WO2021196717A1 - 组播流量传输方法、装置、通信节点及存储介质 - Google Patents

组播流量传输方法、装置、通信节点及存储介质 Download PDF

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Publication number
WO2021196717A1
WO2021196717A1 PCT/CN2020/135268 CN2020135268W WO2021196717A1 WO 2021196717 A1 WO2021196717 A1 WO 2021196717A1 CN 2020135268 W CN2020135268 W CN 2020135268W WO 2021196717 A1 WO2021196717 A1 WO 2021196717A1
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Prior art keywords
communication node
bier
information
forwarding
message
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PCT/CN2020/135268
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English (en)
French (fr)
Inventor
张征
徐本崇
朱小龙
马汝胜
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中兴通讯股份有限公司
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Priority claimed from CN202010260534.3A external-priority patent/CN112511444B/zh
Application filed by 中兴通讯股份有限公司 filed Critical 中兴通讯股份有限公司
Priority to EP20928727.5A priority Critical patent/EP4131872A4/en
Priority to US17/916,416 priority patent/US20230155932A1/en
Publication of WO2021196717A1 publication Critical patent/WO2021196717A1/zh

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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L45/00—Routing or path finding of packets in data switching networks
    • H04L45/16—Multipoint routing
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L45/00—Routing or path finding of packets in data switching networks
    • H04L45/56—Routing software
    • H04L45/566—Routing instructions carried by the data packet, e.g. active networks
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L45/00—Routing or path finding of packets in data switching networks
    • H04L45/02—Topology update or discovery
    • H04L45/04—Interdomain routing, e.g. hierarchical routing
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L45/00—Routing or path finding of packets in data switching networks
    • H04L45/12—Shortest path evaluation
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L45/00—Routing or path finding of packets in data switching networks
    • H04L45/34—Source routing
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L45/00—Routing or path finding of packets in data switching networks
    • H04L45/50—Routing or path finding of packets in data switching networks using label swapping, e.g. multi-protocol label switch [MPLS]
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L45/00—Routing or path finding of packets in data switching networks
    • H04L45/74—Address processing for routing
    • H04L45/745—Address table lookup; Address filtering
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L45/00—Routing or path finding of packets in data switching networks
    • H04L45/74—Address processing for routing
    • H04L45/745—Address table lookup; Address filtering
    • H04L45/748—Address table lookup; Address filtering using longest matching prefix

Definitions

  • This application relates to the field of communications, for example, to a method, device, communication node, and storage medium for multicast traffic transmission.
  • Multicast technology is getting more and more applications on the Internet, such as multi-party conferences, distance education, telemedicine, and webcasting. These applications also promote the development and improvement of multicast technology.
  • Bit Indexed Explicit Replication is a new type of multicast data forwarding technology.
  • BIER Bit Indexed Explicit Replication
  • This application provides a method, device, communication node, and storage medium for multicast traffic transmission.
  • the embodiment of the present application provides a multicast traffic transmission method, which is applied to a first communication node, and includes:
  • the first forwarding entry includes the bit index of the autonomous system border router ASBR to explicitly copy BIER information; obtain multicast traffic; encapsulate the multicast traffic based on the first forwarding entry , Confirm and transmit the BIER message.
  • the embodiment of the present application also provides a method for transmitting multicast traffic, which is applied to a second communication node, and includes:
  • the embodiment of the present application also provides a multicast traffic transmission method, which is applied to a third communication node, and includes:
  • the embodiment of the present application also provides a multicast traffic transmission device, which is configured at the first communication node, and includes:
  • the first determining module is configured to determine a first forwarding entry, where the first forwarding entry includes the bit index of the autonomous system border router ASBR to explicitly copy the BIER information; the acquiring module is configured to acquire multicast traffic; the second determining module , It is set to encapsulate the multicast traffic based on the first forwarding entry, and determine and transmit a BIER message.
  • An embodiment of the present application also provides a multicast traffic transmission device, which is configured at a second communication node, and includes:
  • the sending module is configured to send the BIER information of the ASBR to the first communication node;
  • the acquiring module is configured to obtain the BIER message sent by the first communication node, the BIER message is determined based on the first forwarding entry, and the first A forwarding entry is determined based on the BIER information of the ASBR sent to the first communication node;
  • the transmission module is set to transmit the BIER message based on the switching information of the BIER forwarding plane of the second communication node and the second forwarding entry .
  • An embodiment of the present application also provides a multicast traffic transmission device, which is configured at a third communication node, and includes:
  • the sending module is configured to send the BIER information of the ASBR to the second communication node; the acquiring module is configured to obtain the BIER message of the second communication node, and the BIER message is the BIER forwarding plane of the second communication node. The switching information and the second forwarding entry are transmitted; the transmission module is configured to transmit the BIER message according to the second association relationship.
  • the embodiment of the present application also provides a communication node, including:
  • One or more processors a storage device for storing one or more programs; when the one or more programs are executed by the one or more processors, the one or more processors implement the application Any one of the methods in the embodiment.
  • the embodiments of the present application also provide a storage medium, where the storage medium stores a computer program, and when the computer program is executed by a processor, any one of the methods in the embodiments of the present application is implemented.
  • FIG. 1 is a schematic flowchart of a method for transmitting multicast traffic provided by this application
  • Figure 1a is a schematic diagram of a cross-domain network provided by this application.
  • Figure 1b is a schematic diagram of another cross-domain network provided by this application.
  • FIG. 2 is a schematic flowchart of another method for transmitting multicast traffic provided by this application.
  • FIG. 3 is a schematic flowchart of another method for transmitting multicast traffic provided by this application.
  • Figure 3a is a schematic diagram of another cross-domain network provided by this application.
  • Figure 3b is a schematic diagram of another cross-domain network provided by this application.
  • FIG. 3c is a schematic diagram of a second association relationship provided by this application.
  • FIG. 3d is a schematic diagram of another second association relationship provided by this application.
  • FIG. 3e is a schematic diagram of a first association relationship provided by this application.
  • FIG. 3f is a schematic diagram of the multi-level mapping relationship on the first communication node provided by this application.
  • FIG. 3g is a schematic diagram of the multi-level mapping relationship on the second communication node provided by this application.
  • FIG. 4 is a schematic structural diagram of a multicast traffic transmission device provided by this application.
  • FIG. 5 is a schematic structural diagram of a multicast traffic transmission device provided by this application.
  • FIG. 6 is a schematic structural diagram of a multicast traffic transmission device provided by this application.
  • FIG. 7 is a schematic structural diagram of a communication node provided by this application.
  • FIG. 1 is a schematic flow chart of a method for transmitting multicast traffic provided by this application.
  • the method may be suitable for cross-domain transmission of multicast traffic.
  • the method may be configured by the method provided in this application.
  • the multicast traffic transmission device of the first communication node is executed, and the device may be implemented by software/or hardware and integrated on the first communication node.
  • the first communication node may be an entrance operator edge (Provider Edge, PE) of the autonomous system to which it belongs.
  • PE Provide Edge
  • the first communication node can be considered as a communication node that directly or indirectly communicates with the server.
  • BIER uses only one bit (ie bit) to represent the nodes at the edge of the network.
  • the multicast traffic is transmitted in the intermediate network, and a specific BIER header is additionally encapsulated. This packet header is used to mark the multicast in the form of a bit string. All destination nodes of the flow, and intermediate network forwarding nodes perform routing according to the bits to ensure that the flow can be sent to all destination nodes.
  • the intermediate node forwarding device passes internal protocols in advance, such as the Open Shortest Path First (OSPF) protocol in the three-layer network, the Intermediate System-to-Intermediate System (ISIS) protocol, and the boundary Gateway Protocol (Border Gateway Protocol, BGP) or Babel protocol to flood and send node information to form a Bit Index Forwarding Table (BIFT) used to guide BIER forwarding.
  • OSPF Open Shortest Path First
  • ISIS Intermediate System-to-Intermediate System
  • BGP Border Gateway Protocol
  • Babel protocol Babel protocol
  • the data plane forwarding technology of BIER eliminates the delay of the establishment of the multicast tree because there is no problem of the establishment of the multicast tree, and when there is a link or node problem in the network, the convergence speed is the same as that of the OSPF and ISIS protocols, which is faster than the original multicast. Tree reconstruction reduces the huge time delay. Protocols such as OSPF/ISIS or BGP used to establish BIER forwarding entries are called the underlying layer (ie underlay) technology of BIER.
  • BIER Bit-Forwarding Ingress Router
  • BFER Bit-Forwarding Egress Routers
  • the cross-domain scenario is a very common networking scenario in the Internet.
  • the concept of cross-domain comes from the unicast multi-domain backbone network of Request For Comments (RFC) 4364.
  • the standard for Multicast Virtual Private Network (MVPN) is RFC6513.
  • Cross-domain refers to across multiple autonomous system (Autonomous System, AS) domains.
  • AS Autonomous System
  • Option A refers to the back-to-back cross-domain method.
  • Multiple virtual private networks Virtual Private Network, VPN
  • ASBR autonomous system border routers
  • VRF Forwarding table
  • the ASBR is the relationship between PE and Customer Edge (CE).
  • the traffic is restored to private network traffic, and then encapsulated on the opposite ASBR so that it can be on the public network of another AS transfer.
  • Figure 1a is a schematic diagram of a cross-domain network provided by this application.
  • IP Internet Protocol
  • FIG. 1a when traffic comes out of PE1, it is encapsulated according to the public network tunnel, and when it reaches ASBR1, it will be restored to the private network interconnection protocol ( Internet Protocol (IP) traffic is sent by ASBR1 to ASBR2 and ASBR3, and then encapsulated in the public network tunnel for transmission in AS2.
  • IP Internet Protocol
  • ASBR1 Internet Protocol
  • ASBR3 Internet Protocol
  • AS1, AS2, and AS3 each establish their own BIER domains
  • PE1 and ASBR1 are used as the BFIR and BFER devices of AS1
  • ASBR2 and PE2 are used as the BFIR and BFER devices of AS2
  • ASBR3 is used as the BFIR of AS3
  • PE3 and PE4 are used as the BFER of AS3.
  • Between ASBRs is the PE-CE traffic transmission method, which has nothing to do with BIER.
  • Option B is another cross-domain implementation method.
  • multiple VRFs are not established between ASBRs to restore private network traffic, but are implemented through re-announcement of routes between ASBRs.
  • traffic is encapsulated according to the public network tunnel and sent from PE1.
  • ASBR2 When it reaches ASBR1, it is directly sent to ASBR2 and ASBR3 in the form of label switching.
  • ASBR2/3 then performs label switching and encapsulates the tunnel in its domain, and then sends it to The recipient of the respective AS.
  • BIER technology is applied in this scenario, single-domain BIER technology cannot be directly applied, especially for traffic processing between ASBRs. There is no corresponding technology to solve how to implement BIER forwarding.
  • Option C is the third cross-domain implementation method.
  • a multi-hop External Border Gateway Protocol (EBGP) is established between PEs, but the path that spans multiple ASs needs to be opened.
  • EBGP External Border Gateway Protocol
  • the route import of multiple domains can be used to realize the BIER forwarding path of the entire network.
  • Figure 1b is a schematic diagram of another cross-domain network provided by this application.
  • PE1 can directly encapsulate the traffic with PE2/3/4 as the BIER header of the destination bit string (ie, Bitstring), which is sent to the BFER by the BIER forwarding plane of the entire network, and the BFER includes PE2/3/4.
  • the ASBR in the middle only implements the forwarding behavior of the Bit-Forwarding Router (BFR) device to deliver the message.
  • BFR Bit-Forwarding Router
  • RFC8556 combines MVPN and BIER technology, but it is only applicable to scenarios in the same domain, and it still cannot support cross-domain scenarios.
  • BIER technology is being widely used on the network. How to apply BIER technology to large-scale networking of multiple AS domains is an important issue that needs to be solved. This application aims at multiple multicast cross-domain scenarios and improves the BIER technology so that BIER technology serves large-scale networks well and promotes the development of network multicast technology.
  • a multicast traffic transmission method provided by the present application, as shown in FIG. 1, includes the following steps:
  • the first forwarding entry can be used to encapsulate the multicast traffic to obtain the BIER message.
  • the destination bit string of the multicast traffic is determined based on the first forwarding entry to realize the cross-domain transmission of the multicast traffic.
  • the first forwarding entry may be established based on the obtained BIER information of the ASBR.
  • the first forwarding entry may include BIER information of the ASBR, where the ASBR may be one or more of the egress ASBR of the autonomous system to which the first communication node belongs and the ingress ASBR of the downstream autonomous system of the autonomous system to which the first communication node belongs.
  • the first forwarding entry may also include BIER information of the egress PE or egress ASBR of the downstream autonomous system of the autonomous system to which the first communication node belongs.
  • This application can obtain the BFR-ID of the cross-hop BFER, establish a multi-level mapping table of the BFR-ID, and obtain the first forwarding entry.
  • the first communication node may determine the next hop device of the fourth communication node in an iterative manner to establish a multi-level mapping table.
  • Multicast traffic can be considered as traffic in a multicast scenario.
  • the multicast traffic can be indirectly transmitted to the fourth communication node interested in the multicast traffic.
  • S130 Encapsulate the multicast traffic based on the first forwarding entry, and determine and transmit a BIER message.
  • this application can encapsulate the multicast traffic to obtain the BIER message, and then transmit the BIER message.
  • one or more of the first communication node, the second communication node, the third communication node, and the fourth communication node in this application can predetermine the sense of each fourth communication node.
  • Interested multicast traffic or the VPN to which the multicast traffic belongs and assign a label or SID to the multicast traffic or the VPN to which the multicast traffic belongs to each fourth communication node to identify the corresponding multicast traffic or the VPN to which the multicast traffic belongs .
  • an association relationship is established on the communication node that needs to switch the BIER forwarding plane.
  • the association relationship established by the first communication node may include the traffic that the fourth communication node is interested in or the VPN to which the traffic belongs, and the corresponding label or SID.
  • the association relationship of the first communication node is established based on the traffic of interest and the corresponding label, or the association relationship of the first communication node is established based on the VPN to which the traffic of interest belongs and the corresponding label.
  • one or two layers of BIER headers can be encapsulated based on the first forwarding entry, and the BIER can be performed in the cross-domain network according to the association relationship, such as the multi-level mapping table of the BIER forwarding table and the BFR-ID. Forwarding of messages.
  • the outer BIER header may be used to indicate the protocol field of the inner BIER header, such as Ethernet, Internet Protocol version (IPv6), or BIER type.
  • determining whether to switch the BIER forwarding plane can be determined by obtaining information from the current communication node, such as the forwarding plane to which the BIER message belongs when sending the BIER message, and whether the forwarding plane when sending to the next-hop device is the same forwarding plane.
  • the association relationship may be based on the received indication information used to identify the communication node sent to the communication node label or SID, the sent label or SID (identification information), and the label assigned by the communication node. Or the SID and the instruction information of the communication node are established.
  • the “first”, “second”, “third”, etc. mentioned in this application are only used to distinguish the corresponding content.
  • the first indication information and the second indication information are only used to distinguish the indication information.
  • the first indication information may be used to indicate that the first identification information is sent by the first communication node; the second indication information may be used to indicate that the second identification information is sent by the second communication node.
  • the BIER message can be transmitted through the BIER forwarding plane of the first communication node.
  • This application can establish the BIER domain and the corresponding BIER forwarding plane based on the routing prefix of the ASBR or PE and the routing capabilities in other ASs.
  • the BIER forwarding plane of the first communication node is determined based on the routing capability of the third communication node in the autonomous system to which the first communication node belongs.
  • the third communication node may be an ingress ASBR of an autonomous system downstream of the autonomous system to which the first communication node belongs.
  • a first forwarding entry is determined, and the first forwarding entry includes a bit index of an autonomous system border router ASBR, which explicitly replicates BIER information; obtains multicast traffic; based on the first forwarding entry.
  • a forwarding entry encapsulates the multicast traffic, determines and transmits the BIER message.
  • the bit index of the autonomous system border router ASBR explicitly replicates BIER information including one or more of the following: BIER information of a second communication node, where the second communication node belongs to the first communication node The egress ASBR of the autonomous system; the BIER information of the third communication node, the autonomous system to which the third communication node belongs is located downstream of the autonomous system to which the first communication node belongs; the BIER information of the fourth communication node, the fourth communication node It is the egress operator edge or egress ASBR of the autonomous system to which the third communication node belongs.
  • the autonomous system ASBR may be one or more of the second communication node, the third communication node, and the fourth communication node.
  • the BIER information is not limited here, and the information needed to realize cross-domain transmission using BIER technology can be determined based on the actual situation.
  • the BIER information includes a bit forwarding router identifier BFR-ID; the BIER information further includes one or more of the following: subdomain information; bit index forwarding table identifier; bit string length.
  • the BIER information may include the BFR-ID, and the BFR-ID of the communication node corresponding to the multicast traffic may be set as the destination bit string when the multicast traffic is encapsulated.
  • the communication node corresponding to the multicast traffic can be considered as the communication node interested in the multicast traffic.
  • the subdomain information can be considered as information used to identify the BIER domain.
  • This application can determine whether to switch the forwarding plane based on the subdomain information, thereby re-encapsulating the BIER message. For example, when a BIER message is transmitted, the corresponding BIER domain of the receiving BIER message and the domain of sending the BIER message are different domains, and the forwarding plane can be switched.
  • bit index forwarding table identifier and bit string length are not limited here, and can be set according to actual needs.
  • the determining the first forwarding entry includes one or more of the following:
  • the BIER information of the second communication node and the third communication node and determine the first forwarding entry based on the BIER information of the second communication node and the third communication node; obtain the BIER information of the second communication node, and based The BIER information of the second communication node determines the first forwarding entry; the BIER information of the second communication node, the third communication node, and the fourth communication node is acquired, and the BIER information is based on the second communication node, the third communication node, and the second communication node.
  • the BIER information of the communication node determines the first forwarding table entry; obtains the BIER information of the second communication node and the fourth communication node, and determines the first forwarding table based on the BIER information of the second communication node and the fourth communication node item.
  • this application can obtain the BIER information of the third communication node, based on the The BIER information of the three communication nodes establishes the first forwarding entry.
  • this application can also obtain the BIER information of the second communication node to establish the first forwarding entry based on the BIER information of the second communication node.
  • the BIER information of the third communication node and the fourth communication node can be obtained to be based on The BIER information of the third communication node and the fourth communication node establishes the first forwarding entry.
  • this application can also obtain the BIER information of the second communication node to establish the first forwarding entry based on the BIER information of the second communication node.
  • this application can obtain the BIER information of the second communication node to be based on the second communication node.
  • the BIER information of the communication node establishes the first forwarding entry.
  • this application can obtain the BIER information of the fourth communication node based on the fourth communication node.
  • the BIER information of the communication node establishes the first forwarding entry.
  • this application can also obtain the BIER information of the second communication node to establish a first forwarding entry based on the BIER information of the second communication node.
  • transmitting the BIER message includes:
  • the BIER packet is transmitted through the BIER forwarding plane of the first communication node, and the BIER forwarding plane of the first communication node is determined based on the routing capability of the routing prefix of the third communication node in the autonomous system to which the first communication node belongs .
  • This application may determine the BIER forwarding plane of the first communication node based on the routing capability of the routing prefix of the third communication node in the autonomous system to which the first communication node belongs. For example, based on the routing capability of the routing prefix of the third communication node in the autonomous system to which the first communication node belongs, the communication nodes included in the BIER forwarding plane are determined.
  • the BIER forwarding plane when the routing prefix of the third communication node is routable in the autonomous system to which the first communication node belongs, includes the BIER forwarding plane of the autonomous system to which the first communication node belongs The forwarding plane formed after being extended to the third communication node; in the case that the routing prefix of the third communication node is not routable in the autonomous system to which the first communication node belongs, the BIER forwarding plane includes the first communication node The forwarding plane formed by the autonomous system to which the second communication node belongs.
  • the BIER forwarding plane may include extending the forwarding plane to which the first communication node and the second communication node belong to the third communication node, so that the first communication node
  • the BIER forwarding plane of a communication node includes a third communication node.
  • the obtained multicast traffic is the multicast traffic that the fourth communication node is interested in
  • the cross-domain mode is Option B
  • the routing prefix of the third communication node is in the first communication node
  • the destination bit string in the header of the BIER message includes the BFR-ID of the third communication node
  • the obtained multicast traffic is the multicast traffic that the fourth communication node is interested in
  • the header of the BIER message is encapsulated in two layers, and the inner BIER header
  • the destination bit string includes the BFR-ID of the fourth communication node
  • the destination bit string in the outer BIER header includes the BFR-ID of the third communication node
  • the protocol field of the outer BIER header is based on the encapsulation of the inner BIER header.
  • the form is determined; the obtained multicast traffic is the multicast traffic that the fourth communication node is interested in, the cross-domain mode is Option B, and the routing prefix of the third communication node is not available in the autonomous system of the first communication node
  • the destination bit string in the header of the BIER message includes the BFR-ID of the second communication node; when the obtained multicast traffic is the multicast traffic that the fourth communication node is interested in, the cross-domain method Is Option C, and the routing prefix of the third communication node is not routable in the autonomous system of the first communication node, the header of the BIER message is encapsulated in two layers, and the purpose of the inner BIER header is
  • the bit string includes the BFR-ID of the fourth communication node
  • the destination bit string in the outer BIER header includes the BFR-ID of the second communication node
  • the protocol field of the outer BIER header is determined according to the encapsulation form of the inner BIER header .
  • the obtained multicast traffic is the multicast traffic that the fourth communication node is interested in
  • the cross-domain mode is Option B
  • the routing prefix of the third communication node is in the first communication node If the autonomous system is routable, the first communication node and the third communication node belong to the same transfer plane, and when encapsulating the multicast traffic, the destination bit string is set as the BFR-ID of the third communication node.
  • the obtained multicast traffic is the multicast traffic that the fourth communication node is interested in
  • the cross-domain method is Option C
  • the routing prefix of the third communication node is in the autonomous system to which the first communication node belongs
  • the first communication node knows the BFR-ID of the fourth communication node and the first communication node and the fourth communication node belong to the same forwarding plane, so the header of the message is encapsulated in two layers.
  • the destination bit string of the inner BIER header is set to the BFR-ID of the fourth communication node
  • the destination bit string of the outer BIER header is set to the BFR-ID of the third communication node.
  • the obtained multicast traffic is the multicast traffic that is of interest to the fourth communication node
  • the cross-domain method is Option B
  • the routing prefix of the third communication node is in the autonomous region of the first communication node.
  • the first communication node and the third communication node do not belong to the same forwarding plane
  • the destination bit string of the BIER packet header is set to the BFR-ID of the second communication node.
  • the obtained multicast traffic is the multicast traffic that the fourth communication node is interested in
  • the cross-domain mode is Option C
  • the routing prefix of the third communication node is in the autonomous region of the first communication node.
  • the method further includes:
  • the receiving end node is the second communication node or the fourth communication node
  • the information of interest sent by the receiving end node indicates the multicast traffic or multicast that the fourth communication node is interested in The virtual private network to which the traffic belongs
  • sending first identification information and first indication information corresponding to the information of interest to the receiving end node where the first identification information includes a tag or a segment identifier, and the first indication information indicates The first identification information is sent by the first communication node.
  • this application can also obtain the information of interest sent by the receiving end node.
  • the first communication node may establish an association relationship of the first communication node based on the first identification information, the information of interest, and the receiving end node, and perform the transmission of the BIER message based on the association relationship.
  • the BIER message may include the first identification information corresponding to the multicast traffic.
  • this application also provides a method for transmitting multicast traffic.
  • FIG. 2 is a schematic flowchart of another method for transmitting multicast traffic provided by this application.
  • the method may be suitable for performing multicast traffic transmission.
  • this method can be executed by the multicast traffic transmission device configured on the second communication node provided in this application, and the device can be implemented by software/or hardware and integrated on the second communication node.
  • the second communication node may be an egress autonomous system border router (Autonomous System Border Router, ASBR) of the autonomous system to which it belongs.
  • ASBR Autonomous System Border Router
  • the method for transmitting multicast traffic includes the following steps:
  • S210 Send the BIER information of the ASBR to the first communication node.
  • the BIER information of the ASBR can be sent to the first communication node for the first communication node to determine the first forwarding entry, so as to realize the transmission of the BIER message.
  • S230 Transmit the BIER message based on the switching information of the BIER forwarding plane of the second communication node and the second forwarding entry.
  • the switching information may indicate whether the BIER forwarding plane needs to be switched when the second communication node transmits the BIER message.
  • the switching information may include switching and non-switching.
  • the second forwarding entry can be considered as the forwarding entry of the second communication node.
  • the second communication node may transmit or re-encapsulate the BIER message based on the second forwarding entry.
  • this step can determine whether the BIER forwarding plane needs to be switched based on the switching information, and then the manner of transmitting the BIER message based on the second forwarding entry can be determined based on the result of the determination.
  • this application may directly forward the BIER message based on the second forwarding table entry; in the case where the determined result is handover, this application may rewrite the BIER message based on the second forwarding table entry. Encapsulate the BIER message and transmit the re-encapsulated BIER message.
  • This application provides a method for transmitting multicast traffic, sending ASBR BIER information to a first communication node; acquiring a BIER message sent by the first communication node, and the BIER message is determined based on a first forwarding entry, so The first forwarding entry is determined based on the BIER information of the ASBR sent to the first communication node; based on the switching information of the BIER forwarding plane of the second communication node and/or the second forwarding entry, the BIER message is transmitted.
  • the application scenarios of BIER technology are enriched, and the application of BIER technology in large-scale networks is realized.
  • the BIER information of the ASBR includes one or more of the following: BIER information of the second communication node; BIER information of the third communication node.
  • the BIER information of the third communication node may be notified to the second communication node by the third communication node.
  • the BIER forwarding plane when the routing prefix of the third communication node is routable in the autonomous system to which the first communication node belongs, includes the BIER forwarding plane of the autonomous system to which the first communication node belongs The forwarding plane formed after being extended to the third communication node, the switching information of the BIER forwarding plane of the second communication node is no switching; the routing prefix of the third communication node is in the autonomous system of the first communication node
  • the BIER forwarding plane includes a forwarding plane formed by the second communication node and the first communication node, and a forwarding plane formed by a third communication node and the second communication node.
  • the switching information of the BIER forwarding plane of the second communication node is switching.
  • the transmitting the BIER message based on the switching information of the BIER forwarding plane of the second communication node and the second forwarding entry includes:
  • the BIER message is forwarded according to the first sub-forwarding entry in the second forwarding entry, and the first sub-forwarding entry is Is the forwarding entry in the forwarding plane formed after the BIER forwarding plane of the autonomous system to which the first communication node belongs is extended to the third communication node, and the first sub-forwarding entry includes the BIER information of the third communication node;
  • the switching information of the BIER forwarding plane of the second communication node is switching, the BIER message is received based on the second sub-forwarding entry in the second forwarding entry, and the third sub-forwarding entry in the second forwarding entry is used.
  • the sub-forwarding table entry re-encapsulates the BIER message and transmits the re-encapsulated BIER message
  • the second sub-forwarding table entry forms a forwarding table in the forwarding plane for the first communication node and the second communication node Item
  • the second forwarding entry includes the BIER information of the second communication node
  • the third sub-forwarding entry is a forwarding entry in the forwarding plane formed by the second communication node and the third communication node
  • the third sub-forwarding entry includes BIER information of the third communication node.
  • the BIER message may be forwarded based on the BIER information of the third communication node in the first sub-forwarding table entry.
  • the first sub-forwarding entry can be considered as the forwarding entry of the second communication node when the switching information is not switching.
  • the BIER message is transmitted based on the second sub-forwarding entry and the third sub-forwarding entry.
  • the second sub-forwarding entry and the third sub-forwarding entry can be considered as the forwarding entry of the second communication node when the handover information is handover.
  • repackaging the BIER message based on the third sub-forwarding entry in the second forwarding entry includes:
  • Update the destination bit string in the outer BIER header of the BIER message to the BFR-ID of the third communication node, and the BFR-ID of the third communication node is based on the third sub-forwarding entry in the second forwarding entry Determine; based on the first association relationship, update the identification information of the multicast traffic in the BIER message.
  • the destination bit string can be set to the BFR-ID of the third communication node, and based on the first association relationship, the identification information of the multicast traffic is updated. For example, the first identification information in the multicast traffic is updated to the second identification information.
  • the first association relationship can be considered as an association relationship established by the second communication node.
  • the method further includes:
  • the timing of determining the first association relationship is not limited, as long as it can be determined when the BIER message is transmitted. This application may determine the first association relationship when the second communication node needs to switch the BIER forwarding plane.
  • the method further includes:
  • the information of interest sent by the third communication node transmit the information of interest sent by the third communication node to the first communication node; obtain the first information corresponding to the information of interest sent by the first communication node Identification information and first indication information; in the case that the BIER forwarding plane includes a forwarding plane formed by a third communication node and a second communication node, determine the second identification information of the information of interest, and send it to the third communication node
  • the second identification information and second indication information the second indication information indicating that the second identification information is sent by the second communication node, based on the first identification information, the first indication information, and the second identification Information and second indication information to determine a first association relationship.
  • the first indication information indicates that the first identification information is sent by the first communication node;
  • the BIER forwarding plane includes the information of the autonomous system to which the first communication node belongs When the BIER forwarding plane is extended to the forwarding plane formed on the third communication node, sending the first identification information and the first indication information to the third communication node.
  • the second communication node may allocate second identification information to the information of interest, and transmit the second identification information and the second indication information to the third communication node.
  • the second communication node may determine the first association relationship based on the first identification information, the first indication information, the second identification information, and the second indication information, so as to facilitate re-encapsulation of the BIER message.
  • this application also provides a method for transmitting multicast traffic.
  • FIG. 3 is a schematic flowchart of another method for transmitting multicast traffic provided by this application.
  • this method can be executed by the multicast traffic transmission device configured on the third communication node provided by this application, and the device can be implemented by software/or hardware and integrated on the third communication node.
  • the autonomous system to which the third communication node belongs may be located downstream of the autonomous system to which the first communication node belongs.
  • the third communication node may be the entry ASBR of the autonomous system to which it belongs.
  • a method for transmitting multicast traffic includes the following steps:
  • the BIER information of the ASBR can be sent to the second communication node for the first communication node to determine the first forwarding entry, so as to realize the transmission of the BIER message.
  • the second association relationship can be considered as the association relationship of the third communication node.
  • the third communication node may transmit the BIER message based on the third association relationship.
  • the BIER message may be transmitted based on the cross-domain method and the second association relationship.
  • the cross-domain mode is Option B
  • the BIER message is re-encapsulated based on the second association relationship, and then re-encapsulated, that is, the re-encapsulated BIER message is transmitted.
  • the cross-domain method is Option C
  • forwarding is directly based on the inner BIER header, that is, the BIER packet with the outer BIER header removed is transmitted.
  • the multicast traffic transmission method provided by this application sends the BIER information of ASBR to a second communication node; obtains the BIER message of the second communication node, and the BIER message is the BIER forwarding plane of the second communication node.
  • the switching information and the second forwarding entry are transmitted; according to the second association relationship, the BIER message is transmitted.
  • the application scenarios of BIER technology are enriched, and the application of BIER technology in large-scale networks is realized.
  • the BIER information of the ASBR includes the BIER information of the third communication node.
  • transmitting the BIER message according to the second association relationship includes:
  • the routing prefix of the third communication node is routable in the autonomous system to which the first communication node belongs, and the cross-domain mode is Option B, or the routing prefix of the third communication node is in the autonomous system of the first communication node
  • the BIER message is re-encapsulated based on the second association relationship and the BFR-ID of the fourth communication node, and the re-encapsulated BIER message is transmitted; in the third communication
  • the routing prefix of the node is routable in the autonomous system to which the first communication node belongs, and the cross-domain mode is Option C, or the routing prefix of the third communication node is in the autonomous system of the first communication node
  • the outer BIER header of the BIER message is removed, and the BIER message with the outer BIER header removed is transmitted.
  • the re-encapsulation of the BIER message may include updating the identification information and the destination bit string of the multicast traffic.
  • re-encapsulating the BIER message based on the second association relationship and the BFR-ID of the fourth communication node includes:
  • the method further includes:
  • the timing of determining the second association relationship is not limited, as long as it can be determined when the BIER message is transmitted.
  • This application may determine the second association relationship after receiving the feedback information.
  • the feedback information may be considered as the first identification information and the first indication information sent by the first communication node; it may also be the second indication information and the second identification information sent by the second communication node.
  • This application may determine the second association relationship based on the feedback information and the third identification information and the third indication information determined by the third communication node for the information of interest.
  • the method further includes:
  • the third identification information includes a tag or a segment identification
  • the third indication information indicates that the third identification information is Three communication nodes send; in the case that the feedback information is the first identification information and the first indication information sent by the first communication node, based on the first identification information, the first indication information, the third identification information, and the third indication information , Determine the second association relationship; in the case where the feedback information is the second identification information and the second indication information sent by the second communication node, based on the second identification information, the second indication information, and the third indication
  • the information and the third instruction information determine the second association relationship.
  • the third indication information may indicate that the third identification information is generated by the third communication node.
  • the method for determining the third identification information is not limited. The identification information determined by each communication node for different traffic or VPN to which the traffic belongs may not be repeated.
  • the fourth communication node may send the information of interest to the third communication node or the first communication node; then receive the first identification information and the first indication information sent by the first communication node; or receive the third identification information sent by the third communication node And the third instruction information.
  • the fourth communication node may establish an association relationship based on the received first identification information, the first indication information, and the fourth identification information and the fourth until information allocated by the fourth communication node for the information of interest, so that after receiving the BIER message, Based on the association relationship established by the fourth communication node, the BIER message is transmitted.
  • the fourth identification information includes a label or a segment identification.
  • the fourth indication information may indicate that the fourth identification information is generated by the fourth communication node.
  • transmitting the BIER message may be based on the association relationship, determining the communication node interested in the multicast traffic, and then forwarding the multicast traffic to the determined communication node.
  • the BIER forwarding plane when the routing prefix of the third communication node is routable in the autonomous system to which the first communication node belongs, includes the BIER forwarding plane of the autonomous system to which the first communication node belongs.
  • the multicast traffic transmission method provided in this application can be considered as a method for realizing multicast cross-domain.
  • the related BIER technology is in realizing BIER cross-domain. In the domain, it only adapts to the cross-domain Option A scenario well, but it cannot adapt to the cross-domain Option B and Option C scenarios with more application value.
  • the restrictions on the application of cross-domain scenarios will greatly limit the BIER technology in the actual network. In the deployment of the Internet, the advantages of BIER technology cannot be fully utilized to realize the transmission of cross-domain multicast traffic.
  • this application proposes a method for realizing the cross-domain combination of BIER technology in multicast, so that the BIER technology can be applied to a variety of cross-domain scenarios, so that large-scale deployment applications can be obtained.
  • a BFR-ID used to indicate BIER forwarding and the corresponding Sub-Domain (SD) information are allocated on the cross-domain ASBR.
  • the optional encapsulation information bit index forwarding table identifier (Bit Index Forwarding Table Identifier, BIFT-ID) corresponding to the BFR-ID, optional bit string length (Bit String Length, BSL) and other information are allocated .
  • the BFR-ID information of the ingress ASBR of the cross-domain downstream (closer to the receiver) AS is advertised to the upstream ASBR along with the routing prefix of the ASBR using BGP signaling extension.
  • the BFR-ID assigned to the ASBR can be in the same SD with the BFR-IDs of other nodes on the entire network, and there is no conflict between them.
  • ASBRs need to be distinguished from each other when they participate in multiple forwarding planes.
  • the difference between forwarding planes can be achieved through different SDs or other methods, which are not limited here.
  • the value of BFR-ID may be the same or different in different forwarding planes.
  • Figure 3a is a schematic diagram of another cross-domain network provided by this application. See Figure 3a. If the prefix of the ingress ASBR of the downstream AS (ASBR2/ASBR3 in Figure 3a) is in the upstream AS (closer to If the source's upper-level AS1) is routable and reachable, an extended BIER domain including the upstream AS and the downstream ASBR can be established. In this case, the BFR-ID assigned by the ASBR cannot be the same as the node in the upstream AS. BFR-ID conflict, as shown in Figure 3a.
  • the BIER forwarding plane is formed, so that the traffic can be encapsulated into BIER packets in the PE of the connection source, and directly forwarded to the downstream ASBR through the BIER, and then converted by the downstream ASBR through the BIER forwarding plane, encapsulating the new BIER header in the downstream AS Delivery until the receiver PE.
  • Figure 3b is a schematic diagram of another cross-domain network provided by this application. See Figure 3b. If the prefix of the ingress ASBR of the downstream AS cannot be routed in the upstream AS, it needs to be established on the cross-domain ASBR A single BIER domain, BIER domain 10 shown in Figure 3b. At this time, the egress ASBR in the upstream AS also needs to allocate the BFR-ID used to indicate the BIER forwarding, and the corresponding SD, optional encapsulation information BIFT-ID, optional BSL and other information.
  • the BIER forwarding plane between ASBRs is independent of the forwarding planes of the upstream AS and the downstream AS, and can be distinguished by different SDs or other methods, and the BFR-IDs within different forwarding planes cannot be repeated.
  • the ingress PE collects information that is interested in a piece of traffic from the ASBR or the egress PE of the downstream AS through BGP protocol signaling.
  • the ingress PE will learn the egress ASBR of the local domain through BGP signaling, or the ingress ASBR of the downstream AS that wants to receive traffic information; in the cross-domain Option C scenario, the ingress PE will use BGP signaling Directly know the traffic information that the downstream AS egress PE wants to receive.
  • the egress ASBR of the upstream AS will learn the interesting traffic information of the ingress ASBR of the downstream AS through BGP, that is, the information sent by the second communication node
  • the information of interest may be traffic information of interest to the ingress ASBR of the downstream AS.
  • the ingress PE will assign a corresponding label or device segment ID (Segment ID, SID), that is, the first identification information, for the traffic that the downstream device is interested in, and notify the sensor according to different cross-domain methods.
  • SID Segment ID
  • the downstream device of interest can be the ASBR device or the export PE device of the downstream AS.
  • the assigned device SID is for an IPv6 encapsulation scenario.
  • the SID can have a 128-bit structure, which is the same as the number of bits in an IPv6 address. It can also contain functions for checking IPv4, IPv6, or Layer 2 forwarding tables, etc. And the parameters (ie Arguments) that represent specific VPN or other information.
  • the SID can be assigned to a VPN or a piece of traffic in a VPN.
  • BIER encapsulation is performed for traffic, that is, multicast traffic, so that the encapsulated traffic can be forwarded in the established BIER forwarding plane.
  • the BIER header encapsulated by the ingress PE carries the BFR-ID of the downstream AS ingress ASBR.
  • the entire network is uniformly allocated BFR-ID, that is, when there is no BFR-ID conflict in the entire network
  • the ingress PE can also encapsulate an inner BIER header and corresponding The encapsulation form, such as Ethernet, Multiprotocol Label Switching (MPLS) or IPv6, or directly adopts the BIER type.
  • the protocol (ie protocol) field in the outer BIER header fill in the outer encapsulation protocol type indicating the inner BIER header. If the inner BIER header adopts Ethernet encapsulation, the protocol field in the outer BIER header should be filled with the Ethernet type; if If the inner BIER header adopts MPLS encapsulation, the protocol in the outer BIER header should be filled with the MPLS type; if the inner BIER header adopts IPv6 encapsulation, the protocol in the outer BIER header should be filled with the IPv6 type; if no other encapsulation is used, the BIER should be encapsulated directly Type, then fill in the BIER type in the protocol in the outer BIER header.
  • the IPv6 destination address (DA) filled in is the device SID information assigned by the ingress PE; when MPLS encapsulation is used, it carries the label assigned by the ingress PE .
  • the downstream ingress ASBR when the downstream ingress ASBR cannot establish the same forwarding plane with the upstream AS, but can only establish the forwarding plane with the egress ASBR of the upstream AS, as shown in Figure 3b, the purpose of the BIER message encapsulated by the ingress PE
  • the bit string fills in the BFR-ID of the export ASBR of the upstream AS.
  • the ASBR switches to the corresponding BIER forwarding plane between ASBRs for forwarding.
  • the BIER forwarding plane in AS2 is composed of MPLS
  • the BIER forwarding plane in AS3 is composed of Ethernet.
  • the egress ASBR of the upstream AS performs forwarding plane switching, it can be based on the BIER forwarding plane encapsulation mode announced by the downstream ASBR. Perform conversion to avoid intercommunication problems caused by different encapsulation methods of the BIER forwarding plane of the entire network.
  • the ingress PE of the upstream AS can perform the following steps:
  • the prefix of the ingress ASBR of the downstream AS can be routed in the upstream AS, that is, the ingress ASBR of the downstream AS is used as the loopback address of the BGP advertisement.
  • the BIER forwarding plane is extended to the ingress ASBR range of the downstream AS, that is, the BIER forwarding plane is established between the ingress PE of the upstream AS and the ingress ASBR of the downstream AS. Both the ingress PE of the upstream AS and the BIER forwarding entries of other nodes in the upstream AS have forwarding entries of the ingress ASBR of the downstream AS.
  • Step 1 The ingress PE is the label or SID information assigned to a VPN or a piece of traffic, and advertises it to the egress ASBR of the upstream AS through the BGP protocol, that is, the ASBR of interest.
  • Step 2 The ingress PE performs one or more layers of BIER encapsulation on the source, such as the stream sent by the upstream communication node of the upstream AS, that is, the multicast traffic, and forwards it through the BIER forwarding plane.
  • the double-layer BIER header format can be encapsulated, and the BFR-ID corresponding to the egress PE of the downstream AS can be encapsulated in
  • the inner BIER header is supplemented by corresponding outer encapsulation such as Ethernet encapsulation, MPLS encapsulation, IPv6 encapsulation or BIER encapsulation, and then the outer BIER header is encapsulated, and the destination bit string encapsulates the BFR-ID information of the downstream AS ingress ASBR.
  • the egress ASBR of the upstream AS can perform the following steps:
  • the egress ASBR of the upstream AS participates in the establishment of the BIER forwarding plane between the ingress PE and the ingress ASBR of the downstream AS; the ingress ASBR route of the downstream AS cannot be distributed to the upstream AS From time to time, a BIER forwarding plane is established between the ingress ASBR of the downstream AS alone.
  • Step 1 The egress ASBR of the upstream AS receives the BGP notification message that is interested in a flow from the ingress ASBR of the downstream AS. If the route of the ingress ASBR of the downstream AS can be accessed in the upstream AS, the next hop notification is not changed to the ingress. PE; If the route of the ingress ASBR of the downstream AS cannot be accessed in the upstream AS, the next hop is modified to be itself, that is, the BFR-ID of the egress ASBR of the upstream AS is notified to the ingress PE. When receiving a label or SID assigned to a piece of traffic from the ingress PE, the label or SID is allocated and notified to the downstream AS ingress ASBR, and the originating PE is carried as the ingress PE, and an association relationship is generated.
  • Step 2 When the egress ASBR of the upstream AS receives a BIER packet from the upstream AS, it determines whether to switch the BIER forwarding plane. If it does not need to switch, it forwards it directly according to the BIER forwarding table; if it needs to switch the BIER forwarding plane Processing, then switch to the BIER forwarding plane established with the ingress ASBR of the downstream AS for forwarding.
  • the method to determine whether to perform BIER forwarding plane switching processing can be to determine whether the target bit string in the BIER message is the communication node, that is, the BFR-ID of the egress ASBR of the upstream AS, and the reception is determined based on the label or SID in the BIER message. In order to determine whether forwarding plane switching is required.
  • the ingress ASBR of the downstream AS can perform the following steps:
  • the ingress ASBR of the downstream AS is assigned BFR-ID. If the ingress ASBR route of the downstream AS is reachable in the upstream AS, the same forwarding plane is established with the upstream AS; if the ingress ASBR route of the downstream AS cannot be reachable in the upstream AS, Then establish a separate BIER forwarding plane with the egress ASBR of the upstream AS.
  • Step 1 The ingress ASBR of the downstream AS advertises to the egress ASBR of the upstream AS through BGP according to the traffic interest notification received from the egress PE of the local AS; when it receives the label or SID assigned by the upstream ASBR for a flow, it is assigned locally The label or SID is sent to the egress PE of the downstream AS. And associate the received tag or SID with the locally assigned tag or SID.
  • Step 2 When the ingress ASBR of the downstream AS receives the BIER message, it switches the BIER forwarding plane according to the label or SID association relationship, and forwards it to the corresponding receiver.
  • the multicast traffic transmission method provided in this application completes the deployment of BIER technology in the entire network, so that cross-domain scenarios can also make full use of the multicast forwarding advantages of BIER technology to realize the application of BIER technology in large-scale networks.
  • AS1 is used as the upstream AS, where PE1 of the connection source is the upstream AS ingress PE, ASBR1 is the egress ASBR of the upstream AS; AS2 and AS3 are used as the downstream AS, and ASBR2, ASBR3 are used as the entrance of the downstream AS.
  • ASBR, PE2, PE3, and PE4 connected to the receiver serve as the egress PE of the downstream AS.
  • the network shown in Figure 3a is assumed to be a cross-domain Option B scenario, first at the underlay level, assuming that the prefixes of ASBR2 and ASBR3 can be routed in AS1, that is, all devices in AS1 reach ASBR2 Route with ASBR3 prefix.
  • ASBR2/3 can participate in AS1 to establish an extended BIER forwarding plane, that is, BIER domain 1.
  • the BFR-ID allocated on ASBR2/3 cannot overlap with other nodes in AS1. Assume that the BFR-ID assigned to ASBR2/3 is 21, 31.
  • the BFR-ID, SD and other information of ASBR2/3 will be advertised to ASBR1 along with the BGP prefix (this prefix is the routable prefix in AS1), and ASBR1 will then pass the prefix and BIER information through OSPF, ISIS or other protocols in AS1
  • OSPF OSPF
  • ISIS ISIS
  • AS1 When transferred to AS1, all devices in AS1, including PE1, will receive the BIER information and create forwarding entries for BIER domain 1, including forwarding entries for BFR-ID 21 and BFR-ID 31 that can reach ASBR 2/3.
  • AS2 and AS3 each establish their own BIER forwarding planes, BIER domain 2 and BIER domain 3.
  • ASBR2/3 also has its own BFR-ID value in their BIER forwarding plane, ASBR2/3's ASBR2/3 value and BIER domain
  • the values in 1 are not related, and the values can be the same or different. Therefore, there is no impact on the BFR-ID planning for the entire network or the BFR-ID planning by domain at this time.
  • PE2/3/4 will transfer the information that is interested in a piece of traffic, that is, the interested information sent by the fourth communication node, to ASBR2/3 through the MVPN extension of BGP, and ASBR2/3 will then pass the received information to ASBR2/3.
  • Interest information is advertised to ASBR1, and ASBR1 is then advertised to PE1, and the next hop is not changed to ASBR2/3.
  • PE1 assigns labels or SID information to distinguish the traffic or the VPN to which the traffic belongs, and advertises the assigned label or SID information to ASBR1; ASBR1 advertises the label or SID information assigned by PE to ASBR2/3 , And carry the information that the originating PE is PE1; ASBR2/3 then advertises the route to PE2/3/4, and carries the label or SID assigned by ASBR2/3 for this purpose, and the label advertised by ASBR1 is the same as that assigned locally
  • Figure 3c is a schematic diagram of a second association relationship provided by this application
  • Figure 3d is a schematic diagram of another second association relationship provided by this application, as shown in Figure 3c and Figure 3d.
  • ASBR2/3 is based on The locally assigned label and the label advertised by ASBR1 establish an association relationship. On PE2/3/4, the label or SID allocated by ASBR2/3 is associated with the receiver.
  • PE1 When traffic, that is, multicast traffic, enters PE1 for BIER encapsulation, PE1 will encapsulate the traffic, or the label or SID information assigned by the VPN to which the traffic belongs, into the BIER header, and encapsulate the BFR of ASBR2 and ASBR3 in the destination bit string. -ID information and BFR-ID information of the PEs of other receivers that may be in AS1 to obtain the BIER message.
  • the BIER message will be forwarded in AS1 through the first BIER forwarding table until it reaches the ASBR1 device, and ASBR1 directly Forward the BIER message to ASBR2/3 according to the second BIER forwarding table.
  • ASBR2/3 generates the associated table entries as shown in Figure 3c and Figure 3d, and re-encapsulates the BIER header to carry the locally assigned label/SID.
  • ASBR2 sets the BFR-ID of PE2 in the destination bit string, and ASBR3 sets it in the destination bit string.
  • PE2/3/4 will identify the VPN or specific traffic corresponding to the traffic based on the label or SID assigned by the ASBR2/3, strip the BIER encapsulation, and forward it to the receiver.
  • the network shown in Figure 3a assumes that it is a scenario where the cross-domain Option C and the BFR-ID of the entire network are planned uniformly.
  • the prefixes of ASBR2 and ASBR3 can be routed in AS1, but the route of PE2/3/4 It can only be reached through ASBR2/3, which is a scenario where the entire network is not routed.
  • the intermediate device (non-PE, non-ASBR) in AS1 has no route to PE2/3/4.
  • ASBR2/3 can participate in AS1 to establish the extended BIER forwarding plane BIER domain 1.
  • the respective BIER forwarding planes are also established in AS2 and AS3.
  • PE1 will directly establish BGP neighbor relationships with PE2, PE3, and PE4.
  • PE1 can directly learn that PE2/3/4 are interested in a traffic, and PE1 will be the traffic or the VPN for the traffic. Allocate label or SID information and advertise it to PE2/3/4 through BGP protocol.
  • PE2/3/4 associate the label/SID information allocated by PE1 with the local receiver.
  • PE1 When traffic enters PE1 for BIER encapsulation to obtain a BIER packet, because the route of PE2/3/4 is not visible in the intermediate node of AS1, PE1 will perform two-layer BIER header encapsulation, and the inner destination bit string is set to PE2/3/ 4 BFR-ID.
  • the outer BIER header encapsulates the BFR-ID of ASBR2/3 into the bit string.
  • the protocol in the outer BIER header is determined according to the encapsulation form of the inner BIER header carried later, which can be in the form of Ethernet, MPLS or IPv6 encapsulation, or directly BIER type.
  • the forwarding of BIER packets in AS1 will proceed according to the outer BIER header until ASBR2/3. After ASBR2/3 strips off the outer BIER header, it forwards it according to the inner BIER header until it is forwarded to PE2/3/4. PE2/3/4 strips off the BIER header and forwards it to the desired receiver according to the association relationship generated by the overlay layer.
  • the network shown in Figure 3b assumes that it is a cross-domain Option B scenario.
  • the prefix of ASBR2/3 cannot be routed in AS1. Therefore, at the underlay level, except for AS1, AS2, and AS3, each establishes its own BIER For the forwarding plane, an independent BIER forwarding plane needs to be established between ASBR1/2/3.
  • ASBR1/2/3 the BFR-ID allocated by ASBR1/2/3 is unique in the entire network. If the BFR-ID is allocated independently for each domain, ASBR1/2/3 may need to re-allocate the BFR-ID in BIER domain 10. Therefore, in the scenario shown in Figure 3b, there will be four forwarding planes, namely BIER domain 1 of AS1, BIER domain 2 of AS2, BIER domain 3 of AS3, and BIER domain 10 composed of ASBR.
  • ASBR2/3 notifies ASBR1 of the collected information that is interested in a flow, and ASBR1 notifies the ingress PE1.
  • PE1 assigns the corresponding label/SID to the traffic or the VPN to which the traffic belongs, and advertises it to ASBR1.
  • ASBR1 also assigns the label/SID to the traffic, and establishes an association relationship with the label/SID received from PE1.
  • Figure 3e is this application A schematic diagram of a first association relationship is provided. As shown in FIG. 3e, ASBR1 establishes a first association relationship based on the label/SID sent by PE1 and the label/SID allocated by ASBR1. ASBR1 notifies ASBR2/3 of the established first association relationship.
  • ASBR2/3 also allocates a label/SID, establishes an association relationship with the received from ASBR1, and advertises it to PE2/3/4, similar to Figure 3c and Figure 3d, except that the entry is replaced with the label/SID allocated by ASBR1.
  • PE2 associates the label/SID received from ASBR2 with the corresponding receiver.
  • PE3/4 also associates the label/SID received from ASBR3 with the corresponding receiver.
  • PE1 When the traffic is BIER encapsulated on PE1 to obtain a BIER message, PE1 encapsulates the BFR-ID of ASBR1 into the bit string of the BIER header, and forwards it through the BIER forwarding plane in AS1.
  • the BIER message reaches ASBR1 and after stripping the BIER header, According to the previously established association relationship, ASBR1 encapsulates the locally assigned label/SID, re-encapsulates the BIER header, and sets the BFR-ID of ASBR2/3 to the destination bit string.
  • ASBR2/3 After the packet reaches ASBR2/3, after stripping off the BIER header, re-encapsulate the BIER header according to the previously established association relationship.
  • ASBR2 sets the BFR-ID of PE2 to the destination bit string
  • ASBR3 sets the BFR-ID of PE3/4 to the destination bit.
  • the string forwarded to AS2 and AS3.
  • BIER forwarding planes of AS2 and AS3 the message finally reaches PE2/3/4.
  • PE2/3/4 forwards the message to the desired receiver according to the previously established association relationship.
  • the network shown in Figure 3b is assumed to be cross-domain Option C, and the BFR-ID is assigned uniformly across the entire network.
  • the prefixes of PE2/3/4 are visible through BGP notifications on ASBR1 and PE1, but in It is not visible on the intermediate device of AS1.
  • the Underlay layer establishes four independent BIER forwarding planes.
  • BGP is advertised on PE and ASBR, it carries the assigned BFR-ID information, thereby establishing a multi-level mapping relationship between BFR-ID and BGP next hop.
  • Figure 3f provides a schematic diagram of the multi-level mapping relationship on the first communication node for this application. See Figure 3f.
  • the multi-level mapping relationship is the multi-level mapping relationship of the BFR-ID on PE1.
  • FIG. 3g is a schematic diagram of the multi-level mapping relationship on the second communication node provided by this application. As shown in Figure 3g, the multi-level mapping relationship is the BFR-ID multi-level mapping table on ASBR1. You can see the BFR-ID and PE2 of PE2. The next hop device is ASBR2, the BFR-ID of PE3/4 and the next hop device are ASBR3.
  • PE1 directly learns the information that PE2/3/4 is interested in a flow from PE2/3/4 through multi-hop BGP, PE1 allocates label/SID information for the flow or the VPN to which the flow belongs, and advertises it Give PE2/3/4. PE2/3/4 establishes an association relationship between the label/SID information allocated by PE1 and the local receiver.
  • PE1 Double-layer BIER header encapsulation is performed on the BIER message, the inner BIER header encapsulates the label/SID information allocated by PE1 for traffic, and encapsulates the BFR-ID of PE2/3/4 into the destination bit string.
  • the outer BIER header encapsulates the BFR-ID of ASBR1 into the destination bit string.
  • the outer BIER header is coupled with the inner BIER header through inner encapsulation, and the protocol in the outer BIER header is set as possible for the inner BIER header.
  • Encapsulation form such as Ethernet, MPLS or IPv6, or direct BIER type.
  • AS1 forwarding is performed according to the outer BIER header. After the message reaches ASBR1, ASBR1 strips off the outer BIER header.
  • ASBR1 When processing the inner BIER header, it is found that it needs to be iterated to ASBR2 and ASBR3, so ASBR1 will optionally encapsulate an outer layer BIER header, set the BFR-ID of ASBR2/3 to the destination bit string.
  • the outer BIER header can also be omitted, but the BIER packet is directly forwarded to ASBR2/3.
  • the outer BIER header needs to be encapsulated.
  • ASBR2/3 strips off the outer BIER header and forwards it according to the inner BIER header until the BIER packet reaches PE2/3/4.
  • PE2/3/4 will forward the traffic to the receiver after removing the BIER header according to the association relationship established at the overlay level.
  • the methods in the above embodiments can be used independently or in combination, so that cross-domain scenarios can also make full use of the multicast forwarding advantages of the BIER technology to realize the application of the BIER technology in large-scale networks.
  • this application provides a multicast traffic transmission device.
  • FIG. 4 is a schematic structural diagram of a multicast traffic transmission device provided by this application.
  • the device for transmitting the broadcast traffic may be configured at the first communication node, and the device includes: a first determining module 41 configured to determine a first forwarding entry, the first forwarding entry including an explicit copy of the bit index of the autonomous system border router ASBR BIER information; the obtaining module 42 is configured to obtain multicast traffic; the second determining module 43 is configured to encapsulate the multicast traffic based on the first forwarding entry, and determine and transmit a BIER message.
  • the multicast traffic transmission device provided in this embodiment is used to implement the multicast traffic transmission method shown in FIG. 1.
  • the implementation principles and technical effects of the multicast traffic transmission device provided in this embodiment are the same as those shown in FIG. 1 The method is similar, so I won't repeat it here.
  • the bit index of the autonomous system border router ASBR explicitly replicates BIER information including one or more of the following: BIER information of a second communication node, where the second communication node belongs to the first communication node The egress ASBR of the autonomous system; the BIER information of the third communication node, the autonomous system to which the third communication node belongs is located downstream of the autonomous system to which the first communication node belongs; the BIER information of the fourth communication node, the fourth communication node It is the egress operator edge or egress ASBR of the autonomous system to which the third communication node belongs.
  • the BIER information includes a bit forwarding router identifier BFR-ID; the BIER information further includes one or more of the following: subdomain information; bit index forwarding table identifier; bit string length.
  • the first determining module 41 is configured to include one or more of the following:
  • the BIER information of the second communication node and the third communication node and determine the first forwarding entry based on the BIER information of the second communication node and the third communication node; obtain the BIER information of the second communication node, and based The BIER information of the second communication node determines the first forwarding entry; the BIER information of the second communication node, the third communication node, and the fourth communication node is acquired, and the BIER information is based on the second communication node, the third communication node, and the second communication node.
  • the BIER information of the communication node determines the first forwarding table entry; obtains the BIER information of the second communication node and the fourth communication node, and determines the first forwarding table based on the BIER information of the second communication node and the fourth communication node item.
  • the acquiring module 42 transmits the BIER message, including:
  • the BIER packet is transmitted through the BIER forwarding plane of the first communication node, and the BIER forwarding plane of the first communication node is determined based on the routing capability of the routing prefix of the third communication node in the autonomous system to which the first communication node belongs .
  • the BIER forwarding plane when the routing prefix of the third communication node is routable in the autonomous system to which the first communication node belongs, includes the BIER forwarding plane of the autonomous system to which the first communication node belongs The forwarding plane formed after being extended to the third communication node; in the case that the routing prefix of the third communication node is not routable in the autonomous system to which the first communication node belongs, the BIER forwarding plane includes the first communication node The forwarding plane formed by the autonomous system to which the second communication node belongs.
  • the obtained multicast traffic is the multicast traffic that the fourth communication node is interested in
  • the cross-domain mode is Option B
  • the routing prefix of the third communication node is in the first communication node
  • the destination bit string in the header of the BIER message includes the BFR-ID of the third communication node
  • the obtained multicast traffic is the multicast traffic that the fourth communication node is interested in
  • the header of the BIER message is encapsulated in two layers, and the inner BIER header
  • the destination bit string includes the BFR-ID of the fourth communication node
  • the destination bit string in the outer BIER header includes the BFR-ID of the third communication node
  • the protocol field of the outer BIER header is based on the encapsulation of the inner BIER header.
  • the form is determined; the obtained multicast traffic is the multicast traffic that the fourth communication node is interested in, the cross-domain mode is Option B, and the routing prefix of the third communication node is not available in the autonomous system of the first communication node
  • the destination bit string in the header of the BIER message includes the BFR-ID of the second communication node; when the obtained multicast traffic is the multicast traffic that the fourth communication node is interested in, the cross-domain method Is Option C, and the routing prefix of the third communication node is not routable in the autonomous system of the first communication node, the header of the BIER message is encapsulated in two layers, and the purpose of the inner BIER header is
  • the bit string includes the BFR-ID of the fourth communication node
  • the destination bit string in the outer BIER header includes the BFR-ID of the second communication node
  • the protocol field of the outer BIER header is determined according to the encapsulation form of the inner BIER header .
  • the device further includes: a transmission module configured to:
  • the receiving end node is the second communication node or the fourth communication node
  • the information of interest sent by the receiving end node indicates the multicast traffic or multicast that the fourth communication node is interested in The virtual private network to which the traffic belongs
  • sending first identification information and first indication information corresponding to the information of interest to the receiving end node where the first identification information includes a tag or a segment identifier, and the first indication information indicates The first identification information is sent by the first communication node.
  • FIG. 5 is a schematic structural diagram of a multicast traffic transmission device provided by this application.
  • the present embodiment provides The multicast traffic transmission device may be configured in the second communication node, and the device includes: a sending module 51 configured to send BIER information of the ASBR to the first communication node; and an obtaining module 52 configured to obtain the BIER information sent by the first communication node Message, the BIER message is determined based on a first forwarding entry, and the first forwarding entry is determined based on the BIER information of the ASBR sent to the first communication node; the transmission module 53 is set to be based on the second communication node The switching information of the BIER forwarding plane and the second forwarding entry of the BIER forwarding plane are transmitted, and the BIER message is transmitted.
  • the multicast traffic transmission device provided in this embodiment is used to implement the multicast traffic transmission method shown in FIG. 2.
  • the implementation principles and technical effects of the multicast traffic transmission device provided in this embodiment are the same as those shown in FIG. 2 The method is similar, so I won't repeat it here.
  • the BIER information of the ASBR includes one or more of the following: BIER information of the second communication node; BIER information of the third communication node.
  • the BIER forwarding plane when the routing prefix of the third communication node is routable in the autonomous system to which the first communication node belongs, includes the BIER forwarding plane of the autonomous system to which the first communication node belongs The forwarding plane formed after being extended to the third communication node, the switching information of the BIER forwarding plane of the second communication node is no switching; the routing prefix of the third communication node is in the autonomous system of the first communication node
  • the BIER forwarding plane includes a forwarding plane formed by the second communication node and the first communication node, and a forwarding plane formed by a third communication node and the second communication node.
  • the switching information of the BIER forwarding plane of the second communication node is switching.
  • the transmission module 53 is configured to:
  • the BIER message is forwarded according to the first sub-forwarding entry in the second forwarding entry, and the first sub-forwarding entry is Is the forwarding entry in the forwarding plane formed after the BIER forwarding plane of the autonomous system to which the first communication node belongs is extended to the third communication node, and the first sub-forwarding entry includes the BIER information of the third communication node;
  • the switching information of the BIER forwarding plane of the second communication node is switching, the BIER message is received based on the second sub-forwarding entry in the second forwarding entry, and the third sub-forwarding entry in the second forwarding entry is used.
  • the sub-forwarding table entry re-encapsulates the BIER message and transmits the re-encapsulated BIER message
  • the second sub-forwarding table entry forms a forwarding table in the forwarding plane for the first communication node and the second communication node Item
  • the second forwarding entry includes the BIER information of the second communication node
  • the third sub-forwarding entry is a forwarding entry in the forwarding plane formed by the second communication node and the third communication node
  • the third sub-forwarding entry includes BIER information of the third communication node.
  • the transmission module 53 re-encapsulates the BIER message based on the third sub-forwarding entry in the second forwarding entry, including:
  • Update the destination bit string in the outer BIER header of the BIER message to the BFR-ID of the third communication node, and the BFR-ID of the third communication node is based on the third sub-forwarding entry in the second forwarding entry Determine; based on the first association relationship, update the identification information of the multicast traffic in the BIER message.
  • the device further includes: a determining module, configured to:
  • the device further includes: a sending module, configured to:
  • the information of interest sent by the third communication node transmit the information of interest sent by the third communication node to the first communication node; obtain the first information corresponding to the information of interest sent by the first communication node Identification information and first indication information; in the case that the BIER forwarding plane includes a forwarding plane formed by a third communication node and a second communication node, determine the second identification information of the information of interest, and send it to the third communication node
  • the second identification information and second indication information the second indication information indicating that the second identification information is sent by the second communication node, based on the first identification information, the first indication information, and the second identification Information and second indication information to determine a first association relationship.
  • the first indication information indicates that the first identification information is sent by the first communication node;
  • the BIER forwarding plane includes the information of the autonomous system to which the first communication node belongs When the BIER forwarding plane is extended to the forwarding plane formed on the third communication node, sending the first identification information and the first indication information to the third communication node.
  • this application also provides a multicast traffic transmission device.
  • FIG. 6 is a schematic structural diagram of a multicast traffic transmission device provided by this application.
  • the device provided in this embodiment The multicast traffic transmission device may be configured in the third communication node, and the device includes: a sending module 61 configured to send BIER information of the ASBR to the second communication node; and an acquiring module 62 configured to obtain the BIER report of the second communication node
  • the BIER message is transmitted by the second communication node based on the switching information of the BIER forwarding plane and the second forwarding entry; the transmission module 63 is configured to transmit the BIER message according to the second association relationship.
  • the multicast traffic transmission device provided in this embodiment is used to implement the multicast traffic transmission method shown in FIG. 3.
  • the implementation principle and technical effect of the multicast traffic transmission device provided in this embodiment are the same as the multicast traffic transmission shown in FIG. 3 The method is similar, so I won't repeat it here.
  • the BIER information of the ASBR includes the BIER information of the third communication node.
  • the transmission module 63 is configured to:
  • the routing prefix of the third communication node is routable in the autonomous system to which the first communication node belongs, and the cross-domain mode is Option B, or the routing prefix of the third communication node is in the autonomous system of the first communication node
  • the BIER message is re-encapsulated based on the second association relationship and the BFR-ID of the fourth communication node, and the updated and re-encapsulated BIER message is transmitted; in the third The routing prefix of the communication node is routable in the autonomous system to which the first communication node belongs, and the cross-domain method is Option C, or the routing prefix of the third communication node is in the autonomous system of the first communication node
  • the outer BIER header of the BIER message is removed, and the BIER message with the outer BIER header removed is transmitted.
  • the transmission module 63 re-encapsulates the BIER message based on the second association relationship and the BFR-ID of the fourth communication node, including:
  • the device further includes: a determining module, configured to:
  • the device further includes: a sending module, configured to:
  • the third identification information includes a tag or a segment identification
  • the third indication information indicates that the third identification information is Three communication nodes send; in the case that the feedback information is the first identification information and the first indication information sent by the first communication node, based on the first identification information, the first indication information, the third identification information, and the third indication information , Determine the second association relationship; in the case where the feedback information is the second identification information and the second indication information sent by the second communication node, based on the second identification information, the second indication information, and the third indication
  • the information and the third instruction information determine the second association relationship.
  • the BIER forwarding plane when the routing prefix of the third communication node is routable in the autonomous system to which the first communication node belongs, includes the BIER forwarding plane of the autonomous system to which the first communication node belongs.
  • FIG. 7 is a schematic structural diagram of a communication node provided by this application.
  • the communication node provided by the present application includes one or more processors 71 and a storage device 72; there may be one or more processors 71 in the communication node.
  • one processor 71 is used as Example; the storage device 72 is used to store one or more programs; the one or more programs are executed by the one or more processors 71, so that the one or more processors 71 implement as in the embodiments of the present application
  • the described multicast traffic transmission method When the multicast traffic transmission method described in FIG. 1 is executed, the communication node is the first communication node. When the multicast traffic transmission method described in FIG. 2 is executed, the communication node is the second communication node. During the said multicast traffic transmission, the communication node is the third communication node.
  • the communication node further includes: a communication device 73, an input device 74, and an output device 75.
  • the processor 71, the storage device 72, the communication device 73, the input device 74, and the output device 75 in the communication node may be connected by a bus or other means.
  • the connection by a bus is taken as an example.
  • the input device 74 can be used to receive input digital or character information, and generate key signal input related to user settings and function control of the communication node.
  • the output device 75 may include a display device such as a display screen.
  • the communication device 73 may include a receiver and a transmitter.
  • the communication device 73 is configured to perform information transceiving and communication under the control of the processor 71.
  • the storage device 72 can be configured to store software programs, computer-executable programs, and modules, such as the program instructions/modules corresponding to the multicast traffic transmission method described in the embodiments of the present application (for example, multicast traffic).
  • the storage device 72 may include a storage program area and a storage data area.
  • the storage program area may store an operating system and an application program required by at least one function; the storage data area may store data created according to the use of the communication node, and the like.
  • the storage device 72 may include a high-speed random access memory, and may also include a non-volatile memory, such as at least one magnetic disk storage device, a flash memory device, or other non-volatile solid-state storage devices.
  • the storage device 72 may include memories remotely provided with respect to the processor 71, and these remote memories may be connected to a communication node through a network. Examples of the aforementioned networks include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof.
  • An embodiment of the present application further provides a storage medium that stores a computer program that, when executed by a processor, implements the multicast traffic transmission method described in any of the embodiments of the present application.
  • a storage medium that stores a computer program that, when executed by a processor, implements the multicast traffic transmission method described in any of the embodiments of the present application.
  • the multicast traffic transmission method applied to the first communication node includes:
  • the first forwarding entry includes the bit index of the autonomous system border router ASBR to explicitly copy BIER information; obtain multicast traffic; encapsulate the multicast traffic based on the first forwarding entry , Confirm and transmit the BIER message.
  • the multicast traffic transmission method applied to the second communication node includes:
  • the multicast traffic transmission method applied to the third communication node includes:
  • the computer storage medium of the embodiment of the present application may adopt any combination of one or more computer-readable media.
  • the computer-readable medium may be a computer-readable signal medium or a computer-readable storage medium.
  • the computer-readable storage medium may be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, device, or device, or a combination of any of the above.
  • Examples of computer-readable storage media include: electrical connections with one or more wires, portable computer disks, hard disks, random access memory (Random Access Memory, RAM), read-only memory (Read Only) Memory, ROM), Erasable Programmable Read Only Memory (EPROM), flash memory, optical fiber, portable CD-ROM, optical storage device, magnetic storage device, or any suitable combination of the foregoing.
  • the computer-readable storage medium may be any tangible medium that contains or stores a program, and the program may be used by or in combination with an instruction execution system, apparatus, or device.
  • the computer-readable signal medium may include a data signal propagated in baseband or as a part of a carrier wave, and computer-readable program code is carried therein. This propagated data signal can take many forms, including but not limited to: electromagnetic signals, optical signals, or any suitable combination of the foregoing.
  • the computer-readable signal medium may also be any computer-readable medium other than the computer-readable storage medium, and the computer-readable medium may send, propagate, or transmit the program for use by or in combination with the instruction execution system, apparatus, or device .
  • the program code contained on the computer-readable medium can be transmitted by any suitable medium, including but not limited to: wireless, wire, optical cable, radio frequency (RF), etc., or any suitable combination of the foregoing.
  • suitable medium including but not limited to: wireless, wire, optical cable, radio frequency (RF), etc., or any suitable combination of the foregoing.
  • the computer program code used to perform the operations of this application can be written in one or more programming languages or a combination thereof.
  • the programming languages include object-oriented programming languages—such as Java, Smalltalk, C++, and also conventional Procedural programming language-such as "C" language or similar programming language.
  • the program code can be executed entirely on the user's computer, partly on the user's computer, executed as an independent software package, partly on the user's computer and partly executed on a remote computer, or entirely executed on the remote computer or server.
  • the remote computer can be connected to the user's computer through any kind of network-including Local Area Network (LAN) or Wide Area Network (WAN)-or it can be connected to an external computer (For example, use an Internet service provider to connect via the Internet).
  • LAN Local Area Network
  • WAN Wide Area Network
  • the various embodiments of the present application can be implemented in hardware or dedicated circuits, software, logic or any combination thereof.
  • some aspects may be implemented in hardware, while other aspects may be implemented in firmware or software that may be executed by a controller, microprocessor, or other computing device, although the present application is not limited thereto.
  • Computer program instructions can be assembly instructions, Instruction Set Architecture (ISA) instructions, machine instructions, machine-related instructions, microcode, firmware instructions, state setting data, or written in any combination of one or more programming languages Source code or object code.
  • ISA Instruction Set Architecture
  • the block diagram of any logic flow in the drawings of the present application may represent program steps, or may represent interconnected logic circuits, modules, and functions, or may represent a combination of program steps and logic circuits, modules, and functions.
  • the computer program can be stored on the memory.
  • the memory can be of any type suitable for the local technical environment and can be implemented using any suitable data storage technology, such as but not limited to read-only memory (Read-Only Memory, ROM), random access memory (Random Access Memory, RAM), optical Memory devices and systems (Digital Video Disc (DVD) or Compact Disk (CD)), etc.
  • Computer-readable media may include non-transitory storage media.
  • the data processor can be any type suitable for the local technical environment, such as but not limited to general-purpose computers, special-purpose computers, microprocessors, digital signal processors (Digital Signal Processing, DSP), application specific integrated circuits (ASICs) ), programmable logic devices (Field-Programmable Gate Array, FPGA), and processors based on multi-core processor architecture.
  • DSP Digital Signal Processing
  • ASICs application specific integrated circuits
  • FPGA Field-Programmable Gate Array
  • FPGA Field-Programmable Gate Array

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Abstract

本文公开一种组播流量传输方法、装置、通信节点及存储介质。该组播流量传输方法包括：确定第一转发表项，所述第一转发表项包括自治系统边界路由器ASBR的位索引显式复制BIER信息；获取组播流量；基于所述第一转发表项对所述组播流量进行封装，确定并传输BIER报文。

Description

组播流量传输方法、装置、通信节点及存储介质
本申请要求在2020年04月03日提交中国专利局、申请号为202010260534.3的中国专利申请的优先权，该申请的全部内容通过引用结合在本申请中。
技术领域
本申请涉及通信领域，例如涉及一种组播流量传输方法、装置、通信节点及存储介质。
背景技术
组播技术在互联网上正得到越来越多的应用，比如多方会议，远程教育，远程医疗，网络直播等。这些应用也促使着组播技术的发展与完善。
位索引显式复制(Bit Indexed Explicit Replication，BIER)是一种新型组播数据转发技术。BIER技术在实现BIER跨域时，仅对跨域可选方式(即Option)A的场景适应较好，但无法适应具有更多应用价值的跨域Option B，Option C场景。跨域场景应用的限制，将极大的限制BIER技术在实际网络中的部署，不能充分利用BIER技术的优势实现跨域组播流量传输。
发明内容
本申请提供一种组播流量传输方法、装置、通信节点及存储介质。
本申请实施例提供一种组播流量传输方法，应用于第一通信节点，包括：
确定第一转发表项，所述第一转发表项包括自治系统边界路由器ASBR的位索引显式复制BIER信息；获取组播流量；基于所述第一转发表项对所述组播流量进行封装，确定并传输BIER报文。
本申请实施例还提供了一种组播流量传输方法，应用于第二通信节点，包括：
向第一通信节点发送ASBR的BIER信息；获取所述第一通信节点发送的BIER报文，所述BIER报文基于第一转发表项确定，所述第一转发表项基于向第一通信节点发送的ASBR的BIER信息确定；基于所述第二通信节点的BIER转发平面的切换信息和第二转发表项，传输所述BIER报文。
本申请实施例还提供了一种组播流量传输方法，应用于第三通信节点，包括：
向第二通信节点发送ASBR的BIER信息；获取所述第二通信节点的BIER报文，所述BIER报文为所述第二通信节点基于BIER转发平面的切换信息和第二转发表项传输；根据第二关联关系，传输所述BIER报文。
本申请实施例还提供了一种组播流量传输装置，配置于第一通信节点，包括：
第一确定模块，设置为确定第一转发表项，所述第一转发表项包括自治系统边界路由器ASBR的位索引显式复制BIER信息；获取模块，设置为获取组播流量；第二确定模块，设置为基于所述第一转发表项对所述组播流量进行封装，确定并传输BIER报文。
本申请实施例还提供了一种组播流量传输装置，配置于第二通信节点，包括：
发送模块，设置为向第一通信节点发送ASBR的BIER信息；获取模块，设置为获取所述第一通信节点发送的BIER报文，所述BIER报文基于第一转发表项确定，所述第一转发表项基于向第一通信节点发送的ASBR的BIER信息确定；传输模块，设置为基于所述第二通信节点的BIER转发平面的切换信息和第二转发表项，传输所述BIER报文。
本申请实施例还提供了一种组播流量传输装置，配置于第三通信节点，包括：
发送模块，设置为向第二通信节点发送ASBR的BIER信息；获取模块，设置为获取所述第二通信节点的BIER报文，所述BIER报文为所述第二通信节点基于BIER转发平面的切换信息和第二转发表项传输；传输模块，设置为根据第二关联关系，传输所述BIER报文。
本申请实施例还提供了一种通信节点，包括：
一个或多个处理器；存储装置，用于存储一个或多个程序；当所述一个或多个程序被所述一个或多个处理器执行，使得所述一个或多个处理器实现本申请实施例中的任意一种方法。
本申请实施例还提供了一种存储介质，所述存储介质存储有计算机程序，所述计算机程序被处理器执行时实现本申请实施例中的任意一种方法。
附图说明
图1为本申请提供的一种组播流量传输方法的流程示意图；
图1a为本申请提供的一种跨域网络的示意图；
图1b为本申请提供的又一种跨域网络的示意图；
图2为本申请提供的又一种组播流量传输方法的流程示意图；
图3为本申请提供的另一种组播流量传输方法的流程示意图；
图3a为本申请提供的另一种跨域网络的示意图；
图3b为本申请提供的再一种跨域网络的示意图；
图3c为本申请提供的一种第二关联关系的示意图；
图3d为本申请提供的又一种第二关联关系的示意图；
图3e为本申请提供的一种第一关联关系的示意图；
图3f为本申请提供第一通信节点上的多级映射关系示意图；
图3g为本申请提供的第二通信节点上的多级映射关系示意图；
图4为本申请提供的一种组播流量传输装置的结构示意图；
图5为本申请提供的一种组播流量传输装置的结构示意图；
图6为本申请提供的一种组播流量传输装置的结构示意图；
图7为本申请提供的一种通信节点的结构示意图。
具体实施方式
下文中将结合附图对本申请的实施例进行说明。
在附图的流程图示出的步骤可以在诸如一组计算机可执行指令的计算机系统中执行。并且，虽然在流程图中示出了逻辑顺序，但是在一些情况下，可以以不同于此处的顺序执行所示出或描述的步骤。
在一个示例性实施方式中，图1为本申请提供的一种组播流量传输方法的流程示意图，该方法可以适用于进行组播流量跨域传输的情况，该方法可以由本申请提供的配置于第一通信节点的组播流量传输装置执行，该装置可以由软件/或硬件实现，并集成在第一通信节点上。第一通信节点可以为所属自治系统的入口运营商边缘(Provider Edge，PE)。第一通信节点可以认为是直接或间接与服务器通信的通信节点。
BIER将网络边缘的节点都只用一个比特(即bit)位来表示，组播流量在中间网络传输，额外封装一个特定的BIER头，这个报文头以bit位串的形式标注了该组播流的所有目的节点，中间网络转发节点根据bit位进行路由，保障流量能够发送到所有目的节点。中间节点转发设备事先通过内部协议，比如三层网络中的开放式最短路径优先(OSPF Open Shortest Path First，OSPF)协议，中间 系统到中间系统(Intermediate System-to-Intermediate System，ISIS)协议、边界网关协议(Border Gateway Protocol，BGP)或者Babel协议等来泛洪和发送节点信息，形成用于指导BIER转发的位索引转发表(Bit Index Forwarding Table，BIFT)，在收到封装BIER头的流量时，依据BIFT来完成报文到目的节点的转发。BIER这种数据面转发技术因为没有组播树的建立问题，消除了组播树建立的时延，并且在网络出现链路或者节点问题时，收敛速度同OSPF和ISIS协议，比原来的组播树重建降低了巨大的时延。用来建立BIER转发表项的OSPF/ISIS或者BGP等协议，称之为BIER的基础层(即underlay)技术。
BIER技术在传输的时候，仅需要将一条组播流量封装在BIER报文内作为载荷(即payload)传输。对于BIER域的入口设备位转发入口路由器(Bit-Forwarding Ingress Router，BFIR)来说，需要知道哪些BIER域的出口设备位转发出口路由器(Bit-Forwarding Egress Routers，BFER)需要这条组播流量，这样在BFER收到这条组播流量后，才能转发给BIER域外需要收到这条流量的组播接收者。在BFIR和BFER之间，除了采用静态配置的方式，还可以采用运行动态通告的协议来让BFIR知道一条组播流量所对应的BFERs。这称之为BIER叠加层(即overlay)技术。该BIER域内的设备上所形成的BIER转发表，形成该域的BIER转发平面。
跨域场景是互联网中很常见的组网场景，跨域的概念从请求评论(Request For Comments，RFC)4364的单播多域骨干网而来。组播虚拟专用网络(Multicast Virtual Private Network，MVPN)的标准则是RFC6513。跨域指的是跨多个自治系统(Autonomous System，AS)域。跨域有三种方式，Option A指的是背靠背的跨域方式，自治系统边界路由器(AS Border Router，ASBR)之间会建立多个虚拟专用网络(Virtual Private Network，VPN)路由转发表(VPN Routing and Forwarding table，VRF)，ASBR之间是PE和用户边缘(Customer Edge，CE)的关系，将流量还原成私网流量，然后在对端ASBR上再封装使之能在另一个AS的公网上传递。
图1a为本申请提供的一种跨域网络的示意图，如图1a所示，流量从PE1出来时，根据公网隧道进行封装，在到达ASBR1时，会还原成私网的网际互连协议(Internet Protocol，IP)流量，由ASBR1发送给ASBR2和ASBR3后，再次封装公网隧道在AS2中传输。Option A作为最简单的跨域实现方法，能够适应比较简单的跨域场景。在该场景中，用同一个域内的解决方案就可以实现在AS1，AS2，AS3内部依靠BIER技术实现组播传递。也就是AS1，AS2，AS3各自建立自己的BIER域，PE1和ASBR1作为AS1的BFIR和BFER设备，ASBR2和PE2作为AS2的BFIR和BFER设备，ASBR3作为AS3的BFIR，PE3和PE4则作为AS3的BFER。ASBR之间则是PE-CE的流量传输方式，与BIER无关。
Option B是另一种跨域实现方法，在该方法中，ASBR之间不会建立多个VRF进行私网流量的还原，而是通过ASBR之间进行路由的再次通告方式实现。如图1a所示，流量根据公网隧道进行封装从PE1发出，到达ASBR1时，直接通过标签交换的形式发送给ASBR2和ASBR3，ASBR2/3再进行标签交换并封装自己域内的隧道，从而发送到各自AS的接收者。当BIER技术应用在该场景中时，单域的BIER技术无法直接应用，尤其是ASBR间的流量处理，没有相应的技术能解决如何实现BIER转发。
Option C则是第三种跨域实现方法，在该方法中，PE之间会建立多跳外部边界网关协议(External Border Gateway Protocol，EBGP)，但是中间跨多个AS的路径则需要打通。在相关的BIER技术应用在该场景时，可以通过多个域的路由导入，实现整网BIER转发路径，图1b为本申请提供的又一种跨域网络的示意图，参见图1b，ASBR2/ASBR3需要将本域所有的BFER设备(即PE2/PE3/PE4)的路由前缀以及对应的位转发路由器标识(Bit-Forwarding Router Identifier，BFR-ID)等信息，逐一或者汇总通告给ASBR1，ASBR1将学习到的这些路由前缀以及对应的BFR-ID等信息，完全导入到AS1的用以建立BIER转发平面的underlay协议中，如OSPF，ISIS，BGP等。从而建立一个BIER域(即domain)，即整网的BIER转发平面。这样PE1可以直接为流量封装PE2/3/4为目的位串(即Bitstring)的BIER头，由整网的BIER转发平面发送给BFER，BFER包括PE2/3/4。中间的ASBR仅实现位转发路由器(Bit-Forwarding Router，BFR)设备的转发行为即可传递报文。这种实现方法在整网路由都打通的情况下是可行的。但在实际组网中，往往不能实现整网路由的全部打通，这种情况下BIER技术仍然无法部署，无法利用BIER技术实现组播流量的传输。
RFC8556将MVPN与BIER技术进行结合，但也仅仅是适用在同一域内场景，对跨域的场景仍然无法支持。
这里仅指一条流的状态来给出角色定义，实际应用中根据流的走向不同会有不同的BFIR及BFER，以及上游AS，下游AS等角色，并不影响本申请的技术描述，都在本申请所包含的范围之内。
因此，在跨域Option B和Option C的场景中，因相关BIER技术无法直接应用，给BIER技术部署造成困难，使BIER技术无法得到大规模的应用。
BIER技术正在网络上进行广泛应用，如何将BIER技术应用到多个AS域的大规模组网中是需要解决的重要问题，本申请针对多种组播跨域场景，对BIER技术进行改进，使BIER技术很好的服务于大规模网络，促进了网络组播技术的发展。
在一个示例性实施方式中，本申请提供的一种组播流量传输方法，如图1 所示，该方法包括如下步骤：
S110、确定第一转发表项，所述第一转发表项包括自治系统边界路由器ASBR的位索引显式复制BIER信息。
第一转发表项可以用于封装组播流量，以得到BIER报文。如基于第一转发表项确定组播流量的目的位串，以实现组播流量的跨域传输。本步骤可以基于获取的ASBR的BIER信息，建立第一转发表项。
第一转发表项可以包括ASBR的BIER信息，其中，ASBR可以为第一通信节点所属自治系统的出口ASBR和第一通信节点所属自治系统下游自治系统的入口ASBR中的一个或多个。第一转发表项还可以包括第一通信节点所属自治系统下游自治系统的出口PE或出口ASBR的BIER信息。
本申请可以获取跨跳的BFER的BFR-ID，建立BFR-ID的多级映射表，从而获得第一转发表项。示例性的，第一通信节点可以通过迭代的方式确定第四通信节点的下一跳设备，以建立多级映射表。
S120、获取组播流量。
组播流量可以认为是组播场景下的流量。组播流量可以间接传输至对该组播流量感兴趣的第四通信节点。
S130、基于所述第一转发表项对所述组播流量进行封装，确定并传输BIER报文。
获取组播流量后本申请可以对该组播流量进行封装，以得到BIER报文，然后传输BIER报文。
封装组播流量之前，本申请中的第一通信节点、第二通信节点、第三通信节点和第四通信节点中的一个或多个，即PE或ASBR，可以预先确定各第四通信节点感兴趣的组播流量或组播流量所属的VPN，并为各第四通信节点所感兴趣的组播流量或组播流量所属VPN分配标签或SID，以标识对应的组播流量或组播流量所属VPN。在分配标签或SID后，在需要进行BIER转发平面切换的通信节点上建立关联关系。第一通信节点建立的关联关系可以包括第四通信节点感兴趣的流量或流量所属VPN，以及对应的标签或SID。如基于感兴趣的流量及对应的标签建立第一通信节点的关联关系或基于感兴趣的流量所属VPN及对应的标签建立第一通信节点的关联关系。
本步骤在封装组播流量时，可以基于第一转发表项封装一层或双层BIER头，并根据关联关系，如BIER转发表和BFR-ID的多级映射表在跨域网络中进行BIER报文的转发。其中，外层BIER头可以用于指示内层BIER头的协议字段，如以太、网际协议版本(Internet Protocol version，IPv)6或BIER类型。
在一个实施例中，确定是否进行BIER转发平面切换可以通过当前通信节点获取信息，如发送BIER报文时所属的转发平面，和发送至下一跳设备时的转发平面是否为同一转发平面确定。
在一个实施例中，关联关系可以基于接收到的用于标识发送至本通信节点标签或SID的通信节点的指示信息、所发送的标签或SID(即标识信息)、本通信节点所分配的标签或SID和本通信节点的指示信息建立。
本申请中所述的“第一”、“第二”、“第三”等仅用于区分相应的内容，示例性的，第一指示信息和第二指示信息仅用于区分指示信息，其中，第一指示信息可以用于指示第一标识信息由第一通信节点发送；第二指示信息可以用于指示第二标识信息由第二通信节点发送。
本申请可以通过所述第一通信节点的BIER转发平面传输BIER报文。本申请可以根据ASBR或PE的路由前缀，在其他AS内的路由能力，建立BIER域及相应的BIER转发平面。如基于第三通信节点在第一通信节点所属自治系统的路由能力确定第一通信节点的BIER转发平面。其中，第三通信节点可以是第一通信节点所属自治系统下游的自治系统的入口ASBR。
本申请提供的一种组播流量传输方法，确定第一转发表项，所述第一转发表项包括自治系统边界路由器ASBR的位索引显式复制BIER信息；获取组播流量；基于所述第一转发表项对所述组播流量进行封装，确定并传输BIER报文。利用该方法，丰富了BIER技术的应用场景，实现了BIER技术在大规模网络的应用。
在上述实施例的基础上，提出了上述实施例的变型实施例，为了使描述简要，在变型实施例中仅描述与上述实施例的不同之处。
在一个实施例中，所述自治系统边界路由器ASBR的位索引显式复制BIER信息包括如下一个或多个：第二通信节点的BIER信息，所述第二通信节点为所述第一通信节点所属自治系统的出口ASBR；第三通信节点的BIER信息，所述第三通信节点所属自治系统位于所述第一通信节点所属自治系统的下游；第四通信节点的BIER信息，所述第四通信节点为第三通信节点所属自治系统的出口运营商边缘或出口ASBR。
自治系统ASBR可以为第二通信节点、第三通信节点和第四通信节点中的一个或多个。对BIER信息此处不作限定，可以基于实际情况确定利用BIER技术实现跨域传输所需的信息。
在一个实施例中，BIER信息包括位转发路由器标识BFR-ID；BIER信息还包括如下一个或多个：子域信息；位索引转发表标识；位串长度。
示例性的，BIER信息可以包括BFR-ID，在封装组播流量时可以将组播流量对应的通信节点的BFR-ID设置为目的位串。组播流量对应的通信节点可以认为是对该组播流量感兴趣的通信节点。
子域信息可以认为是用于标识BIER域的信息，本申请可以基于子域信息确定是否进行转发平面的切换，从而重新封装BIER报文。如当传输BIER报文时对应的接收BIER报文的BIER域和发送BIER报文的域为不同域可以进行转发平面的切换。
此处不对位索引转发表标识和位串长度的应用进行限定，可以根据实际需求设定。
在一个实施例中，所述确定第一转发表项，包括如下一个或多个：
获取第二通信节点和第三通信节点的BIER信息，并基于所述第二通信节点和所述第三通信节点的BIER信息确定第一转发表项；获取第二通信节点的BIER信息，并基于所述第二通信节点的BIER信息确定第一转发表项；获取第二通信节点、第三通信节点和第四通信节点的BIER信息，并基于所述第二通信节点、第三通信节点和第四通信节点的BIER信息确定第一转发表项；获取第二通信节点和第四通信节点的BIER信息，并基于所述第二通信节点和所述第四通信节点的BIER信息确定第一转发表项。
在跨域方式为可选方式Option B，且第三通信节点的路由前缀在所述第一通信节点所属自治系统中可路由的情况下，本申请可以获取第三通信节点的BIER信息，基于第三通信节点的BIER信息建立第一转发表项。此外，本申请还可以获取第二通信节点的BIER信息，以基于第二通信节点的BIER信息建立第一转发表项。
在跨域方式为Option C，且第三通信节点的路由前缀在所述第一通信节点所属自治系统中可路由的情况下，可以获取第三通信节点和第四通信节点的BIER信息，以基于第三通信节点和第四通信节点的BIER信息建立第一转发表项。此外，本申请还可以获取第二通信节点的BIER信息，以基于第二通信节点的BIER信息建立第一转发表项。
在跨域方式为Option B，且第三通信节点的路由前缀在所述第一通信节点所述自治系统中不可路由的情况下，本申请可以获取第二通信节点的BIER信息，以基于第二通信节点的BIER信息建立第一转发表项。
在跨域方式为Option C，且第三通信节点的路由前缀在所述第一通信节点所述自治系统中不可路由的情况下，本申请可以获取第四通信节点的BIER信息，以基于第四通信节点的BIER信息建立第一转发表项。此外，本申请还可以获取 第二通信节点的BIER信息，以基于第二通信节点的BIER信息建立第一转发表项。
在一个实施例中，传输BIER报文，包括：
通过所述第一通信节点的BIER转发平面，传输BIER报文，所述第一通信节点的BIER转发平面基于第三通信节点的路由前缀在所述第一通信节点所属自治系统中的路由能力确定。
本申请可以基于第三通信节点的路由前缀在第一通信节点所属自治系统中的路由能力确定第一通信节点的BIER转发平面。如基于第三通信节点的路由前缀在第一通信节点所属自治系统中的路由能力确定BIER转发平面所包括的通信节点。
在一个实施例中，在第三通信节点的路由前缀在所述第一通信节点所属自治系统中可路由的情况下，所述BIER转发平面包括所述第一通信节点所属自治系统的BIER转发平面扩展到第三通信节点上后形成的转发平面；在第三通信节点的路由前缀在所述第一通信节点所属自治系统中不可路由的情况下，所述BIER转发平面包括所述第一通信节点和第二通信节点所属自治系统形成的转发平面。
在第三通信节点的路由前缀在第一通信节点所属自治系统可路由的情况下，BIER转发平面可以包括将第一通信节点和第二通信节点所属转发平面扩展至第三通信节点，以使第一通信节点的BIER转发平面包括第三通信节点。
在一个实施例中，在所获取的组播流量为第四通信节点感兴趣的组播流量、跨域方式为可选方式Option B，且第三通信节点的路由前缀在所述第一通信节点所属自治系统中可路由的情况下，BIER报文的报文头中目的位串包括第三通信节点的BFR-ID；在所获取的组播流量为第四通信节点感兴趣的组播流量、跨域方式为Option C，且第三通信节点的路由前缀在所述第一通信节点所属自治系统中可路由的情况下，所述BIER报文的报文头进行两层封装，内层BIER头中目的位串包括第四通信节点的BFR-ID，外层BIER头中目的位串包括第三通信节点的BFR-ID，所述外层BIER头的协议字段根据所述内层BIER头的封装形式确定；在所获取的组播流量为第四通信节点感兴趣的组播流量、跨域方式为Option B，且第三通信节点的路由前缀在所述第一通信节点所述自治系统中不可路由的情况下，所述BIER报文的报文头中目的位串包括第二通信节点的BFR-ID；在所获取的组播流量为第四通信节点感兴趣的组播流量、跨域方式为Option C，且第三通信节点的路由前缀在所述第一通信节点所述自治系统中不可路由的情况下，所述BIER报文的报文头进行两层封装，内层BIER头中目的位串包括第四通信节点的BFR-ID，外层BIER头中目的位串包括第二通信节点的 BFR-ID，所述外层BIER头的协议字段根据所述内层BIER头的封装形式确定。
在一个实施例中，在所获取的组播流量为第四通信节点感兴趣的组播流量、跨域方式为可选方式Option B，且第三通信节点的路由前缀在所述第一通信节点所属自治系统中可路由的情况下，第一通信节点与第三通信节点属于同一转平面，在封装组播流量时，将目的位串设置为第三通信节点的BFR-ID。
在一个实施例中，在所获取的组播流量为第四通信节点感兴趣的组播流量、跨域方式为Option C，且第三通信节点的路由前缀在所述第一通信节点所属自治系统中可路由的情况下，第一通信节点已知第四通信节点的BFR-ID且第一通信节点与第四通信节点属于同一转发平面，故将报文的报文头进行两层封装。内层BIER头的目的位串设置为第四通信节点的BFR-ID，外层BIER头中目的位串设置为第三通信节点的BFR-ID。
在一个实施例中，在所获取的组播流量为第四通信节点感兴趣的组播流量、跨域方式为Option B，且第三通信节点的路由前缀在所述第一通信节点所述自治系统中不可路由的情况下，第一通信节点与第三通信节点不属于同一转发平面，将BIER报文头的中目的位串设置为第二通信节点的BFR-ID。
在一个实施例中，在所获取的组播流量为第四通信节点感兴趣的组播流量、跨域方式为Option C，且第三通信节点的路由前缀在所述第一通信节点所述自治系统中不可路由的情况下，第一通信节点与第三通信节点不属于同一转发平面且第一通信节点已知第四通信节点的BFR-ID，故将报文的报文头进行两层封装。内层BIER头的目的位串设置为第四通信节点的BFR-ID，外层BIER头中目的位串设置为第二通信节点的BFR-ID。
在一个实施例中，该方法，还包括：
获取接收端节点发送的感兴趣信息，所述接收端节点为第二通信节点或第四通信节点，所述接收端节点发送的感兴趣信息指示第四通信节点感兴趣的组播流量或组播流量所属虚拟专用网络；向所述接收端节点发送所述感兴趣信息对应的第一标识信息和第一指示信息，所述第一标识信息包括标签或分段标识，所述第一指示信息指示所述第一标识信息由所述第一通信节点发送。
在进行组播流量封装前，本申请还可以获取接收端节点发送的感兴趣信息。
第一通信节点可以基于第一标识信息、感兴趣信息和接收端节点建立第一通信节点的关联关系，基于该关联关系进行BIER报文的传输。BIER报文中可以包括该组播流量对应的第一标识信息。
在一个示例性实施方式中，本申请还提供了一种组播流量传输方法，图2为本申请提供的又一种组播流量传输方法的流程示意图，该方法可以适用于进 行组播流量跨域传输的情况，该方法可以由本申请提供的配置于第二通信节点的组播流量传输装置执行，该装置可以由软件/或硬件实现，并集成在第二通信节点上。第二通信节点可以为所属自治系统的出口自治系统边界路由器(Autonomous System Border Router，ASBR)。本实施例尚未详尽的内容可以参见上述实施例，此处不作赘述。
如图2所示，本申请实施例提供的一种组播流量传输方法，包括如下步骤：
S210、向第一通信节点发送ASBR的BIER信息。
本步骤可以向第一通信节点发送ASBR的BIER信息，以供第一通信节点确定第一转发表项，从而实现BIER报文的传输。
S220、获取所述第一通信节点发送的BIER报文，所述BIER报文基于第一转发表项确定，所述第一转发表项基于向第一通信节点发送的ASBR的BIER信息确定。
S230、基于所述第二通信节点的BIER转发平面的切换信息和第二转发表项，传输所述BIER报文。
切换信息可以指示第二通信节点传输BIER报文时是否需要进行BIER转发平面的切换。切换信息可以包括切换和不切换。第二转发表项可以认为是第二通信节点的转发表项。第二通信节点可以基于第二转发表项传输或重封装BIER报文。
在获取BIER报文后，本步骤可以基于切换信息确定是否需要进行BIER转发平面的切换，然后可以基于确定的结果确定基于第二转发表项传输BIER报文的方式。示例性的，在确定的结果为不切换的情况下，本申请可以基于第二转发表项直接转发BIER报文；在确定的结果为切换的情况下，本申请可以基于第二转发表项重封装BIER报文，并传输重封装后的BIER报文。
本申请提供的一种组播流量传输方法，向第一通信节点发送ASBR的BIER信息；获取所述第一通信节点发送的BIER报文，所述BIER报文基于第一转发表项确定，所述第一转发表项基于向第一通信节点发送的ASBR的BIER信息确定；基于所述第二通信节点的BIER转发平面的切换信息和/或第二转发表项，传输所述BIER报文。利用该方法，丰富了BIER技术的应用场景，实现了BIER技术在大规模网络的应用。
在上述实施例的基础上，提出了上述实施例的变型实施例，为了使描述简要，在变型实施例中仅描述与上述实施例的不同之处。
在一个实施例中，所述ASBR的BIER信息包括如下一个或多个：第二通信节点的BIER信息；第三通信节点的BIER信息。
第三通信节点的BIER信息可以由第三通信节点通告给第二通信节点。
在一个实施例中，在第三通信节点的路由前缀在所述第一通信节点所属自治系统中可路由的情况下，所述BIER转发平面包括所述第一通信节点所属自治系统的BIER转发平面扩展到第三通信节点上后形成的转发平面，所述第二通信节点的BIER转发平面的切换信息为不切换；在第三通信节点的路由前缀在所述第一通信节点所述自治系统中不可路由的情况下，所述BIER转发平面包括所述第二通信节点与所述第一通信节点形成的转发平面，以及第三通信节点和所述第二通信节点形成的转发平面，所述第二通信节点的BIER转发平面的切换信息为切换。
在一个实施例中，所述基于所述第二通信节点的BIER转发平面的切换信息和第二转发表项，传输所述BIER报文，包括：
在所述第二通信节点的BIER转发平面的切换信息为不切换的情况下，根据第二转发表项中的第一子转发表项转发所述BIER报文，所述第一子转发表项为所述第一通信节点所属自治系统的BIER转发平面扩展到第三通信节点上后形成的转发平面内的转发表项，所述第一子转发表项包括第三通信节点的BIER信息；在所述第二通信节点的BIER转发平面的切换信息为切换的情况下，基于第二转发表项中的第二子转发表项接收所述BIER报文，基于第二转发表项中的第三子转发表项重封装所述BIER报文，传输重封装后的BIER报文，所述第二子转发表项为所述第一通信节点和所述第二通信节点形成转发平面内的转发表项，所述第二转发表项包括所述第二通信节点的BIER信息，所述第三子转发表项为所述第二通信节点和第三通信节点形成的转发平面内的转发表项，所述第三子转发表项包括第三通信节点的BIER信息。
在切换信息为不切换的情况下，可以基于第一子转发表项中的第三通信节点的BIER信息转发BIER报文。第一子转发表项可以认为是切换信息为不切换时第二通信节点的转发表项。
在切换信息为切换的情况下，基于第二子转发表项和第三子转发表项传输BIER报文。第二子转发表项和第三子转发表项可以认为是切换信息为切换的情况下，第二通信节点的转发表项。
在一个实施例中，基于第二转发表项中的第三子转发表项重封装所述BIER报文，包括：
将所述BIER报文的外层BIER头中目的位串更新为第三通信节点的BFR-ID，所述第三通信节点的BFR-ID基于第二转发表项中的第三子转发表项确定；基于第一关联关系，更新所述BIER报文中组播流量的标识信息。
更新BIER报文时可以将目的位串设置为第三通信节点的BFR-ID，基于第一关联关系，更新组播流量的标识信息。如将组播流量中的第一标识信息更新为第二标识信息。
第一关联关系可以认为是第二通信节点建立的关联关系。
在一个实施例中，该方法，还包括：
确定第一关联关系。
对确定第一关联关系的时机不作限定，只要保证在传输BIER报文时，能够确定即可。本申请可以在第二通信节点需要进行BIER转发平面的切换时，确定第一关联关系。
在一个实施例中，该方法，还包括：
获取第三通信节点发送的感兴趣信息；将所述第三通信节点发送的感兴趣信息传输至所述第一通信节点；获取所述第一通信节点发送的所述感兴趣信息对应的第一标识信息和第一指示信息；在BIER转发平面包括第三通信节点和第二通信节点形成的转发平面的情况下，确定所述感兴趣信息的第二标识信息，向所述第三通信节点发送所述第二标识信息和第二指示信息，所述第二指示信息指示所述第二标识信息由所述第二通信节点发送，基于所述第一标识信息、第一指示信息、第二标识信息、和第二指示信息确定第一关联关系，所述第一指示信息指示所述第一标识信息由所述第一通信节点发送；在BIER转发平面包括所述第一通信节点所属自治系统的BIER转发平面扩展到第三通信节点上后形成的转发平面的情况下，向所述第三通信节点发送所述第一标识信息和第一指示信息。
在BIER转发平面需要切换的情况下，第二通信节点可以为该感兴趣信息分配第二标识信息，并将第二标识信息和第二指示信息传输至第三通信节点。第二通信节点可以基于第一标识信息、第一指示信息、第二标识信息、和第二指示信息确定第一关联关系，以便于重封装BIER报文。
在一个示例性实施方式中，本申请还提供了一种组播流量传输方法，图3为本申请提供的另一种组播流量传输方法的流程示意图，该方法可以适用于进行组播流量跨域传输的情况，该方法可以由本申请提供的配置于第三通信节点的组播流量传输装置执行，该装置可以由软件/或硬件实现，并集成在第三通信节点上。第三通信节点所属自治系统可以位于第一通信节点所属自治系统的下游。第三通信节点可以为所属自治系统的入口ASBR。本实施例尚未详尽的内容可以参见上述实施例，此处不作赘述。
如图3所示，本申请实施例提供的一种组播流量传输方法，包括如下步骤：
S310、向第二通信节点发送ASBR的BIER信息。
本步骤可以向第二通信节点发送ASBR的BIER信息，以供第一通信节点确定第一转发表项，从而实现BIER报文的传输。
S320、获取所述第二通信节点的BIER报文，所述BIER报文为所述第二通信节点基于BIER转发平面的切换信息和第二转发表项传输。
S330、根据第二关联关系，传输所述BIER报文。
第二关联关系可以认为是第三通信节点的关联关系。第三通信节点可以基于第三关联关系传输BIER报文。示例性的，可以基于跨域方式及第二关联关系传输BIER报文。在跨域方式为Option B的情况下，基于第二关联关系重封装所述BIER报文，然后传输重新封装，即重封装后的BIER报文。在跨域方式为Option C的情况下，直接基于内层BIER头进行转发，即传输去除外层BIER头的BIER报文。
本申请提供的组播流量传输方法，向第二通信节点发送ASBR的BIER信息；获取所述第二通信节点的BIER报文，所述BIER报文为所述第二通信节点基于BIER转发平面的切换信息和第二转发表项传输；根据第二关联关系，传输所述BIER报文。利用该方法，丰富了BIER技术的应用场景，实现了BIER技术在大规模网络的应用。
在上述实施例的基础上，提出了上述实施例的变型实施例，为了使描述简要，在变型实施例中仅描述与上述实施例的不同之处。
在一个实施例中，所述ASBR的BIER信息包括第三通信节点的BIER信息。
在一个实施例中，根据第二关联关系，传输所述BIER报文，包括：
在第三通信节点的路由前缀在第一通信节点所属自治系统中可路由，且跨域方式为Option B的情况下，或在第三通信节点的路由前缀在所述第一通信节点所述自治系统中不可路由且跨域方式为Option B的情况下，基于第二关联关系和第四通信节点的BFR-ID重封装所述BIER报文，传输重封装后的BIER报文；在第三通信节点的路由前缀在所述第一通信节点所属自治系统中可路由，且跨域方式为Option C的情况下，或在第三通信节点的路由前缀在所述第一通信节点所述自治系统中不可路由，且跨域方式为Option C的情况下，去除所述BIER报文的外层BIER头，传输去除外层BIER头的BIER报文。
重封装所述BIER报文可以包括更新组播流量的标识信息和目的位串。
在一个实施例中，基于第二关联关系和第四通信节点的BFR-ID重封装所述BIER报文，包括：
基于第二关联关系更新所述BIER报文中组播流量的标识信息；将所述BIER报文头中目的位串设置为第四通信节点的BFR-ID。
在一个实施例中，该方法，还包括：
确定第二关联关系。
对确定第二关联关系的时机不作限定，只要保证在传输BIER报文时，能够确定即可。本申请可以在接收到反馈信息后确定第二关联关系。反馈信息可以认为是第一通信节点发送的第一标识信息和第一指示信息；也可以为第二通信节点发送的第二指示信息和第二标识信息。本申请可以基于反馈信息和第三通信节点为感兴趣信息确定的第三标识信息和第三指示信息，确定第二关联关系。
在一个实施例中，该方法，还包括：
获取第四通信节点发送的感兴趣消息；将所述第四通信节点发送的感兴趣消息传输至第二通信节点；在接收到反馈信息的情况下，确定所述感兴趣信息的第三标识信息和第三指示信息，向第四通信节点发送所述第三标识信息和所述第三指示信息，第三标识信息包括标签或分段标识，第三指示信息指示所述第三标识信息由第三通信节点发送；在所述反馈信息为第一通信节点发送的第一标识信息和第一指示信息的情况下，基于第一标识信息、第一指示信息、第三标识信息和第三指示信息，确定第二关联关系；在所述反馈信息为所述第二通信节点发送的第二标识信息和第二指示信息的情况下，基于所述第二标识信息、第二指示信息、第三指示信息和第三指示信息，确定第二关联关系。
第三指示信息可以指示第三标识信息由第三通信节点生成。对确定第三标识信息的手段不作限定。每个通信节点为不同流量或流量所属VPN确定的标识信息可以不重复。
第四通信节点可以向第三通信节点或第一通信节点发送感兴趣信息；然后接收第一通信节点发送的第一标识信息和第一指示信息；或接收第三通信节点发送的第三标识信息和第三指示信息。第四通信节点可以基于接收的第一标识信息、第一指示信息和第四通信节点为感兴趣信息分配的第四标识信息和第四直至信息建立关联关系，以在接收到BIER报文后，基于第四通信节点建立的关联关系，传输BIER报文。第四标识信息包括标签或分段标识。第四指示信息可以指示第四标识信息由第四通信节点生成。基于第四通信节点建立的关联关系，传输BIER报文可以为基于该关联关系，确定对该组播流量感兴趣的通信节点，然后向确定的通信节点转发组播流量。
在一个实施例中，在第三通信节点的路由前缀在第一通信节点所属自治系统中可路由的情况下，所述BIER转发平面包括所述第一通信节点所属自治系统 的BIER转发平面扩展到第三通信节点上后形成的转发平面；在第三通信节点的路由前缀在所述第一通信节点所述自治系统中不可路由的情况下，所述BIER转发平面包括第三通信节点和第二通信节点形成的转发平面。
以下对本申请提供的一种组播流量传输方法进行示例性的描述，本申请提供的一种组播流量传输方法，可以认为是一种实现组播跨域的方法，相关BIER技术在实现BIER跨域时，仅对跨域Option A的场景适应较好，但无法适应具有更多应用价值的跨域Option B，Option C场景，跨域场景应用的限制，将极大的限制BIER技术在实际网络中的部署，不能充分利用BIER技术的优势实现跨域组播流量传输。
为了充分发挥BIER组播的优势，本申请提出一种实现组播跨域结合BIER技术的方法，使BIER技术适用多种跨域场景，由此可以得到大规模的部署应用。
首先，在跨域的ASBR上分配用于指示BIER转发的BFR-ID，以及所对应的子域(Sub-Domain，SD)信息。
在一个实施例中，分配与该BFR-ID对应的可选封装信息位索引转发表标识(Bit Index Forwarding Table Identifier，BIFT-ID)，可选位串长度(Bit String Length，BSL)等其他信息。
将跨域的下游(靠近接收者方向)AS入口ASBR的BFR-ID信息，随着该ASBR的路由前缀，利用BGP信令扩展进行通告给上游ASBR。
在整网BFR-ID统一分配的场景下，为ASBR所分配的BFR-ID可以与整网的其他节点BFR-ID在同一个SD内，且互相之间没有冲突。在整网BFR-ID非统一分配的情况下，也要保证同一转发平面的BFR-ID不能冲突。因此ASBR参与多个转发平面时需要互相区别，转发平面的区别可以通过不同SD或者别的方法来实现，此处不作限定。BFR-ID的值在不同转发平面中可以相同也可以不相同。
在一个实施例中，图3a为本申请提供的另一种跨域网络的示意图，参见图3a，如果下游AS的入口ASBR(如图3a中的ASBR2/ASBR3)的前缀在上游AS(更靠近源的上一级AS1)中可以路由可达，则可以建立包括上游AS，以及下游ASBR在内的一个扩展BIER域，这种情况下ASBR所分配的BFR-ID，不能与上游AS中的节点BFR-ID冲突，如图3a所示。从而形成BIER转发平面，这样流量可以在连接源的PE封装成BIER报文，并直接经过BIER转发到下游ASBR上，然后再由下游ASBR通过BIER转发平面转换，封装新的BIER头在下游AS中传递直到接收者PE。
在一个实施例中，图3b为本申请提供的再一种跨域网络的示意图，参见图 3b，如果下游AS的入口ASBR的前缀在上游AS中不能路由，则需要在跨域的ASBR上建立一个单独的BIER域，如图3b所示的BIER域10。这时上游AS中的出口ASBR也需要分配用于指示BIER转发的BFR-ID，以及所对应的SD，可选封装信息BIFT-ID，可选BSL等其他信息。
在一个实施例中，ASBR之间的BIER转发平面，独立于上游AS以及下游AS的转发平面，可以通过不同的SD或者其他方式来进行区分，并且不同的转发平面内部BFR-ID不能重复。
其次，入口PE通过BGP协议信令，收集到ASBR或者下游AS的出口PE的对一条流量感兴趣的信息。在跨域Option B场景中，入口PE将通过BGP信令得知本域的出口ASBR，或者下游AS的入口ASBR想接收的流量信息；在跨域Option C场景中，入口PE将通过BGP信令直接得知下游AS出口PE想接收的流量信息。
在一个实施例中，当下游AS的入口ASBR前缀在上游AS中可路由时，则上游AS的出口ASBR将通过BGP得知下游AS的入口ASBR感兴趣的流量信息，即第二通信节点发送的感兴趣信息可以为下游AS的入口ASBR感兴趣的流量信息。
在一个实施例中，入口PE将为下游设备感兴趣的流量，分配相应的标签或者设备分段标识(Segment ID，SID)，即第一标识信息，并根据不同的跨域方式，通知给感兴趣的下游设备，可以是ASBR设备，或者下游AS的出口PE设备。
在一个实施例中，所分配的设备SID是针对IPv6封装场景，SID可以为128位的结构，与IPv6地址位数相同，其中还可以含有表示查IPv4，IPv6或者二层转发表等的功能，以及表示特定VPN或者其他信息的参数(即Arguments)。SID可以为一个VPN所分配，也可以为一个VPN中的一条流量所分配。
在一个实施例中，为流量，即组播流量进行BIER封装，使封装后的流量能在建立的BIER转发平面中进行转发。
在一个实施例中，在下游入口ASBR与上游AS建立同一转发平面，并非整网同一转发平面时，入口PE封装的BIER报文头中携带下游AS入口ASBR的BFR-ID。
在一个实施例中，在跨域Option C场景，整网统一分配BFR-ID，也就是保证整网没有BFR-ID冲突的情况下，入口PE还可以先封装一个内层BIER报文头以及相应的封装形式，如以太，多协议标签交换(Multiprotocol Label Switching，MPLS)或者IPv6，或者直接采用BIER类型。在BIER报文头中封装下游AS 的出口PE(如图3a中的PE2/3/4)的BFR-ID信息。然后在外层再封装BIER头，携带下游入口ASBR的BFR-ID。外层BIER头中的协议(即protocol)字段，填上表示内层BIER头的外层封装协议类型，如果内层BIER头采用以太封装，则外层BIER头中的protocol字段填写以太类型；如果内层BIER头采用MPLS封装，则外层BIER头中的protocol填写MPLS类型；如果内层BIER头采用IPv6封装，则外层BIER头中的protocol填写IPv6类型；如果不采用其他封装，直接封装BIER类型，那就在外层BIER头中的protocol填写BIER类型。在一个实施例中，内层BIER头在采用IPv6封装时，填写的IPv6目的地址(Destination Address，DA)是入口PE所分配的设备SID信息；采用MPLS封装时，则携带入口PE所分配的标签。
在一个实施例中，在下游入口ASBR不能与上游AS建立同一转发平面，而是只能与上游AS的出口ASBR建立转发平面时，如图3b所示，入口PE封装的BIER报文中的目的位串填写上游AS的出口ASBR的BFR-ID。在封装过的报文到达上游AS的出口ASBR时，ASBR切换到对应的，ASBR间的BIER转发平面进行转发。
在一个实施例中，针对不同的部署场景，在下一个转发平面采用不同的BIER封装形式时，可以实现自动封装转换。如图3b所示，AS2内的BIER转发平面由MPLS组成，AS3内的BIER转发平面由以太组成，上游AS的出口ASBR在进行转发平面切换时，可以根据下游ASBR所通告的BIER转发平面封装方式进行转换，从而避免整网BIER转发平面封装方式不同所带来的互通问题。
在一个示例中，上游AS的入口PE可以执行如下步骤：
在下游AS的入口ASBR的前缀能够在上游AS内路由，即下游AS的入口ASBR用来做BGP通告的回送(即Loopback)地址，可以在上游AS内访问时，可以将本来只在上游AS内的BIER转发平面扩展到下游AS的入口ASBR范围上，即上游AS的入口PE与下游AS的入口ASBR间建立BIER转发平面。上游AS的入口PE及上游AS中的其他节点的BIER转发表项中都有下游AS的入口ASBR的转发表项。
步骤1：入口PE为一个VPN或者一条流量所分配的标签或者SID信息，通过BGP协议通告给上游AS的出口ASBR，即感兴趣的ASBR。
建立转发平面和分配标签或者SID信息没有先后之分。
步骤2：入口PE对源，如该上游AS上游的通信节点发来的流，即组播流量进行一层或多层BIER封装，并通过BIER转发平面转发。在入口PE知晓下游AS的出口PE需要接收流量时，在整网BFR-ID统一规划的情况下，可以封 装双层BIER报文头格式，将下游AS的出口PE所对应的BFR-ID封装在内层BIER头中，辅以相应的外层封装如以太封装，MPLS封装，IPv6封装或者BIER封装等，再封装外层BIER头，其中的目的位串封装下游AS入口ASBR的BFR-ID信息。
在一个示例中，上游AS的出口ASBR可以执行如下步骤：
在下游AS的入口ASBR的路由能分发到上游AS间时，上游AS的出口ASBR参与入口PE到下游AS的入口ASBR之间的BIER转发平面建立；在下游AS的入口ASBR路由不能分发到上游AS间时，单独与下游AS的入口ASBR之间建立BIER转发平面。
步骤1：上游AS的出口ASBR收到下游AS入口ASBR所发来的对一条流感兴趣的BGP通告消息，如果下游AS入口ASBR的路由能在上游AS内访问，则不改变下一跳通告给入口PE；如果下游AS入口ASBR的路由不能在上游AS内访问，则修改下一跳为自己，即上游AS的出口ASBR的BFR-ID通告给入口PE。在收到入口PE发来的为一条流量分配的标签或者SID时，分配标签或者SID并通告给下游AS入口ASBR，并携带源发PE为入口PE，并生成关联关系。
建立转发平面和分配标签或SID消息没有先后之分。
步骤2：上游AS的出口ASBR收到来自上游AS的BIER报文时，判断是否要进行BIER转发平面切换处理，如果不需要切换，则直接根据BIER转发表进行转发；如果需要进行BIER转发平面切换处理，则切换到与下游AS的入口ASBR之间所建立的BIER转发平面进行转发。
判断是否要进行BIER转发平面切换处理的手段可以为确定BIER报文中的目标位串是否为本通信节点，即上游AS的出口ASBR的BFR-ID，基于BIER报文中的标签或SID确定接收者，以确定是否需要进行转发平面切换。
在一个示例中，下游AS的入口ASBR可以执行如下步骤：
下游AS的入口ASBR分配BFR-ID，如果下游AS的入口ASBR路由能在上游AS内可达，则与上游AS建立BIER同一转发平面；如果下游AS的入口ASBR路由不能在上游AS内可达，则与上游AS的出口ASBR建立单独BIER转发平面。
步骤1：下游AS的入口ASBR根据从本AS的出口PE所收到的流量感兴趣通告，通过BGP通告给上游AS的出口ASBR；收到上游ASBR为一流量分配的标签或者SID时，本地分配标签或SID并发送给下游AS的出口PE。并将收到的标签或SID与本地分配的标签或SID关联起来。
建立转发平面和分配流量或SID之间没有先后之分。
步骤2：下游AS的入口ASBR收到BIER报文时，根据标签或者SID关联关系进行BIER转发平面的切换，转发至对应的接收者。
本申请提供的组播流量传输方法完成了BIER技术在整网的部署，使得跨域场景也可以充分利用BIER技术的组播转发优势，实现BIER技术在大规模网络的应用。
在本申请中为了描述方便，将AS1作为上游AS，其中连接源的PE1为上游AS入口PE，ASBR1则是上游AS的出口ASBR；AS2和AS3则作为下游AS，ASBR2，ASBR3作为下游AS的入口ASBR，连接接收者的PE2，PE3和PE4则作为下游AS的出口PE。
在一个实施例中，如图3a所示的网络，假设是跨域Option B场景，首先是underlay层面，假设ASBR2和ASBR3的前缀可以在AS1中路由，也就是AS1中的设备上均有到达ASBR2与ASBR3前缀的路由。ASBR2/3可以参与AS1建立扩展的BIER转发平面，即BIER域1，ASBR2/3上所分配的BFR-ID不能与AS1中的其他节点重合。假设这里给ASBR2/3所分配的BFR-ID为21，31。ASBR2/3的BFR-ID，SD等信息，将随着BGP前缀(这个前缀即AS1中可路由的前缀)通告给ASBR1，ASBR1再将该前缀及BIER信息通过AS1中的OSPF，ISIS或者其他协议传递到AS1中，AS1中的所有设备，包括PE1都会收到BIER信息，并建立BIER域1的转发表项，包含可以到达ASBR2/3的BFR-ID 21，BFR-ID 31的转发表项。
AS2和AS3中各自建立自身的BIER转发平面BIER域2和BIER域3，同样，ASBR2/3在各自的BIER转发平面中也有自身的BFR-ID值，ASBR2/3的ASBR2/3值与BIER域1中的值没有关联关系，值可以相同也可以不同。因此这时对于整网规划BFR-ID或者分域规划BFR-ID，都没有影响。
在overlay层面，PE2/3/4会将对一条流量感兴趣的信息，即第四通信节点发送的感兴趣信息，通过BGP的MVPN扩展传递给ASBR2/3，ASBR2/3再将接收到的感兴趣信息通告给ASBR1，ASBR1再通告给PE1，并且没有改变下一跳是ASBR2/3。PE1为该流量，或者该流量所属的VPN，分配用以区分的标签或者SID信息，并将分配后的标签或SID信息通告给ASBR1；ASBR1将PE所分配的标签或者SID信息通告给ASBR2/3，并且携带源发PE是PE1的信息；ASBR2/3再分别把路由通告给PE2/3/4，并携带ASBR2/3为此分配的标签或者SID，并将ASBR1通告的标签与本地所分配的标签关联起来，图3c为本申请提供的一种第二关联关系的示意图，图3d为本申请提供的又一种第二关联关系的示意图，如图3c，图3d所示，ASBR2/3基于本地所分配的标签和ASBR1通告的标签建立了关联关系。PE2/3/4上将ASBR2/3分配的标签或者SID与接收者 进行关联。
在流量，即组播流量进入PE1进行BIER封装时，PE1将为该流量，或者该流量所属VPN所分配的标签或者SID信息，封装到BIER头中，在目的位串则封装ASBR2和ASBR3的BFR-ID信息，以及AS1内可能有的其他接收者的PE的BFR-ID信息，以得到BIER报文，BIER报文将在AS1中通过第一BIER转发表进行转发，直至到达ASBR1设备，ASBR1直接根据第二BIER转发表转发BIER报文给ASBR2/3。ASBR2/3根据之前生成关联表项如图3c，图3d，重新封装BIER头，携带本地所分配的标签/SID，ASBR2在目的位串中设置PE2的BFR-ID，ASBR3在目的位串中设置PE3，PE4的BFR-ID。通过AS2，AS3中的BIER转发，最终到达PE2/3/4。PE2/3/4上将根据该ASBR2/3分配的标签或者SID辨识出流量所对应的VPN或者具体流量，剥掉BIER封装，转发给接收者。
在一个实施例中，如图3a所示的网络，假设是跨域Option C，整网BFR-ID统一规划的场景，ASBR2和ASBR3的前缀可以在AS1中路由，但PE2/3/4的路由只能通过ASBR2/3可达，也就是非整网打通路由的场景。AS1中的中间设备(非PE，非ASBR)没有通往PE2/3/4的路由。在underlay层面，ASBR2/3可以参与AS1建立扩展的BIER转发平面BIER域1。另外在AS2和AS3中也建立各自的BIER转发平面。
在overlay层面，因为跨域Option C，PE1将直接与PE2和PE3，PE4建立BGP邻居关系，PE1可以直接获知PE2/3/4对一流量感兴趣，PE1将为该流量或者该流量所述VPN分配标签或者SID信息，并通过BGP协议通告给PE2/3/4。PE2/3/4将PE1所分配的标签/SID信息，与本地的接收者进行关联。
当流量进入PE1进行BIER封装得到BIER报文时，因PE2/3/4的路由在AS1的中间节点不可见，因此PE1会进行两层BIER头封装，内层目的位串设置为PE2/3/4的BFR-ID。外层BIER头则封装ASBR2/3的BFR-ID到位串中。外层BIER头中的协议根据后面携带的内层BIER头封装形式决定，可以是以太，MPLS或者IPv6封装形式，也可以直接是BIER类型。BIER报文在AS1中的转发将根据外层BIER头进行，直到ASBR2/3。ASBR2/3剥掉外层BIER头后，根据内层的BIER头进行转发，直至转发到PE2/3/4。PE2/3/4根据overlay层生成的关联关系，剥掉BIER头后转发给需要的接收者。
在一个实施例中，如图3b所示的网络，假设是跨域Option B场景，ASBR2/3的前缀不能在AS1中路由，因此，underlay层面，除了AS1，AS2，AS3中各自建立自己的BIER转发平面，ASBR1/2/3之间也需要建立一个独立的BIER转发平面。这时是否是全局分配BFR-ID信息与各个转发平面的BFR-ID没有决定性 的关系，如果是全局分配BFR-ID的情况，则ASBR1/2/3所分配的BFR-ID在整网唯一，如果是各域独立分配BFR-ID的情况，则ASBR1/2/3可能需要重新分配在BIER域10里的BFR-ID。由此在图3b所示场景中会有四个转发平面，分别是AS1的BIER域1，AS2的BIER域2，AS3的BIER域3，以及ASBR所组成的BIER域10。
在overlay层面，ASBR2/3将收集到对一流量感兴趣的信息通知给ASBR1，ASBR1再通知给入口PE1。PE1为该流量或者该流量所属的VPN，分配相应的标签/SID，通告给ASBR1，ASBR1也为该流量分配标签/SID，与从PE1收到标签/SID的建立关联关系，图3e为本申请提供的一种第一关联关系的示意图，如图3e所示，ASBR1基于PE1发送的标签/SID与ASBR1分配的标签/SID建立了第一关联关系。ASBR1将建立的第一关联关系通告给ASBR2/3。ASBR2/3也分配标签/SID，与从ASBR1收到的建立关联关系，并通告给PE2/3/4，与图3c，图3d类似，只是入项替换成ASBR1分配的标签/SID。PE2将从ASBR2收到的标签/SID与相应的接收者关联起来，同理PE3/4也将从ASBR3收到的标签/SID与相应的接收者关联起来。
当流量在PE1进行BIER封装得到BIER报文时，PE1将ASBR1的BFR-ID封装到BIER头的位串中，通过AS1中的BIER转发平面转发，BIER报文到达ASBR1，剥掉BIER头后，ASBR1根据之前建立的关联关系，封装本地所分配的标签/SID，重新封装BIER头，设置ASBR2/3的BFR-ID到目的位串中。报文到达ASBR2/3，剥掉BIER头后，根据之前建立的关联关系，重新封装BIER头，ASBR2设置PE2的BFR-ID到目的位串中，ASBR3设置PE3/4的BFR-ID到目的位串中，转发到AS2和AS3中。通过AS2和AS3的BIER转发平面，报文最终到达PE2/3/4，剥掉BIER头后，根据之前建立的关联关系，PE2/3/4将报文转发给需要的接收者。
在一个实施例中，如图3b所示的网络，假设是跨域Option C，全网统一分配BFR-ID的场景，PE2/3/4的前缀在ASBR1及PE1上通过BGP通告可见，但在AS1的中间设备上是不可见的。Underlay层面建立四个独立的BIER转发平面。BGP在PE，ASBR上通告时，携带所分配的BFR-ID信息，由此建立BFR-ID与BGP下一跳的多级映射关系。图3f为本申请提供第一通信节点上的多级映射关系示意图，参见图3f，多级映射关系为PE1上BFR-ID的多级映射关系，可以看到PE2/3/4的BFR-ID下一跳为ASBR1。图3g为本申请提供的第二通信节点上的多级映射关系示意图，如图3g所示，多级映射关系为ASBR1上的BFR-ID多级映射表，可以看到PE2的BFR-ID及下一跳设备为ASBR2，PE3/4的BFR-ID及下一跳设备为ASBR3。
在overlay层面，因为PE1直接通过多跳BGP从PE2/3/4学习到PE2/3/4对一流量感兴趣的信息，PE1为该流量或者该流量所属的VPN分配标签/SID信息，并通告给PE2/3/4。PE2/3/4将PE1所分配的标签/SID信息与本地接收者建立关联关系。
当流量进入PE1进行BIER封装得到BIER报文时，根据BGP路由下一跳迭代，可以得出去往PE2/3/4的下一跳是ASBR1，再根据建立的多级BFR-ID映射表，PE1对BIER报文进行双层BIER头封装，内层BIER头封装PE1为流量分配的标签/SID信息，封装PE2/3/4的BFR-ID到目的位串中。外层BIER头则封装ASBR1的BFR-ID到目的位串中，外层BIER头中与内层BIER头中通过内层封装方式耦合，外层BIER头中的协议设置为内层BIER头可能的封装形式，如以太，MPLS或者IPv6，或者直接的BIER类型。在AS1中根据外层BIER头进行转发，报文到达ASBR1后，ASBR1剥掉外层BIER头，对内层BIER头进行处理时发现需要迭代到ASBR2和ASBR3，因此ASBR1将可选封装一个外层BIER头，将ASBR2/3的BFR-ID设置到目的位串中。在ASBR1直接与ASBR2/3相连的情况下，该外层BIER头也可以省略，而是直接将BIER报文转发给ASBR2/3。在ASBR1与ASBR2/3之间可能存在多台设备的情况下，则需要封装外层BIER头。当报文到达ASBR2/3时，ASBR2/3剥掉外层BIER头，并根据内层BIER头进行转发，直到BIER报文到达PE2/3/4。PE2/3/4根据overlay层面建立的关联关系，去掉BIER头后，将流量转发给接收者。
随着部署方式的不同，以上各个实施例中的方法可以独立使用，也可以结合使用，从而使得跨域场景也可以充分利用BIER技术的组播转发优势，实现BIER技术在大规模网络的应用。
在一个示例性实施方式中，本申请提供了一种组播流量传输装置，图4为本申请提供的一种组播流量传输装置的结构示意图，如图4所示，本实施例提供的组播流量传输装置可以配置于第一通信节点，该装置包括：第一确定模块41，设置为确定第一转发表项，所述第一转发表项包括自治系统边界路由器ASBR的位索引显式复制BIER信息；获取模块42，设置为获取组播流量；第二确定模块43，设置为基于所述第一转发表项对所述组播流量进行封装，确定并传输BIER报文。
本实施例提供的组播流量传输装置用于实现如图1所示的组播流量传输方法，本实施例提供的组播流量传输装置实现原理和技术效果与图1所示的组播流量传输方法类似，此处不再赘述。
在上述实施例的基础上，提出了上述实施例的变型实施例，为了使描述简要，在变型实施例中仅描述与上述实施例的不同之处。
在一个实施例中，所述自治系统边界路由器ASBR的位索引显式复制BIER信息包括如下一个或多个：第二通信节点的BIER信息，所述第二通信节点为所述第一通信节点所属自治系统的出口ASBR；第三通信节点的BIER信息，所述第三通信节点所属自治系统位于所述第一通信节点所属自治系统的下游；第四通信节点的BIER信息，所述第四通信节点为第三通信节点所属自治系统的出口运营商边缘或出口ASBR。
在一个实施例中，BIER信息包括位转发路由器标识BFR-ID；BIER信息还包括如下一个或多个：子域信息；位索引转发表标识；位串长度。
在一个实施例中，第一确定模块41，设置为包括如下一个或多个：
获取第二通信节点和第三通信节点的BIER信息，并基于所述第二通信节点和所述第三通信节点的BIER信息确定第一转发表项；获取第二通信节点的BIER信息，并基于所述第二通信节点的BIER信息确定第一转发表项；获取第二通信节点、第三通信节点和第四通信节点的BIER信息，并基于所述第二通信节点、第三通信节点和第四通信节点的BIER信息确定第一转发表项；获取第二通信节点和第四通信节点的BIER信息，并基于所述第二通信节点和所述第四通信节点的BIER信息确定第一转发表项。
在一个实施例中，获取模块42传输BIER报文，包括：
通过所述第一通信节点的BIER转发平面，传输BIER报文，所述第一通信节点的BIER转发平面基于第三通信节点的路由前缀在所述第一通信节点所属自治系统中的路由能力确定。
在一个实施例中，在第三通信节点的路由前缀在所述第一通信节点所属自治系统中可路由的情况下，所述BIER转发平面包括所述第一通信节点所属自治系统的BIER转发平面扩展到第三通信节点上后形成的转发平面；在第三通信节点的路由前缀在所述第一通信节点所属自治系统中不可路由的情况下，所述BIER转发平面包括所述第一通信节点和第二通信节点所属自治系统形成的转发平面。
在一个实施例中，在所获取的组播流量为第四通信节点感兴趣的组播流量、跨域方式为可选方式Option B，且第三通信节点的路由前缀在所述第一通信节点所属自治系统中可路由的情况下，BIER报文的报文头中目的位串包括第三通信节点的BFR-ID；在所获取的组播流量为第四通信节点感兴趣的组播流量、跨域方式为Option C，且第三通信节点的路由前缀在所述第一通信节点所属自治系统中可路由的情况下，所述BIER报文的报文头进行两层封装，内层BIER头中目的位串包括第四通信节点的BFR-ID，外层BIER头中目的位串包括第三通 信节点的BFR-ID，所述外层BIER头的协议字段根据所述内层BIER头的封装形式确定；在所获取的组播流量为第四通信节点感兴趣的组播流量、跨域方式为Option B，且第三通信节点的路由前缀在所述第一通信节点所述自治系统中不可路由的情况下，所述BIER报文的报文头中目的位串包括第二通信节点的BFR-ID；在所获取的组播流量为第四通信节点感兴趣的组播流量、跨域方式为Option C，且第三通信节点的路由前缀在所述第一通信节点所述自治系统中不可路由的情况下，所述BIER报文的报文头进行两层封装，内层BIER头中目的位串包括第四通信节点的BFR-ID，外层BIER头中目的位串包括第二通信节点的BFR-ID，所述外层BIER头的协议字段根据所述内层BIER头的封装形式确定。
在一个实施例中，该装置，还包括：传输模块，设置为：
获取接收端节点发送的感兴趣信息，所述接收端节点为第二通信节点或第四通信节点，所述接收端节点发送的感兴趣信息指示第四通信节点感兴趣的组播流量或组播流量所属虚拟专用网络；向所述接收端节点发送所述感兴趣信息对应的第一标识信息和第一指示信息，所述第一标识信息包括标签或分段标识，所述第一指示信息指示所述第一标识信息由所述第一通信节点发送。
在一个示例性实施方式中，本申请还提供了一种组播流量传输装置，图5为本申请提供的一种组播流量传输装置的结构示意图，如图5所示，本实施例提供的组播流量传输装置可以配置于第二通信节点，该装置包括：发送模块51，设置为向第一通信节点发送ASBR的BIER信息；获取模块52，设置为获取所述第一通信节点发送的BIER报文，所述BIER报文基于第一转发表项确定，所述第一转发表项基于向第一通信节点发送的ASBR的BIER信息确定；传输模块53，设置为基于所述第二通信节点的BIER转发平面的切换信息和第二转发表项，传输所述BIER报文。
本实施例提供的组播流量传输装置用于实现如图2所示的组播流量传输方法，本实施例提供的组播流量传输装置实现原理和技术效果与图2所示的组播流量传输方法类似，此处不再赘述。
在上述实施例的基础上，提出了上述实施例的变型实施例，为了使描述简要，在变型实施例中仅描述与上述实施例的不同之处。
在一个实施例中，所述ASBR的BIER信息包括如下一个或多个：第二通信节点的BIER信息；第三通信节点的BIER信息。
在一个实施例中，在第三通信节点的路由前缀在所述第一通信节点所属自治系统中可路由的情况下，所述BIER转发平面包括所述第一通信节点所属自治系统的BIER转发平面扩展到第三通信节点上后形成的转发平面，所述第二通信 节点的BIER转发平面的切换信息为不切换；在第三通信节点的路由前缀在所述第一通信节点所述自治系统中不可路由的情况下，所述BIER转发平面包括所述第二通信节点与所述第一通信节点形成的转发平面，以及第三通信节点和所述第二通信节点形成的转发平面，所述第二通信节点的BIER转发平面的切换信息为切换。
在一个实施例中，传输模块53，设置为：
在所述第二通信节点的BIER转发平面的切换信息为不切换的情况下，根据第二转发表项中的第一子转发表项转发所述BIER报文，所述第一子转发表项为所述第一通信节点所属自治系统的BIER转发平面扩展到第三通信节点上后形成的转发平面内的转发表项，所述第一子转发表项包括第三通信节点的BIER信息；在所述第二通信节点的BIER转发平面的切换信息为切换的情况下，基于第二转发表项中的第二子转发表项接收所述BIER报文，基于第二转发表项中的第三子转发表项重封装所述BIER报文，传输重封装后的BIER报文，所述第二子转发表项为所述第一通信节点和所述第二通信节点形成转发平面内的转发表项，所述第二转发表项包括所述第二通信节点的BIER信息，所述第三子转发表项为所述第二通信节点和第三通信节点形成的转发平面内的转发表项，所述第三子转发表项包括第三通信节点的BIER信息。
在一个实施例中，传输模块53基于第二转发表项中的第三子转发表项重封装所述BIER报文，包括：
将所述BIER报文的外层BIER头中目的位串更新为第三通信节点的BFR-ID，所述第三通信节点的BFR-ID基于第二转发表项中的第三子转发表项确定；基于第一关联关系，更新所述BIER报文中组播流量的标识信息。
在一个实施例中，该装置，还包括：确定模块，设置为：
确定第一关联关系。
在一个实施例中，该装置，还包括：发送模块，设置为：
获取第三通信节点发送的感兴趣信息；将所述第三通信节点发送的感兴趣信息传输至所述第一通信节点；获取所述第一通信节点发送的所述感兴趣信息对应的第一标识信息和第一指示信息；在BIER转发平面包括第三通信节点和第二通信节点形成的转发平面的情况下，确定所述感兴趣信息的第二标识信息，向所述第三通信节点发送所述第二标识信息和第二指示信息，所述第二指示信息指示所述第二标识信息由所述第二通信节点发送，基于所述第一标识信息、第一指示信息、第二标识信息、和第二指示信息确定第一关联关系，所述第一指示信息指示所述第一标识信息由所述第一通信节点发送；在BIER转发平面包 括所述第一通信节点所属自治系统的BIER转发平面扩展到第三通信节点上后形成的转发平面的情况下，向所述第三通信节点发送所述第一标识信息和第一指示信息。
在一个示例性实施方式中，本申请还提供了一种组播流量传输装置，图6为本申请提供的一种组播流量传输装置的结构示意图，如图6所示，本实施例提供的组播流量传输装置可以配置于第三通信节点，该装置包括：发送模块61，设置为向第二通信节点发送ASBR的BIER信息；获取模块62，设置为获取所述第二通信节点的BIER报文，所述BIER报文为所述第二通信节点基于BIER转发平面的切换信息和第二转发表项传输；传输模块63，设置为根据第二关联关系，传输所述BIER报文。
本实施例提供的组播流量传输装置用于实现如图3所示的组播流量传输方法，本实施例提供的组播流量传输装置实现原理和技术效果与图3所示的组播流量传输方法类似，此处不再赘述。
在上述实施例的基础上，提出了上述实施例的变型实施例，为了使描述简要，在变型实施例中仅描述与上述实施例的不同之处。
在一个实施例中，所述ASBR的BIER信息包括第三通信节点的BIER信息。
在一个实施例中，传输模块63，设置为：
在第三通信节点的路由前缀在第一通信节点所属自治系统中可路由，且跨域方式为Option B的情况下，或在第三通信节点的路由前缀在所述第一通信节点所述自治系统中不可路由且跨域方式为Option B的情况下，基于第二关联关系和第四通信节点的BFR-ID重封装所述BIER报文，传输更新重封装后的BIER报文；在第三通信节点的路由前缀在所述第一通信节点所属自治系统中可路由，且跨域方式为Option C的情况下，或在第三通信节点的路由前缀在所述第一通信节点所述自治系统中不可路由，且跨域方式为Option C的情况下，去除所述BIER报文的外层BIER头，传输去除外层BIER头的BIER报文。
在一个实施例中，传输模块63基于第二关联关系和第四通信节点的BFR-ID重封装所述BIER报文，包括：
基于第二关联关系更新所述BIER报文中组播流量的标识信息；将所述BIER报文头中目的位串设置为第四通信节点的BFR-ID。
在一个实施例中，该装置，还包括：确定模块，设置为：
确定第二关联关系。
在一个实施例中，该装置，还包括：发送模块，设置为：
获取第四通信节点发送的感兴趣消息；将所述第四通信节点发送的感兴趣消息传输至第二通信节点；在接收到反馈信息的情况下，确定所述感兴趣信息的第三标识信息和第三指示信息，向第四通信节点发送所述第三标识信息和所述第三指示信息，第三标识信息包括标签或分段标识，第三指示信息指示所述第三标识信息由第三通信节点发送；在所述反馈信息为第一通信节点发送的第一标识信息和第一指示信息的情况下，基于第一标识信息、第一指示信息、第三标识信息和第三指示信息，确定第二关联关系；在所述反馈信息为所述第二通信节点发送的第二标识信息和第二指示信息的情况下，基于所述第二标识信息、第二指示信息、第三指示信息和第三指示信息，确定第二关联关系。
在一个实施例中，在第三通信节点的路由前缀在第一通信节点所属自治系统中可路由的情况下，所述BIER转发平面包括所述第一通信节点所属自治系统的BIER转发平面扩展到第三通信节点上后形成的转发平面；在第三通信节点的路由前缀在所述第一通信节点所述自治系统中不可路由的情况下，所述BIER转发平面包括第三通信节点和第二通信节点形成的转发平面。
在一个示例性实施方式中，图7为本申请提供的一种通信节点的结构示意图。如图7所示，本申请提供的通信节点，包括一个或多个处理器71和存储装置72；该通信节点中的处理器71可以是一个或多个，图7中以一个处理器71为例；存储装置72用于存储一个或多个程序；所述一个或多个程序被所述一个或多个处理器71执行，使得所述一个或多个处理器71实现如本申请实施例中所述的组播流量传输方法。在执行图1所述的组播流量传输方法时，该通信节点为第一通信节点，在执行图2所述的组播流量传输方法时，该通信节点为第二通信节点，在执行图3所述的组播流量传输时，该通信节点为第三通信节点。
通信节点还包括：通信装置73、输入装置74和输出装置75。
通信节点中的处理器71、存储装置72、通信装置73、输入装置74和输出装置75可以通过总线或其他方式连接，图7中以通过总线连接为例。
输入装置74可用于接收输入的数字或字符信息，以及产生与通信节点的用户设置以及功能控制有关的按键信号输入。输出装置75可包括显示屏等显示设备。
通信装置73可以包括接收器和发送器。通信装置73设置为根据处理器71的控制进行信息收发通信。
存储装置72作为一种计算机可读存储介质，可设置为存储软件程序、计算机可执行程序以及模块，如本申请实施例所述组播流量传输方法对应的程序指令/模块(例如，组播流量传输装置中的第一确定模块41，获取模块42和第二 确定模块43；或组播流量传输装置中的发送模块51、获取模块52和传输模块53；或组播流量传输装置中的发送模块61、获取模块62和传输模块63)。存储装置72可包括存储程序区和存储数据区，其中，存储程序区可存储操作系统、至少一个功能所需的应用程序；存储数据区可存储根据通信节点的使用所创建的数据等。此外，存储装置72可以包括高速随机存取存储器，还可以包括非易失性存储器，例如至少一个磁盘存储器件、闪存器件、或其他非易失性固态存储器件。在一些实例中，存储装置72可包括相对于处理器71远程设置的存储器，这些远程存储器可以通过网络连接至通信节点。上述网络的实例包括但不限于互联网、企业内部网、局域网、移动通信网及其组合。
本申请实施例还提供一种存储介质，所述存储介质存储有计算机程序，所述计算机程序被处理器执行时实现本申请实施例中任一所述的组播流量传输方法。如应用于第一通信节点的组播流量传输方法、应用于第二通信节点的组播流量传输方法和应用于第三通信节点的组播流量传输方法。
应用于第一通信节点的组播流量传输方法包括：
确定第一转发表项，所述第一转发表项包括自治系统边界路由器ASBR的位索引显式复制BIER信息；获取组播流量；基于所述第一转发表项对所述组播流量进行封装，确定并传输BIER报文。
应用于第二通信节点的组播流量传输方法包括：
向第一通信节点发送ASBR的BIER信息；获取所述第一通信节点发送的BIER报文，所述BIER报文基于第一转发表项确定，所述第一转发表项基于向第一通信节点发送的ASBR的BIER信息确定；基于所述第二通信节点的BIER转发平面的切换信息和第二转发表项，传输所述BIER报文。
应用于第三通信节点的组播流量传输方法，包括：
向第二通信节点发送ASBR的BIER信息；获取所述第二通信节点的BIER报文，所述BIER报文为所述第二通信节点基于BIER转发平面的切换信息和第二转发表项传输；根据第二关联关系，传输所述BIER报文。
本申请实施例的计算机存储介质，可以采用一个或多个计算机可读的介质的任意组合。计算机可读介质可以是计算机可读信号介质或者计算机可读存储介质。计算机可读存储介质例如可以是——但不限于——电、磁、光、电磁、红外线、或半导体的系统、装置或器件，或者任意以上的组合。计算机可读存储介质的例子(非穷举的列表)包括：具有一个或多个导线的电连接、便携式计算机磁盘、硬盘、随机存取存储器(Random Access Memory，RAM)、只读存储器(Read Only Memory，ROM)、可擦式可编程只读存储器(Erasable  Programmable Read Only Memory，EPROM)、闪存、光纤、便携式CD-ROM、光存储器件、磁存储器件、或者上述的任意合适的组合。计算机可读存储介质可以是任何包含或存储程序的有形介质，该程序可以被指令执行系统、装置或者器件使用或者与其结合使用。
计算机可读的信号介质可以包括在基带中或者作为载波一部分传播的数据信号，其中承载了计算机可读的程序代码。这种传播的数据信号可以采用多种形式，包括但不限于：电磁信号、光信号或上述的任意合适的组合。计算机可读的信号介质还可以是计算机可读存储介质以外的任何计算机可读介质，该计算机可读介质可以发送、传播或者传输用于由指令执行系统、装置或者器件使用或者与其结合使用的程序。
计算机可读介质上包含的程序代码可以用任何适当的介质传输，包括但不限于：无线、电线、光缆、无线电频率(Radio Frequency，RF)等等，或者上述的任意合适的组合。
可以以一种或多种程序设计语言或其组合来编写用于执行本申请操作的计算机程序代码，所述程序设计语言包括面向对象的程序设计语言—诸如Java、Smalltalk、C++，还包括常规的过程式程序设计语言—诸如“C”语言或类似的程序设计语言。程序代码可以完全地在用户计算机上执行、部分地在用户计算机上执行、作为一个独立的软件包执行、部分在用户计算机上部分在远程计算机上执行、或者完全在远程计算机或服务器上执行。在涉及远程计算机的情形中，远程计算机可以通过任意种类的网络——包括局域网(Local Area Network，LAN)或广域网(Wide Area Network，WAN)——连接到用户计算机，或者，可以连接到外部计算机(例如利用因特网服务提供商来通过因特网连接)。
一般来说，本申请的多种实施例可以在硬件或专用电路、软件、逻辑或其任何组合中实现。例如，一些方面可以被实现在硬件中，而其它方面可以被实现在可以被控制器、微处理器或其它计算装置执行的固件或软件中，尽管本申请不限于此。
本申请的实施例可以通过移动装置的数据处理器执行计算机程序指令来实现，例如在处理器实体中，或者通过硬件，或者通过软件和硬件的组合。计算机程序指令可以是汇编指令、指令集架构(Instruction Set Architecture，ISA)指令、机器指令、机器相关指令、微代码、固件指令、状态设置数据、或者以一种或多种编程语言的任意组合编写的源代码或目标代码。
本申请附图中的任何逻辑流程的框图可以表示程序步骤，或者可以表示相 互连接的逻辑电路、模块和功能，或者可以表示程序步骤与逻辑电路、模块和功能的组合。计算机程序可以存储在存储器上。存储器可以具有任何适合于本地技术环境的类型并且可以使用任何适合的数据存储技术实现，例如但不限于只读存储器(Read-Only Memory，ROM)、随机访问存储器(Random Access Memory，RAM)、光存储器装置和系统(数码多功能光碟(Digital Video Disc，DVD)或光盘(Compact Disk，CD))等。计算机可读介质可以包括非瞬时性存储介质。数据处理器可以是任何适合于本地技术环境的类型，例如但不限于通用计算机、专用计算机、微处理器、数字信号处理器(Digital Signal Processing，DSP)、专用集成电路(Application Specific Integrated Circuit，ASIC)、可编程逻辑器件(Field-Programmable Gate Array，FPGA)以及基于多核处理器架构的处理器。

Claims (27)

  1. 一种组播流量传输方法，应用于第一通信节点，包括：
    确定第一转发表项，所述第一转发表项包括自治系统边界路由器ASBR的位索引显式复制BIER信息；
    获取组播流量；
    基于所述第一转发表项对所述组播流量进行封装，确定并传输BIER报文。
  2. 根据权利要求1所述的方法，其中，所述ASBR的BIER信息包括如下至少一个：第二通信节点的BIER信息，所述第二通信节点为所述第一通信节点所属自治系统的出口ASBR；第三通信节点的BIER信息，所述第三通信节点所属自治系统位于所述第一通信节点所属自治系统的下游；第四通信节点的BIER信息，所述第四通信节点为第三通信节点所属自治系统的出口运营商边缘或出口ASBR。
  3. 根据权利要求2所述的方法，其中，所述BIER信息包括位转发路由器标识BFR-ID以及如下至少一个：子域信息；位索引转发表标识；位串长度。
  4. 根据权利要求1所述的方法，其中，所述确定第一转发表项，包括如下至少一个：
    获取第二通信节点的BIER信息和第三通信节点的BIER信息，并基于所述第二通信节点的BIER信息和所述第三通信节点的BIER信息确定所述第一转发表项；
    获取第二通信节点的BIER信息，并基于所述第二通信节点的BIER信息确定所述第一转发表项；
    获取第二通信节点的BIER信息、第三通信节点的BIER信息和第四通信节点的BIER信息，并基于所述第二通信节点的BIER信息、所述第三通信节点的BIER信息和所述第四通信节点的BIER信息确定所述第一转发表项；
    获取第二通信节点的BIER信息和第四通信节点的BIER信息，并基于所述第二通信节点的BIER信息和所述第四通信节点的BIER信息确定所述第一转发表项。
  5. 根据权利要求1所述的方法，其中，所述传输BIER报文，包括：
    通过所述第一通信节点的BIER转发平面，传输所述BIER报文，所述第一通信节点的BIER转发平面基于第三通信节点的路由前缀在所述第一通信节点所属自治系统中的路由能力确定。
  6. 根据权利要求5所述的方法，其中，
    在所述第三通信节点的路由前缀在所述第一通信节点所属自治系统中可路由的情况下，所述BIER转发平面包括所述第一通信节点所属自治系统的BIER转发平面扩展到所述第三通信节点上后形成的转发平面；
    在所述第三通信节点的路由前缀在所述第一通信节点所属自治系统中不可路由的情况下，所述BIER转发平面包括所述第一通信节点和第二通信节点所属自治系统形成的转发平面。
  7. 根据权利要求1所述的方法，其中，
    在所获取的组播流量为第四通信节点感兴趣的组播流量、跨域方式为可选方式Option B，且第三通信节点的路由前缀在所述第一通信节点所属自治系统中可路由的情况下，所述BIER报文的报文头中的目的位串包括所述第三通信节点的BFR-ID；
    在所获取的组播流量为第四通信节点感兴趣的组播流量、跨域方式为Option C，且第三通信节点的路由前缀在所述第一通信节点所属自治系统中可路由的情况下，所述BIER报文的报文头进行两层封装，内层BIER头中的目的位串包括所述第四通信节点的BFR-ID，外层BIER头中的目的位串包括所述第三通信节点的BFR-ID，所述外层BIER头的协议字段根据所述内层BIER头的封装形式确定；
    在所获取的组播流量为第四通信节点感兴趣的组播流量、跨域方式为Option B，且第三通信节点的路由前缀在所述第一通信节点所述自治系统中不可路由的情况下，所述BIER报文的报文头中的目的位串包括第二通信节点的BFR-ID；
    在所获取的组播流量为第四通信节点感兴趣的组播流量、跨域方式为Option C，且第三通信节点的路由前缀在所述第一通信节点所述自治系统中不可路由的情况下，所述BIER报文的报文头进行两层封装，内层BIER头中的目的位串包括所述第四通信节点的BFR-ID，外层BIER头中的目的位串包括第二通信节点的BFR-ID，所述外层BIER头的协议字段根据所述内层BIER头的封装形式确定。
  8. 根据权利要求1所述的方法，还包括：
    获取接收端节点发送的感兴趣信息，所述接收端节点为第二通信节点或第四通信节点，所述接收端节点发送的感兴趣信息指示所述第四通信节点感兴趣的组播流量或组播流量所属虚拟专用网络；
    向所述接收端节点发送所述感兴趣信息对应的第一标识信息和第一指示信息，所述第一标识信息包括标签或分段标识，所述第一指示信息指示所述第一标识信息由所述第一通信节点发送。
  9. 一种组播流量传输方法，应用于第二通信节点，包括：
    向第一通信节点发送自治系统边界路由器ASBR的位索引显式复制BIER信息；
    获取所述第一通信节点发送的BIER报文，所述BIER报文基于第一转发表项确定，所述第一转发表项基于向所述第一通信节点发送的ASBR的BIER信息确定；
    基于所述第二通信节点的BIER转发平面的切换信息和第二转发表项，传输所述BIER报文。
  10. 根据权利要求9所述的方法，其中，所述ASBR的BIER信息包括如下至少一个：所述第二通信节点的BIER信息；第三通信节点的BIER信息。
  11. 根据权利要求9所述的方法，其中，
    在第三通信节点的路由前缀在所述第一通信节点所属自治系统中可路由的情况下，所述BIER转发平面包括所述第一通信节点所属自治系统的BIER转发平面扩展到所述第三通信节点上后形成的转发平面，所述第二通信节点的BIER转发平面的切换信息为不切换；
    在第三通信节点的路由前缀在所述第一通信节点所述自治系统中不可路由的情况下，所述BIER转发平面包括所述第二通信节点与所述第一通信节点形成的转发平面，以及所述第三通信节点和所述第二通信节点形成的转发平面，所述第二通信节点的BIER转发平面的切换信息为切换。
  12. 根据权利要求9所述的方法，其中，所述基于所述第二通信节点的BIER转发平面的切换信息和第二转发表项，传输所述BIER报文，包括：
    在所述第二通信节点的BIER转发平面的切换信息为不切换的情况下，根据所述第二转发表项中的第一子转发表项转发所述BIER报文，所述第一子转发表项为所述第一通信节点所属自治系统的BIER转发平面扩展到第三通信节点上后形成的转发平面内的转发表项，所述第一子转发表项包括所述第三通信节点的BIER信息；
    在所述第二通信节点的BIER转发平面的切换信息为切换的情况下，基于所述第二转发表项中的第二子转发表项接收所述BIER报文，基于所述第二转发表项中的第三子转发表项重封装所述BIER报文，传输重封装后的BIER报文，所述第二子转发表项为所述第一通信节点和所述第二通信节点形成的转发平面内的转发表项，所述第二转发表项包括所述第二通信节点的BIER信息，所述第三子转发表项为所述第二通信节点和第三通信节点形成的转发平面内的转发表项，所述第三子转发表项包括所述第三通信节点的BIER信息。
  13. 根据权利要求12所述的方法，其中，所述基于所述第二转发表项中的第三子转发表项重封装所述BIER报文，包括：
    将所述BIER报文的外层BIER头中的目的位串更新为所述第三通信节点的位转发路由器标识BFR-ID，所述第三通信节点的BFR-ID基于所述第二转发表项中的所述第三子转发表项确定；
    基于第一关联关系，更新所述BIER报文中的组播流量的标识信息。
  14. 根据权利要求13所述的方法，还包括：
    确定所述第一关联关系。
  15. 根据权利要求14所述的方法，还包括：
    获取所述第三通信节点发送的感兴趣信息；
    将所述第三通信节点发送的感兴趣信息传输至所述第一通信节点；
    获取所述第一通信节点发送的所述感兴趣信息对应的第一标识信息和第一指示信息；
    在所述BIER转发平面包括所述第一通信节点所属自治系统的BIER转发平面扩展到所述第三通信节点上后形成的转发平面的情况下，向所述第三通信节点发送所述第一标识信息和所述第一指示信息；
    所述确定所述第一关联关系，包括：
    在所述BIER转发平面包括第三通信节点和第二通信节点形成的转发平面的情况下，确定所述感兴趣信息的第二标识信息，向所述第三通信节点发送所述第二标识信息和第二指示信息，所述第二指示信息指示所述第二标识信息由所述第二通信节点发送，基于所述第一标识信息、所述第一指示信息、所述第二标识信息、和所述第二指示信息确定所述第一关联关系，所述第一指示信息指示所述第一标识信息由所述第一通信节点发送。
  16. 一种组播流量传输方法，应用于第三通信节点，包括：
    向第二通信节点发送自治系统边界路由器ASBR的位索引显式复制BIER信息；
    获取所述第二通信节点的BIER报文，所述BIER报文为所述第二通信节点基于BIER转发平面的切换信息和第二转发表项传输；
    根据第二关联关系，传输所述BIER报文。
  17. 根据权利要求16所述的方法，其中，所述ASBR的BIER信息包括所述第三通信节点的BIER信息。
  18. 根据权利要求16所述的方法，其中，所述根据第二关联关系，传输所述BIER报文，包括：
    在所述第三通信节点的路由前缀在第一通信节点所属自治系统中可路由，且跨域方式为可选方式Option B的情况下，或在所述第三通信节点的路由前缀在第一通信节点所述自治系统中不可路由且跨域方式为Option B的情况下，基于所述第二关联关系和第四通信节点的位转发路由器标识BFR-ID重封装所述BIER报文，传输重封装后的BIER报文；
    在所述第三通信节点的路由前缀在第一通信节点所属自治系统中可路由，且跨域方式为Option C的情况下，或在所述第三通信节点的路由前缀在第一通信节点所述自治系统中不可路由，且跨域方式为Option C的情况下，去除所述BIER报文的外层BIER头，传输去除外层BIER头的BIER报文。
  19. 根据权利要求18所述的方法，其中，所述基于所述第二关联关系和第四通信节点的BFR-ID重封装所述BIER报文，包括：
    基于所述第二关联关系更新所述BIER报文中的组播流量的标识信息；
    将所述BIER报文头中的目的位串设置为所述第四通信节点的BFR-ID。
  20. 根据权利要求16所述的方法，还包括：
    确定所述第二关联关系。
  21. 根据权利要求16所述的方法，还包括：
    获取第四通信节点发送的感兴趣消息；
    将所述第四通信节点发送的感兴趣消息传输至所述第二通信节点；
    在接收到反馈信息的情况下，确定所述感兴趣信息的第三标识信息和第三指示信息，向所述第四通信节点发送所述第三标识信息和所述第三指示信息，所述第三标识信息包括标签或分段标识，所述第三指示信息指示所述第三标识信息由所述第三通信节点发送；
    在所述反馈信息为第一通信节点发送的第一标识信息和第一指示信息的情况下，基于所述第一标识信息、所述第一指示信息、所述第三标识信息和所述第三指示信息，确定所述第二关联关系；
    在所述反馈信息为所述第二通信节点发送的第二标识信息和第二指示信息的情况下，基于所述第二标识信息、所述第二指示信息、所述第三指示信息和所述第三指示信息，确定所述第二关联关系。
  22. 根据权利要求16所述的方法，其中，
    在所述第三通信节点的路由前缀在第一通信节点所属自治系统中可路由的情况下，所述BIER转发平面包括所述第一通信节点所属自治系统的BIER转发平面扩展到所述第三通信节点上后形成的转发平面；
    在所述第三通信节点的路由前缀在所述第一通信节点所述自治系统中不可路由的情况下，所述BIER转发平面包括所述第三通信节点和所述第二通信节点形成的转发平面。
  23. 一种组播流量传输装置，配置于第一通信节点，包括：
    第一确定模块，设置为确定第一转发表项，所述第一转发表项包括自治系统边界路由器ASBR的位索引显式复制BIER信息；
    获取模块，设置为获取组播流量；
    第二确定模块，设置为基于所述第一转发表项对所述组播流量进行封装，确定并传输BIER报文。
  24. 一种组播流量传输装置，配置于第二通信节点，包括：
    发送模块，设置为向第一通信节点发送自治系统边界路由器ASBR的位索引显式复制BIER信息；
    获取模块，设置为获取所述第一通信节点发送的BIER报文，所述BIER报文基于第一转发表项确定，所述第一转发表项基于向所述第一通信节点发送的ASBR的BIER信息确定；
    传输模块，设置为基于所述第二通信节点的BIER转发平面的切换信息和第二转发表项，传输所述BIER报文。
  25. 一种组播流量传输装置，配置于第三通信节点，包括：
    发送模块，设置为向第二通信节点发送自治系统边界路由器ASBR的位索引显式复制BIER信息；
    获取模块，设置为获取所述第二通信节点的BIER报文，所述BIER报文为所述第二通信节点基于BIER转发平面的切换信息和第二转发表项传输；
    传输模块，设置为根据第二关联关系，传输所述BIER报文。
  26. 一种通信节点，包括：
    至少一个处理器；
    存储装置，设置为存储至少一个程序；
    当所述至少一个程序被所述至少一个处理器执行，使得所述至少一个处理器实现如权利要求1-22任一项所述的组播流量传输方法。
  27. 一种存储介质，存储有计算机程序，所述计算机程序被处理器执行时实现权利要求1-22任一项所述的组播流量传输方法。
PCT/CN2020/135268 2020-04-03 2020-12-10 组播流量传输方法、装置、通信节点及存储介质 WO2021196717A1 (zh)

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