WO2013117165A1

WO2013117165A1 - Method and node for realizing e-tree service based on vpls

Info

Publication number: WO2013117165A1
Application number: PCT/CN2013/071509
Authority: WO
Inventors: 陈然; 金利忠
Original assignee: 中兴通讯股份有限公司
Priority date: 2012-02-08
Filing date: 2013-02-07
Publication date: 2013-08-15
Also published as: CN103248548A; CN103248548B

Abstract

A method and node for realizing an Ethernet-tree (E-tree) service based on Virtual Private LAN Service (VPLS). The method comprises: the node automatically generates a Virtual LAN Identification (VLAN ID) or accepts the VLAN ID fixedly allocated by a standard organization, wherein the VLAN ID is used for identifying whether the data message comes from a root attachment circuit (AC) or a leaf AC; the node determines to transmit the AC attribute of the data message, and adds the VLAN ID with the AC attribute into the data message to transmit. The method and node above for realizing an E-tree service based on VPLS solve the problems that configuring the ROOT and Leaf VLAN ID manually is more complicated and time consuming; the method and node are simply realized, make less change to the existing protocol, and have low realization cost.

Description

Method and node for implementing VPLS-based E-tree service

Technical field

The present invention relates to an Ethernet Tree (E-tree) technology, and in particular, to a method and a node for implementing an E-tree service based on a Virtual Private Lan Service (VPLS). Background technique

The Metro Ethernet Forum (MEF) defines two types of multipoint Ethernet services: multi-point to multi-point (E-LAN) services and root-to-multipoint (E-Tree) services. The difference between these two services is mainly: All nodes of E-LAN can communicate with each other without any restrictions; E-Tree has two types of nodes: Root and Leaf, in Leaf and Leaf. They cannot communicate with each other. For details, please refer to MEF6.1 and MEF10.2.

The Virtual Private Lan Service (VPLS) defined by the Layer 2 Virtual Private Networks (L2VPN) working group of the Internet Engineering Task Force (IETF) is in IP/ In a multi-protocol label switching (MPLS) network, a multi-point to multi-point connection is provided for Ethernet. It simulates the function of an Ethernet switch. There are two ways to establish VPLS: Label Distribute Protocol (LDP) The allocation label (IETF RFC4762) and the Border Gateway Protocol (BGP) allocation label (IETF RFC4761). However, VPLS currently does not provide any mechanism for restricting communication between Leaf and Leaf, resulting in the need to establish E-Tree services on IP/Multiprotocol Label Switching (MPLS) networks. The main requirements are as follows: Leaf and leaf cannot be mutually Communication; need to support multiple Root Access Circuits (AC); Root and Leaf AC can exist on the same carrier edge device (PE). See Draft-key-12vpn-vpls-etree-reqt-04 for details. At the same time, some main application scenarios of E-tree are also defined. It can be seen that E-tree has a very broad application prospect, such as broadcast/multicast service, Internet access, American Institute of Electrical and Electronics Engineers (IEEE) 1588v2 clock synchronization. , Mobile Backhaul network, virtual private network (VPN), device management network, etc. So how to establish E-Tree service on IP/MPLS network is an urgent problem to be solved. The related technology is to use the virtual local area network (VLAN) identifier (ID) to identify whether the packet is from the root or the leaf, but the root and the leaf VLAN ID are manually configured, and the extended signaling is required for the root and the Leaf VLAN notification, which is more complicated and time consuming. Summary of the invention

The embodiment of the invention provides a method and a node for implementing the VPLS-based E-tree service, which solves the problem that the manual configuration Root and the Leaf VLAN ID are complicated and time-consuming.

In order to solve the above technical problem, an embodiment of the present invention provides a method for implementing a VPLS-based E-tree service, where the method includes:

The node automatically generates or accepts a virtual local area network identifier (VLAN ID) from the root access link (AC) or leaf AC in the VPLS domain of the standard organization fixed allocation;

The node sends a message including E-tree information to the opposite node and receives a message including the E-tree information sent by the opposite node, where the message includes a label distribution (LDP) message and a border gateway protocol (BGP) ) update the message;

The node determines to send an AC attribute of the data packet, and adds the VLAN ID of the AC attribute to the data packet and sends the data identifier.

Preferably, the node automatically generates a VLAN ID in the VPLS domain for identifying the data packet from the root AC or the leaf AC, including:

The PE automatically obtains the VLAN ID from a pseudowire type, an sum of an ingress route destination and an egress route destination (Im-RT+Ex-RT) or a related group identifier (AGI).

Preferably, the E-tree information is carried in an interface parameter newly extended by the LDP message or in a community attribute of the BGP update message.

Preferably, the E-tree information is carried in an interface parameter newly extended by the LDP message or an extended community attribute of the BGP update message or an existing group of the BGP update message in the process of establishing a pseudo line Or; the E-tree information is carried in the extended community attribute of the BGP update message in the VPLS member auto-discovery process.

Preferably, the E-tree information includes means for indicating whether the node only contains a leaf AC Instructions.

Preferably, the E-tree information further includes a Label Protocol Identity (TPID) field for determining whether the data packet carries a virtual local area network (VLAN) tag.

Preferably, the node determines to send the AC attribute of the data packet, and before the data packet is sent with the VLAN ID of the AC attribute, the method further includes:

And determining, by the node, that the same TPID parameter value is locally configured according to the received message sent by the opposite node and carrying the E-tree information.

The node accepts the TPID parameter value for the E-Tree that is fixedly allocated by the standard organization.

An embodiment of the present invention further provides a node, where the node includes:

The obtaining module is configured to: automatically generate or accept a virtual local area network identifier (VLAN ID) for identifying a data packet from a root access link (AC) or a leaf AC in a VPLS domain that is fixedly allocated by a standard organization; the sending module is set to: Determining an AC attribute of the data packet, adding a VLAN ID of the AC attribute to the data packet, and sending the data identifier;

a determining module, configured to: before the sending module sends the data packet with the VLAN ID, send a message including the E-tree information to the opposite node, and receive the E-tree information sent by the opposite node A message, the message including a Label Distribution (LDP) message and a Border Gateway Protocol (BGP) update message.

Preferably, the acquiring module is configured to:

The VLAN ID is automatically obtained from the pseudowire type, the sum of the ingress route destination and the egress route destination (Im-RT+Ex-RT) or the associated group identifier (AGI).

Preferably, the E-tree information includes indication information indicating whether the node only contains the leaf AC.

Preferably, the E-tree information further includes: determining whether the data packet has a virtual office The Label Protocol Identifier (TPID) field of the Domain Network (VLAN) tag.

The above-mentioned method and node for implementing the VPLS-based E-tree service solve the problem that the manual configuration ROOT and the Leaf VLAN ID are complicated and time-consuming; and the implementation is simple, the existing protocol is changed little, and the implementation cost is low. BRIEF abstract

1 is a schematic structural diagram of a typical VPLS-based E-tree embodiment;

2 is a schematic diagram of Embodiment 1 of a method for implementing VPLS-based E-tree service according to the present invention. FIG. 3 is a schematic diagram of Embodiment 2 of a method for implementing VPLS-based E-tree service according to the present invention. FIG. Schematic diagram of Embodiment 3 of the method of the -tree service FIG. 5 is a schematic structural diagram of the embodiment of the node of the present invention. Preferred embodiment of the invention

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be noted that, in the case of no conflict, the features in the embodiments and the embodiments in the present application may be arbitrarily combined with each other.

The embodiment of the invention provides a method for implementing a root-to-multipoint (E-Tree) service based on a virtual private local area network service (VPLS), the method comprising:

Step 1: The node automatically generates or accepts a virtual local area network identifier (VLAN ID) for identifying a data packet from a root access link (AC) or a leaf AC in a VPLS domain that is fixedly allocated by a standard organization; wherein, two methods are used. Whether the VLAN ID identifier packet is from Root AC or Leaf.

AC, the method is through the pseudo-line type (PW type), the associated group identifier (AGI), or the sum of the ingress route target and the egress route target (Import-route-target (Route-Target) RT)+Export-RT) automatically obtains the VLAN ID to identify whether the message is from Root AC or Leaf AC. Another method is to assign two fixed VLAN IDs through a standard organization such as IEEE to identify whether the message is from Root AC or Leaf AC.

Step 2: The node determines the AC attribute of the data packet, and adds the VLAN ID of the AC attribute to the data packet and sends the data. Before the step, the method may further include: sending, by the node, a message that includes E-tree information to the correspondent node, and receiving, by the peer node, a message that includes the E-tree information, where the message includes label distribution ( LDP) Message and Border Gateway Protocol (BGP) update messages.

The E-tree information is carried in an interface parameter newly extended by the LDP message or in a community attribute of the BGP update message. And the E-tree information is carried in an interface parameter newly extended by the LDP message or an extended community attribute of the BGP update message or an existing community attribute of the BGP update message in the process of establishing a pseudo line. Or the E-tree information is carried in the extended community attribute of the BGP update message in the VPLS member auto-discovery process.

The E-tree information includes a Tag Protocol Identifier (TPID) field for indicating whether the node only has a label of the leaf AC. And sending, by the PE, the data packet with the VLAN ID, after determining that the same TPID parameter value is configured locally according to the received message that is sent by the peer PE and carrying the E-tree information.

In addition, the node may also accept a standard organization, such as an IEEE fixed allocation of TPID parameter values for E-Tree. At this time, the E-Tree information is not carried in the message, and the VLAN ID may be sent without negotiation. Data ^艮文.

As shown in FIG. 1 , it is a schematic structural diagram of a typical VPLS-based E-tree embodiment. This embodiment introduces a method for implementing a VPLS-based E-tree from a data forwarding layer. The method includes the following steps:

Step 101: Configure a pseudowire service on PE1, and configure a leaf/root attribute for each AC.

The pseudowire service configured on PE1 includes information such as the configuration of the pseudowire ID, the pseudowire type, and the peer node ID. Specific to RFC4447, there is not much to introduce here.

Specifies the value of the pseudowire type to "module" the operation to identify the Root / Leaf VLAN. specifically:

Root VLAN ID = (pseudowire type) MOD 4094 + 1

Leaf VLAN ID = (pseudowire type) MOD 4094 + 2

As shown in Figure 1, the pseudowire type of PE1 and PE2 is 0X0005, then PE1 and PE2 are divided. Do not perform "modulo" operation, Root VLAN ID: 0X0005 mod 4094+1=6 , Leaf VLAN ID: 0X0005 mod 4094+2=7.

Step 102: PE2 configures a pseudowire service, and configures a leaf/root attribute for each AC. Step 103: PE1 receives a data packet from AC2 (the leaf AC), and PE1 adds a leaf VLAN ID (7) to identify the packet. From the leaf AC;

Step 104: After receiving the data packet by using the Pseudo Wire (PW), the PE2 checks the VLAN ID and finds that the packet is from the leaf AC. After the MAC address is forwarded, the port is found to be AC4 ( Leaf AC ). The packet will be discarded.

As shown in FIG. 2, it is a schematic diagram of Embodiment 1 of a method for implementing VPLS-based E-tree service according to the present invention. At the data level, this embodiment uses a VLAN ID to identify whether a packet is from a root AC or a leaf node, and is based on The principle that the E-tree leaf node cannot communicate with the leaf node. The receiving node further determines whether to discard the packet or continue to forward the packet. At the signaling level, this embodiment implements the negotiated E-tree function by redefining a new interface parameter to carry E-tree related information based on the method of establishing VPLS using LDP proposed in RFC4762. As shown in FIG. 2, the method for implementing a VPLS-based E-tree based on the LDP protocol includes the following steps:

Step 201: The PE1 sends an LDP label mapping message carrying the E-tree information to the PE2.

The E-tree information includes: an indication that the local node only has a leaf AC, and optionally carries a TPID field, where the TPID field is used to determine whether the data packet carries a VLAN label, and the field needs two endpoints to negotiate. The PW is enabled only when both ends of PE1 and PE2 carry the same parameter value. The TPID can also be configured without the TPID. The IEEE can define a unified TPID.

If the LDP mapping message sent by PE1 to PE2 carries the E-tree information, PE1 supports the E-tree function. Otherwise, it indicates that the E-tree function is not supported.

LDP label mapping messages are also used to assign labels to PWs. For details on how to assign labels, see

RFC4762, I won't introduce too much here.

Step 202: The PE2 sends an LDP label mapping message carrying the E-tree information to the PE1.

The E-tree information includes: used to indicate whether the node only contains the leaf AC, and optionally carries The TPID field, the TPID field is used to determine whether the data packet carries a VLAN tag. The field needs to be negotiated by the two endpoints. Only the two parameters of the PE1 and the PE2 carry the same parameter value, and the PW is available. TPID, which defines a unified TPID through IEEE, that is, no negotiation is required.

If the LDP label mapping message sent by PE2 to PE1 carries the E-tree information, PE2 supports the E-tree function. Otherwise, it indicates that the E-tree function is not supported.

Step 203: After receiving the LDP label mapping message, the PE2 checks and knows whether: the same TPID parameter is configured locally, and whether the PE1 only contains the leaf AC;

Specifically, if the E-tree information carried in the LDP label mapping message includes the TPID, the PW of the PE2 end is enabled only if the same TPID parameter value is configured on both ends of the PE1 and the PE2; The -tree information does not carry the TPID, that is, the IEEE defines a unified TPID, and no negotiation is required. After receiving the LDP label mapping message, the PE2 only needs to know whether the PE1 contains only the leaf AC.

If PE1 only contains the leaf AC, PE2 will decide whether to discard the packet according to the principle that the leaf AC and the leaf AC cannot communicate.

Step 204: After receiving the LDP label mapping message, the PE1 checks whether the same TPID parameter is configured locally, and whether the PE2 only contains the leaf AC.

Specifically, if the E-tree information carried in the LDP label mapping message includes the TPID, the PW of the PE1 end is enabled only if the same TPID parameter value is configured on both ends of the PE1 and the PE2; The -tree information does not carry the TPID, that is, a unified TPID is defined by the IEEE, and no negotiation is required. After receiving the LDP label mapping message, the PE2 only needs to know whether the PE2 contains only the leaf AC.

As shown in FIG. 3, it is a schematic diagram of Embodiment 2 of a method for implementing VPLS-based E-tree service according to the present invention. At the data level, this embodiment uses a VLAN ID to identify whether a packet is from a root AC or a leaf node, and is based on The principle that the E-tree leaf node cannot communicate with the leaf node. The receiving node further determines whether to discard the packet or continue to forward the packet. At the signaling level, this embodiment implements negotiation based on the E-tree related information carried in the Layer 2 extended community attribute defined in RFC4761. E-tree function. As shown in FIG. 3, the method for implementing a VPLS-based E-tree based on the BGP protocol includes the following steps:

Step 301: The PE1 sends a BGP update message carrying the E-tree information to the PE2.

Specifically, the PE1 sends the VPLS update message to the PE2. The premise is that the virtual switch instance (VSI) is configured on the PE1, and the BGP peer node is configured as the PE2.

The BGP update message also carries the VPLS BGP network layer reachability information (NLRI) for assigning labels to the pseudowire (PW). For the specific method of assigning labels, see RFC4761, which is not described here.

The E-tree information is carried in the BGP update message. Specifically, a new Layer 2 extended community attribute is extended to carry the information, or a type length value (Type-length-value) is extended in the existing Layer 2 extended community attribute. , referred to as TLV) to carry this information. The E-tree information includes: an indication that the local node only has a leaf AC, and optionally carries a TPID field, where the TPID field is used to determine whether the data packet carries a VLAN label, and the field needs two endpoints to negotiate. The PW can be used only if both ends of PE1 and PE2 carry the same parameter value. The TPID can also be used without the TPID. The IEEE can define a unified TPID.

If the BGP update message sent by PE1 to PE2 carries the E-tree information, PE1 supports the E-tree function. Otherwise, the E-tree function is not supported.

Step 302: The PE2 sends a BGP update message carrying the E-tree information to the PE1.

Specifically, the PE2 sends the VPLS update message to the PE1. The premise is that the PE2 is configured with the VSI and the BGP peer node is the PE1.

The BGP update message also carries the VPLS BGP NLRI to assign labels to the PW. For details about how to assign labels, see RFC4761.

The E-tree information is carried in the BGP update message. Specifically, a new Layer 2 extended community attribute is extended to carry the information, or a TLV is extended in the existing Layer 2 extended community attribute to carry the information. The E-tree information content is the same as the E-tree content described in step 201.

If the BGP update message sent by PE2 to PE1 carries the E-tree information, PE2 supports the E-tree function. Otherwise, the E-tree function is not supported.

Step 303: After receiving the BGP update message, the PE2 verifies: whether the local is configured with the same VSI, same TPID parameter, and whether PE2 only contains leaf AC;

Specifically, if the E-tree information carried in the BGP update message includes the TPID, the PW of the PE2 is enabled only if the same TPID parameter value is configured on both ends of the PE1 and the PE2; if the E-tree is carried in the BGP update message, The information does not carry the TPID, that is, a unified TPID is defined by the IEEE, and no negotiation is required. Therefore, the PE2 receives the BGP update message only needs to check whether the local VSI is configured and whether the PE2 only contains the leaf AC.

Step 304: After receiving the BGP update message, the PE1 verifies: whether the same VSL same TPID parameter is configured locally, and whether the PE2 only contains the leaf AC.

Specifically, if the E-tree information carried in the BGP update message includes the TPID, the PW of the PE1 is enabled only if the same TPID parameter value is configured on both ends of the PE1 and the PE2; if the E-tree is carried in the BGP update message, The information does not carry the TPID, that is, a unified TPID is defined by the IEEE, and no negotiation is required. Therefore, the PE1 receiving the BGP update message only needs to check whether the local VSI is configured and whether the PE1 only contains the leaf AC.

As shown in FIG. 4, it is a schematic diagram of Embodiment 3 of a method for implementing VPLS-based E-tree service according to the present invention. This embodiment is only an optimization scheme for implementing a VPLS-based E-tree method. This embodiment is extended based on BGP automatic discovery of VPLS. The BGP automatic discovery mechanism of VPLS can be found in RFC6074. As shown in FIG. 4, the method for implementing a VPLS-based E-tree based on the BGP automatic discovery mechanism includes the following steps:

Step 401: Node 1 sends and carries all the BGP sessions of the VPLS address family.

BGP update message of E-tree information;

The BGP update message carries the RD information of the VPLS instance and some extended community attributes. The information carried in the specific update message can be found in RFC6074. Here, we extend a new community attribute to carry E-tree information.

Further, the BGP update message in this embodiment is only used to discover the same VPLS instance.

The PE node has nothing to do with the establishment of the PW. The establishment of the PW can be established using the LDP protocol (RFC4762) or by using the BGP protocol (RFC4761). By extending a new community attribute to carry E-tree information, the purpose is to hope that the nodes in the same VPLS instance can further know which These nodes only contain the leaf AC. After knowing this information, you can directly discard the packets between the leaf and the leaf on the sender, thus saving traffic.

Here, the E-tree information includes information indicating whether the node that sent the BGP update message contains only the leaf node and whether the E-tree function information is enabled.

Step 402: The node 2 that receives the BGP update message saves the information of the VPLS instance and

E-tree information.

The method for implementing the VPLS-based E-tree service automatically solves the problem that the manual configuration of the ROOT and the leaf VLAN ID is complicated and time-consuming by automatically obtaining the root and the leaf VLAN ID. The implementation is simple, and the existing protocol is changed little. The implementation cost is lower.

As shown in FIG. 5, it is a schematic structural diagram of a node embodiment of the present invention. The node includes an obtaining module 51 and a sending module 52. The acquiring module is configured to automatically generate or accept a standard organization fixed allocation in the VPLS domain for identifying data packets. a virtual local area network identifier (VLAN ID) of the root access link (AC) or the leaf AC; a sending module, configured to determine an AC attribute for sending the data packet, and tag the data packet with a VLAN ID of the AC attribute And send.

The acquiring module is specifically configured to: automatically obtain the VLAN ID from a pseudowire type, an sum of an ingress route target and an egress route target (Im-RT+Ex-RT) or a related group identifier (AGI).

In addition, the node further includes: a determining module, configured to: before the sending module sends the data packet with the VLAN ID, send a message including the E-tree information to the opposite node, and send the peer node to send A message containing the E-tree information, the message including a Label Distribution (LDP) message and a Border Gateway Protocol (BGP) update message.

The E-tree information may be carried in an interface parameter newly extended by the LDP message or in a community attribute of the BGP update message. The E-tree information includes a Label Protocol Identity (TPID) field for indicating whether the node is only a local area network (VLAN) tag.

The above node can be a PE.

The above-mentioned node solves the problem that the manual configuration of the ROOT and the leaf VLAN ID is complicated and time consuming by automatically obtaining the ROOT and the leaf VLAN ID. One of ordinary skill in the art will appreciate that all or a portion of the above steps may be accomplished by a program that instructs the associated hardware, such as a read-only memory, a magnetic disk, or an optical disk. Alternatively, all or part of the steps of the above embodiments may also be implemented using one or more integrated circuits. Correspondingly, each module/unit in the foregoing embodiment may be implemented in the form of hardware, or may be implemented in the form of a software function module. The invention is not limited to any specific form of combination of hardware and software.

The above embodiments are only intended to illustrate the technical solutions of the present invention and are not to be construed as limiting the invention. It should be understood by those skilled in the art that the present invention may be modified or equivalently substituted without departing from the spirit and scope of the invention.

Industrial applicability

The above-mentioned method and node for implementing the VPLS-based E-tree service solve the problem that the manual configuration ROOT and the Leaf VLAN ID are complicated and time-consuming; and the implementation is simple, the existing protocol is changed little, and the implementation cost is low.

Claims

Claim

A method for implementing an Ethernet Tree (E-Tree) service based on Virtual Private Local Area Network Service (VPLS), the method comprising:

2. The method according to claim 1, wherein

The node automatically generates a VLAN ID in the VPLS domain for identifying the data packet from the root AC or the leaf AC, including:

3. The method according to claim 1, wherein

The E-tree information is carried in an interface parameter newly extended by the LDP message or in a community attribute of the BGP update message.

4. The method according to claim 3, wherein

The E-tree information is carried in an interface parameter newly extended by the LDP message or in an extended community attribute of the BGP update message or an existing community attribute of the BGP update message in the process of establishing a pseudo line; Or

The E-tree information is carried in the extended community attribute of the BGP update message during the automatic discovery process of the VPLS member.

5. The method according to claim 1, wherein

The E-tree information includes indication information indicating whether the node contains only leaves AC.

6. The method according to claim 5, wherein The Label Protocol Identifier (TPID) field of the (VLAN) tag.

7. The method according to claim 6, wherein

Determining, by the node, the AC attribute of the data packet, before the data packet is tagged with the VLAN ID of the AC attribute, and the method further includes:

8. The method according to claim 1, wherein

9. A node, the node comprising:

10. The node according to claim 9, wherein

The obtaining module is configured to: automatically obtain the VLAN ID from a pseudowire type, an sum of an ingress route target and an egress route target (Im-RT+Ex-RT) or a related group identifier (AGI).

11. The node according to claim 9, wherein

12. The node according to claim 11, wherein The E-tree information includes indication information indicating whether the node only contains a leaf AC.

13. The node according to claim 12, wherein

The Label Protocol Identifier (TPID) field of the (VLAN) tag.