WO2016188501A1 - 一种实现比特位索引显示复制的方法及比特位转发路由器 - Google Patents

一种实现比特位索引显示复制的方法及比特位转发路由器 Download PDF

Info

Publication number
WO2016188501A1
WO2016188501A1 PCT/CN2016/086462 CN2016086462W WO2016188501A1 WO 2016188501 A1 WO2016188501 A1 WO 2016188501A1 CN 2016086462 W CN2016086462 W CN 2016086462W WO 2016188501 A1 WO2016188501 A1 WO 2016188501A1
Authority
WO
WIPO (PCT)
Prior art keywords
bier
bit
information
tlv
sub
Prior art date
Application number
PCT/CN2016/086462
Other languages
English (en)
French (fr)
Inventor
王翠
张征
胡方伟
黄孙亮
Original Assignee
中兴通讯股份有限公司
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
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 EP16799388.0A priority Critical patent/EP3364614A4/en
Priority to JP2018518734A priority patent/JP6506475B2/ja
Publication of WO2016188501A1 publication Critical patent/WO2016188501A1/zh

Links

Images

Classifications

    • 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
    • H04L45/50—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
    • H04L45/52—Multiprotocol routers

Definitions

  • This document relates to, but is not limited to, the field of IP multicast technology, and in particular, to a method for implementing bit-bit index display replication and a bit-bit forwarding router.
  • the BIER (Bit Index Explicit Replication) technology is a multicast technology that has been studied in the Internet Engineering Task Force (IETF) in the past two years.
  • the basic principle is that each A node in a BIER domain is assigned a unique BFR-id (Bit-Forwarding Router Identifier), and each bit in the bit string (BitString) corresponds to a BFR-id.
  • BitSting corresponding to BFR-1 with BFR-id of 1 is 00001
  • BitSting corresponding to BFR-2 with BFR-id of 2 is 00010, and so on.
  • BFR-1 is used as a BFIR (Bit-Forwarding Ingress Router).
  • BFR-1 determines which BFERs (Bit-Forwarding Egress Router, bits) in some way.
  • the bit forwarding egress router) needs this multicast traffic. For example, if BFR-2 and BFR-3 are required to obtain multicast traffic, the BFR-id corresponding to the BFERs that need this multicast traffic is combined into a bit string BitString 00110 encapsulation.
  • the BIFT Bit Index Forwarding Table
  • IGP Interior Gateway Protocol
  • BFR-5 forwarding with BFR-id of 5
  • BFR-5 can also be connected to BFR-4.
  • BFR-2, BFR-3, and BFR-4 interact with the receiver 2, the receiver 3, and the receiver 4, respectively.
  • Sub-domain Used to represent different BIER topologies, which can correspond to OSPF (Open Shortest Path First)/ISIS (Intermediate System-to-Intermediate System).
  • OSPF Open Shortest Path First
  • ISIS Intermediate System-to-Intermediate System
  • Each sub-domain is represented by a sub-domain-id, with a value of [0-255] and a length of 8 bits.
  • Bit-Frequency Forwarding Router Prefix (BFR-prefix): The address information of each BFR node can be IPv4 or IPv6. The address information of each BFR is unique within a BIER domain, which is equivalent to the Router-id. BFR-prefix is generally the loopback address of the BFR device.
  • Bit Forwarding Router Identifier (BFR-id): The ID information assigned to each BFR node is a natural number and the same BFR. Different BFR-ID information can be assigned in different sub-domains. The value is [1-65535] and the length is 16bits.
  • the BFR-id is identified by the format of ⁇ SI:XYZW>, where SI is the Set Identifier, which is described below. XYZW identifies BitString (bit string). It can be seen that the length of BitStringLength in this format is 4.
  • Bit String Length (BitStringLength, referred to as BSL): The length of the bit string when BIER technology is forwarded.
  • the minimum size is 64 bits, which are 128, 256, 512, 1024, 2048 and 4096 bits in total. It can be identified by 4 bits in the packet. For example, when the BSL is 64, the packet is marked with 0001. When the BSL is 128, the packet is identified by 0010. When the BSL is 256, the packet is identified by 0011. When the BSL is 512, the packet is identified by 0100. When the BSL is 1024, the packet is identified by 0101. When the BSL is 2048, the packet is identified by 0110. When the BSL is 4096, the packet is used with 0111. logo.
  • SI Set Identifier
  • the second position of BitString is 1, so at this time, the BFR whose BFR-id is 10 is ⁇ 10:0010> as indicated by ⁇ SI:XYZW>.
  • the BFR with BFR-id of 8 is ⁇ 01:1000> as indicated by ⁇ SI:XYZW>.
  • Label When the BIER package is an MPLS (Multi-Protocol Label Switching) package, in addition to the package BIER header, it needs to be externally packaged in the BIER header. Label header. This tag is allocated per BFR and has a local meaning. This tag is not a tag assigned to the FEC (Forwarding Equivalence Class), but a triplet allocation for ⁇ sub-domain/BSL/SI> per BFR. Labels, any one element is different, the assigned labels are different, and then, each BFR device advertises the label information through the IGP protocol. Then, along the way BFR, a corresponding label forwarding table is formed according to each ⁇ sub-domain/BSL/SI>.
  • MPLS Multi-Protocol Label Switching
  • the IGP can distribute multiple tags to different SIs at a time.
  • the definition of this label is different from the MPLS label in the traditional sense, and this label is not advertised through the BGP (Border Gateway Protocol) or MPLS protocol, but is advertised together when the BIER basic information is advertised through the IGP protocol.
  • the format of the packet header encapsulated in the packet forwarding is as shown in FIG. 2, including an outer Ethernet header, an MPLS label, a BIER header, and a Payload (payload).
  • the BIER header encapsulated by the MPLS label header is encapsulated.
  • the text format is shown in Figure 3.
  • the intermediate node obtains the information of the corresponding sub-domain/BSL/SI and the BFR-id by using the search tag, and uses the information to perform index search for the corresponding BIER forwarding table BIFT, and then searches for the matching forwarding entry in the forwarding table BIFT according to the value of the BitString.
  • the next hop information is then repackaged with the label header and the BIER header to forward the message to the next hop.
  • the currently supported IGP mainly includes the IS-IS protocol and the OSPF protocol.
  • the IS-IS protocol extends the IS-IS LSA to support the BIER technology.
  • the OSPF protocol extends the OSPF LSA (Link-State Advertisement) in order to support the BIER technology.
  • BIER info sub-TLV sub-type-length-value
  • the carried BIER MPLS Encapsulation (package) sub -sub-TLV (Sub-TLV) includes BSL and tag values or tag ranges.
  • BIER MPLS encapsulation does not support label distribution protocols such as BGP or MPLS at the label level, but only uses the concept of labels to use label distribution, advertisement, and forwarding in scenarios that do not support BGP/MPLS label distribution protocols. Full set of capabilities.
  • This application will bring certain solutions in a complex multi-topology, multi-sub-domain (multi-domain), multi-set multicast network.
  • the advantages For example, to improve the efficiency of network lookup table, because the matching of individual elements of the label is easier than matching the ⁇ sub-domain-id, BSL, Set Identifier> triples.
  • the introduction of the label concept brings complexity to the control plane, and also adds forwarding at the MPLS plane to the forwarding plane.
  • the multicast source is relatively fixed, and the egress router of the multicast domain is relatively fixed.
  • the embodiment of the invention provides a method for implementing multicast and a bit-bit forwarding router, which can support the MPLS control plane and the data plane in the reduced BIER domain.
  • a method for implementing a bit-bit index display copy BIER, which is applied to a bit-bit forwarding router of a BIER domain including:
  • Encapsulating BIER related information including the bit length information in a type-length-value TLV of the same BIER information
  • the TLV of the BIER information is advertised by a routing protocol.
  • bit string length information includes one or more bit string lengths.
  • the BIER related information further includes: sub-domain identification information, set identification information, and an identifier of the bit forwarding router.
  • the BIER related information further includes: multi-topology identifier information.
  • the TLV of the BIER information further includes a label identifier, when the label identifier is set, indicating compatibility and use of a BIER multi-protocol label switching MPLS encapsulation sub-TLV; when the label identifier is not set, indicating Do not use the BIER MPLS Encapsulation Sub-TLV.
  • the routing protocol includes any one of the following protocols:
  • the routing protocol supports an IPv4 network protocol and/or an IPv6 network protocol.
  • a bit-bit forwarding router comprising:
  • Encapsulating module configured to encapsulate BIER related information including the bit length information in a type-length-value TLV of the same BIER information;
  • the notification module is configured to advertise the TLV of the BIER information through a routing protocol.
  • bit string length information acquired by the acquiring module includes one or more bit bit lengths.
  • the BIER related information further includes: sub-domain identification information, set identification information, and an identifier of the bit forwarding router.
  • the TLV of the BIER information encapsulated by the encapsulating module further includes a label identifier, when the label identifier is set, indicating compatibility and use of a BIER multi-protocol label switching MPLS encapsulation sub-TLV; when the label is When the flag is not set, it means that the BIER MPLS encapsulation sub-TLV is not used.
  • a method for implementing a bit-bit index display copy BIER, which is applied to a bit-bit forwarding router of a BIER domain including:
  • the same type-length-value TLV of the BIER information is encapsulated with BIER related information including the bit length information;
  • bit string length information includes one or more bit string lengths.
  • the BIER related information further includes:
  • Subdomain identification information Subdomain identification information, set identification information, and an identifier of a bit forwarding router that transmits the BIER information.
  • the BIER related information further includes: multi-topology identifier information.
  • the broadcast-unknown-multicast BUM packet is received, and the BIER-related information is encapsulated in the BIER packet header of the BUM packet, and the multicast packet is forwarded according to the BIER forwarding rule.
  • processing the BIER information includes:
  • Parsing the label identifier included in the TLV of the BIER information, and when the label identifier is set, is compatible with and using the BIER multi-protocol label exchange MPLS encapsulation sub-TLV; when the label identifier is not set, the BIER MPLS encapsulation is not used. Sub-TLV.
  • a bit-bit forwarding router comprising:
  • a receiving module configured to receive BIER information, where the same type, length, and value TLV of the BIER information is encapsulated with BIER related information including the bit length information;
  • a processing module configured to process the BIER information.
  • bit string length information received by the receiving module includes one or more bit string lengths.
  • the BIER related information received by the receiving module further includes: sub-domain identification information, set identification information, and an identifier of a bit forwarding router that sends the BIER information.
  • bit forwarding router further includes:
  • the forwarding module is configured to receive the broadcast-unknown-multicast BUM packet, and encapsulate the BIER-related information in the BIER packet header of the BUM packet, and forward the multicast packet according to the BIER forwarding rule.
  • the processing module, the processing the BIER information comprises: parsing a label identifier included in a TLV of the BIER information, and when the label identifier is set, compatible and using a BIER multi-protocol label switching MPLS encapsulation sub-TLV When the tag identifier is not set, the BIER MPLS encapsulation sub-TLV is not used.
  • a computer readable storage medium storing computer executable instructions for performing the above method.
  • the embodiment of the present invention provides a method for implementing multicast and a bit-bit forwarding router.
  • the BIER technology implements bit-level index display replication in a non-MPLS network, which can reduce the support for the MPLS control plane and data plane in the BIER domain.
  • FIG. 1 is a schematic diagram of a related art BIER technical architecture
  • FIG. 2 is a schematic diagram of a data plane of a related art BIER-MPLS package
  • FIG. 3 is a schematic diagram showing the structure of a BIER packet header in a BIER-MPLS encapsulation of the related art
  • FIG. 4 is a schematic diagram of a related art IS-IS protocol extension implementing a BIER control plane
  • FIG. 5 is a schematic diagram of a related art OSPF protocol extension implementing a BIER control plane
  • FIG. 6 is a schematic diagram of a BIER-MPLS forwarding principle of the related art
  • FIG. 7 is a flowchart of a method for implementing multicast on a sending side according to an embodiment of the present invention.
  • FIG. 8 is a schematic diagram of a bit-bit forwarding router on a transmitting side according to an embodiment of the present invention.
  • FIG. 9 is a flowchart of a method for implementing multicast on a receiving side according to an embodiment of the present invention.
  • FIG. 10 is a schematic diagram of a bit-bit forwarding router on a receiving side according to an embodiment of the present invention.
  • FIG. 11 is a schematic diagram of a reference format 1 for carrying BIER information based on an IS-IS protocol according to Embodiment 1 of the present invention
  • FIG. 12 is a schematic diagram of a reference format 2 for extending BIER information based on the IS-IS protocol according to the first embodiment of the present invention
  • FIG. 13 is a schematic diagram of a reference format for carrying BIER information based on an OSPF protocol extension according to Embodiment 2 of the present invention.
  • FIG. 14 is a schematic diagram of a reference format for carrying BIER information based on a BGP protocol according to Embodiment 4 of the present invention.
  • FIG. 15 is a schematic diagram of a BIER header reference format according to Embodiment 5 of the present invention.
  • FIG. 16 is a schematic diagram of implementing BIER forwarding according to Embodiment 5 of the present invention.
  • the embodiment of the present invention attempts to introduce a simplified version of the BIER technology that does not need to support tags in a multicast network as simple as IPTV, and implements multicast traffic forwarding in an IP network.
  • the forwarding principle of BIER-MPLS in the related art is shown in FIG. 6, which will be described later.
  • FIG. 7 is a flowchart of a method for implementing a BIER on a transmitting side according to an embodiment of the present invention. As shown in FIG. 7, the method in this embodiment includes steps 11-13:
  • Step 11 Obtain bit length information related to the BIER on the node (ie, the node to which the method is applied);
  • Step 12 Encapsulate BIER related information including the bit length information in a TLV (type-length-value) of the same BIER information;
  • Step 13 Announce the BIER information by using a routing protocol.
  • bit string length information includes one or more bit string lengths.
  • the BIER related information further includes: one or more of sub-domain identification information, set identification information, and identifier of the bit forwarding router, and multi-topology identification information.
  • the TLV of the BIER information further includes a label identifier, when the label identifier is set, indicating compatibility and use of a BIER multi-protocol label switching MPLS encapsulation sub-TLV; when the label identifier is not set, indicating Do not use the BIER MPLS Encapsulation Sub-TLV.
  • the routing protocol includes any one of the following protocols: an IS-IS protocol, an OSPF protocol, and a border gateway protocol.
  • the routing protocol supports an IPv4 network protocol and/or an IPv6 network protocol.
  • FIG. 8 is a schematic diagram of a bit-bit forwarding router on a transmitting side according to an embodiment of the present invention. As shown in FIG. 8, the bit-bit forwarding router in this embodiment includes:
  • Obtaining a module configured to obtain bit length information related to the BIER on the node (ie, the router);
  • Encapsulating module configured to encapsulate BIER related information including the bit length information In the TLV of the same BIER information
  • the notification module is configured to advertise the BIER information through a routing protocol.
  • bit string length information includes one or more bit string lengths.
  • the TLV of the BIER information encapsulated by the encapsulating module further includes a label identifier, when the label identifier is set, indicating compatibility and use of a BIER multi-protocol label switching MPLS encapsulation sub-TLV; when the label is When the flag is not set, it means that the BIER MPLS encapsulation sub-TLV is not used.
  • FIG. 9 is a flowchart of a method for implementing a BIER on the receiving side according to an embodiment of the present invention. As shown in FIG. 9, the method in this embodiment includes steps 21-22:
  • Step 21 Receive BIER information, where the same TLV of the BIER information is encapsulated with BIER related information including the bit length information.
  • Step 22 Process the BIER information.
  • bit string length information includes one or more bit string lengths.
  • the BIER related information further includes:
  • Subdomain identification information set identification information, and an identifier of a bit forwarding router that transmits the BIER information, and multi-topology identification information.
  • the foregoing method may further include:
  • BUM Broadcast-Unkown-Multicast
  • processing the BIER information may include:
  • Parsing the label identifier included in the TLV of the BIER information, and when the label identifier is set, is compatible with and using the BIER multi-protocol label exchange MPLS encapsulation sub-TLV; when the label identifier is not set, the BIER MPLS encapsulation is not used. Sub-TLV.
  • FIG. 10 is a schematic diagram of a bit-bit forwarding router on a receiving side according to an embodiment of the present invention. As shown in FIG. 10, the bit-bit forwarding router in this embodiment includes:
  • a receiving module configured to receive a bit index display copy BIER information, where the same TLV of the BIER information is encapsulated with BIER related information including the bit length information;
  • a processing module configured to process the BIER information.
  • the bit length information received by the receiving module includes one or more bit string lengths.
  • the processing module processing the BIER information may include: parsing a label identifier included in a TLV of the BIER information, and when using the label identifier, compatibility and using a BIER multi-protocol label switching MPLS encapsulation TLV; when the tag identifier is not set, the BIER MPLS encapsulation sub-TLV is not used.
  • bit forwarding router may further include:
  • the forwarding module is configured to receive the BUM message, and encapsulate the BIER related information in the BIER packet header of the BUM message, and forward the multicast packet according to the BIER forwarding rule.
  • BFR3 performs the same update of the MPLS header + BIER header, and forwards the packet to BFER4.
  • BFER4 parses the ⁇ sub-domain/BSL/SI> ternary information according to the label information, and strips the MPLS header + BIER. Header, then forward the message out of the BIER domain.
  • the MPLS header generally includes an MPLS Label.
  • the forwarding between multiple BFRs is no longer dependent on the MPLS label, and only needs to be forwarded according to the BIER header, which simplifies the network processing flow. It is suitable for deploying BIER technology in a simple network that does not need to support MPLS labels.
  • the Extended IP reachability (TLV type 135) and Multi-Topology Reachable IPv4 Prefixes in the IS-IS protocol are available.
  • Extended to IPv4 prefix) TLV (TLV type 235); and IPv6Reachability for IS-IS for IPv6 networks The TLV (TLV type is 236) and Multi-Topology Reachable IPv6 Prefixes TLV (TLV type is 237) are extended.
  • the extended format is shown in Figure 4.
  • the embodiment of the present invention attempts to support the MPLS control plane and the data plane in the reduced BIER domain in a relatively simple multicast network, and only uses the BIER header to forward the data plane. Therefore, the IS-IS BIER Info sub-TLV defined in FIG. 4 is modified, and the sub-TLV packet reference format carrying the BIER information based on the IS-IS protocol may be as shown in FIG. 11 or as shown in FIG. 12 .
  • two new fields can be defined.
  • a new BIER Info sub-TLV can be defined.
  • two new fields are defined.
  • M field indicating whether to use MPLS-BIER, that is, whether to carry the BIER MPLS Encapsulation sub-sub-TLV; when the M field is set to 1, it means to use MPLS-BIER, that is, compatible and use the carried BIER MPLS Encapsulation sub- Sub-TLV; When the M field is set to 0, it means that MPLS-BIER is not used, that is, the BIER MPLS Encapsulation sub-sub-TLV is not carried or used, and the BIER header is directly used for forwarding.
  • BSL identification field which identifies one or more BitStringLength. This field is valid when the M field is 0.
  • the M field When the M field is 1, it is determined according to the rule that the field is valid at this time, or the bit length information field carried in the BIER MPLS Encapsulation sub-sub-TLV is valid. In this way, when the BIER information is forwarded, it can be forwarded without relying on MPLS.
  • the BSL identification field can be implemented by using the following reference format, and each bit identifies one BSL. E.g:
  • 00000001 identifies the BSL as 64bits
  • 00000010 identifies the BSL as 128 bits
  • 00000100 identifies the BSL as 215 bits
  • 00100000 identifies the BSL as 2048bits
  • 01000000 identifies the BSL as 4096 bits
  • the BSL identifier indicates the currently supported BSL. It is 64bits and 4096bits; if there are 3 bits in the BSL identifier, for example, 00011100, it means that the currently supported BSL is 1024bits, 512bits and 256bits.
  • the OSPF protocol is extended to implement the BIER control plane
  • the IPv4 network is extended under the Extended Prefix TLV of the OSPFv2 protocol
  • the extended LSA TLV of OSPFv3 is extended, and the extended format can be seen in FIG. 5.
  • the embodiment of the present invention attempts to support the MPLS control plane and the data plane in the reduced BIER domain in a relatively simple multicast network, and only uses the BIER header to forward the data plane. Therefore, the BIER information sub-TLV extended by the OSPF protocol defined in FIG. 5 is modified.
  • the reference format of the sub-TLV packet carrying the BIER information based on the OSPF protocol may also be as shown in FIG. 11, and may also be as shown in FIG. 12 or 13 is shown.
  • BIER Info sub-TLV for OSPF (see the OSPF protocol extended BIER information sub-TLV) (as shown in Figure 5).
  • OSPF protocol extended BIER information sub-TLV for OSPF
  • two new fields can be defined.
  • a new BIER Info sub-TLV can be defined.
  • two new fields are defined.
  • M field indicating whether to use MPLS-BIER, that is, whether to carry the BIER MPLS Encapsulation sub-sub-TLV; when the M field is set to 1, it means to use MPLS-BIER, that is, compatible and use the carried BIER MPLS Encapsulation sub- Sub-TLV; When the M field is set to 0, it means that MPLS-BIER is not used, that is, the BIER MPLS Encapsulation sub-sub-TLV is not carried or used, and the BIER header is directly used for forwarding.
  • BSL identification field which indicates one or more bit string lengths (BitStringLength). This field is valid when the M field is 0. When the M field is 1, it is determined according to the rule that the field is valid at this time, or the bit length information field carried in the BIER MPLS Encapsulation sub-sub-TLV is valid.
  • the OSPF protocol can support the establishment of an OSPF virtual link on the BFIR and BFER devices in the BIER domain.
  • the extended TLV information mentioned in the embodiment of the present invention is directly sent to the edge device of the BIER domain through the virtual link, and the BFIR and the BFER device directly interact with each other.
  • BIER information reduces the information storage of intermediate nodes in the BIER domain.
  • the advertised format is still a packet reference format that carries the BIER information based on the OSPF protocol extension. It can also be as shown in FIG. 11 or as shown in FIG. 12 or FIG.
  • two new fields can be defined.
  • a new BIER Info sub-TLV can be defined.
  • two new fields are defined.
  • M field indicating whether to use MPLS-BIER, that is, whether to carry the BIER MPLS Encapsulation sub-sub-TLV; when the M field is set to 1, it indicates that MPLS-BIER is used, that is, compatibility and use carries BIER MPLS Encapsulation sub-sub -TLV; When the M field is set to 0, it means that MPLS-BIER is not used, that is, the BIER MPLS Encapsulation sub-sub-TLV is not carried or used, and the BIER header is directly used for forwarding.
  • Another important field is the BSL identification field, which indicates one or more bit string lengths BitStringLength. When the M field is 0, this field is valid. When the M field is 1, it is determined according to the rule that the field is valid at this time, or the bit length information field carried in the BIER MPLS Encapsulation sub-sub-TLV is valid.
  • the BGP protocol can support the establishment of BGP neighbors on the BFIR and BFER devices of the BIER domain.
  • the extended BGP protocol is used to directly send the extended TLV information mentioned in the embodiment of the present invention to the edge device of the BIER domain.
  • the BFIR and the BFER device directly interact with each other.
  • BIER information reduces the information storage of intermediate nodes in the BIER domain.
  • the advertised format is still a packet reference format that carries the BIER information based on the BGP protocol extension, as shown in FIG.
  • BIER TLV of BGP protocol extension two new fields can be defined.
  • a new BIER TLV for BGP can be defined.
  • two new fields are defined.
  • One is the M field, indicating whether to use MPLS-BIER, that is, whether to carry the BIER MPLS Encapsulation sub-sub-TLV (BIER MPLS Encapsulation Sub-TLV); when the M field is set to 1, it means that MPLS-BIER is used, that is, compatible and The BIER MPLS Encapsulation sub-sub-TLV is used.
  • the M field When the M field is set to 0, it means that the MPLS-BIER is not used, that is, the BIER MPLS Encapsulation sub-sub-TLV is not carried or used, and the BIER header is directly used for forwarding.
  • Another important field is the BSL identification field, which indicates one or more bit string lengths BitStringLength. When the M field is 0, this field is valid. When the M field is 1, it is determined according to the rule that the field is valid at this time, or the bit length information field carried in the BIER MPLS Encapsulation sub-sub-TLV is valid.
  • the BIER information extension on the routing protocol in the embodiment of the present invention because the information carried by the MPLS label in the related art is actually the information of the corresponding ⁇ sub-domain/BSL/SI> triplet, so when the MPLS label does not participate in the forwarding When necessary, add ⁇ sub-domain/BSL/SI> triplet information to the BIER header defined in Figure 3.
  • the BIER header reference format defined by the embodiment of the present invention can be as shown in FIG.
  • the packet forwarding process, in conjunction with FIG. 16, may include steps 101-104:
  • Step 101 The ingress node BFIR1 receives the multicast packet, determines the sub-domain and the Set Identifier to which the multicast packet belongs, and the used BSL, and then according to the mapping relationship between the previously obtained multicast address and the BitString (the mapping relationship)
  • the bit sequence 1 corresponding to the multicast packet is determined by the control plane, and the multicast packet needs to be forwarded to the destination node BFER4 and BFER5, and then the BIER header is encapsulated (as shown in FIG. 13). Forward this BIER information.
  • Step 102 After receiving the packet, BFR2 searches for the corresponding BIFT according to the sub-domain information and the Set Identifier information in the BIER header, and the BSL information, and finds that the corresponding next hop neighbor is BFR3 and BFER5, and then copies.
  • the message, an update bit string 2 is a bit string 3, the message is forwarded to BFR3, and an update bit string 2 is a bit string 5, and the message is forwarded to BFER5.
  • Step 103 After receiving the packet, the BFR3 searches for the corresponding BIFT according to the sub-domain information and the Set Identifier information in the BIER header, and the BSL information, and finds that the corresponding next hop neighbor is BFER4, and then updates the bit.
  • the string 3 information is bit string 4 information, and the message is forwarded to BFER4.
  • BFER5 searches for the corresponding BIFT according to the sub-domain information and Set Identifier information in the BIER header and the BSL information, and finds that the local is BFER, then decapsulates the BIER header and forwards the multicast. The message is sent to the corresponding receiving device.
  • Step 104 After receiving the message, the BFER4 searches for the corresponding BIFT according to the sub-domain information and the Set Identifier information in the BIER header, and the BSL information, and finds that the local BFER is the de-encapsulated BIER packet header and the forwarding group. Broadcast the message to the corresponding receiving device.
  • a computer readable storage medium storing computer executable instructions for performing the above method.
  • the embodiment of the invention provides a method for implementing multicast and a bit-bit forwarding router.
  • the BIER technology implements bit-bit index display replication in a non-MPLS network, and can support the MPLS control plane and the data plane in the BIER domain.

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Data Exchanges In Wide-Area Networks (AREA)

Abstract

一种实现组播的方法与比特位转发路由器，该方法包括：获取本节点上与比特位索引显示复制BIER相关的比特位串长度信息；将包括所述比特位串长度信息的BIER相关信息封装在同一个BIER信息的类型-长度-值TLV字段中；通过路由协议通告所述BIER信息的TLV。

Description

一种实现比特位索引显示复制的方法及比特位转发路由器 技术领域
本文涉及但不限于IP组播技术领域，尤其涉及一种实现比特位索引显示复制的方法及比特位转发路由器。
背景技术
BIER(Bit Index Explicit Replication，比特位索引显示复制)技术是近两年在IETF(Internet Engineering Task Force，国际工程任务组)开始研究的组播技术，如图1所示，其基本原理是为每一个BIER域内的节点分配一个唯一的BFR-id(Bit-Forwarding Router Identifier，比特位转发路由器标识)，比特位串(BitString)中的每一位Bit都对应于一个BFR-id。例如，BFR-id为1的BFR-1对应的BitSting是00001，BFR-id为2的BFR-2对应的BitSting是00010，以此类推。当组播报文到达BFR-1时，此时BFR-1作为BFIR(Bit-Forwarding Ingress Router，比特位转发入口路由器)，BFR-1通过某种方式决定哪些BFERs(Bit-Forwarding Egress Router，比特位转发出口路由器)需要这个组播流量，例如，获取到BFR-2和BFR-3需要组播流量，则将这些需要此组播流量的BFERs对应的BFR-id组合成比特位串BitString 00110封装在BIER报文头中，然后通过扩展IGP(Interior Gateway Protocol，内部网关协议)生成的BIFT(Bit Index Forwarding Table，比特位索引转发表)转发此封装有BIER头的组播数据报文；转发时通过BFR-id为5的BFR-5转发；BFR-5还可以和BFR-4连接。其中，BFR-2、BFR-3、BFR-4分别与接收器2、接收器3、接收器4交互。
BIER技术中有几个基本概念：
子域(Sub-domain)：用来表示不同的BIER拓扑，可对应到OSPF(Open Shortest Path First，开放式最短路径优先)/ISIS(Intermediate System-to-Intermediate System，中间系统到中间系统)的多拓扑上，一个BIER域内可以有多个sub-domain，每个sub-domain由子域标识(sub-domain-id)来表示，取值为[0-255]，长度为8bits。
比特位转发路由器前缀(BFR-prefix)：每个BFR节点的地址信息，可以为IPv4或者IPv6，每台BFR的地址信息在一个BIER域内是唯一的，相当于Router-id(路由器标识)。BFR-prefix一般为BFR设备的loopback(环回)地址。
比特位转发路由器标识(BFR-id)：为每个BFR节点所分配的ID信息，是自然数，同一个BFR，在不同的sub-domain中，可以分配不同的BFR-ID信息。取值为[1-65535]，长度为16bits。一般情况下，BFR-id通过<SI:XYZW>的格式标识，其中，SI是Set Identifier(集标识)，下面进行介绍。XYZW标识BitString(比特位串)，可以看出，这个格式中BitStringLength的长度为4。
比特位串长度(BitStringLength，简称BSL)：BIER技术转发时比特位串的长度，最小64位，依次有128，256，512，1024，2048，最大4096位。可以在报文中通过4bits来标识，例如当BSL为64时，报文中用0001标识，当BSL为128时，报文中用0010标识，当BSL为256时，报文中用0011标识,当BSL为512时，报文中用0100标识，当BSL为1024时，报文中用0101标识，当BSL为2048时，报文中用0110标识，当BSL为4096时，报文中用0111标识。
集标识(Set Identifier，简称SI)：当使用的BSL长度不足以包括一个sub-domain所有节点的BFR-id时，比如说，一个sub-domain中有10个节点，但是BSL只有4位时，需要分不同的层，则不同层使用不同的SI来标识。Sub-domain比SI的意义更上层一些。
BFR-id/BSL/SI三者之间的推算关系如下：SI＝(BFR-id-1)/BSL。BP＝(BFR-id-1)modulo(BSL)+1。其中，BP是Bit Position(比特位位置)的缩写，标识此BFR-id属于相应Set(集)的BitString格式。比如，域内有10个节点，BSL为4，计算得到，SI＝(10-1)/BSL＝2，BP＝(BFR-id-1)modulo(BSL)+1＝2，BP为2即标识此时的BitString中第2位置1，故此时，BFR-id为10的BFR通过<SI:XYZW>标识的结果是<10:0010>。同样，BFR-id为8的BFR通过<SI:XYZW>标识的结果是<01:1000>。
标签(Label)：当BIER封装为MPLS(Multi-Protocol Label Switching，多协议标签交换)封装时，除了封装BIER头外，还需要在BIER头外部封装 标签头。该标签为每BFR分配，具有本地意义，该标签不是针对FEC(Forwarding Equivalence Class，转发等价类)分配的标签，而是每BFR上针对<sub-domain/BSL/SI>的三元组分配标签，任何一个元素不一样，分配的标签不一样，进而，由每BFR设备通过IGP协议通告此标签信息。然后沿路BFR根据每<sub-domain/BSL/SI>形成相应的标签转发表。当Sub-domain ID和BSL相同时，IGP可以一次分发多个标签给不同的SI。这个标签的定义不同于传统意义上的MPLS标签，而且此标签不是通过BGP(Border Gateway Protocol，边界网关协议)或者MPLS协议通告，而是通过IGP协议通告BIER基本信息的时候一起通告的。在组播报文进行数据面封装的时候，如果是支持MPLS格式封装，在入口路由器BFIR上需要进行sub-domain/BSL/SI和标签的映射，映射完成后，BIER头中不再需要封装sub-domain/BSL/SI信息，只需要封装上此标签头，另外加上基本的BIER头信息即可。其中，报文转发时封装的报文头格式如图2所示，包括外层以太网头、MPLS标签、BIER头和Payload(有效载荷)；其中，MPLS标签头封装后封装的BIER头的报文格式如图3所示。中间节点通过查找标签获得对应的sub-domain/BSL/SI以及BFR-id的信息，利用这些信息进行索引查找对应的BIER转发表BIFT，再根据BitString的值查找转发表BIFT中匹配的转发表项中下一跳信息，然后重新封装上标签头和BIER头，将报文转发到下一跳。
上面提到，BIFT是基于IGP协议进行扩展的，当前支持扩展的IGP主要包括IS-IS协议和OSPF协议，如图4所示，是IS-IS协议为了支持BIER技术的协议扩展IS-IS LSA；如图5所示，是OSPF协议为了支持BIER技术的技术扩展OSPF LSA(Link-State Advertisement，链路状态通告)。可以看出，协议扩展中携带的BIER info sub-TLV(sub-type-length-value，子类型-长度-值)包括sub-domain-id和BFR-id，携带的BIER MPLS Encapsulation(封装)sub-sub-TLV(子子TLV)包括BSL和标签值或者标签范围。
可见，所谓BIER的MPLS封装，其实并不是标签层面支持BGP或者MPLS等标签分发协议，而只是利用了标签的概念在不支持BGP/MPLS标签分发协议的场景下去使用标签的分发、通告以及转发等全套能力。这个应用，在复杂的多拓扑、多sub-domain(子域)、多Set的组播网络中，会带来一定 的优势。比如说提升网络查表的效率，因为标签单个元素的匹配要比匹配<sub-domain-id，BSL，Set Identifier>三元组要更容易。但是，标签概念的引入给控制面带了复杂性，也给转发面增加了MPLS层面的转发。对于像IPTV(Internet Protocol Television，互联网电视)这种简单的组播应用场景下，组播源相对固定，组播域的出口路由器也相对固定，此种场景下，没有必要使用复杂的MPLS作为控制面和数据面的转发技术。
发明内容
以下是对本文详细描述的主题的概述。本概述并非是为了限制权利要求的保护范围。
本发明实施例提供一种实现组播的方法与比特位转发路由器，可以减径BIER域中对MPLS控制面和数据面的支持。
本发明实施例提供如下技术方案。
一种实现比特位索引显示复制BIER的方法，应用于BIER域的比特位转发路由器，包括：
获取本节点上与BIER相关的比特位串长度信息；
将包括所述比特位串长度信息的BIER相关信息封装在同一个BIER信息的类型-长度-值TLV中；
通过路由协议通告所述BIER信息的TLV。
可选地，所述比特位串长度信息包括一个或多个比特位串长度。
可选地，所述BIER相关信息还包括：子域标识信息、集标识信息和所述比特位转发路由器的标识。
可选地，所述BIER相关信息还包括：多拓扑标识信息。
可选地，所述BIER信息的TLV中还包括标签标识，当所述标签标识置位时，表示兼容和使用BIER多协议标签交换MPLS封装子TLV；当所述标签标识未置位时，表示不使用BIER MPLS封装子TLV。
可选地，所述路由协议包括以下任一种协议：
中间系统到中间系统协议、开放式最短路径优先协议和边界网关协议。
可选地，所述路由协议支持IPv4网络协议和/或IPv6网络协议。
一种比特位转发路由器，包括：
获取模块，设置成获取本节点上与比特位索引显示复制BIER相关的比特位串长度信息；
封装模块，设置成将包括所述比特位串长度信息的BIER相关信息封装在同一个BIER信息的类型-长度-值TLV中；
通告模块，设置成通过路由协议通告所述BIER信息的TLV。
可选地，所述获取模块所获取的所述比特位串长度信息包括一个或多个比特位串长度。
可选地，所述BIER相关信息还包括：子域标识信息、集标识信息和所述比特位转发路由器的标识。
可选地，所述封装模块所封装的所述BIER信息的TLV中还包括标签标识，当所述标签标识置位时，表示兼容和使用BIER多协议标签交换MPLS封装子TLV；当所述标签标识未置位时，表示不使用BIER MPLS封装子TLV。
一种实现比特位索引显示复制BIER的方法，应用于BIER域的比特位转发路由器，包括：
接收BIER信息，所述BIER信息的同一个类型-长度-值TLV中封装有包括所述比特位串长度信息的BIER相关信息；
处理所述BIER信息。
可选地，所述比特位串长度信息包括一个或多个比特位串长度。
可选地，所述BIER相关信息还包括：
子域标识信息、集标识信息和发送所述BIER信息的比特位转发路由器的标识。
可选地，所述BIER相关信息还包括：多拓扑标识信息。
可选地，接收到广播-未知-组播BUM报文，封装所述BIER相关信息在所述BUM报文的BIER报文头中，按照BIER转发规则转发所述组播报文。
可选地，所述处理所述BIER信息包括：
解析所述BIER信息的TLV中包括的标签标识，当所述标签标识置位时，兼容和使用BIER多协议标签交换MPLS封装子TLV；当所述标签标识未置位时，不使用BIER MPLS封装子TLV。
一种比特位转发路由器，包括：
接收模块，设置成接收BIER信息，所述BIER信息的同一个类型\长度\值TLV中封装有包括所述比特位串长度信息的BIER相关信息；
处理模块，设置成处理所述BIER信息。
可选地，所述接收模块所接收的比特位串长度信息包括一个或多个比特位串长度。
可选地，所述接收模块所接收的所述BIER相关信息还包括：子域标识信息、集标识信息和发送所述BIER信息的比特位转发路由器的标识。
可选地，所述的比特位转发路由器，还包括：
转发模块，设置成接收到广播-未知-组播BUM报文，封装所述BIER相关信息在所述BUM报文的BIER报文头中，按照BIER转发规则转发所述组播报文。
可选地，所述处理模块，处理所述BIER信息包括：解析所述BIER信息的TLV中包括的标签标识，当所述标签标识置位时，兼容和使用BIER多协议标签交换MPLS封装子TLV；当所述标签标识未置位时，不使用BIER MPLS封装子TLV。
一种计算机可读存储介质，存储有计算机可执行指令，所述计算机可执行指令用于执行上述方法。
综上，本发明实施例提出一种实现组播的方法与比特位转发路由器，通 过BIER技术在非MPLS网络中实现比特位索引显示复制，可以减径BIER域中对MPLS控制面和数据面的支持。
在阅读并理解了附图和详细描述后，可以明白其它方面。
附图概述
图1是相关技术的BIER技术架构的示意图；
图2是相关技术的BIER-MPLS封装的数据面的示意图；
图3是相关技术的BIER-MPLS封装下BIER报文头的结构的示意图；
图4是相关技术的IS-IS协议扩展实现BIER控制面的示意图；
图5是相关技术的OSPF协议扩展实现BIER控制面的示意图；
图6是相关技术的BIER-MPLS转发原理的示意图；
图7为本发明实施例的发送侧的一种实现组播的方法的流程图；
图8为本发明实施例的发送侧的比特位转发路由器的示意图；
图9为本发明实施例的接收侧的一种实现组播的方法的流程图；
图10为本发明实施例的接收侧的比特位转发路由器的示意图；
图11是本发明实施例一的基于IS-IS协议扩展携带BIER信息的参考格式一的示意图；
图12是本发明实施例一的基于IS-IS协议扩展携带BIER信息的参考格式二的示意图；
图13是本发明实施例二的基于OSPF协议扩展携带BIER信息的参考格式的示意图；
图14为本发明实施例四的基于BGP协议扩展携带BIER信息的参考格式的示意图；
图15为本发明实施例五的BIER头参考格式的示意图；
图16是本发明实施例五的实现BIER转发的示意图。
本发明的实施方式
需要说明的是，在不冲突的情况下，本申请中的实施例及实施例中的特征可以相互任意组合。
本发明实施例试图在像IPTV一样简单的组播网络中，引入简化版的不需要支持标签的BIER技术，实现IP网络中组播流量的转发。相关技术中的BIER-MPLS的转发原理参见图6，后文有描述。
图7为本发明实施例的发送侧的一种实现BIER的方法的流程图，如图7所示，本实施例的方法包括步骤11～13：
步骤11、获取本节点(即应用该方法的节点)上与BIER相关的比特位串长度信息；
步骤12、将包括所述比特位串长度信息的BIER相关信息封装在同一个BIER信息的TLV(type-length-value，类型-长度-值)中；
步骤13、通过路由协议通告所述BIER信息。
可选地，所述比特位串长度信息包括一个或多个比特位串长度。
可选地，所述BIER相关信息还包括：子域标识信息、集标识信息和所述比特位转发路由器的标识，以及多拓扑标识信息中的一项或多项。
可选地，所述BIER信息的TLV中还包括标签标识，当所述标签标识置位时，表示兼容和使用BIER多协议标签交换MPLS封装子TLV；当所述标签标识未置位时，表示不使用BIER MPLS封装子TLV。
可选地所述路由协议包括以下的任一种协议：IS-IS协议、OSPF协议和边界网关协议。
可选地所述路由协议支持IPv4网络协议和/或IPv6网络协议。
图8为本发明实施例的发送侧的比特位转发路由器的示意图，如图8所示，本实施例的比特位转发路由器包括：
获取模块，设置成获取本节点(即本路由器)上与BIER相关的比特位串长度信息；
封装模块，设置成将包括所述比特位串长度信息的BIER相关信息封装 在同一个BIER信息的TLV中；
通告模块，设置成通过路由协议通告所述BIER信息。
可选地，所述比特位串长度信息包括一个或多个比特位串长度。
可选地，所述封装模块所封装的所述BIER信息的TLV中还包括标签标识，当所述标签标识置位时，表示兼容和使用BIER多协议标签交换MPLS封装子TLV；当所述标签标识未置位时，表示不使用BIER MPLS封装子TLV。
图9为本发明实施例的接收侧的一种实现BIER的方法的流程图，如图9所示，本实施例的方法包括步骤21～22：
步骤21、接收BIER信息，所述BIER信息的同一个TLV中封装有包括所述比特位串长度信息的BIER相关信息；
步骤22、处理所述BIER信息。
可选地，所述比特位串长度信息包括一个或多个比特位串长度。
可选地，所述BIER相关信息还包括：
子域标识信息、集标识信息和发送所述BIER信息的比特位转发路由器的标识，以及多拓扑标识信息。
在一可选实施例中，上述方法还可以包括：
接收到BUM(Broadcast-Unkown-Multicast，广播-未知-组播)报文，封装所述BIER相关信息在所述BUM报文的BIER报文头中，按照BIER转发规则转发所述组播报文。
可选地，步骤22中，处理所述BIER信息可以包括：
解析所述BIER信息的TLV中包括的标签标识，当所述标签标识置位时，兼容和使用BIER多协议标签交换MPLS封装子TLV；当所述标签标识未置位时，不使用BIER MPLS封装子TLV。
图10为本发明实施例的接收侧的比特位转发路由器的示意图，如图10所示，本实施例的比特位转发路由器包括：
接收模块，设置成接收比特位索引显示复制BIER信息，所述BIER信息的同一个TLV中封装有包括所述比特位串长度信息的BIER相关信息；
处理模块，设置成处理所述BIER信息。
可选地，所述接收模块所接收的所述比特位串长度信息包括一个或多个比特位串长度。
可选地，，所述处理模块处理所述BIER信息可以包括：解析所述BIER信息的TLV中包括的标签标识，当所述标签标识置位时，兼容和使用BIER多协议标签交换MPLS封装子TLV；当所述标签标识未置位时，不使用BIER MPLS封装子TLV。
在一可选实施例中，所述比特位转发路由器还可以包括：
转发模块，设置成接收到BUM报文，封装所述BIER相关信息在所述BUM报文的BIER报文头中，按照BIER转发规则转发所述组播报文。
下面结合实施示例进行描述。如图6所示，按照相关技术中的BIER-MPLS的转发原理，当BFIR(即BFR1)节点收到组播报文时，会封装上MPLS头+BIER头，然后转发报文到BFR2，BFR2收到报文后，根据标签查找标签转发表获取出标签的信息和BIFT信息，同时，根据标签解析对应该标签的<sub-domain/BSL/SI>三元信息，然后结合BIER头中的BitString(比特位串)查找BIFT，查出下一跳邻居信息后，更新封装上下一跳邻居分发的新的MPLS头+BIER头进行转发。以此类推，BFR3上同理进行MPLS头+BIER头的更新，转发报文到BFER4上，BFER4根据标签信息解析出<sub-domain/BSL/SI>三元信息，并剥掉MPLS头+BIER头，然后将报文转发出BIER域。MPLS头一般包括MPLS Label(标签)。
使用本发明实施例的技术部署BIER后，多个BFR之间的转发不再依赖于MPLS标签，只需要根据BIER头进行转发即可，简化了网络处理流程。适用于简单的不需要支持MPLS标签的网络中部署BIER技术。
实施示例一：
当前，IS-IS协议扩展实现BIER控制面时，对于IPv4网络，在IS-IS协议的Extended IP reachability(扩展IP可达性)TLV(TLV类型为135)和Multi-Topology Reachable IPv4Prefixes(多拓扑可达IPv4前缀)TLV(TLV类型为235)下进行了扩展；以及对于IPv6网络，在IS-IS的IPv6Reachability  TLV(TLV类型为236)和Multi-Topology Reachable IPv6Prefixes TLV(TLV类型为237)下进行了扩展，扩展格式见图4。
本发明实施例试图在相对简单的组播网络中，减径BIER域中对MPLS控制面和数据面的支持，只使用BIER头进行数据面的转发。于是对上述图4中定义的IS-IS BIER Info sub-TLV进行了修改，基于IS-IS协议扩展携带BIER信息的sub-TLV报文参考格式可以如图11或者如图12所示。
其中，在相关技术的BIER Info sub-TLV for IS-IS的格式基础上(如图4)，可以定义2个新字段。或者可以新定义一个BIER Info sub-TLV，除了携带相关技术中BIER Info sub-TLV中携带的信息外，还定义2个新字段。一个是M字段，表示是否使用MPLS-BIER，即是否需要携带BIER MPLS Encapsulation sub-sub-TLV；当M字段设置为1时，表示使用MPLS-BIER，即兼容和使用携带的BIER MPLS Encapsulation sub-sub-TLV；当M字段设置为0时，表示不使用MPLS-BIER，即不携带或不使用BIER MPLS Encapsulation sub-sub-TLV，直接使用BIER头进行转发。另外一个重要字段是BSL标识字段，标识一个或多个BitStringLength，当M字段是0时，此字段有效。当M字段是1时，按照规则选择此时是以此字段有效，还是BIER MPLS Encapsulation sub-sub-TLV中携带的比特位串长度信息字段有效。这样，BIER信息转发的时候，就可以不必要依托于MPLS进行转发了。
其中，BSL标识字段可以通过以下参考格式实现，每个bit标识一个BSL。例如：
00000001标识BSL为64bits；
00000010标识BSL为128bits；
00000100标识BSL为215bits；
00001000标识BSL为512bits；
00010000标识BSL为1024bits；
00100000标识BSL为2048bits；
01000000标识BSL为4096bits；
如果BSL标识中有2个bit置位，例如01000001，则表示当前支持的BSL 为64bits和4096bits；如果BSL标识中有3个bit置位，例如00011100，则表示当前支持的BSL为1024bits，512bits和256bits。
实施示例二：
相关技术中，OSPF协议扩展实现BIER控制面，对IPv4网络，在OSPFv2协议的Extended Prefix TLV下进行了扩展；以及对于IPv6网络，在OSPFv3的Extended LSA TLV下进行了扩展，扩展格式可以见图5。
本发明实施例试图在相对简单的组播网络中，减径BIER域中对MPLS控制面和数据面的支持，只使用BIER头进行数据面的转发。于是对上述图5中定义的OSPF协议扩展的BIER信息子TLV进行了修改，基于OSPF协议扩展携带BIER信息的sub-TLV报文参考格式可以也如图11所示，还可以如图12或者图13所示。
其中，在相关技术的BIER Info sub-TLV for OSPF(OSPF协议扩展的BIER信息子TLV)的格式基础上(如图5)，可以定义2个新字段。或者可以新定义一个BIER Info sub-TLV，除了携带相关技术中BIER Info sub-TLV中携带的信息外，还定义2个新字段。一个是M字段，表示是否使用MPLS-BIER，即是否需要携带BIER MPLS Encapsulation sub-sub-TLV；当M字段设置为1时，表示使用MPLS-BIER，即兼容和使用携带的BIER MPLS Encapsulation sub-sub-TLV；当M字段设置为0时，表示不使用MPLS-BIER，即不携带或不使用BIER MPLS Encapsulation sub-sub-TLV，直接使用BIER头进行转发。另外一个重要字段是BSL标识字段，表示一个或多个比特位串长度(BitStringLength)，当M字段是0时，此字段有效。当M字段是1时，按照规则选择此时是以此字段有效，还是BIER MPLS Encapsulation sub-sub-TLV中携带的比特位串长度信息字段有效。
实施示例三：
OSPF协议可以支持在BIER域的BFIR和BFER设备上建立OSPF虚链，通过虚链，将本发明实施例所提到的扩展TLV信息直接发送到BIER域的边缘设备，BFIR和BFER设备直接互相交互BIER信息，减少BIER域中间节点的信息存储。所通告的格式仍然为基于OSPF协议扩展携带BIER信息的报文参考格式，可以也如图11所示，还可以如图12或者图13所示。
其中，在相关技术的BIER Info sub-TLV for OSPF的格式基础上(如图5)，可以定义2个新字段。或者可以新定义一个BIER Info sub-TLV，除了携带相关技术中BIER Info sub-TLV中携带的信息外，还定义2个新字段。一个是M字段，表示是否使用MPLS-BIER，即是否需要携带BIER MPLS Encapsulation sub-sub-TLV；当M字段设置为1时，表示使用MPLS-BIER，即兼容和使用携带BIER MPLS Encapsulation sub-sub-TLV；当M字段设置为0时，表示不使用MPLS-BIER，即不携带或不使用携带BIER MPLS Encapsulation sub-sub-TLV，直接使用BIER头进行转发。另外一个重要字段是BSL标识字段，表示一个或多个比特位串长度BitStringLength，当M字段是0时，此字段有效。当M字段是1时，按照规则选择此时是以此字段有效，还是BIER MPLS Encapsulation sub-sub-TLV中携带的比特位串长度信息字段有效。
实施示例四：
BGP协议可以支持在BIER域的BFIR和BFER设备上建立BGP邻居，通过扩展BGP协议，将本发明实施例所提到的扩展TLV信息直接发送到BIER域的边缘设备，BFIR和BFER设备直接互相交互BIER信息，减少BIER域中间节点的信息存储。所通告的格式仍然是基于BGP协议扩展携带BIER信息的报文参考格式，可以如图14所示。
其中，在BIER TLV for BGP(BGP协议扩展的BIER TLV)的格式基础上，可以定义2个新字段。或者可以新定义一个BIER TLV for BGP，除了携带相关技术中BIER TLV中携带的信息外，还定义2个新字段。一个是M字段，表示是否使用MPLS-BIER，即是否需要携带BIER MPLS Encapsulation sub-sub-TLV(BIER MPLS封装子子TLV)；当M字段设置为1时，表示使用MPLS-BIER，即兼容和使用携带BIER MPLS Encapsulation sub-sub-TLV；当M字段设置为0时，表示不使用MPLS-BIER，即不携带或不使用携带BIER MPLS Encapsulation sub-sub-TLV，直接使用BIER头进行转发。另外一个重要字段是BSL标识字段，表示一个或多个比特位串长度BitStringLength，当M字段是0时，此字段有效。当M字段是1时，按照规则选择此时是以此字段有效，还是BIER MPLS Encapsulation sub-sub-TLV中携带的比特位串长度信息字段有效。
实施示例五：
基于本发明实施例在路由协议上的BIER信息扩展，因为相关技术中MPLS标签携带的信息其实是对应的<sub-domain/BSL/SI>三元组的信息，所以，当MPLS标签不参与转发时，需要在图3定义的BIER头上添加<sub-domain/BSL/SI>三元组信息。本发明实施例定义的BIER头参考格式可以如图15所示。报文转发过程结合图16，可以包括步骤101～104：
步骤101：入口节点BFIR1收到了组播报文，确定该组播报文隶属的sub-domain和Set Identifier，和使用的BSL，然后根据事先获取的组播地址和BitString的映射关系(该映射关系由控制面事先指定)，确定该组播报文对应的比特位串1，获知该组播报文需要转发到目的节点BFER4和BFER5，然后封装BIER报文头(可以如图13所示)，转发此BIER信息。
步骤102：BFR2收到了报文后，根据BIER报文头中的sub-domain信息和Set Identifier信息，以及BSL信息，查找相应的BIFT，查找到对应的下一跳邻居是BFR3和BFER5，则复制报文，一份更新比特位串2为比特位串3，将报文转发到BFR3，一份更新比特位串2为比特位串5，将报文转发到BFER5。
步骤103：BFR3收到了报文后，根据BIER报文头中的sub-domain信息和Set Identifier信息，以及BSL信息，查找相应的BIFT，查找到对应的下一跳邻居是BFER4，则更新比特位串3信息为比特位串4信息，将报文转发到BFER4。同时，BFER5收到报文后，根据BIER报文头中的sub-domain信息和Set Identifier信息，以及BSL信息，查找相应的BIFT，发现本地是BFER，则解封装BIER报文头，转发组播报文到相应的接收设备。
步骤104：BFER4收到报文后，根据BIER报文头中的sub-domain信息和Set Identifier信息，以及BSL信息，查找相应的BIFT，发现本地是BFER，则解封装BIER报文头，转发组播报文到相应的接收设备。
一种计算机可读存储介质，存储有计算机可执行指令，所述计算机可执行指令用于执行上述方法。
本领域普通技术人员可以理解上述方法中的全部或部分步骤可通过程序来指令相关硬件完成，所述程序可以存储于计算机可读存储介质中，如只读存储器、磁盘或光盘等。可选地，上述实施例的全部或部分步骤也可以使用一个或多个集成电路来实现。相应地，上述实施例中的模块/单元可以采用硬件的形式实现，也可以采用软件功能模块的形式实现。本发明实施例不限制于任何特定形式的硬件和软件的结合。
工业实用性
本发明实施例提出一种实现组播的方法与比特位转发路由器，通过BIER技术在非MPLS网络中实现比特位索引显示复制，可以减径BIER域中对MPLS控制面和数据面的支持。

Claims (22)

  1. 一种实现比特位索引显示复制BIER的方法，应用于BIER域的比特位转发路由器，包括：
    获取本节点上与BIER相关的比特位串长度信息；
    将包括所述比特位串长度信息的BIER相关信息封装在同一个BIER信息的类型-长度-值TLV中；
    通过路由协议通告所述BIER信息的TLV。
  2. 如权利要求1所述的方法，其中：
    所述比特位串长度信息包括一个或多个比特位串长度。
  3. 如权利要求1所述的方法，其中：
    所述BIER相关信息还包括：子域标识信息、集标识信息和所述比特位转发路由器的标识。
  4. 如权利要求3所述的方法，其中：
    所述BIER相关信息还包括：多拓扑标识信息。
  5. 如权利要求1所述的方法，其中：
    所述BIER信息的TLV中还包括标签标识，当所述标签标识置位时，表示兼容和使用BIER多协议标签交换MPLS封装子TLV；当所述标签标识未置位时，表示不使用BIER MPLS封装子TLV。
  6. 如权利要求1～5任一项所述的方法，其中：所述路由协议包括以下任一种协议：
    中间系统到中间系统协议、开放式最短路径优先协议和边界网关协议。
  7. 如权利要求6所述的方法，其中：
    所述路由协议支持IPv4网络协议和/或IPv6网络协议。
  8. 一种比特位转发路由器，包括：
    获取模块，设置成获取本节点上与比特位索引显示复制BIER相关的比特位串长度信息；
    封装模块，设置成将包括所述比特位串长度信息的BIER相关信息封装在同一个BIER信息的类型-长度-值TLV中；
    通告模块，设置成通过路由协议通告所述BIER信息的TLV。
  9. 如权利要求8所述的比特位转发路由器，其中：
    所述获取模块所获取的所述比特位串长度信息包括一个或多个比特位串长度。
  10. 如权利要求8所述的比特位转发路由器，其中：
    所述BIER相关信息还包括：子域标识信息、集标识信息和所述比特位转发路由器的标识。
  11. 如权利要求8所述的比特位转发路由器，其中：
    所述封装模块所封装的所述BIER信息的TLV中还包括标签标识，当所述标签标识置位时，表示兼容和使用BIER多协议标签交换MPLS封装子TLV；当所述标签标识未置位时，表示不使用BIER MPLS封装子TLV。
  12. 一种实现比特位索引显示复制BIER的方法，应用于BIER域的比特位转发路由器，包括：
    接收BIER信息，所述BIER信息的同一个类型-长度-值TLV中封装有包括所述比特位串长度信息的BIER相关信息；
    处理所述BIER信息。
  13. 如权利要求12所述的方法，其中：
    所述比特位串长度信息包括一个或多个比特位串长度。
  14. 如权利要求12所述的方法，其中，所述BIER相关信息还包括：
    子域标识信息、集标识信息和发送所述BIER信息的比特位转发路由器的标识。
  15. 如权利要求14所述的方法，其中：
    所述BIER相关信息还包括：多拓扑标识信息。
  16. 如权利要求12所述的方法，还包括：
    接收到广播-未知-组播BUM报文，封装所述BIER相关信息在所述BUM报文的BIER报文头中，按照BIER转发规则转发所述组播报文。
  17. 如权利要求12～16任一项所述的方法，其中，所述处理所述BIER信息包括：
    解析所述BIER信息的TLV中包括的标签标识，当所述标签标识置位时，兼容和使用BIER多协议标签交换MPLS封装子TLV；当所述标签标识未置位时，不使用BIER MPLS封装子TLV。
  18. 一种比特位转发路由器，包括：
    接收模块，设置成接收BIER信息，所述BIER信息的同一个类型\长度\值TLV中封装有包括所述比特位串长度信息的BIER相关信息；
    处理模块，设置成处理所述BIER信息。
  19. 如权利要求18所述的比特位转发路由器，其中：
    所述接收模块所接收的比特位串长度信息包括一个或多个比特位串长度。
  20. 如权利要求18所述的比特位转发路由器，其中：
    所述接收模块所接收的所述BIER相关信息还包括：子域标识信息、集标识信息和发送所述BIER信息的比特位转发路由器的标识。
  21. 如权利要求18所述的比特位转发路由器，还包括：
    转发模块，设置成接收到广播-未知-组播BUM报文，封装所述BIER相关信息在所述BUM报文的BIER报文头中，按照BIER转发规则转发所述组播报文。
  22. 如权利要求18～21任一项所述的比特位转发路由器，其中：
    所述处理模块，处理所述BIER信息包括：解析所述BIER信息的TLV中包括的标签标识，当所述标签标识置位时，兼容和使用BIER多协议标签交换MPLS封装子TLV；当所述标签标识未置位时，不使用BIER MPLS封装子TLV。
PCT/CN2016/086462 2015-10-12 2016-06-20 一种实现比特位索引显示复制的方法及比特位转发路由器 WO2016188501A1 (zh)

Priority Applications (2)

Application Number Priority Date Filing Date Title
EP16799388.0A EP3364614A4 (en) 2015-10-12 2016-06-20 METHOD FOR IMPLEMENTING EXPLICIT BINARY INDEX REPLICATION AND BINARY ROUTING ROUTER
JP2018518734A JP6506475B2 (ja) 2015-10-12 2016-06-20 ビットインデックス付きエクスプリシットレプリケーションを実現する方法及びビット転送ルータ

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN201510658730.5A CN106572023B (zh) 2015-10-12 2015-10-12 一种实现比特位索引显示复制的方法及比特位转发路由器
CN201510658730.5 2015-10-12

Publications (1)

Publication Number Publication Date
WO2016188501A1 true WO2016188501A1 (zh) 2016-12-01

Family

ID=57393542

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2016/086462 WO2016188501A1 (zh) 2015-10-12 2016-06-20 一种实现比特位索引显示复制的方法及比特位转发路由器

Country Status (4)

Country Link
EP (1) EP3364614A4 (zh)
JP (1) JP6506475B2 (zh)
CN (1) CN106572023B (zh)
WO (1) WO2016188501A1 (zh)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108234311A (zh) * 2016-12-15 2018-06-29 中兴通讯股份有限公司 一种位索引显式复制信息传递方法及装置
WO2020087398A1 (en) * 2018-10-31 2020-05-07 Huawei Technologies Co., Ltd. Method and apparatus for advertising and processing bier capability of link, and communication node
CN113114576A (zh) * 2019-12-25 2021-07-13 华为技术有限公司 报文发送的方法、设备和系统

Families Citing this family (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108989208B (zh) * 2017-05-31 2021-08-10 中兴通讯股份有限公司 一种标识分配方法和装置
CN108989209B (zh) * 2017-05-31 2022-04-19 中兴通讯股份有限公司 Bier mpls网络设备、及其报文转发方法和介质
CN109391478B (zh) * 2017-08-10 2021-09-10 中兴通讯股份有限公司 一种组播业务控制方法和装置、计算机可读存储介质
CN109428825A (zh) * 2017-09-04 2019-03-05 中兴通讯股份有限公司 一种组播报文转发方法及装置
CN109474526B (zh) * 2017-09-07 2021-10-19 中兴通讯股份有限公司 通告bier-mpls标签的方法、设备及存储介质
CN109756425B (zh) * 2017-11-07 2022-01-18 中国电信股份有限公司 组播转发方法、装置以及bfr
CN110417657B (zh) 2018-04-27 2022-05-17 华为技术有限公司 一种处理组播数据报文的方法及装置
CN110460522B (zh) 2018-05-08 2021-11-19 华为技术有限公司 组播数据传输方法、相关装置及系统
US10644900B2 (en) * 2018-06-19 2020-05-05 Juniper Networks, Inc. Forwarding multicast data packets using bit index explicit replication (BIER) for BIER-incapable network devices
US10841111B2 (en) 2018-06-19 2020-11-17 Juniper Networks, Inc. Forwarding multicast data packets using bit index explicit replication (BIER) for BIER-incapable network devices
CN113595913B (zh) * 2018-11-02 2023-02-14 华为技术有限公司 报文转发的方法、发送报文的装置和接收报文的装置
CN110784411B (zh) * 2019-09-30 2021-10-01 华为技术有限公司 建立bier转发表项的方法、装置和系统
CN112995091B (zh) * 2019-12-02 2023-06-23 中兴通讯股份有限公司 数据压缩方法、装置、网络设备及存储介质
CN113542188B (zh) * 2020-04-13 2023-04-18 华为技术有限公司 报文检测的方法以及第一网络设备
EP3917093A1 (en) 2020-05-30 2021-12-01 Huawei Technologies Co., Ltd. Bierv6 packet forwarding method and device
CN112511319A (zh) * 2020-07-03 2021-03-16 中兴通讯股份有限公司 信息通告、报文转发、报文消除方法、装置、设备和介质
CN114465946B (zh) * 2020-11-09 2023-08-04 华为技术有限公司 获取转发表项的方法、装置以及系统

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104811387A (zh) * 2014-01-24 2015-07-29 思科技术公司 具有位索引显式复制的等价多路径

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9571897B2 (en) * 2013-09-17 2017-02-14 Cisco Technology, Inc. Bit indexed explicit replication for professional media networks
WO2015042152A1 (en) * 2013-09-17 2015-03-26 Cisco Technology, Inc. Bit indexed explicit replication using multiprotocol label switching
US9544230B2 (en) * 2013-09-17 2017-01-10 Cisco Technology, Inc. Migration support for bit indexed explicit replication
US9749220B2 (en) * 2014-09-19 2017-08-29 Telefonaktiebolaget L M Ericsson (Publ) Automated determination of tree attributes and assignment of receiver identifiers by distributed election in multicast architectures relying on packets identifying intended receivers

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104811387A (zh) * 2014-01-24 2015-07-29 思科技术公司 具有位索引显式复制的等价多路径

Non-Patent Citations (4)

* Cited by examiner, † Cited by third party
Title
GINSBERG, L.ED. ET AL.: "BIER support via ISIS draft-ietf-bier-isis-extensions-00", IETF INTERNET ENGINEERING TASK FORCE INTERNET -DRAFT, 27 April 2015 (2015-04-27), XP015105988 *
See also references of EP3364614A4 *
WANG, C. ET AL.: "IS - IS Extension for BIER-Lite Draft-wang-isis-bier-1ite-extension-00", IETF ISIS WG INTERNET DRAFT, 16 October 2015 (2015-10-16), XP015109076 *
WANG, C. ET AL.: "OSPF Extension for BIER-Lite Draft-wang-bier-lite-ospf-extension-00", IETF BIER WG INTERNET -DRAFT, 13 October 2015 (2015-10-13), XP015108968 *

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108234311A (zh) * 2016-12-15 2018-06-29 中兴通讯股份有限公司 一种位索引显式复制信息传递方法及装置
CN108234311B (zh) * 2016-12-15 2020-11-17 中兴通讯股份有限公司 一种位索引显式复制信息传递方法及装置
WO2020087398A1 (en) * 2018-10-31 2020-05-07 Huawei Technologies Co., Ltd. Method and apparatus for advertising and processing bier capability of link, and communication node
CN113114576A (zh) * 2019-12-25 2021-07-13 华为技术有限公司 报文发送的方法、设备和系统

Also Published As

Publication number Publication date
JP2018530969A (ja) 2018-10-18
CN106572023B (zh) 2020-08-11
EP3364614A1 (en) 2018-08-22
EP3364614A4 (en) 2019-04-03
CN106572023A (zh) 2017-04-19
JP6506475B2 (ja) 2019-04-24

Similar Documents

Publication Publication Date Title
WO2016188501A1 (zh) 一种实现比特位索引显示复制的方法及比特位转发路由器
WO2021063232A1 (zh) 建立bier转发表项的方法、装置和系统
JP7123174B2 (ja) マルチキャストデータ送信方法、関連装置、およびシステム
WO2016177087A1 (zh) 一种传输bier报文的方法及装置
US8208377B2 (en) MAC-address based virtual route aggregation
JP5992602B2 (ja) ＩＰｖ６ネットワークにおいてラベル配布プロトコル（ＬＤＰ）を使用するためのシステムおよび方法
WO2018188464A1 (zh) 一种实现ioam的方法、装置及存储介质
WO2019214589A1 (zh) 组播数据传输方法、相关装置及系统
US10637687B2 (en) EVPN implicit aliasing
WO2018228490A1 (zh) 组播跨域方法、装置、系统及计算机可读存储介质
EP2869512A1 (en) Dynamic area filtering for link-state routing protocols
WO2018072728A1 (zh) 段标识sid获取
US20060164995A1 (en) Method and apparatus for context-based prefix updates in border gateway protocol
KR20100106560A (ko) 링크 상태 프로토콜 제어형 이더넷 네트워크를 통한 ｖｐｎ의 구현
WO2021121065A1 (zh) Bier报文转发方法、装置、设备和存储介质
US11405307B2 (en) Information transfer method and device
CN106572021B (zh) 一种实现网络虚拟化叠加的方法与网络虚拟化边缘节点
CN113228572A (zh) 用于分段路由（sr）代理段标识（sid）的内部网关协议（igp）
US9686381B1 (en) Control word decapsulation in a hybrid BGP-VPLS network
WO2018177273A1 (zh) 一种基于bier信息的处理及装置
US20230269165A1 (en) Next Hop Determining Method and Apparatus
WO2021189993A1 (zh) 路由方法、路由装置及计算机可读存储介质
WO2022188488A1 (zh) 路径建立方法及其装置、节点、计算机可读存储介质
WO2023016550A1 (zh) 一种路由发送方法及设备
CN114598634A (zh) 报文传输的方法、获取对应关系的方法、装置及系统

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 16799388

Country of ref document: EP

Kind code of ref document: A1

WWE Wipo information: entry into national phase

Ref document number: 2018518734

Country of ref document: JP

NENP Non-entry into the national phase

Ref country code: DE

WWE Wipo information: entry into national phase

Ref document number: 2016799388

Country of ref document: EP