Method and device for instructing multicast forwarding entry

0001This present application claims priority to Chinese Patent Application No. CN <patcit id="pcit0001" dnum="CN201410169740"><text>201410169740.8, filed with the Chinese Patent Office on April 24, 2014</text></patcit>, and entitled "METHOD FOR INDICATING MULTICAST FORWARDING ENTRY AND DEVICE", which is incorporated herein by reference in its entirety.

TECHNICAL FIELD

0002The present invention relates to the field of computer network technologies, and in particular, to a method for indicating a multicast forwarding entry and a device.

BACKGROUND

0003<figref idref="f0001">FIG. 1</figref> is a schematic diagram of a typical scenario of an access network in the prior art. As shown by arrows in <figref idref="f0001">FIG. 1</figref>, each network node (Node) on a multicast path must support a listening/proxy function of an internet group management protocol (Internet Group Management Protocol, IGMP)/multicast listener discovery protocol (Multicast Listener Discovery, MLD), so as to implement a transmission of an IGMP/MLD message on the multicast path, and generate a corresponding multicast forwarding entry, respectively.

0004For example, if IGMP/MLD versions of a Node 1 and a Node 2 in <figref idref="f0001">FIG. 1</figref> are same, after receiving an IGMP/MLD message forwarded by the Node 1, the Node 2 parses the IGMP/MLD message to obtain a multicast IP address, hereby obtaining a multicast MAC address, and then establishes a correspondence between a port which receives the IGMP/MLD message and the multicast MAC address, that is, generates a multicast forwarding entry which is composed of the port and the multicast MAC address. Only when each node generates a respective multicast forwarding entry during a process of transmitting the IGMP/MLD message, can each node identify its own multicast data packet subsequently and continue to transmit the multicast data packet to a next node through a port recorded in the multicast forwarding entry to implement a data multicast. However, if IGMP/MLD versions are different, not all of nodes on the multicast path can certainly parse the IGMP/MLD message correctly to generate a multicast forwarding entry, so that a multicast fails to be realized. For this reason, an engineering technical personnel generally needs to take into account IGMP/MLD version of each network node when a network node (for example, a digital subscriber line access multiplexer (DSL Access Multiplexer, DSLAM)), an optical network unit (Optical Network Unit, ONU), an optical line termination (Optical Line Termination, OLT), an Ethernet switch, a broadband network gateway (Broadband Network Gateway, BNG)/a broadband remote access server (Broadband Remote Access Server, BRAS) or the like) is introduced, and perform a large amount of compatibility and matching operation on an access network. Apparently, such manner increases operation and maintenance complexity.

0005In the prior art, there has not been put forward a convenient solution which may realize that each network node may acquire a multicast forwarding entry when an IGMP/MLD protocol version of each network node is different.

SUMMARY

0006Embodiments of the present invention provide a method for indicating a multicast forwarding entry and a device, so as to resolve a problem of failing to acquire a multicast forwarding entry by each network node caused due to difference of IGMP/MLD protocol versions of network nodes in the prior art.

0007According to a first aspect, an embodiment of the present invention provides a method for indicating a multicast forwarding entry, including: <ul id="ul0001" list-style="none" compact="compact"><li>receiving a multicast control message and an access loop identifier sent by a first node;</li><li>determining an identifier of a first port of a second node and an identifier of a second port of a third node on a multicast path corresponding to the access loop identifier, where both the first port and the second port are egress ports on the multicast path;</li><li>determining, according to a multicast Internet Protocol IP address in the multicast control message, a multicast Media Access Control MAC address corresponding to the multicast path;</li><li>sending a first forwarding entry to the second node, where a destination address of the first forwarding entry is the multicast MAC address and egress port information of the first forwarding entry is the identifier of the first port; and</li><li>sending a second forwarding entry to the third node, where a destination address of the second forwarding entry is the multicast MAC address and egress port information of the second forwarding entry is the identifier of the second port.</li></ul>

0008With reference to the first aspect, in a first possible implementation manner, the access loop identifier is an access loop identifier of the first node; <ul id="ul0002" list-style="none" compact="compact"><li>the determining an identifier of a first port of a second node and an identifier of a second port of a third node on a multicast path corresponding to the access loop identifier includes: <ul id="ul0003" list-style="none" compact="compact"><li>determining, according to the access loop identifier of the first node and a pre-stored mapping relationship between the access loop identifier and port information of each network node and a multicast path corresponding to the access loop identifier of the first node determined according to a pre-stored network topology relationship, the identifier of the first port of the second node and the identifier of the second port of the third node on a multicast path corresponding to the access loop identifier of the first node; or</li><li>sending the access loop identifier of the first node to a server, where a mapping relationship between an access loop identifier and port information of each network node and a network topology relationship are pre-stored in the server; receiving the identifier of the first port of the second node and the identifier of the second port of the third node on the multicast path corresponding to the access loop identifier of the first node fed back by the server.</li></ul></li></ul>

0009With reference to the first aspect, in a second possible implementation manner, the access loop identifier includes an access loop identifier of the first node, an access loop identifier of the second node and an access loop identifier of the third node, and both the second node and the third node are on a multicast path corresponding to the access loop identifier of the first node; <ul id="ul0004" list-style="none" compact="compact"><li>the determining an identifier of a first port of a second node and an identifier of a second port of a third node on a multicast path corresponding to the access loop identifier includes: <ul id="ul0005" list-style="none" compact="compact"><li>acquiring, according to the access loop identifier of the second node and the access loop identifier of the third node on the multicast path, the identifier of the first port of the second node and the identifier of the second port of the third node on the multicast path, respectively.</li></ul></li></ul>

0010With reference to the first aspect, in a third possible implementation manner, the determining, according to a multicast Internet Protocol IP address in the multicast control message, a multicast Media Access Control MAC address corresponding to the multicast path includes: <ul id="ul0006" list-style="none" compact="compact"><li>determining, according to the multicast IP address in the multicast control message and a predetermined mapping relationship between the multicast IP address and the multicast MAC address, the multicast MAC address corresponding to the multicast path.</li></ul>

0011With reference to the first aspect, in a fourth possible implementation manner, the multicast control message is an Internet Group Management Protocol IGMP packet or a Multicast Listener Discovery protocol MLD packet.

0012With reference to the first aspect or any possible implementation manner of the first to the fourth possible implementation manners in the first aspect, in a fifth possible implementation manner, the method further includes: <ul id="ul0007" list-style="none" compact="compact"><li>sending the IGMP packet or the MLD packet to a fourth node; or</li><li>generating a multicast routing protocol packet according to the IGMP packet or the MLD packet and sending the multicast routing protocol packet to a fourth node.</li></ul>

0013With reference to the first aspect or any possible implementation manner of the first to the fourth possible implementation manners, in a sixth possible implementation manner, the receiving a multicast control message and an access loop identifier sent by a first node includes: <ul id="ul0008" list-style="none" compact="compact"><li>receiving the multicast control message and the access loop identifier sent by the first node according to an openflow protocol, or an access management or control protocol, or an Ethernet operation, administration and maintenance protocol, or a tunneling protocol.</li></ul>

0014According to a second aspect, a device for indicating a multicast forwarding entry is provided, including: <ul id="ul0009" list-style="none" compact="compact"><li>a first receiving unit, configured to receive a multicast control message and an access loop identifier sent by a first node;</li><li>a first determining unit, configured to determine an identifier of a first port of a second node and an identifier of a second port of a third node on a multicast path corresponding to the access loop identifier, where both the first port and the second port are egress ports on the multicast path;</li><li>a second determining unit, configured to determine, according to a multicast Internet Protocol IP address in the multicast control message, a multicast Media Access Control MAC address corresponding to the multicast path;</li><li>a first sending unit, configured to send a first forwarding entry to the second node, where a destination address of the first forwarding entry is the multicast MAC address and egress port information of the first forwarding entry is the identifier of the first port; and</li><li>a second sending unit, configured to send a second forwarding entry to the third node, where a destination address of the second forwarding entry is the multicast MAC address and egress port information of the second forwarding entry is the identifier of the second port.</li></ul>

0015With reference to the second aspect, in a first possible implementation manner, the access loop identifier received by the first receiving unit is an access loop identifier of the first node; <ul id="ul0010" list-style="none" compact="compact"><li>the first determining unit is specifically configured to: <ul id="ul0011" list-style="none" compact="compact"><li>determine, according to the access loop identifier of the first node and a pre-stored mapping relationship between an access loop identifier and port information of each network node and a multicast path corresponding to the access loop identifier of the first node determined according to a pre-stored network topology relationship, the identifier of the first port of the second node and the identifier of the second port of the third node on a multicast path corresponding to the access loop identifier of the first node; or</li><li>send the access loop identifier of the first node to a server, where a mapping relationship between an access loop identifier and port information of each network node and a network topology relationship are pre-stored in the server; receive the identifier of the first port of the second node and the identifier of the second port of the third node on the multicast path corresponding to the access loop identifier of the first node fed back by the server.</li></ul></li></ul>

0016With reference to the second aspect, in a second possible implementation manner, the access loop identifier received by the first receiving unit includes an access loop identifier of the first node, an access loop identifier of the second node and an access loop identifier of the third node, and both the second node and the third node are on a multicast path corresponding to the access loop identifier of the first node; <ul id="ul0012" list-style="none" compact="compact"><li>the first determining unit is specifically configured to: <ul id="ul0013" list-style="none" compact="compact"><li>acquire, according to the access loop identifier of the second node and the access loop identifier of the third node on the multicast path, the identifier of the first port of the second node and the identifier of the second port of the third node on the multicast path, respectively.</li></ul></li></ul>

0017With reference to the second aspect, in a third possible implementation manner, the second determining unit is specifically configured to: <ul id="ul0014" list-style="none" compact="compact"><li>determine, according to the multicast IP address in the multicast control message and a predetermined mapping relationship between the multicast IP address and the multicast MAC address, the multicast MAC address corresponding to the multicast path.</li></ul>

0018With reference to the second aspect, in a fourth possible implementation manner, the multicast control message received by the first receiving unit is an internet group management protocol IGMP packet or a Multicast Listener Discovery protocol MLD packet.

0019With reference to the second aspect or any possible implementation manner of the first to the fourth possible implementation manners in the second aspect, in a fifth possible implementation manner, the device further includes: <ul id="ul0015" list-style="none" compact="compact"><li>a third sending unit, configured to send the IGMP packet or the MLD packet to a fourth node; or</li><li>generate a multicast routing protocol packet according to the IGMP packet or the MLD packet and send the multicast routing protocol packet to a fourth node.</li></ul>

0020With reference to the second aspect or any possible implementation manner of the first to the fourth possible implementation manners in the second aspect, in a sixth possible implementation manner, the first receiving unit is specifically configured to: <ul id="ul0016" list-style="none" compact="compact"><li>receive the multicast control message and the access loop identifier sent by the first node according to an openflow protocol, or an access management or control protocol, or an Ethernet operation, administration and maintenance protocol, or a tunneling protocol.</li></ul>

0021In the embodiments of the present invention, a multicast control message and an access loop identifier sent by a first node are received; an identifier of a first port of a second node and an identifier of a second port of a third node on a multicast path corresponding to the access loop identifier are determined, where both the first port and the second port are egress ports on the multicast path; a multicast Media Access Control MAC address corresponding to the multicast path is determined according to a multicast Internet Protocol IP address in the multicast control message; a first forwarding entry is sent to the second node, where a destination address of the first forwarding entry is the multicast MAC address and egress port information of the first forwarding entry is the identifier of the first port. a second forwarding entry is sent to the third node, where a destination address of the second forwarding entry is the multicast MAC address and egress port information of the second forwarding entry is the identifier of the second port; and a separate device is used to generate a multicast forwarding entry for each network node on a multicast path, so as to enable each network node may acquire a multicast forwarding entry without parsing an IGMP packet or an MLD packet.

BRIEF DESCRIPTION OF DRAWINGS

0022To illustrate the technical solutions in the embodiments of the present invention more clearly, the following briefly introduces accompanying drawings required for describing the embodiments. Apparently, the accompanying drawings in the following description are some embodiments of the present invention, and a person of ordinary skill in the art may still derive other drawings according to these accompanying drawings without creative efforts. <ul id="ul0017" list-style="none" compact="compact"><li><figref idref="f0001">FIG. 1</figref> is a schematic diagram of a typical scenario of an access network in the prior art;</li><li><figref idref="f0001">FIG. 2</figref> is a schematic diagram of an access network scenario according to an embodiment of the present invention;</li><li><figref idref="f0002">FIG. 3</figref> is a schematic flowchart of a method for indicating a multicast forwarding entry according to an embodiment of the present invention;</li><li><figref idref="f0003">FIG. 4</figref> is a schematic flowchart of a method for indicating a multicast forwarding entry according to another embodiment of the present invention;</li><li><figref idref="f0003">FIG. 5</figref> is a diagram of message flow according to an embodiment of the present invention;</li><li><figref idref="f0004">FIG. 6</figref> is a schematic flowchart of specific embodiment 1 of the present invention;</li><li><figref idref="f0005">FIG. 7</figref> is a schematic flowchart of specific embodiment 2 of the present invention;</li><li><figref idref="f0005">FIG. 8</figref> is a schematic structural diagram of a device according to an embodiment of the present invention;</li><li><figref idref="f0006">FIG. 9</figref> is another schematic structural diagram of a device according to an embodiment of the present invention.</li></ul>

DESCRIPTION OF EMBODIMENTS

0023To make the objectives, technical solutions, and advantages of embodiments of the present invention clearer, the following clearly and completely describes the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Apparently, the described embodiments are some but not all of the embodiments of the present invention. All other embodiments obtained by persons of ordinary skill in the art based on the embodiments of the present invention shall fall within the protection scope of the present invention.

0024The embodiments of the present invention provide a method for indicating a multicast forwarding entry and a device, so as to enable each network node to acquire a multicast forwarding entry without parsing an IGMP packet or an MLD packet.

0025Referring to <figref idref="f0001">FIG. 2, FIG. 2</figref> is a schematic diagram of a new access network scenario provided in an embodiment of the present invention. Control plane functions including listening/proxy of an IGMP/MLD of a network node are centralized on an access controller (Access Controller) for implementation. Each network node is connected to the access controller through an Openflow protocol, an access management or control (for example, an optical network unit management and control interface (ONU Management and Control Interface, OMCI) or Ethernet operation, administration, and maintenance (Ethernet Operation, Administration, and Maintenance, Eth OAM)) protocol or a tunneling protocol. The access controller may be a stand-alone device, or may be embedded in a device such as an OLT, an aggregation node, or a router (for example, a BNG/BRAS) as a functional module.

0026Referring to <figref idref="f0002">FIG. 3</figref>, a method for indicating a multicast forwarding entry provided in an embodiment of the present invention includes: <ul id="ul0018" list-style="none" compact="compact"><li>S310. A multicast control message and an access loop identifier sent by a first node are received.</li><li>S320. An identifier of a first port of a second node and an identifier of a second port of a third node on a multicast path corresponding to the access loop identifier are determined, where both the first port and the second port are egress ports on the multicast path.</li><li>S330. According to a multicast Internet Protocol IP address in the multicast control message, a multicast Media Access Control MAC address corresponding to the multicast path is determined.</li><li>S340. A first forwarding entry is sent to the second node, where a destination address of the first forwarding entry is the multicast MAC address and egress port information of the first forwarding entry is the identifier of the first port.</li><li>S350. A second forwarding entry is sent to the third node, where a destination address of the second forwarding entry is the multicast MAC address and egress port information of the second forwarding entry is the identifier of the second port.</li></ul>

0027According to the embodiment of the present invention, a separate controller device is used to generate a multicast forwarding entry for a second node and a third node on a multicast path according to a message from a first node, so as to enable the second node and the third node to acquire a multicast forwarding entry of the current node without receiving and parsing an IGMP packet or an MLD packet from a previous hop node of the current node, avoiding a problem of failing to parse an IGMP or MLD message to establish multicast forwarding entry respectively by the second node and the third node when IGMP or MLD protocol versions of the first node, the second node and the third node are different.

0028Further, with reference to a flow shown in <figref idref="f0002">FIG. 3</figref>, with regards to a scenario in which multiple network nodes exist in a network and even a scenario in which a multicast path crosses a network administration domain of a controller device, an embodiment of the present invention provides a method for indicating a multicast forwarding entry, as shown in <figref idref="f0003">FIG. 4</figref>, including: <ul id="ul0019" list-style="none" compact="compact"><li>S410. A multicast control message and an access loop identifier sent by an edge node of a network administration domain are received, where the multicast control message is an internet group management protocol IGMP packet or a Multicast Listener Discovery protocol MLD packet.</li><li>S420. Port information of each network node on a multicast path corresponding to the access loop identifier is determined according to the access loop identifier, respectively, and a multicast media access control (Media Access Control, MAC) address corresponding to the multicast path is determined according to a multicast internet protocol (Internet Protocol, IP) address in the IGMP packet or the MLD packet.</li><li>S430. With respect to the each network node on the multicast path, a multicast forwarding entry corresponding to a network node is formed by port information of the network node and the multicast MAC address, and then the multicast forwarding entry is sent to the network node.</li></ul>

0029The edge node is an ingress network node or an egress network node in a current network administration domain. With respect to a multicast service, the edge node is generally an ingress network node or an egress network node on a multicast path within a network administration domain. The network node may be a device such as customer premises equipment (Customer Premises Equipment, CPE), an AN (for example, an ONU/DSLAM/OLT), or an aggregation node, or a router (for example, a BNG/BRAS). The multicast control message includes an IGMP/MLD and an access loop identifier (Line ID).

0030Optionally, the access loop identifier is an access loop identifier of the edge node; in step S420, the port information of each network node on a multicast path corresponding to the access loop identifier is determined according to the access loop identifier respectively includes: <ul id="ul0020" list-style="none" compact="compact"><li>determining, according to the access loop identifier of the edge node, a pre-stored mapping relationship between the access loop identifier and the port information of each network node, and the multicast path corresponding to the access loop identifier of the edge node determined according to a pre-stored network topology relationship, the port information of each network node on the multicast path corresponding to the access loop identifier of the edge node; or</li><li>sending the access loop identifier of the edge node to a server, where a mapping relationship between the access loop identifier and the port information of the each network node and a network topology relationship are pre-stored in the server; receiving the port information of the each network node on the multicast path corresponding to the access loop identifier of the edge node fed back by the server.</li></ul>

0031That is, a separate server may be set and an access controller may inquire the port information of the each network node on the multicast path corresponding to the access loop identifier from the server; or the access controller may preset the mapping relationship between the access loop identifier and the port of the each network node and the network topology relationship, and the access controller may inquire the mapping relationship and the network topology relationship to obtain the port information of the each network node.

0032The access loop identifier is an identifier that is widely used in various network systems, and with respect to a digital subscriber line (Digital Subscriber Line, DSL) system or an Ethernet (ETH) access system, formats of the access loop identifier are as follows: <ul id="ul0021" list-style="none" compact="compact"><li>when an AN accesses a DSL line based on an asynchronous transfer mode (Asynchronous Transfer Mode, ATM), the access loop identifier is Access-Node-Identifier atm slot/port:vpi.vci. when the AN accesses a DSL/ETH line base on an ETH, a format of the access loop identifier is Access-Node-Identifier eth slot/port [:vlan-id]. Where the Access-Node-Identifier is an identifier of the AN; the slot/port is one or any combination of information such as a chassis (chassis) number, a rack (rack) number, a frame (frame) number, a slot (slot) number, a sub-slot (sub-slot) number, a port (port) number on the AN, and specific content thereof is related to a layout condition of a device in a field; the vpi.vci is a virtual path identifier and a virtual channel identifier on a DSL line; "[ ]" in the format indicates it is optional.</li></ul>

0033With respect to a passive optical network (Passive Optical Network, PON) system, the access loop identifier has two format options as follows: <ul id="ul0022" list-style="none" compact="compact"><li>Option 1 is that the access loop identifier only includes port information of an ONU and formats are as follows: when the ONU accesses a DSL line based on an ATM, a format is ONUID atm slot2/port2:vpi.vci. When the ONU accesses a DSL line based on an ETH, a format is ONUID eth slot2/port2[:vlan-id]. Normally, with respect to an ONU port, the vlan-id is a C-VLAN ID (Customer VLAN ID, customer virtual local area network identifier), which is used for identifying a user or an access line, and the vlan-id is generally added or removed by the ONU.</li><li>Option 2 is that the access loop identifier not only includes port information of an ONU, but also includes port information of an OLT, and formats are as follows: when the ONU accesses a DSL line based on an ATM, a format is Access-Node-Identifier atm slot1/port1/ONUID/slot2/port2:vpi.vci. When the ONU accesses a DSL/ETH line based on an ETH, a format is Access-Node-Identifier eth slot1/port1/ONUID/slot2/port2[:vlan-id]. Where the Access-Node-Identifier is an identifier of the OLT; the slot1/port1 is one or any combination of a chassis (chassis) number, a rack (rack) number, a frame (frame) number, a slot (slot) number, a sub-slot (sub-slot) number and a port (port) number on the OLT, and specific content is related to field layout condition of a device; the slot2/port2 is one or the any combination of a chassis (chassis) number, a rack (rack) number, a frame (frame) number, a slot (slot) number, a sub-slot (sub-slot) number and a port (port) number on the ONU.</li></ul>

0034In a word, an access loop identifier reported by a network node includes port information, and each node on a multicast path and port information thereof may be determined according to the access loop identifier reported by the network node. Optionally, the access loop identifier is an access loop identifier of each access node on the multicast path; in step S420, the port information of each network node on a multicast path corresponding to the access loop identifier is determined according to the access loop identifier respectively includes: <ul id="ul0023" list-style="none" compact="compact"><li>acquiring, according to the access loop identifier of each access node on the multicast path, the port information included in the access loop identifier of each access node on the multicast path, respectively.</li></ul>

0035That is, in a scenario shown in <figref idref="f0001">FIG. 2</figref>, another embodiment is also provided, that is, an IGMP/MLD message is still transmitted on a multicast path, and each network node on the multicast path does not parse the IGMP/MLD message, but inserts an access loop identifier of the current node in the message before forwarding the IGMP/MLD message, and then an edge node of a network administration domain reports the IGMP/MLD message and an access loop identifier of each node to an access controller. Finally, the access controller parse the IGMP/MLD message, acquires port information in the access loop identifier and indicates to each network node a multicast forwarding entry corresponds to the each network node. Specifically, in the step S420, that a multicast Media Access Control MAC address corresponding to the multicast path is determined according to a multicast Internet Protocol IP address in the multicast control message includes: <ul id="ul0024" list-style="none" compact="compact"><li>determining, according to the multicast IP address in the multicast control message and a predetermined mapping relationship between the multicast IP address and the multicast MAC address, the multicast MAC address corresponding to the multicast path.</li></ul>

0036Specifically, after the step S410, the method further includes: sending the IGMP packet or the MLD packet to another edge node except the edge node; or <ul id="ul0025" list-style="none" compact="compact"><li>generating a multicast routing protocol packet according to the IGMP packet or the MLD packet and sending the multicast routing protocol packet to another edge node except the edge node.</li></ul>

0037When the another edge node (for example, Node n in <figref idref="f0001">FIG. 2</figref>) is an access node (for example, an OLT, a DSLAM) or an aggregation node, the access controller forwards the IGMP/MLD message to the another edge node through an Openflow protocol, an access management or control protocol (for example, an OMCI or an ETH OAM) or a tunnel protocol. When the another edge node is a router (for example, a BNG/BRAS), the access controller forwards a generated multicast routing protocol (for example, a protocol independent multicast (Protocol Independent Multicast, PIM)/source-specific multicast (Source-Specific Multicast, SSM)) message to the another edge node serving as the router through the Openflow protocol, the access management or control protocol or the tunneling protocol. After receiving the IGMP packet or the MLD packet or the multicast routing protocol packet, the another edge node continues to transmit the packet.

0038A diagram of message flow in the foregoing embodiment is shown in <figref idref="f0003">FIG. 5</figref>, where an access controller receives an IGMP/MLD message sent by an edge serving as an ingress network node, sends a multicast forwarding entry to each network node, and sends the IGMP/MLD message to an edge node serving as an egress network node.

0039Several specific embodiments of the present invention will be given below.

0040Referring to <figref idref="f0004">FIG. 6</figref>, specific embodiment 1 of the present invention includes steps as follows: <ul id="ul0026" list-style="none" compact="compact"><li>S610. A user sends an IGMP/MLD packet to a remote access node (Remote AN).</li><li>S620. The Remote AN sends the IGMP/MLD packet and a Line ID to an access controller by extending an openflow message.</li><li>S630. The access controller sends an AAA message to an AAA (an abbreviation of Authentication, Authorisation and Accounting) server, where the Line ID is carried in the AAA message, and the AAA message is used for inquiring port information.</li><li>S640. The AAA server obtains port information corresponding to network nodes at all levels according to the Line ID.</li><li>S650. The AAA server sends an AAA message to the access controller, where the Line ID and the port information corresponding to the network nodes at all levels are carried in the AAA message.</li><li>S660. The access controller acquires a multicast IP address according to the IGMP/MLD, forms group membership entries at all levels according to the port information and the multicast IP address and maps the multicast IP address to a multicast MAC address, so as to further form corresponding multicast forwarding entries at all levels.</li><li>S670. Corresponding multicast forwarding entries on the network nodes at all levels are configured through an openflow protocol.</li><li>S680. A corresponding multicast forwarding entry is sent to each network node through an openflow message.</li><li>S690. The each network node implements multicast forwarding entry configuration.</li></ul>

0041In the specific embodiment 1, when the Remote AN is an ONU, an AN 1 is an OLT and an AN 2 is a DSLAM, the Line ID carried in the openflow message in the step S620 may be Option 1, and in this case, the access controller inquires the AAA server to obtain port information of the OLT and the DSLAM according to Line ID information; or the Line ID carried in the openflow message in the step S620 is Option 2, the ONU needs to obtain or set port information of the OLT in advance, and in this case, the access controller inquires the AAA server to obtain port information of the DSLAM according to Line ID information.

0042Referring to <figref idref="f0005">FIG. 7</figref>, specific embodiment 2 of the present invention includes steps as follows: <ul id="ul0027" list-style="none" compact="compact"><li>S710. A user sends an IGMP/MLD packet to an ONU.</li><li>S720. The ONU sends the IGMP/MLD packet and a Line ID 1 (port information of the ONU) to an OLT by extending an openflow message.</li><li>S730. The OLT sends the IGMP/MLD packet and a Line ID 2 (port information of the ONU and port information of the OLT) to an access controller by extending an openflow message.</li><li>S740. The access controller acquires a multicast IP address according to an IGMP/MLD, forms group membership entries at all levels according to the port information and the multicast IP address and maps the multicast IP address to a multicast MAC address, so as to further form corresponding multicast forwarding entries at all levels.</li><li>S750. Corresponding multicast forwarding entries on the network nodes at all levels are configured through an openflow protocol.</li><li>S760. A corresponding multicast forwarding entry is sent to each network node through an openflow message.</li><li>S770. The each network node implements multicast forwarding entry configuration.</li></ul>

0043Referring to <figref idref="f0005">FIG. 8</figref>, a device 80 for indicating a multicast forwarding entry is provided in an embodiment of the present invention, including: <ul id="ul0028" list-style="none" compact="compact"><li>a first receiving unit 810, configured to receive a multicast control message and an access loop identifier sent by a first node;</li><li>a first determining unit 820, configured to determine an identifier of a first port of a second node and an identifier of a second port of a third node on a multicast path corresponding to the access loop identifier, where both the first port and the second port are egress ports on the multicast path;</li><li>a second determining unit 830, configured to determine, according to a multicast Internet Protocol IP address in the multicast control message, a multicast Media Access Control MAC address corresponding to the multicast path;</li><li>a first sending unit 840, configured to send a first forwarding entry to the second node, where a destination address of the first forwarding entry is the multicast MAC address and egress port information of the first forwarding entry is the identifier of the first port; and</li><li>a second sending unit 850, configured to send a second forwarding entry to the third node, where a destination address of the second forwarding entry is the multicast MAC address and egress port information of the second forwarding entry is the identifier of the second port.</li></ul>

0044Optionally, the access loop identifier received by the first receiving unit 810 is an access loop identifier of the first node.

0045The first determining unit 820 is specifically configured to: <ul id="ul0029" list-style="none" compact="compact"><li>determine, according to the access loop identifier of the first node and a pre-stored mapping relationship between an access loop identifier and port information of each network node and a multicast path corresponding to the access loop identifier of the first node determined according to a pre-stored network topology relationship, the identifier of the first port of the second node and the identifier of the second port of the third node on the multicast path corresponding to the access loop identifier of the first node; or</li><li>send the access loop identifier of the first node to a server, where a mapping relationship between the access loop identifier and the port information of each network node and a network topology relationship are pre-stored in the server; receive the identifier of the first port of the second node and the identifier of the second port of the third node on the multicast path corresponding to the access loop identifier of the first node fed back by the server.</li></ul>

0046Optionally, the access loop identifier received by the first receiving unit 810 includes an access loop identifier of the first node, an access loop identifier of the second node and an access loop identifier of the third node, and both the second node and the third node are on a multicast path corresponding to the access loop identifier of the first node.

0047The first determining unit 820 is specifically configured to: <ul id="ul0030" list-style="none" compact="compact"><li>acquire, according to the access loop identifier of the second node and the access loop identifier of the third node on the multicast path, the identifier of the first port of the second node and the identifier of the second port of the third node on the multicast path, respectively.</li></ul>

0048Optionally, the second determining unit 830 is specifically configured to: <ul id="ul0031" list-style="none" compact="compact"><li>determine, according to the multicast IP address in the multicast control message and a predetermined mapping relationship between the multicast IP address and the multicast MAC address, the multicast MAC address corresponding to the multicast path.</li></ul>

0049Optionally, the multicast control message received by the first receiving unit 810 is an internet group management protocol IGMP packet or a Multicast Listener Discovery protocol MLD packet.

0050Further, the device 80 also includes: <ul id="ul0032" list-style="none" compact="compact"><li>a third sending unit, configured to send the IGMP packet or the MLD packet to a fourth node; or</li><li>generate a multicast routing protocol packet according to the IGMP packet or the MLD packet and send the multicast routing protocol packet to a fourth node.</li></ul>

0051Further, the first receiving unit 810 is specifically configured to: <ul id="ul0033" list-style="none" compact="compact"><li>receive the multicast control message and the access loop identifier sent by the first node according to an openflow protocol, or an access management or control protocol, or an Ethernet operation, administration and maintenance protocol, or a tunneling protocol.</li></ul>

0052Referring to <figref idref="f0006">FIG. 9</figref>, a device 90 for indicating a multicast forwarding entry is provided in an embodiment of the present invention, including: <ul id="ul0034" list-style="none" compact="compact"><li>a processor 910, a memory 920 and a communication interface 930, where the processor 910, the memory 920 and the communication interface 930 are connected to each other through a bus or in another manner.</li></ul>

0053The memory 920 is configured to store a program. Specifically, the program may include a program code, and the program code includes a computer operating instruction. The memory may include a high-speed random access memory (random access memory, RAM for short), and may further include a non-volatile memory (non-volatile memory), for example at least one magnetic disk memory.

0054The communication interface 930 is configured to communicate with each node.

0055When executing the program stored in the memory 920, the processor 910 may execute S310-S350 in the embodiment corresponding to <figref idref="f0002">FIG. 3</figref>, S410-S430 in the embodiment corresponding to <figref idref="f0003">FIG. 4</figref> and all operations of the access controller in the embodiments corresponding to <figref idref="f0003 f0004 f0005">FIG. 5 to FIG. 7</figref>, and may display all functions of the device 80 of the multicast forwarding entry.

0056The forgoing processor may be a general-purpose processor, including a central processing unit (Central Processing Unit, CPU for short), a network processor (Network Processor, NP for short) or the like; it may also be a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA) or other programmable logic devices, a discrete gate or a transistor logic device or a discrete hardware component.

0057In a word, according to the embodiments of the present invention, control plane functions of a network node are centralized at an access controller side, and the network node is simplified as a programmable forwarding device. In this way the network node does not have to support listening/proxy of an IGMP/MLD, achieving decoupling the network node from a multicast service. The network node does not need to consider compatibility and matching with a terminal and a multicast router, thereby greatly reducing operation and maintenance complexity and management cost.

0058Those skilled in the art should understand that the embodiments of the present invention may be provided as a method, a system or a computer program product. Therefore, the present invention may adopt the forms of complete hardware embodiments, complete software embodiments or combined embodiments of software and hardware. Moreover, the present invention may adopt the form of a computer program product implemented on one or multiple computer available storage media (including, but not limited to, a disk storage, an optical memory) including computer available program codes.

0059The present invention is described in accordance with the flowchart and/or block diagram of the method, the device (system) and the computer program product in the embodiments of the present invention. It should be understood that, computer program instructions may achieve each flow and/or block in the flowchart and/or the block diagram and the combination of the flows and/or blocks in the flowchart and/or the block diagram. These computer program instructions may be provided to a general-purpose computer, a special-purpose computer, an embedded processor or processors of other programmable data processing devices to generate a machine, such that the instructions executed by the computers or the processors of the other programmable data processing devices generate apparatuses used for achieving appointed functions in one flow or multiple flows of the flowchart and/or one block or multiple blocks of the block diagram.

0060These computer program instructions may also be stored in a computer readable memory capable of guiding the computers or the other programmable data processing devices to work in particular manners, such that the instructions stored in the computer readable memory generate products including instruction apparatuses, and the instruction apparatuses achieve the appointed functions in one flow or multiple flows of the flowchart and/or one block or multiple blocks of the block diagram.

0061These computer program instructions may also be loaded onto the computers or the other programmable data processing devices, to execute a series of operation steps on the computers or the other programmable data processing devices to produce processing implemented by the computers, such that the instructions executed on the computers or the other programmable data processing devices provide steps used for achieving the appointed functions in one flow or multiple flows of the flowchart and/or one block or multiple blocks of the block diagram.

0062Obviously, persons skilled in the art may make various modifications and variations to the present invention without departing from the spirit and scope of the present invention. In this way, if these modifications and variations of the present invention belong to the scope of the claims of the present invention and the equivalent technologies thereof, then the present invention is intended to encompass these modifications and variations.