtains a bit string and a slice ID according to multicast source group information (S, G) in the multicast packet. Wherein S represents the address of the multicast source and G represents the address of the multicast group. S and G indicate that the first multicast service device 107 corresponding to the slice ID 2 obtains the corresponding bit string and slice ID 2 with a value of 0110 according to (S, G). The device 107 serving as the BFIR may add a BIER header to the obtained multicast packet to obtain a first BIER multicast packet. Optionally, the device 107 may also carry the bit string in the BIER option of the first BIER multicast packet, which is not limited in this embodiment of the present application.

The embodiment of the present application provides the following method for adding a slice ID to a multicast packet, which specifically includes:

in a first mode

For the BIERv6 message format shown in fig. 4, a Next Header (NH) field included in the IPv6 header is assigned with a first preset value, which indicates that a hop-by-hop options header (hop-by-hop) follows the IPv6 header. The first preset value may be 0, and the first preset value may be replaced by other possible values, which is not limited in this embodiment of the application. The next header field included in the hop-by-hop options header is assigned a value of 60, indicating that the header following the hop-by-hop options header is the destination options header. Optionally, the destination options header may further include a BIER option. An option type (option type) included in the hop-by-hop options header is assigned with a first specific value, which indicates that the hop-by-hop-options header carries a first TLV for carrying a slice ID. Optionally, the hop-by-hop options header includes a flag field for identifying the matching of the slices. The slice ID in the embodiment of the present application is 4 bytes (byte), and the slice ID can be represented by a high-low byte split form shown in fig. 4. The NH field included in the destination options header is assigned 4, which indicates that the IPv6 payload (payload) after the destination options header carries IPv4 multicast data, such as an IPv4 multicast packet. The NH field included in the destination options header is assigned 41, which indicates that the IPv6 payload after the destination options header carries IPv6 multicast data, such as an IPv6 multicast packet. In this embodiment of the application, the first multicast message adopts the message format shown in fig. 4, and the device 107 serving as the BFIR may add the slice ID 2 to the first TLV of the hop-by-hop options header according to the definition in the message format shown in fig. 4, to obtain the first BIER multicast message.

Mode two

For the BIERv6 message format shown in fig. 5, the NH field included in the IPv6 header is assigned with a second preset value, which indicates that the IPv6 header is followed by an IPv6 extension header. The IPv6 extension header is a new IPv6 header. The NH field included in the IPv6 extension header is assigned a value of 60, indicating that the header following the IPv6 extension header is a destination options header. Optionally, the destination options header may also include a BIER option. An option type included in the IPv6 extension header is assigned with a third preset value, and the fact that the IPv6 extension header carries a second TLV is shown. The second TLV is used to carry a slice ID. Optionally, a flag field included in the IPv6 extension header is used to identify the slice matching. The slice ID in the embodiment of the present application is 4 bytes (byte), and the slice ID can be represented by a high-low byte split form shown in fig. 5. The NH field included in the destination options header is assigned a value of 4 or 41, and the corresponding content can be seen in the corresponding content of manner one. In this embodiment of the present application, the first multicast packet adopts the packet format shown in fig. 5, and the device 107 serving as the BFIR may add the slice ID 2 to the second TLV of the IPv6 extension header according to the definition in the packet format shown in fig. 5, to obtain the first multicast packet.

Mode III

For the Destination Address (DA) field in the BIERv6 message shown in fig. 6(a) and 6(b), the DA field is used to carry the slice ID, for example, the space carrying the slice ID is divided from 64 bits included in the DA field for carrying the interface identifier, which may be 32 bits, that is, 4 bytes. The BIER node (end) address is used for routing forwarding. Fig. 6(a) and 6(b) include a 64-bit interface identifier field in which a device can be identified by address type, configuration of the aggregation network and access network device. The positional relationship between slice ID and end may be as shown in fig. 6(a) and 6 (b). The first multicast packet in the embodiment of the present application may adopt the formats shown in fig. 6(a) and fig. 6(b), and the device 107 serving as the BFIR may add slice ID 2 to the DA field according to the above configuration to obtain the first BIER multicast packet. When the DA field is a Segment Identifier (SID) in a Segment Routing over IPv6, SRv6 based on IPv6, a Bit Index of the SID shows that a duplicate (Bit Index extension) node (end. In other possible implementation manners, the end-bier address can be set as an address corresponding to the slice ID, the device serving as the BFIR and the intermediate BFR can store the corresponding relationship between the end-bier address and the slice ID, further obtain the slice ID according to the end-bier address and the corresponding relationship, and then determine the interface corresponding to the identifier of the network fragment by using a slice ID table lookup. The end-bier address is set to be the address corresponding to the slice ID, so that the device in a common network scene can be better compatible, and the multicast message is prevented from being changed as much as possible.

Mode IV

For the BIERv6 message format shown in fig. 7, the NH field included in the IPv6 header is assigned with a second preset value, which indicates that the IPv6 header is followed by an IPv6 extension header. The Next Header field included in the IPv6 extension Header is assigned a value of 60, indicating that the Header following the IPv6 extension Header is a destination options Header. The functions of the BFIR-id, next protocol (next protocol) and Differentiated Services Code Point (DSCP) fields included in the BIER header included in the destination options header are repeated with the functions of the Source Address (SA), NH and Traffic Class (Traffic Class) fields included in the IPv6 header. Thus, the BIER Header included in the destination options Header includes BFIR-ID, Proto and DSCP fields that may select the 32bit space to carry the slice ID. In the embodiment of the present application, the first multicast message adopts the message format shown in fig. 7, and the device 107 serving as the BFIR may add the slice ID 2 to the 32 bits selected from the fields of BFIR-ID, Proto, and DSCP of the IPv6 extension header according to the definition in the message format shown in fig. 7, to obtain the first BIER multicast message.

Mode five

For the BIERv6 message format shown in fig. 4 or fig. 5, 32bit space is divided in a Source Address (SA) field included in the IPv6 header for carrying a slice ID. If the SA carries the slice ID, because the SA also carries DTx information (the DTx information refers to VPN information), enough space needs to be reserved to ensure that DTx can be used, and 32bit is subdivided into the remaining space to be used as the slice ID. In this embodiment of the application, the first multicast message adopts the message format shown in fig. 4 or fig. 5, and the device 107 serving as the BFIR may add the slice ID 2 to the 32bit included in the SA of the IPv6 header according to the definition in the message format shown in fig. 4 or fig. 5, to obtain the first BIER multicast message.

For example, the BFIR device 107 may add the slice ID 2 to the first BIER multicast packet including bit string according to any one of the first to fifth manners, so that the subsequent intermediate BFR sends the first BIER multicast packet through the corresponding network segment 2 according to the slice ID 2 carried in the packet.

S302, the device 107 determines its own next hop according to the configured second forwarding table entry and sends the first BIER multicast packet.

For example, the device 107 serving as the BFIR may obtain the second forwarding entry by the method of the first embodiment. When the second forwarding table entry uses tables 2 to 10 of the first embodiment, the device 107 serving as the BFIR obtains the subinterface according to the bit string and the slice ID included in the first BIER multicast packet. When the second forwarding table entry uses tables 2 to 11 and 2 to 12 of the first embodiment, the device 107 serving as the BFIR may obtain the physical interface by looking up the tables 2 to 12 according to the bit string included in the first BIER multicast packet, and obtain the sub-interface by looking up the tables 2 to 11 using the physical interface and the slice ID. The sub-interface may be the above mentioned channelized sub-interface or a FlexE interface. When the first BIER multicast packet further includes SI, the device 107 as a BFIR may use the SI and bit string included in the first multicast packet, look up the BFR-id fields of tables 2-10 to determine the corresponding sub-interfaces, or look up the BFR-id fields of tables 2-12 to determine the corresponding physical interfaces. Specifically, the device 107 may determine that the sub-interface is 7-1-1 by using the above two manners according to 0110 and slice ID 2 included in the first BIER multicast packet. The device 107 sends the first BIER multicast message over the subinterface 7-1-1. When the intermediate BFR is not included in the path between the BFIR device and the BFER device, the method provided in the second embodiment of the present application may directly jump from S302 to S305.

And S303, the device 106 determines the next hop of the device according to the configured first forwarding table entry and the first BIER multicast, and sends the next hop.

In one implementation, at least one intermediate BFR, such as device 105 and device 106 in fig. 1, is included in the path between the device acting as a BFIR and the device acting as a BFER. And the equipment as the BFIR sends a first BIER multicast message to the equipment as the BFER, and the equipment as the BFIR sends the first BIER multicast message to the equipment as the BFER through at least one intermediate BFR. For the slice ID carrying manner provided in the first, second, fourth, or fifth manner in S301, the intermediate BFR obtains the slice ID from the slice ID carrying field of the first BIER multicast packet sent by the BFIR device. And the intermediate BFR searches a first forwarding table item according to the bit string and the slice ID included in the first BIER multicast message, and determines the sub-interface. And the intermediate BFR sends a first BIER multicast message through a subinterface. For the carrying mode of the slice ID provided in the third mode in S301, the slice ID is carried in the DA field of the first multicast packet, and in order to avoid the influence of the slice ID on forwarding during routing forwarding, when the intermediate BFR determines whether the received first BIER multicast packet is forwarded to itself according to table lookup performed by the DA, it is determined that the first BIER multicast packet is sent to itself according to the address of the slice ID in the DA after being set to zero, and then the first forwarding table entry is checked by using the slice ID and bit string, so as to obtain the sub-interface for sending the first BIER multicast packet. The slice ID needs to be added to the DA field of the first BIER multicast packet sent by the intermediate BFR, and the specific addition manner may refer to the manner three of S301, which is not described herein again.

In the scenario shown in fig. 1, the device 106 may obtain the slice ID 2 from the first BIER multicast packet by using any one of the above-described manners one to five. The device 106 queries the table 2-3 obtained in the first embodiment according to the slice ID 2 and 0110 included in the first BIER multicast packet, to obtain the subinterface 6-2-2. Or the device 106 queries the table 2-9 obtained in the first embodiment according to 0110 included in the first BIER multicast packet, and obtains the physical interface 6-2; the device 106 obtains the subinterface 6-2-2 based on the physical interface 6-2 and the slice ID 2. The device 106 sends a first BIER multicast message to the device 105 via the sub-interface 6-2-2. Wherein, the device 106 may perform and operation on the bit string with the F-BM of 0110 in tables 2 to 9 and the value of 0110 in the first BIER multicast message, and perform no replacement or copy operation, which is the same as the bit string in the operated bit string and the first BIER multicast message.

S304, the device 105 determines its own next hop according to the configured first forwarding table entry and the first BIER multicast, and sends the next hop.

For example, device 105 is an intermediate BFR and may determine the subinterface in the same manner as device 106. Specifically, the device 105 may acquire the slice ID 2 from the first BIER multicast packet by using any one of the first to fifth manners in S301. In an implementation manner, the device 105 may use the slice ID and the bit string with the value of 0110 in the first BIER multicast packet to search the table 2-2 obtained in the first embodiment, and obtain the sub-interface 5-1-1 and the sub-interface 5-2-1. The device 105 copies the first BIER multicast packet to obtain a second BIER multicast packet and a third BIER multicast packet. The device 105 may replace the bit string with a value of 0110 in the first BIER multicast packet with 0010 by using a normal method of processing the BIER multicast packet, so as to obtain a second BIER multicast packet. Bit string in the second BIER multicast message is 0010. The device 105 may replace the bit string with a value of 0110 in the first BIER multicast packet with 0100 to obtain the third BIER multicast packet by using a normal method for processing the BIER multicast packet. And bit string in the third BIER multicast message is 0100. The general mode for processing the BIER multicast message refers to that when a next hop includes two devices respectively connected with the BFER, bit string in the BIER multicast message is replaced by the BFR-id of the BFER connected with the next hop device. Device 105 may know through IGP flooding that its next hop connects two devices, such as device 102 and device 103, while device 102 and device 103 are BFERs, respectively. The device 105 sends a second BIER multicast message over the subinterface 5-1-1. The device 105 sends a third BIER multicast message over the subinterface 5-2-1. In another implementation, the device 105 searches the table 2-7 obtained according to the first embodiment with the bit string with a value of 0110 in the first BIER multicast packet to obtain the physical interface 5-1 and the physical interface 5-2 (the bit in the bit string middle 1 included in the F-BM is overlapped with the bit in the bit string middle 1 of the first BIER multicast packet). The device 105 performs an and operation with 0100 of the F-BM and 0110 in the first BIER multicast packet, and obtains a bit string with a value of 0100. The device 105 replaces the bit string in the first BIER multicast packet with 0100 to obtain a third BIER multicast packet. The third BIER multicast packet includes a bit string with a value of 0100. The device 105 searches the table 2-6 obtained in the first embodiment according to the physical interface 5-2 and the slice ID 2 included in the first BIER multicast packet, and obtains the subinterface 5-2-1. Device 105 performs an and operation with 0010 of the F-BM of tables 2-7 and 0110 in the first BIER multicast message to obtain a bit string with a value of 0010. The device 105 replaces the bit string in the first BIER multicast packet with 0010 to obtain a second BIER multicast packet. The second BIER multicast packet includes a bit string with a value of 0010. The device 105 searches the table 2-6 obtained in the first embodiment according to the physical interface 5-1 and the slice ID 2 included in the first BIER multicast packet, and obtains the subinterface 5-1-1. Device 105 sends a second BIER multicast message to device 102 via sub-interface 5-1-1. The device 105 sends a third BIER multicast message to the device 103 via the subinterface 5-2-1.

S305, the device as BFER obtains the multicast message and sends it to the multicast receiver.

For example, after receiving the second BIER multicast packet, the device 102 serving as the BFER determines, according to the bit string in the second BIER multicast packet, that the bit string includes its own BFR-id, that is, the 2 nd bit from right to left, which is set to 1, represents the BFR-id of the device 102. The device 102, which is a BFER, strips the BIER header in the second BIER multicast packet and sends it to the multicast receiver 2 connected to itself. After receiving the third BIER multicast packet, the device 103 serving as the BFER determines that the bit string includes its own BFR-id according to the bit string in the third BIER multicast packet, i.e., the 3 rd bit from right to left, which is set to 1, represents the BFR-id of the device 103. The device 103 as a BFER strips the BIER header in the third BIER multicast packet and transmits it to the multicast receiver 3 connected to itself.

Fig. 8 is a schematic structural diagram of an apparatus for sending a multicast packet according to an embodiment of the present application. The apparatus 800 for sending multicast packets provided in the embodiment corresponding to fig. 8 is described from the perspective of a logical structure, and may be disposed in the device serving as a BFIR or a device serving as an intermediate BFR in the second embodiment, such as the device 107, the device 106, or the device 105 in the scenario shown in fig. 3. Next, with reference to fig. 8, a structure of an apparatus for transmitting a multicast packet according to an embodiment of the present application will be described.

The apparatus 800 for sending a multicast packet is disposed in a first network device, and the apparatus 800 includes: a first obtaining unit 801, a second obtaining unit 802, and a transmitting unit 803. The first obtaining unit 801 is configured to obtain a first multicast packet, where the first multicast packet includes a bit string and an identifier of a network segment, the bit string corresponds to a second network device, and the network segment corresponds to a multicast service of the second network device. The second obtaining unit 802 is configured to obtain a first interface corresponding to the network segment according to the bit string and the identifier of the network segment. The sending unit 803 is configured to send the first multicast packet to the second network device through the first interface. The apparatus 800 is configured to configure the first network device as the device 107 in the second embodiment, where the first obtaining unit 801 is configured to support the device 107 to execute S301 in the second embodiment, and the second obtaining unit 802 and the sending unit 803 are configured to support the device 107 to execute S302 in the second embodiment. The first network device in which the apparatus 800 is disposed is the device 106 in the second embodiment, the first obtaining unit 801 is configured to support the device 106 to execute the step of acquiring the first BIER multicast packet in the second embodiment, and the second obtaining unit 802 and the sending unit 803 are configured to support the device 106 to execute the S303 in the second embodiment. The first network device in which the apparatus 800 is disposed is the device 105 in the second embodiment, the first obtaining unit 801 is configured to support the device 105 to execute the step of acquiring the first BIER multicast packet in the second embodiment, and the second obtaining unit 802 and the sending unit 803 are configured to support the device 105 to execute the S304 in the second embodiment.

In a possible implementation manner, the second obtaining unit 802 is specifically configured to: and searching a first forwarding table item by using the bit string included in the first multicast message and the identifier of the network fragment, and acquiring the identifier of a first interface, wherein the first forwarding table item comprises the bit string, the identifier of the network fragment and the identifier of the first interface. Based on the possible implementation manners, the second obtaining unit 802 is further configured to: acquiring the identifier of the network fragment and the BFR-id of the second network equipment; obtaining the bit string according to the BFR-id; and obtaining the first forwarding table entry according to the bit string and the identifier of the network fragment.

In a possible implementation manner, the second obtaining unit 802 is specifically configured to: searching a second forwarding table item by using the bit string included in the first multicast message, and acquiring an identifier of a second interface communicated with the second network equipment, wherein the second forwarding table item comprises the bit string and the identifier of the second interface; and searching a first forwarding table entry by using the identifier of the second interface and the identifier of the network fragment included in the first multicast message to obtain the identifier of the first interface, wherein the first forwarding table entry includes the identifier of the second interface, the identifier of the network fragment and the identifier of the first interface. Based on the possible implementation manners, the second obtaining unit 802 is further configured to: acquiring the identifier of the network fragment and the BFR-id of the second network equipment; obtaining the bit string according to the BFR-id; obtaining the second forwarding table entry according to the bit string and the identifier of the second interface; acquiring the identifier of the first interface corresponding to the identifier of the network fragment according to the identifier of the second interface; and obtaining the first forwarding table entry according to the identifier of the second interface, the identifier of the first interface and the identifier of the network fragment.

For example, the first network device is a BFIR or a BFR. Wherein the first network device is a BFIR, and the first obtaining unit 801 is specifically configured to: receiving a second multicast message from a multicast source, where the second multicast message includes multicast source group information, and the multicast source group information corresponds to the second network device; acquiring the bit string corresponding to the multicast source group information and the identifier of the network fragment according to the multicast source group information; and obtaining the first multicast message according to the second multicast message, the bit string and the identifier of the network fragment, wherein the first multicast message also comprises the second multicast message. The first network device is an intermediate BFR, and the first obtaining unit 801 is specifically configured to receive the first multicast packet sent by the BFIR.

For example, the carrying manner of the identifier of the network segment may include the following: in a first possible implementation manner, the first multicast packet includes an IPv6 header, and the IPv6 header includes an identifier of the network fragment. The destination address DA field of the IPv6 header comprises the identification of the network fragment; or the source address SA field of the IPv6 header includes an identification of the network fragment. In a second possible implementation manner, the first multicast packet includes an IPv6 extension header, and the IPv6 extension header includes an identifier of the network fragment. In a third possible implementation manner, the first multicast packet includes a hop-by-hop option header, where the hop-by-hop option header includes an identifier of the network segment. In a fourth possible implementation manner, the first multicast packet includes a destination option header, and the destination option header includes an identifier of the network segment. Wherein, the BIER header in the destination option header includes the identifier of the network fragment. See the corresponding contents of example two.

Illustratively, the first interface is a logical interface associated with a second interface for communicating with the second network device. Wherein, the first interface is a Flexe interface or a subinterface. In one implementation, the network slice corresponds to one or more MVPN services. In another implementation, the network segments correspond to one or more VPN services.

Fig. 9 is a schematic structural diagram of an apparatus for obtaining a forwarding entry according to an embodiment of the present application. The apparatus 900 for acquiring a forwarding table entry provided in the embodiment corresponding to fig. 9 is described from the perspective of a logical structure, and may be disposed in the device serving as a BFIR or a device serving as an intermediate BFR in the first embodiment, such as the device 107, the device 106, or the device 105 in the scenario shown in fig. 2. The following describes a structure of an apparatus for obtaining a forwarding table entry according to an embodiment of the present application with reference to fig. 9.

The apparatus 900 for obtaining a forwarding table entry may be disposed in a first network device, and the apparatus 900 includes: a first obtaining unit 901 and a second obtaining unit 902. The first obtaining unit 901 is configured to obtain an identifier of a network segment, where the network segment corresponds to a multicast service of a second network device. Second obtaining unit 902 is configured to obtain, according to the identifier of the network fragment, a first forwarding table entry, where the first forwarding table entry includes the identifier of the network fragment and an identifier of a first interface communicating with the second network device.

In a possible implementation manner, the first forwarding table entry further includes a bit string, where the bit string corresponds to the second network device, and the apparatus 900 further includes a receiving unit (not shown in fig. 9). The receiving unit is used for receiving the BFR-id sent by the second network equipment. The second obtaining unit 902 is further configured to obtain the bit string according to the BFR-id. Based on the possible implementation manners described above, the apparatus 900 further includes a third obtaining unit (not shown in fig. 9). The third obtaining unit is specifically configured to: acquiring a first multicast message, wherein the first multicast message comprises the bit string and the identifier of the network fragment; searching the first forwarding table entry by using the bit string and the identifier of the network fragment included in the first multicast message, and acquiring the identifier of the first interface; and sending the first multicast message to the second network equipment according to the identifier of the first interface.

In a possible implementation, the first forwarding table entry further includes an identification of a second interface for communicating with the second network device, and the apparatus 900 further includes a receiving unit (not shown in fig. 9). The receiving unit is used for receiving the BFR-id sent by the second network equipment. The second obtaining unit 902 is further configured to: obtaining bit string according to the BFR-id, wherein the bit string corresponds to the second network equipment; and obtaining a second forwarding table item according to the bit string and the identifier of the second interface, wherein the second forwarding table item comprises the bit string and the identifier of the second interface. Based on the possible implementation manners described above, the apparatus 900 further includes a third obtaining unit (not shown in fig. 9). The third obtaining unit is specifically configured to: acquiring a first multicast message, wherein the first multicast message comprises the bit string and the identifier of the network fragment; searching the second forwarding table entry by using the bit string included in the first multicast message, and acquiring the identifier of the second interface; and searching the first forwarding table entry by using the identifier of the second interface and the identifier of the network fragment included in the first multicast message to obtain the identifier of the first interface.

In this embodiment, the specific form of the first multicast packet carrying the identifier of the network segment may refer to corresponding content in the embodiment corresponding to fig. 8, and is not described herein again. The setting granularity of the identifier of the network segment in this embodiment may refer to corresponding content in the embodiment corresponding to fig. 8, and is not described herein again. In this embodiment, the first network device is a BFIR or an intermediate BFR, and the second network device is a BFER.

Fig. 10 is a schematic structural diagram of an apparatus for sending a multicast packet according to an embodiment of the present application. The apparatus 1000 for sending multicast packets provided in the embodiment corresponding to fig. 10 may be the apparatus 8008 for sending multicast packets provided in the embodiment corresponding to fig. 8. The apparatus 1000 for sending multicast packets according to the embodiment of fig. 10 is described from the perspective of a hardware structure. The apparatus 1000 for transmitting a multicast packet includes a processor 1001, a memory 1002, a communication bus 1004, and a communication interface 1003. The processor 1001, the memory 1002, and the communication interface 1003 are connected by a communication bus 1004. The memory 1002 is used to store programs. When the apparatus 1000 for sending a multicast packet is installed in a device that is a BFIR, the processor 1001 executes the method executed by the device 107 in the second embodiment according to the executable instructions included in the program read from the memory 1002. When the apparatus 1000 for sending a multicast packet is installed in a device serving as an intermediate BFR, the processor 1001 executes the method executed by the device 106 or the device 105 in the second embodiment according to the executable instructions included in the program read from the memory 1002.

Fig. 11 is a schematic structural diagram of an apparatus for obtaining a forwarding entry according to an embodiment of the present application. The apparatus 1100 for obtaining a forwarding entry provided in the corresponding embodiment of fig. 11 may be an apparatus 900 for obtaining a forwarding entry provided in the corresponding embodiment of fig. 9. The apparatus 1100 for obtaining a forwarding table entry according to the embodiment of fig. 11 is described from a hardware structure perspective. Forwarding device 1100 includes a processor 1101, a memory 1102, a communication bus 1104, and a communication interface 1103. The processor 1101, the memory 1102 and the communication interface 1103 are connected by a communication bus 1104. The memory 1102 is used to store programs. When the apparatus 1100 for acquiring a forwarding table entry is installed in a device that is a BFIR, the processor 1101 executes the method executed by the device 107 in the first embodiment according to the executable instructions included in the program read from the memory 1102. When the apparatus 1100 for acquiring a forwarding table entry is installed in a device serving as an intermediate BFR, the processor 1101 executes the method executed by the device 106 or the device 105 in the first embodiment according to the executable instructions included in the program read from the memory 1102.

The embodiment of the present application provides a system, where the system includes a device 800 for sending a multicast packet or a device 1000 for sending a multicast packet, or the system includes a device 900 for obtaining a forwarding table entry or a device 1100 for obtaining a forwarding table entry. The apparatus 800 for sending multicast packets or the apparatus 1000 for sending multicast packets may be configured to execute the method performed by the device serving as the BFIR in the second embodiment, or execute the method performed by the device serving as the intermediate BFR in the second embodiment. The apparatus 900 for obtaining a forwarding table entry or the apparatus 1100 for obtaining a forwarding table entry may be configured to perform the method performed by the device serving as the BFIR in the first embodiment, or to perform the method performed by the device serving as the intermediate BFR in the first embodiment.

The embodiment of the application provides a chip. The chip may include the memory 1001 and the processor 1001 shown in fig. 10. The memory 1002 is used to store computer instructions. The processor 1001 is configured to call and execute the computer instructions from the memory 1002 to execute the method for sending a multicast packet according to the second embodiment. The chip may include the memory 1101 and the processor 1101 shown in fig. 11. The memory 1102 is used to store computer instructions. The processor 1101 is configured to call and execute the computer instructions from the memory 1102 to perform a method for obtaining a forwarding table entry according to an embodiment. The chip provided by the embodiment of the present application may be disposed on forwarding hardware or a forwarding circuit included in the forwarding hardware is integrated with the chip provided by the embodiment of the present application.

The terms "first," "second," "third," "fourth," and the like in the description and in the claims of the present application and in the above-described drawings are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It will be appreciated that the data so used may be interchanged under appropriate circumstances such that the embodiments described herein may be practiced otherwise than as specifically illustrated or 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 elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.

In the present application, "at least one item(s)" means one or more, "a plurality" means two or more. "at least one of the following" or similar expressions refer to any combination of these items, including any combination of the singular or plural items. For example, at least one (one) of a, b, or c, may represent: a, b, c, a-b, a-c, b-c, or a-b-c, wherein a, b, c may be single or multiple. In the present application, "A and/or B" is considered to include A alone, B alone, and A + B.

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

In the several embodiments provided in the present application, it should be understood that the disclosed system, apparatus and method may be implemented in other manners. For example, the above-described apparatus embodiments are merely illustrative, and for example, the division of the units is only one type of logical module division, and other division manners may be available in actual implementation, for example, a plurality of units or components may be combined or integrated into another system, or some features may be omitted, or not executed. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection through some interfaces, devices or units, and may be in an electrical, mechanical or other form.

The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units can be obtained according to actual needs to achieve the purpose of the solution of the present embodiment.

In addition, each module unit in the embodiments of the present application may be integrated into one processing unit, or each unit may exist alone physically, or two or more units are integrated into one unit. The integrated unit can be realized in a hardware form, and can also be realized in a software module unit form.

The integrated unit, if implemented as a software module unit and sold or used as a stand-alone product, may be stored in a computer-readable storage medium. Based on such understanding, the technical solution of the present application may be substantially implemented or contributed to by the prior art, or all or part of the technical solution may be embodied in a software product, which is stored in a storage medium and includes instructions for causing a computer device (which may be a personal computer, a server, or a network device) to execute all or part of the steps of the method according to the embodiments of the present application. And the aforementioned storage medium includes: a U-disk, a removable hard disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk or an optical disk, and other various media capable of storing program codes.

Those skilled in the art will recognize that, in one or more of the examples described above, the functions described in this invention may be implemented in hardware, software, firmware, or any combination thereof. When implemented in software, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Computer-readable media includes both computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A storage media may be any available media that can be accessed by a general purpose or special purpose computer.

The above-described embodiments are intended to explain the objects, aspects and advantages of the present invention in further detail, and it should be understood that the above-described embodiments are merely exemplary embodiments of the present invention.

The above embodiments are only used for illustrating the technical solutions of the present application, and not for limiting the same; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for sending multicast messages, the method comprising:

a first network device obtains a first multicast message, wherein the first multicast message comprises a bit string and an identifier of a network fragment, the bit string corresponds to a second network device, and the network fragment corresponds to a multicast service of the second network device;

the first network equipment acquires a first interface corresponding to the network fragment according to the bit string and the identifier of the network fragment;

and the first network equipment sends the first multicast message to the second network equipment through the first interface.

2. The method of claim 1, wherein the obtaining, by the first network device, the first interface corresponding to the network segment according to the bit string and the identifier of the network segment comprises:

the first network equipment searches a first forwarding table item by using the bit string included in the first multicast message and the identifier of the network fragment, and acquires the identifier of a first interface, wherein the first forwarding table item comprises the bit string, the identifier of the network fragment and the identifier of the first interface.

3. The method of claim 2, wherein before the first network device obtains the first multicast message, the method further comprises:

the first network equipment acquires the identifier of the network fragment and a bit forwarding router identifier (BFR-id) of the second network equipment;

the first network equipment obtains the bit string according to the BFR-id;

and the first network equipment acquires the first forwarding table item according to the bit string and the identifier of the network fragment.

4. The method of claim 1, wherein the obtaining, by the first network device, the first interface corresponding to the network segment according to the bit string and the identifier of the network segment comprises:

the first network equipment searches a second forwarding table item by using the bit string included in the first multicast message, and acquires an identifier of a second interface communicated with the second network equipment, wherein the second forwarding table item comprises the bit string and the identifier of the second interface;

and the first network device searches a first forwarding table entry by using the identifier of the second interface and the identifier of the network fragment included in the first multicast message, and obtains the identifier of the first interface, wherein the first forwarding table entry includes the identifier of the second interface, the identifier of the network fragment and the identifier of the first interface.

5. The method of claim 4, wherein before the first network device obtains the first multicast message, the method further comprises:

the first network equipment acquires the identifier of the network fragment and the BFR-id of the second network equipment;

the first network equipment obtains the bit string according to the BFR-id;

the first network equipment obtains the second forwarding table item according to the bit string and the identifier of the second interface;

the first network equipment acquires the identifier of the first interface corresponding to the identifier of the network fragment according to the identifier of the second interface;

and the first network equipment obtains the first forwarding table entry according to the identifier of the second interface, the identifier of the first interface and the identifier of the network fragment.

6. Method according to any of claims 1 to 5, wherein said first network device is a bit forwarding ingress router BFIR or an intermediate bit forwarding router BFR.

7. The method according to any one of claims 1 to 5, wherein the first network device is a BFIR, and the obtaining of the first multicast message by the first network device comprises:

the first network equipment receives a second multicast message from a multicast source, wherein the second multicast message comprises multicast source group information, and the multicast source group information corresponds to the second network equipment;

the first network equipment acquires the bit string corresponding to the multicast source group information and the identifier of the network fragment according to the multicast source group information;

and the first network equipment acquires the first multicast message according to the second multicast message, the bit string and the identifier of the network fragment, wherein the first multicast message also comprises the second multicast message.

8. The method according to any one of claims 1 to 5, wherein the first network device is an intermediate BFR, and wherein the obtaining of the first multicast message by the first network device comprises:

and the first network equipment receives the first multicast message sent by BFIR.

9. The method of any of claims 1 to 8, wherein the first multicast message comprises a sixth version internet protocol, IPv6, header, and wherein the IPv6 header comprises an identification of the network slice.

10. The method according to claim 9, wherein the destination address DA field of the IPv6 header includes an identification of the network slice; or

The source address SA field of the IPv6 header includes an identification of the network fragment.

11. The method of any of claims 1 to 8, wherein the first multicast message comprises an IPv6 extension header, and wherein the IPv6 extension header comprises an identification of the network slice.

12. The method according to any of claims 1 to 8, wherein the first multicast message comprises a hop-by-hop option header, the hop-by-hop option header comprising an identification of the network slice.

13. The method according to any one of claims 1 to 8, wherein the first multicast message includes a destination option header, and the destination option header includes an identifier of the network segment.

14. The method of claim 13, wherein the BIER header in the destination option header comprises an identification of the network segment.

15. The method of any of claims 1 to 14, wherein the first interface is a logical interface associated with a second interface for communicating with the second network device.

16. The method according to any of claims 1 to 15, wherein the first interface is a flexible ethernet FlexE interface or a subinterface.

17. The method according to any of claims 1 to 16, wherein said network slice corresponds to one or more multicast virtual private network, MVPN, services or said network slice corresponds to one or more virtual private network, VPN, services.

18. A method for obtaining forwarding table entries, the method comprising:

a first network device acquires an identifier of a network fragment, wherein the network fragment corresponds to a multicast service of a second network device;

and the first network equipment obtains a first forwarding table entry according to the identifier of the network fragment, wherein the first forwarding table entry comprises the identifier of the network fragment and the identifier of a first interface communicated with the second network equipment.

19. The method of claim 18, wherein the first forwarding entry further comprises a bit string, and wherein the bit string corresponds to the second network device, the method further comprising:

the first network equipment receives BFR-id sent by the second network equipment;

and the first network equipment obtains the bit string according to the BFR-id.

20. The method of claim 19, wherein after obtaining the first forwarding table entry, the method further comprises:

the first network equipment acquires a first multicast message, wherein the first multicast message comprises the bit string and the identifier of the network fragment;

the first network device searches the first forwarding table entry by using the bit string and the identifier of the network fragment included in the first multicast message, and acquires the identifier of the first interface;

and the first network equipment sends the first multicast message to the second network equipment according to the identifier of the first interface.

21. The method of claim 18, wherein the first forwarding entry further comprises an identification of a second interface in communication with the second network device, the method further comprising:

the first network equipment receives a bit forwarding router BFR-id sent by the second network equipment;

the first network equipment obtains bit string according to the BFR-id, and the bit string corresponds to the second network equipment;

and the first network equipment acquires a second forwarding table item according to the bit string and the identifier of the second interface, wherein the second forwarding table item comprises the bit string and the identifier of the second interface.

22. The method of claim 21, wherein after the obtaining the first forwarding table entry, the method further comprises:

the first network equipment searches the second forwarding table item by using the bit string included in the first multicast message to acquire the identifier of the second interface;

and the first network equipment searches the first forwarding table entry by using the identifier of the second interface and the identifier of the network fragment included in the first multicast message to obtain the identifier of the first interface.

23. The method of claim 20 or 22, wherein the first multicast message comprises a sixth version internet protocol, IPv6, header, and wherein the IPv6 header comprises an identification of the network slice.

24. The method of claim 23, wherein a Destination Address (DA) field of the IPv6 header includes an identification of the network slice; or

25. The method according to claim 20 or 22, wherein the first multicast message comprises a destination option header, and the destination option header comprises an identifier of the network slice.

26. The method of claim 25, wherein the BIER header in the destination option header comprises an identification of the network segment.

27. The method of any of claims 18 to 26, wherein the first interface is a logical interface associated with a second interface for communicating with the second network device.

28. The method according to any of claims 18 to 27, wherein the first interface is a flexible ethernet FlexE interface or a subinterface.

29. The method according to any of claims 18 to 28, wherein said network slice corresponds to one or more multicast virtual private network, MVPN, services or wherein said network slice corresponds to one or more virtual private network, VPN, services.

30. Method according to any of claims 18 to 29, wherein said first network device is a bit forwarding ingress router, BFIR, or an intermediate forwarding router, BFR, and wherein said second network device is a bit forwarding egress router, BFER.

31. An apparatus for sending a multicast packet, the apparatus being disposed in a first network device, the apparatus comprising:

a first obtaining unit, configured to obtain a first multicast packet, where the first multicast packet includes a bit string and an identifier of a network segment, the bit string corresponds to a second network device, and the network segment corresponds to a multicast service of the second network device;

a second obtaining unit, configured to obtain, according to the bit string and the identifier of the network segment, a first interface corresponding to the network segment;

a sending unit, configured to send the first multicast packet to the second network device through the first interface.

32. The apparatus according to claim 31, wherein the second obtaining unit is specifically configured to:

and searching a first forwarding table item by using the bit string included in the first multicast message and the identifier of the network fragment, and acquiring the identifier of a first interface, wherein the first forwarding table item comprises the bit string, the identifier of the network fragment and the identifier of the first interface.

33. The apparatus of claim 32, wherein the second obtaining unit is further configured to:

acquiring an identifier of the network fragment and a bit forwarding router identifier (BFR-id) of the second network device;

obtaining the bit string according to the BFR-id;

and obtaining the first forwarding table entry according to the bit string and the identifier of the network fragment.

34. The apparatus according to claim 31, wherein the second obtaining unit is specifically configured to:

searching a second forwarding table item by using the bit string included in the first multicast message, and acquiring an identifier of a second interface communicated with the second network equipment, wherein the second forwarding table item comprises the bit string and the identifier of the second interface;

and searching a first forwarding table entry by using the identifier of the second interface and the identifier of the network fragment included in the first multicast message to obtain the identifier of the first interface, wherein the first forwarding table entry includes the identifier of the second interface, the identifier of the network fragment and the identifier of the first interface.

35. The apparatus of claim 34, wherein the second obtaining unit is further configured to:

acquiring the identifier of the network fragment and the BFR-id of the second network equipment;

obtaining the bit string according to the BFR-id;

obtaining the second forwarding table entry according to the bit string and the identifier of the second interface;

acquiring the identifier of the first interface corresponding to the identifier of the network fragment according to the identifier of the second interface;

and obtaining the first forwarding table entry according to the identifier of the second interface, the identifier of the first interface and the identifier of the network fragment.

36. The apparatus according to any of claims 31 to 35, wherein said first network device is a bit forwarding ingress router, BFIR, or an intermediate bit forwarding router, BFR.

37. The apparatus according to any one of claims 31 to 35, wherein the first network device is a BFIR, and the first obtaining unit is specifically configured to:

receiving a second multicast message from a multicast source, where the second multicast message includes multicast source group information, and the multicast source group information corresponds to the second network device;

acquiring the bit string corresponding to the multicast source group information and the identifier of the network fragment according to the multicast source group information;

and obtaining the first multicast message according to the second multicast message, the bit string and the identifier of the network fragment, wherein the first multicast message also comprises the second multicast message.

38. The apparatus according to any one of claims 31 to 35, wherein the first network device is an intermediate BFR, and the first obtaining unit is specifically configured to receive the first multicast packet sent by a BFIR.

39. The apparatus of any of claims 31 to 38, wherein the first multicast message comprises a sixth version internet protocol, IPv6, header, and wherein the IPv6 header comprises an identification of the network slice.

40. The apparatus according to claim 39, wherein the destination address DA field of the IPv6 header includes an identification of the network slice; or

41. The apparatus of any of claims 31 to 38, wherein the first multicast packet comprises an IPv6 extension header, and wherein the IPv6 extension header comprises an identification of the network slice.

42. The apparatus according to any of claims 31 to 38, wherein the first multicast message comprises a hop-by-hop option header, the hop-by-hop option header comprising an identification of the network slice.

43. The apparatus according to any of claims 31 to 38, wherein the first multicast message comprises a destination option header, and the destination option header comprises an identifier of the network slice.

44. The apparatus of claim 43, wherein a BIER header in the destination option header comprises an identification of the network fragment.

45. The apparatus of any of claims 31 to 44, wherein the first interface is a logical interface associated with a second interface for communicating with the second network device.

46. The apparatus according to any of claims 31 to 45, wherein the first interface is a FlexE interface or a subinterface.

47. The apparatus of any of claims 31 to 46, wherein the network slice corresponds to one or more Multicast Virtual Private Network (MVPN) services or wherein the network slice corresponds to one or more Virtual Private Network (VPN) services.

48. An apparatus for obtaining a forwarding table entry, the apparatus being disposed in a first network device, the apparatus comprising:

a first obtaining unit, configured to obtain an identifier of a network segment, where the network segment corresponds to a multicast service of a second network device;

a second obtaining unit, configured to obtain a first forwarding entry according to the identifier of the network fragment, where the first forwarding entry includes the identifier of the network fragment and an identifier of a first interface that communicates with the second network device.

49. The apparatus of claim 48, wherein the first forwarding entry further comprises a bit string, and wherein the bit string corresponds to the second network device, the apparatus further comprising:

the receiving unit is used for receiving the BFR-id sent by the second network equipment;

and the second obtaining list is also used for obtaining the bit string according to the BFR-id.

50. The apparatus according to claim 49, further comprising a third obtaining unit, specifically configured to:

acquiring a first multicast message, wherein the first multicast message comprises the bit string and the identifier of the network fragment;

searching the first forwarding table entry by using the bit string and the identifier of the network fragment included in the first multicast message, and acquiring the identifier of the first interface;

and sending the first multicast message to the second network equipment according to the identifier of the first interface.

51. The apparatus of claim 48, wherein the first forwarding table entry further comprises an identification of a second interface to communicate with the second network device, the apparatus further comprising:

a receiving unit, configured to receive a bit forwarding router BFR-id sent by the second network device;

the second obtaining unit is further configured to: obtaining bit string according to the BFR-id, wherein the bit string corresponds to the second network equipment; and obtaining a second forwarding table item according to the bit string and the identifier of the second interface, wherein the second forwarding table item comprises the bit string and the identifier of the second interface.

52. The apparatus according to claim 51, further comprising a third obtaining unit, specifically configured to:

searching the second forwarding table entry by using the bit string included in the first multicast message, and acquiring the identifier of the second interface;

and searching the first forwarding table entry by using the identifier of the second interface and the identifier of the network fragment included in the first multicast message to obtain the identifier of the first interface.

53. The apparatus of claim 50 or 52, wherein the first multicast message comprises a version six Internet protocol (IPv) 6 header, and wherein the IPv6 header comprises an identification of the network slice.

54. The apparatus according to claim 53, wherein the Destination Address (DA) field of the IPv6 header includes an identification of the network slice; or

55. The apparatus according to claim 50 or 52, wherein the first multicast message comprises a destination option header, and the destination option header comprises an identifier of the network slice.

56. The apparatus of claim 55, wherein a BIER header in the destination option header comprises an identification of the network fragment.

57. The apparatus of any of claims 48 to 56, wherein the first interface is a logical interface associated with a second interface for communicating with the second network device.

58. The apparatus according to any one of claims 48 to 57, wherein the first interface is a FlexE interface or a subinterface.

59. The apparatus of any of claims 48 to 58, wherein the network slice corresponds to one or more Multicast Virtual Private Network (MVPN) services or wherein the network slice corresponds to one or more Virtual Private Network (VPN) services.

60. The apparatus according to any of claims 48 to 59, wherein said first network device is a bit forwarding ingress router BFIR or an intermediate forwarding router BFR and said second network device is a bit forwarding egress router BFER.

61. A system comprising means for sending multicast messages according to any of claims 31 to 47 or means for obtaining forwarding entries according to any of claims 48 to 60.

62. A chip, comprising a memory for storing computer instructions and a processor for calling and executing the computer instructions from the memory to perform the method of sending a multicast packet according to any one of claims 1 to 17 or to perform the method of obtaining a forwarding entry according to any one of claims 18 to 30.

63. A computer program product comprising one or more computer program instructions which, when loaded and executed by a computer, cause the computer to perform the method of sending multicast messages according to any one of claims 1 to 17 or to perform the method of obtaining forwarding entries according to any one of claims 18 to 30.

64. A computer-readable storage medium, for storing instructions, wherein the instructions include a program designed to execute the method for sending multicast packets according to any one of claims 1 to 17, or the instructions include a program designed to execute the method for obtaining forwarding table entry according to any one of claims 18 to 30.

65. An apparatus for sending a multicast message, the apparatus comprising a processor and a non-transitory computer readable storage medium storing program instructions for execution by the processor to instruct the processor to perform the method of sending a multicast message according to any one of claims 1 to 17.

66. An apparatus for obtaining forwarding entries, the apparatus comprising a processor and a non-transitory computer readable storage medium storing program instructions for execution by the processor, the program instructions instructing the processor to perform the method for obtaining forwarding entries according to any one of claims 18 to 30.