CN116743861A

CN116743861A - Multicast joining method and related equipment

Info

Publication number: CN116743861A
Application number: CN202210212267.1A
Authority: CN
Inventors: 张耀坤; 王雷; 谢经荣
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2022-03-04
Filing date: 2022-03-04
Publication date: 2023-09-12

Abstract

The application provides a multicast joining method and related equipment, which are used for reducing the occurrence of transmission interruption in an automatic multicast tunnel (automatic multicast tunneling, AMT) network so as to improve the network stability. In the method, a first network device receives a first message from a second network device, the first message being used for requesting to join the AMT network, the first message including an address of the second network device; the first network device sends a redirection message to a third network device, where the redirection message is used to instruct processing of a request to join the AMT network, and the redirection message includes an address of the second network device.

Description

Multicast joining method and related equipment

Technical Field

The present application relates to the field of communications technologies, and in particular, to a multicast joining method and related devices.

Background

During multicast communication, some intermediate nodes between a multicast source (source) and a receiver (receiver) of multicast information may lack multicast capability (Lack multicast capability), which may easily cause interruption of transmission of the multicast information. For this purpose, automatic multicast tunneling (automatic multicast tunneling, AMT) techniques are currently proposed for solving the problem of transmission interruption.

Currently, in an AMT network, a device connected to a multicast source is called a relay device, a device connected to an information receiving side is called a gateway device, and the relay device and the gateway device are connected through an intermediate network lacking multicast capability. In other words, the relay device and the gateway device are connected through an intermediate network lacking multicast capability, i.e. the relay device may be referred to as a root node of the intermediate network and the gateway device may be referred to as a leaf node of the intermediate network. Before the multicast information is transmitted, the gateway device needs to initiate a request for joining the AMT network, and the intermediate network forwards the request to the relay device with the nearest route. Typically, for a certain relay device in an AMT network, after receiving a request from a certain gateway device, a connection is established with the gateway device, and multicast information from a multicast source is transmitted to the gateway device.

However, in the implementation process, the relay device that receives the request may not necessarily support transmission of the multicast information of the gateway device, for example, when a part of the relay device fails or the load of the relay device is too heavy, transmission interruption is easily caused, which affects stability of the network.

Disclosure of Invention

The application provides a multicast joining method and related equipment, which are used for reducing the occurrence of transmission cut-off in an AMT network so as to improve the network stability.

The first aspect of the present application provides a multicast joining method, applied to an AMT network, where the method is performed by a first network device, or the method is performed by a part of components (such as a processor, a chip, or a system-on-chip) in the first network device, or the method is implemented by a logic module or software capable of implementing all or part of the functions of the first network device. In the first aspect and its possible implementation manner, the multicast joining method is described by taking an example performed by a first network device, where the first network device is a device such as a router, a switch, a virtual machine, and the like. In the method, a first network device receives a first message from a second network device, the first message being used for requesting to join the AMT network, the first message including an address of the second network device; the first network device sends a redirection message to a third network device, where the redirection message is used to instruct processing of a request to join the AMT network, and the redirection message includes an address of the second network device.

Based on the technical scheme, after receiving the first message of the second network device for requesting to join the AMT network, the first network device sends a redirect message for indicating to process the request for joining the AMT network to the third network device, so that the third network device processes the request of the second network device for joining the AMT network based on the redirect message. Thus, compared to an implementation in which the first network device processes a request for the second network device to join the AMT network after receiving the request; in the method, the implementation mode of processing the request of joining the AMT network by the second network device by the third network device can reduce the occurrence of transmission interruption in the AMT network so as to improve the network stability.

It should be understood that, in the embodiment of the present application, the number of the third network devices is not limited, and the number of the third network devices may be 1, or may be an integer greater than 1, which is not limited herein.

Further, "address of the second network device" may include a media access control (media access control, MAC) address of the second network device, an internet protocol (internet protocol, IP) address of the second network device, or other address of the second network device, without limitation herein.

In a possible implementation manner of the first aspect, the sending, by the first network device, the redirection packet to the third network device includes: and the first network equipment sends the redirection message to the third network equipment when the processing capacity of the first network equipment reaches a threshold value.

Based on the technical scheme, when the first network device determines that the processing capability of the first network device reaches the threshold, the first network device sends a redirection message for indicating to process a request for joining the AMT network to the third network device, so that the third network device processes the request for joining the AMT network by the second network device based on the redirection message. Thus, the condition that the network is unstable due to the overload of the processing load of the first network device can be avoided.

In a possible implementation manner of the first aspect, the sending, by the first network device, the redirection packet to the third network device includes: and the first network equipment sends the redirection message to the third network equipment when the attribute corresponding to the second network equipment is not matched with the attribute corresponding to the first network equipment.

Based on the technical scheme, when the first network device determines that the attribute corresponding to the second network device is not matched with the attribute corresponding to the first network device, the first network device sends a redirection message for indicating to process a request for joining the AMT network to the third network device, so that the third network device matched with the attribute corresponding to the second network device processes the request for joining the AMT network by the second network device. Therefore, when a plurality of network devices (including the first network device and the third network device) exist in the AMT network, the load sharing of the plurality of network devices is divided by the attribute difference of the network devices, so that the load balancing of the plurality of network devices is realized to a certain extent, and the occurrence of unstable network caused by overload of a certain network device is reduced.

In a possible implementation manner of the first aspect, the sending, by the first network device, the redirection packet to the third network device includes: and when the attribute corresponding to the second network equipment is not matched with the attribute corresponding to the first network equipment and the processing capacity of the first network equipment reaches a threshold value, the first network equipment sends the redirection message to the third network equipment.

Based on the technical scheme, when the first network device determines that the attribute corresponding to the second network device is not matched with the attribute corresponding to the first network device, and the first network device determines that the processing capability of the first network device reaches the threshold, the first network device sends a redirection message for indicating to process a request for joining the AMT network to the third network device, so that the third network device matched with the attribute corresponding to the second network device processes the request for joining the AMT network by the second network device. Therefore, on one hand, the situation that the network is unstable due to the fact that the processing load of the first network device is too heavy can be avoided, on the other hand, under the condition that a plurality of network devices (including the first network device, the third network device and the like) exist in the AMT network, the load sharing of the network devices is divided through the difference of the attributes of the network devices, the load balancing of the network devices is achieved to a certain extent, and the situation that the network is unstable due to the fact that the load of a certain network device is too heavy is reduced.

In a possible implementation manner of the first aspect, the attribute corresponding to the second network device includes parity corresponding to an address of the second network device; the attributes corresponding to the first network device include attributes corresponding to the parity.

Based on the above technical solution, the attribute corresponding to the second network device may be represented by parity corresponding to the address of the second network device, and because the first message received by the first network device includes the address of the second network device, the first network device determines the attribute corresponding to the second network device based on the first message, which is easy to implement.

It should be understood that, in the embodiment of the present application, the "parity corresponding to an address" may specifically indicate that, in the case where the value of the last bit (or the first bit, the second bit.) in the address is an odd number, the address is an "odd" attribute; and indicates that the last bit (or first, second) in the address has an even value, the address is an "even" attribute. The "attribute corresponding to the parity" may be an attribute determined by negotiating with each other in advance between a plurality of network devices (including the first network device and the third network device) in the AMT network, may be an attribute preconfigured by a factory of the plurality of network devices in the AMT network, may be an attribute determined by the plurality of network devices in the AMT network based on their addresses, or may be an attribute determined by other means, and is not limited herein.

In addition, in the embodiment of the present application, the attribute corresponding to the second network device may further include other attributes, for example, parity of a value corresponding to a sending time of the first packet sent by the second network device, parity of a value corresponding to a receiving time of the first packet sent by the second network device received by the first network device, a size attribute of a value of a last bit (or a first bit, a second bit.) in an address of the second network device (for example, the value is greater than or equal to a 5 corresponding "big" attribute, and the value is less than a 5 corresponding "small" attribute), or other implementation manners, which are not limited herein.

In a possible implementation manner of the first aspect, before the first network device sends the redirection packet to the third network device, the method further includes: the first network device determines that the route of the third network device is reachable, and executes the first network device to send the redirection message to the third network device.

Based on the above technical solution, when the first network device determines that the route of the third network device is reachable, the first network device performs sending the redirection message to the third network device, so as to ensure that after the first network device sends the redirection message to the third network device, the third network device can process a request of joining the AMT network by the second network device.

It should be appreciated that in the embodiment of the present application, the case where the route of the third network device is not reachable includes at least one of a failure of the third network device, a failure of a routing link between the third network device and the second network device, a failure of a routing link between the third network device and the first network device, or other cases.

In a possible implementation manner of the first aspect, the determining, by the first network device, that the third network device route is reachable includes: the first network device sends a keep-alive message and receives a response to the keep-alive message within a first time period.

Based on the above technical solution, after the first network device sends the keep-alive message, if the first network device receives a response of the keep-alive message within a first time period, the first network device determines that a route of a third network device is reachable, and expects that the third network device can process a request of joining the AMT network by the second network device.

In a possible implementation manner of the first aspect, the determining, by the first network device, whether the third network device is reachable by the route includes: the first network device transmits a network quality analysis (network quality analysis, NQA) probe message and receives a response to the NQA probe message within a second time period.

Based on the above technical solution, after the first network device sends the NQA probe packet, if the first network device receives a response of the NQA probe packet within the first time period, the first network device determines that the route of the third network device is reachable, and expects that the third network device can process a request of joining the AMT network by the second network device.

In a possible implementation manner of the first aspect, the determining, by the first network device, that the third network device route is reachable includes: the first network device sends a bidirectional forwarding detection (bidirectional forwarding detection, BFD) message and receives a response to the BFD message for a third duration.

Based on the above technical solution, after the first network device sends the BFD packet, if the first network device receives a response to the BFD packet within the first time period, the first network device determines that the route of the third network device is reachable, and predicts that the third network device can process a request of joining the AMT network by the second network device.

In a possible implementation manner of the first aspect, after the first network device receives the first packet from the second network device, the method further includes: after the fourth duration, the first network device sends a response message corresponding to the request to join the AMT network to the second network device, where the response message includes an address of the first network device.

Based on the above technical solution, after the fourth period of time, the first network device sends a response message corresponding to the request to join the AMT network to the second network device, so that in a case where the third network device cannot process the request (for example, the third network device is overloaded, the third network device fails, the third network device cannot be routed), the second network device can still join the AMT network through the first network device, thereby further improving the stability of the network.

It should be noted that, the values of the corresponding durations, such as the first duration, the second duration, the third duration, the fourth duration, and the like, may be determined based on a factory preset manner, may be determined by a manner of inputting an instruction by a user, may be determined by other manners, and are not limited herein. In addition, the time values corresponding to the first time, the second time, the third time, the fourth time and the like can be realized independently, and the association relationship can exist or does not exist between different time periods, so that the method is not limited.

In a possible implementation manner of the first aspect, the unicast address of the first network device is the same as the unicast address of the third network device; or, the anycast address of the first network device is the same as the anycast address of the third network device.

Based on the above technical solution, since the destination address of the first packet is the unicast address (or anycast address) of the first network device, when the unicast address of the first network device is the same as the unicast address of the third network device (or the anycast address of the first network device is the same as the anycast address of the third network device), the routing path between the third network device and the second network device is ensured to be connected. In other words, after the first network device sends a redirect message to the third network device indicating to process the request to join the AMT network, to ensure that a subsequent third network device can communicate with the second network device based on the switched-on routing path.

In a possible implementation manner of the first aspect, the first network device and the third network device are both a relay device in the AMT network or a device serving as a root in the AMT network, and the second network device is a gateway device in the AMT network or a device serving as a leaf in the AMT network.

It should be understood that the second network device is a sender of the first message in the AMT network (or a receiver of the response message in the AMT network), and the name of the second network device may be a gateway device defined in the current AMT network, and along with development of AMT network technology, the second network device may also be other names, which is not limited by the present application. Similarly, the first network device (or the third network device) is a receiver of the first message of the AMT network device (or a sender of the response message in the AMT network), and the name of the first network device (or the third network device) may be a relay device defined in the current AMT network, and with the development of AMT network technology, the first network device (or the third network device) may also be other names, which is not limited by the present application.

Similarly, the first message is a Discovery (Discovery) message in the AMT network, and the response message corresponding to the request to join the AMT network is an Advertisement (Advertisement) message in the AMT network. With the development of AMT network technology, the first message (and the response message corresponding to the request to join the AMT network) may also be other names, which is not limited by the present application.

A second aspect of the present application provides a multicast joining method applied to an AMT network, where the method is performed by a second network device, or the method is performed by a part of a component (such as a processor, a chip, or a system-on-chip) in the second network device, or the method is implemented by a logic module or software capable of implementing all or part of the functions of the second network device. In a second aspect and its possible implementation manner, the multicast joining method is described by taking as an example that the second network device is a router, a switch, a virtual machine, a home gateway device, an optical line terminal (optical line terminal, OLT) device, a terminal entity, or the like. In the method, a second network device sends a first message, wherein the first message is used for indicating that the request is added into an AMT network, and the first message comprises address information of the second network device; the second network device receives n response messages corresponding to the request to join the AMT network, where n is greater than or equal to 1.

Based on the above technical solution, after the second network device sends the first message for indicating to request to join the AMT network, the second network device receives n response messages corresponding to the request to join the AMT network, that is, the second network device receives one or more response messages corresponding to the request to join the AMT network. Under the condition that the value of n is larger than 1, that is, under the condition that n response messages are a plurality of response messages, the second network device can join the AMT network through a plurality of network devices based on the plurality of response messages. Therefore, compared with the implementation mode that a single network device processes the request of joining the AMT network of the second network device, the situation that the AMT network is easily caused to be cut off when the single network device has faults occurs, the success rate of joining the AMT network of the second network device can be improved because the second network device can join the AMT network through a plurality of network devices based on the response messages, and the network stability can be improved.

In a possible implementation manner of the second aspect, the method further includes: the second network device sends a first request message, wherein the first request message corresponds to a first response message, and the first response message is a response message received first in the n response messages.

Based on the above technical solution, the second network device may further send a first request message corresponding to a first response message received first in the n response messages, where in a case where the value of n is greater than 1, that is, in a case where the n response messages are multiple response messages, the second network device may send the first request message corresponding to the first response message received first in the multiple response messages, so as to facilitate fast joining into the multicast network based on the first request message, so as to improve communication efficiency.

In a possible implementation manner of the second aspect, after the second network device sends the first request packet, the method further includes: and when the second network equipment determines that the response message of the first request message is not received after the preset duration threshold, the second network equipment sends a second request message, wherein the second request message corresponds to other response messages except the first response message in the response messages.

Based on the above technical solution, when the second network device determines that the response message of the first request message is not received after the preset duration threshold, the second network device sends other response messages corresponding to the plurality of response messages except the first response message, so that the second network device can also join the AMT network based on other response messages when the second network device cannot join the AMT network based on the first request message, so as to improve the success rate of joining the AMT network by the second network device.

In a possible implementation manner of the second aspect, the second network device is a gateway device in the AMT network or a device of which the AMT network is a leaf.

It should be understood that the second network device is a sender of the first message in the AMT network (or a receiver of the response message in the AMT network), and the name of the second network device may be a gateway device defined in the current AMT network, and along with development of AMT network technology, the second network device may also be other names, which is not limited by the present application.

A third aspect of the present application provides a multicast joining method applied to an AMT network, where the method is performed by a third network device, or the method is performed by a part of a component (such as a processor, a chip, or a system-on-chip) in the third network device, or the method is implemented by a logic module or software capable of implementing all or part of the functions of the third network device. In a third aspect and its possible implementation manner, the multicast joining method is described by taking as an example that the third network device is a router, a switch, a virtual machine, and other devices. In the method, a third network device receives a redirection message from a first network device, wherein the redirection message is used for indicating to process a request for joining the AMT network, and the redirection message comprises an address of a second network device; the third network device sends a response message corresponding to the request to join the AMT network to the second network device, the response message including an address of the third network device.

Based on the above technical solution, after receiving, by the third network device, a redirect message from the first network device for instructing to process a request for joining the AMT network, the third network device processes, based on the redirect message, a request for joining the AMT network by the second network device, that is, the third network device sends, to the second network device, a response message corresponding to the request for joining the AMT network. Thus, compared to an implementation in which the first network device processes a request for the second network device to join the AMT network after receiving the request; in the method, the implementation mode of processing the request of joining the AMT network by the second network device by the third network device can reduce the occurrence of transmission interruption in the AMT network so as to improve the network stability.

In a possible implementation manner of the third aspect, before the third network device sends a response packet corresponding to the request to join the AMT network to the second network device, the method includes: the third network device determines that the attribute corresponding to the third network device matches the attribute corresponding to the second network device.

Based on the above technical solution, when the third network device determines that the attribute corresponding to the third network device matches the attribute corresponding to the second network device, the third network device sends a response message corresponding to the request for joining the AMT network to the second network device, so as to process the request for joining the AMT network by the second network device. Therefore, when a plurality of network devices (including the first network device and the third network device) exist in the AMT network, the load sharing of the plurality of network devices is divided by the attribute difference of the network devices, so that the load balancing of the plurality of network devices is realized to a certain extent, and the occurrence of unstable network caused by overload of a certain network device is reduced.

In a possible implementation manner of the third aspect, the attribute corresponding to the second network device includes a parity corresponding to an address of the second network device, and the attribute corresponding to the third network device includes an attribute corresponding to the parity.

Based on the above technical solution, the attribute corresponding to the second network device may be represented by parity corresponding to the address of the second network device, and because the redirection packet received by the third network device includes the address of the second network device, the first network device determines the attribute corresponding to the second network device based on the first packet, which is easy to implement.

In a possible implementation manner of the third aspect, the unicast address of the third network device is the same as the unicast address of the first network device; or, the anycast address of the third network device is the same as the anycast address of the first network device.

Based on the above technical solution, since the destination address of the first packet sent by the second network device is the unicast address (or the anycast address) of the first network device, when the unicast address of the first network device is the same as the unicast address of the third network device (or the anycast address of the first network device is the same as the anycast address of the third network device), the routing path between the third network device and the second network device is ensured to be connected. In other words, after the first network device sends a redirect message to the third network device indicating to process the request to join the AMT network, to ensure that a subsequent third network device can communicate with the second network device based on the switched-on routing path.

In a possible implementation manner of the third aspect, the first network device and the third network device are both a relay device in the AMT network or a device serving as a root in the AMT network, and the second network device is a gateway device in the AMT network or a device serving as a leaf in the AMT network.

A fourth aspect of the present application provides a communication device capable of implementing the method of the first aspect or any one of the possible implementation manners of the first aspect. The apparatus comprises corresponding units or modules for performing the above-described methods. The units or modules included in the apparatus may be implemented in a software and/or hardware manner. For example, the apparatus may be a first network device, or the apparatus may be a component (e.g., a processor, a chip, or a system-on-a-chip, etc.) in the first network device, or the apparatus may also be a logic module or software that can implement all or part of the functionality of the first network device.

The device comprises a receiving unit and a transmitting unit;

the receiving unit is used for receiving a first message from second network equipment, wherein the first message is used for requesting the AMT network, and the first message comprises the address of the second network equipment;

the sending unit is configured to send a redirection message to a third network device, where the redirection message is used to indicate to process a request for joining the AMT network, and the redirection message includes an address of the second network device.

In a possible implementation manner of the fourth aspect, the sending unit is configured to send the redirection packet to the third network device when the processing capability of the first network device reaches a threshold value.

In a possible implementation manner of the fourth aspect, the sending unit is configured to send the redirection packet to the third network device when the attribute corresponding to the second network device does not match the attribute corresponding to the first network device.

In a possible implementation manner of the fourth aspect, the sending unit is configured to send the redirection packet to the third network device when the attribute corresponding to the second network device does not match the attribute corresponding to the first network device and the processing capability of the first network device reaches a threshold.

In a possible implementation manner of the fourth aspect, the attribute corresponding to the second network device includes parity corresponding to an address of the second network device; the attributes corresponding to the first network device include attributes corresponding to the parity.

In a possible implementation manner of the fourth aspect, the apparatus further includes a processing unit; the sending unit is further configured to send the redirection packet to the third network device when the processing unit determines that the route of the third network device is reachable.

In a possible implementation manner of the fourth aspect, the sending unit is further configured to send a keep-alive message; the processing unit for determining that the third network device route is reachable includes: and when the receiving unit receives the response of the keep-alive message in the first time period, determining that the route of the third network equipment is reachable.

In a possible implementation manner of the fourth aspect, the sending unit is further configured to send an NQA probe packet, and the processing unit is configured to determine that the third network device route is reachable includes: and when the receiving unit receives the response of the NQA message in the second time period, determining that the route of the third network equipment is reachable.

In a possible implementation manner of the fourth aspect, the sending unit is further configured to send a BFD packet, and the determining, by the processing unit, that the third network device route is reachable includes: and when the receiving unit receives the response of the BFD message within a third time period, determining that the route of the third network device is reachable.

In a possible implementation manner of the fourth aspect, the sending unit is further configured to send, after the fourth time length threshold, a response packet to the second network device, where the response packet corresponds to the request to join the AMT network, and the response packet includes an address of the first network device.

In a possible implementation manner of the fourth aspect, the unicast address of the first network device is the same as the unicast address of the third network device; or, the anycast address of the first network device is the same as the anycast address of the third network device.

In a possible implementation manner of the fourth aspect, the first network device and the third network device are both relay devices in the AMT network or devices serving as a root in the AMT network, and the second network device is a gateway device in the AMT network or a device serving as a leaf in the AMT network.

In the fourth aspect of the embodiment of the present application, the constituent modules of the communication device may also be configured to execute the steps executed in each possible implementation manner of the first aspect, and achieve the corresponding technical effects, and all details may refer to the first aspect, which is not described herein.

A fifth aspect of the present application provides a communication device capable of implementing the method of the second aspect or any one of the possible implementations of the second aspect. The apparatus comprises corresponding units or modules for performing the above-described methods. The units or modules included in the apparatus may be implemented in a software and/or hardware manner. For example, the apparatus may be the second network device, or the apparatus may be a component (e.g., a processor, a chip, or a system-on-a-chip, etc.) in the second network device, or the apparatus may also be a logic module or software that can implement all or part of the functionality of the second network device.

The device comprises a transmitting unit and a receiving unit;

the sending unit is used for sending a first message, the first message is used for indicating to request to join an AMT network, and the first message comprises address information of the second network equipment; the receiving unit is configured to receive n response messages corresponding to the request to join the AMT network, where n is greater than or equal to 1.

In a possible implementation manner of the fifth aspect, the sending unit is further configured to send a first request packet, where the first request packet corresponds to a first response packet, and the first response packet is a response packet that is received first in the n response packets.

In a possible implementation manner of the fifth aspect, the apparatus further includes a processing unit, where the sending unit is further configured to send a second request packet, where the second request packet corresponds to a response packet other than the first response packet in the plurality of response packets, when the processing unit determines that the response packet of the first request packet is not received after a preset duration threshold.

In a possible implementation manner of the fifth aspect, the second network device is a gateway device in the AMT network or a device of which the AMT network is a leaf.

In the fifth aspect of the embodiments of the present application, the constituent modules of the communication device may also be configured to execute the steps executed in each possible implementation manner of the second aspect, and achieve corresponding technical effects, and all details may refer to the second aspect, which is not described herein.

A sixth aspect of the present application provides a communication device capable of implementing the method of the third aspect or any one of the possible implementation manners of the third aspect. The apparatus comprises corresponding units or modules for performing the above-described methods. The units or modules included in the apparatus may be implemented in a software and/or hardware manner. For example, the apparatus may be the third network device, or the apparatus may be a component (e.g., a processor, a chip, or a system-on-a-chip, etc.) in the third network device, or the apparatus may also be a logic module or software that can implement all or part of the functionality of the third network device.

The device comprises a receiving unit and a transmitting unit;

the receiving unit is used for receiving a redirection message from the first network device, wherein the redirection message is used for indicating to process a request for joining the AMT network, and the redirection message comprises an address of the second network device;

the sending unit is configured to send a response packet corresponding to the request for joining the AMT network to the second network device, where the response packet includes an address of the third network device.

In a possible implementation manner of the sixth aspect, the apparatus further includes a processing unit; the sending unit is further configured to send a response packet corresponding to the request for joining the AMT network to the second network device when the processing unit determines that the attribute corresponding to the third network device matches the attribute corresponding to the second network device.

In a possible implementation manner of the sixth aspect, the attribute corresponding to the second network device includes a parity corresponding to an address of the second network device, and the attribute corresponding to the third network device includes an attribute corresponding to the parity.

In a possible implementation manner of the sixth aspect, the unicast address of the third network device is the same as the unicast address of the first network device; or, the anycast address of the third network device is the same as the anycast address of the first network device.

In a possible implementation manner of the sixth aspect, the first network device and the third network device are both relay devices in the AMT network or devices serving as a root in the AMT network, and the second network device is a gateway device in the AMT network or a device serving as a leaf in the AMT network.

In the sixth aspect of the embodiment of the present application, the constituent modules of the communication device may also be configured to execute the steps executed in each possible implementation manner of the third aspect, and achieve corresponding technical effects, and all details may refer to the third aspect, which is not described herein.

A seventh aspect of the embodiments of the present application provides a communication device comprising at least one processor coupled to a memory; the memory is used for storing programs or instructions;

the at least one processor is configured to execute the program or instructions to cause the apparatus to implement the method according to the first aspect or any one of the possible implementation manners of the first aspect.

An eighth aspect of the embodiments of the present application provides a communication device comprising at least one processor coupled to a memory; the memory is used for storing programs or instructions;

The at least one processor is configured to execute the program or instructions to cause the apparatus to implement the method according to the second aspect or any one of the possible implementation manners of the second aspect.

A ninth aspect of the embodiments of the present application provides a communication device comprising at least one processor coupled to a memory; the memory is used for storing programs or instructions;

the at least one processor is configured to execute the program or instructions to cause the apparatus to implement the method according to the foregoing third aspect or any one of the possible implementation manners of the third aspect.

A tenth aspect of the embodiment of the present application provides a communication device, including at least one logic circuit and an input-output interface; the logic circuit is configured to perform a method as described in the foregoing first aspect or any one of the possible implementation manners of the first aspect; or, the logic circuit is configured to perform the method according to the foregoing second aspect or any one of the possible implementations of the second aspect; or, the logic circuitry is to perform the method as described in the foregoing third aspect or any one of the possible implementations of the third aspect.

An eleventh aspect of the embodiment of the present application provides a computer-readable storage medium for storing computer-executable instructions; when executed by a processor, the computer-executable instructions perform the method as described above in the first aspect or any one of the possible implementations of the first aspect; alternatively, the processor performs a method as described in the second aspect or any one of the possible implementations of the second aspect; alternatively, the processor performs the method as described in the third aspect or any one of the possible implementations of the third aspect.

A twelfth aspect of the embodiments of the present application provides a computer program product (or computer program) which, when executed by a processor, performs the method of any one of the above-described first aspect or any one of the possible implementations of the first aspect; alternatively, the processor performs the method of the second aspect or any one of the possible implementations of the second aspect; alternatively, the processor performs the method of the third aspect or any one of the possible implementations of the third aspect.

A thirteenth aspect of the embodiments of the present application provides a chip system comprising at least one processor for supporting a communication device to implement the functionality referred to in the above-mentioned first aspect or any one of the possible implementations of the first aspect, or for supporting a communication device to implement the functionality referred to in the above-mentioned second aspect or any one of the possible implementations of the second aspect, or for supporting a communication device to implement the functionality referred to in the above-mentioned third aspect or any one of the possible implementations of the third aspect.

In one possible design, the system-on-chip may further include a memory to hold the necessary program instructions and data for the communication device. The chip system can be composed of chips, and can also comprise chips and other discrete devices. Optionally, the system on a chip further comprises interface circuitry providing program instructions and/or data to the at least one processor.

A fourteenth aspect of the embodiment of the present application provides a communication system including the communication apparatus of the fourth aspect and the communication apparatus of the sixth aspect.

Optionally, the communication system further comprises the communication device of the fifth aspect.

A fifteenth aspect of an embodiment of the present application provides a communication system including the communication apparatus of the seventh aspect and the communication apparatus of the ninth aspect.

Optionally, the communication system further comprises the communication device of the eighth aspect.

The technical effects of any one of the designs of the fourth aspect to the fifteenth aspect may be referred to the technical effects of the different implementations of the first aspect to the third aspect, and are not described herein.

Drawings

In order to more clearly illustrate the embodiments of the application or the technical solutions of the prior art, the drawings which are used in the description of the embodiments or the prior art will be briefly described, it being obvious that the drawings in the description below are only some embodiments of the application, and that other drawings can be obtained according to these drawings without inventive faculty for a person skilled in the art.

FIG. 1 is a schematic diagram of an application scenario of the present application;

FIG. 2 is another schematic diagram of an application scenario of the present application;

FIG. 3 is another schematic diagram of an application scenario of the present application;

fig. 4 is a schematic diagram of a multicast joining method according to the present application;

FIG. 5 is another schematic diagram of an application scenario of the present application;

FIG. 6a is a diagram illustrating a message format according to the present application;

FIG. 6b is a diagram illustrating a message format according to the present application;

FIG. 7 is another schematic diagram of an application scenario of the present application;

FIG. 8 is a schematic diagram of a communication device according to the present application;

FIG. 9 is another schematic diagram of a communication device according to the present application;

fig. 10 is a schematic diagram of a communication system provided by the present application.

Detailed Description

The technical solutions in the embodiments of the present application will be described below with reference to the accompanying drawings in the embodiments of the present application.

The terms "system" and "network" in embodiments of the application may be used interchangeably. "at least one" means one or more, and "a plurality" means two or more. "and/or", describes an association relationship of an association object, and indicates that there may be three relationships, for example, a and/or B, and may indicate: cases where A alone, both A and B together, and B alone, where A and B may be singular or plural. The character "/" generally indicates that the context-dependent object is an "or" relationship. "at least one of" or the like means any combination of these items, including any combination of single item(s) or plural items(s). For example, "at least one of A, B, and C" includes A, B, C, AB, AC, BC, or ABC. And, unless otherwise specified, references to "first," "second," etc. ordinal words of embodiments of the present application are used for distinguishing between multiple objects and not for defining a sequence, timing, priority, or importance of the multiple objects.

In the present application, the words "exemplary" or "such as" are used to mean serving as an example, instance, or illustration. Any embodiment or design described herein as "exemplary" or "for example" should not be construed as preferred or advantageous over other embodiments or designs. Rather, the use of words such as "exemplary" or "such as" is intended to present related concepts in a concrete fashion.

Referring to fig. 1, a schematic architecture of a communication system according to an embodiment of the present application is provided. As shown in fig. 1, the system includes a plurality of Customer Edge (CE) devices, such as customer edge device 101 and customer edge device 102, as well as other customer edge devices that may be present; the system also includes a plurality of network devices, such as network device 103, network device 104, and network device 105, as well as other network devices that may be present.

In fig. 1, a user edge device 101 or a user edge device 102 is connected to one or more terminal devices, which join the network through CE devices. A terminal device, which may also be referred to as a User Equipment (UE), a Mobile Station (MS), a Mobile Terminal (MT), a terminal, etc., is a device that provides voice and/or data connectivity to a user, or a chip disposed in the device, for example, a handheld device, an in-vehicle device, etc., having a wireless connection function. Currently, examples of some terminal devices are: a mobile phone, desktop computer, tablet computer, notebook computer, palm computer, mobile internet device (mobile internet device, MID), wearable device, virtual Reality (VR) device, augmented reality (augmented reality, AR) device, wireless terminal in industrial control (industrial control), wireless terminal in unmanned (self driving), wireless terminal in teleoperation (remote medical surgery), wireless terminal in smart grid (smart grid), wireless terminal in transportation security (transportation safety), wireless terminal in smart city (smart city), wireless terminal in smart home (smart home), home gateway device supporting 5G-residential gateway,5G-RG supporting 5G joining, etc.

Optionally, in fig. 1, the network device 103, the network device 104, and the network device 105 are routers (routers), switches, virtual machines, and the like.

It should be noted that, the connection between the network device and the user edge device shown in fig. 1 (for example, the user edge device 101 and the network device 103, or the user edge device 102 and the network device 104) may be a wired connection/wireless connection, and the connection may also be transferred through the joining device. For example, other devices may include wireless access network (radio access network, RAN) nodes (or devices), which may also be referred to as base stations. Currently, some examples of RAN equipment are: a new generation base station (generation Node B, gNodeB), a transmission reception point (transmission reception point, TRP), an evolved Node B (eNB), a radio network controller (radio network controller, RNC), a Node B (Node B, NB), a base station controller (base station controller, BSC), a base transceiver station (base transceiver station, BTS), a home base station (e.g., home evolved Node B, or home Node B, HNB), a baseband unit (BBU), or a wireless fidelity (wireless fidelity, wi-Fi) joining point (access point, AP), etc. in the 5G communication system.

Illustratively, in the system of fig. 1, the network device connected to the user edge device is a Provider Edge (PE) device. The PE device is used to transmit messages between the user edge device 101 and the user edge device 102. For example, in fig. 1, the network device 103 and the network device 104 are PE devices, the user edge device 101 is connected to the carrier edge device 103, and the user edge device 102 is connected to the carrier edge device 104. While other network devices include operator (P) devices, such as network device 105. Wherein the carrier edge device 103 and the carrier edge device 104 are connected by one or more carrier (P) devices 105.

In the communication system shown in fig. 1, a plurality of communication modes, such as unicast, multicast or broadcast, can be supported between different devices (including the user edge device 101, the user edge device 102, the network device 103, the network device 104, and the network device 105, etc.), and the present application mainly relates to a multicast communication mode between different devices.

Multicasting, also known as multi-target broadcasting, multicasting, refers to a communication method for transmitting information between an information sender and a plurality of information receivers (receivers) in a network, wherein the information sender may also be referred to as a multicast source (source). Multicast is widely used in network services such as internet protocol television (internet protocol television, IPTV), real-time data transmission, and multimedia conferences, and is capable of saving network bandwidth and reducing network load more effectively than unicast, but requires that all network data communication devices support multicast transmission.

In actual networks, some intermediate nodes between the information sender and the information receiver may lack the ability to enable multicast, which may result in failure to interrupt the transmission of multicast information, subject to service provider policies or network restrictions. Illustratively, devices and networks included in the network (lack multicast capability) lacking multicast capability in the scenario shown in fig. 2 cannot send corresponding multicast messages from source to receiver according to conventional multicast communication.

Request for comments (request for comments, RFC) 7450 defines an AMT technology that addresses the above problems, the nature of AMT networks being devices and networks that traverse Lack multicast capability multicast information by unicast forwarding, requiring no or little modification to existing network infrastructure. In RFC7450, there are also defined roles of relay (i.e., a device connected to a multicast transmission source or a leaf node of a multicast network), gateway (i.e., a device connected to a multicast reception terminal), and the like. The Relay device and the gateway device are connected through an intermediate network which lacks multicast capability, namely the Relay device can be called a root node of the intermediate network, and the gateway device can be called a leaf node of the intermediate network.

For example, as shown in fig. 2, the main task of the AMT network is to encapsulate multicast information by AMT and user datagram protocol (user datagram protocol, UDP), and implement the interconnection of multicast information (including flow control information, data information, etc.) under the condition that the intermediate path network domain of relay and gateway devices does not support the multicast function. Specifically, when the multicast information is forwarded from the multicast source to the relay device, the relay device encapsulates the multicast information into an IP/UDP unicast message as required, forwards the IP/UDP unicast message to the gateway device corresponding to the multicast information, and then decapsulates and strips the IP/UDP unicast message header by the gateway device, and continues multicast forwarding, so that a multicast receiver (receiver) receives the multicast information.

In the implementation procedure of the AMT network, a Relay Discovery (Relay Discovery) implementation stage is included. In this implementation phase, the gateway device "discovers (or looks for)" the nearest relay device of the corresponding network segment by sending the relay discovery information carrying the anycast address (anycast addressing), and uses a randomly generated random nonce (random nonce) to ensure subsequent flow verification; after the relay device receives the message, a relay announcement (Relay Advertisement) message is sent to tell the gateway device the unicast address of the relay device. Through this implementation stage, the gateway device confirms the relay device and its unicast address that need to interact, and can subsequently receive multicast information based on the unicast address. In other words, there may be a plurality of relay devices in the AMT network, and for a certain relay device of the plurality of relay devices, after receiving a request of a certain gateway device, a connection with the gateway device is established, and multicast information is transmitted to the gateway device.

As can be seen from the above implementation process, the technical nature of AMT networks converts multicast forwarding into unicast forwarding to solve the problem of traversing a network or device that does not support multicast, where performance loss occurs naturally, i.e. when multiple multicast receivers occur, forwarding pressure of relay devices is high. In response to this problem, the current protocol standard RFC7450 is relatively lacking in consideration of relay device selection and load sharing.

As described in RFC7450 above, a procedure for how a gateway device discovers a relay device in an AMT deployment scenario is defined, where an anycast address is mainly used to implement the first discovery message of the gateway to find the relay of the corresponding address field. Essentially, a discovery message of a gateway device is sent (routed) to the closest relay device, but this relay device is not necessarily the most suitable relay device. In other words, the relay device that receives the discovery message is not necessarily capable of supporting the transmission of the multicast information of the gateway device. This will be illustrated by several examples.

(1) Under the condition that the flow load of the relay equipment receiving the discover message is heavy, the performance stability of the relay equipment cannot be guaranteed. As shown in the scenario of fig. 3, an AMT network generally includes at least two Relay devices (e.g., "Relay1", "Relay2", and "Relay3" in fig. 3), where a service load is heavy and a forwarding requirement is large, a Relay device (e.g., "Relay 1") may be a node closest to multiple gateway devices, but this Relay device may already currently carry forwarding tasks of more gateway devices, and other Relay nodes (e.g., "Relay2" and "Relay 3") are relatively light and cannot carry more services due to a mechanism setting. Thus, the excessive pressure bearing of the single relay device may affect the forwarding performance and cause network blocking, and in the case of relying on the single relay device, the unstable performance of the single relay device may directly cause a large amount of affected services.

For this reason, for the "Relay1" device, in the case where the "Relay1" device is currently already under heavy load, the "Relay1" device may not support transmission of multicast information of other gateway devices.

(2) The routing of two or more relay devices cannot determine the relay device and gateway device of a pair in the event that the intermediate network may be equivalent. For example, in the scenario shown in fig. 3, if the "Relay1" device and the "Relay2" device use the same anycast address, and the route between the "Relay1" device and the "Relay2" device is far and near determined by the intermediate network, it may be equivalent to the gateway device; at this time, the gateway device sends a discovery message to find a Relay device of the node pair, which cannot determine whether it will send to the "Relay1" device or the "Relay2" device. That is, in this scenario, the lack of a corresponding mechanism, rules directs the gateway device to discover the appropriate relay device, which may lead to confusion in network deployment.

(3) If a node of a certain relay device is damaged, the relay device may not be able to forward multicast information for the gateway device after receiving a discovery message of the gateway device, and service interruption will occur in the corresponding gateway device, so that service is unstable.

In summary, in the current AMT network implementation process, the gateway device relies on the anycast address to find the relay device with the closest route as the forwarding node of the multicast information, but the relay device may not necessarily support the transmission of the multicast information of the gateway device, which easily causes the occurrence of the condition of transmission interruption and affects the stability of the network.

Therefore, the application provides a multicast joining method and related equipment, which are used for reducing the occurrence of transmission cut-off in an AMT network so as to improve the network stability.

Referring to fig. 4, a schematic diagram of a multicast joining method 100 according to the present application is shown, and the method 100 includes the following steps.

S101, the second network equipment sends a first message.

In this embodiment, the second network device sends the first message in step S101, and correspondingly, the first network device receives the first message in step S101. The first message is used for requesting to join an AMT network, and the first message includes an address of the second network device.

It should be noted that the "address of the second network device" related to the present application may include a media access control (media access control, MAC) address of the second network device, an internet protocol (internet protocol, IP) address of the second network device, or other addresses of the second network device, which is not limited herein.

S102, the first network equipment sends a redirection message.

In this embodiment, after the first network device receives the first message in step S101, the first network device generates a redirection message based on the first message. In step S102, the first network device sends the redirection packet, and correspondingly, the third network device receives the redirection packet in step S102. The redirection message is used for indicating to process the request of joining the AMT network, and the redirection message comprises the address of the second network equipment.

In one possible implementation manner, the first network device and the third network device are both a relay device in the AMT network or a device serving as a root in the AMT network, and the second network device is a gateway device in the AMT network or a device serving as a leaf in the AMT network.

In an implementation example, the networking manner of the first network device, the second network device, and the third network device may be implemented in the manner shown in fig. 5.

In fig. 5, "Relay1/Relay2/…/Relay n (n is an integer greater than or equal to 2)" means n Relay devices, and a domain composed of n Relay devices supports routing and forwarding multicast data packets from a multicast Source (i.e., "Source" in fig. 5). The first network device and the third network device are two different Relay devices in the Relay1/Relay2/…/Relay n. For example, the first network device and the third network device may be routers, switches, virtual machines, and the like

"Gateway1/Gateway 2/…/Gateway m (m is an integer greater than or equal to 2)" means m Gateway devices, and a domain made up of m Gateway devices is responsible for encapsulating unicast traffic into multicast traffic for the corresponding multicast Receiver (i.e., "Receiver" in fig. 5). Wherein the second network device is any gateway device of the m gateway devices. For example, the second network device may be a router, a switch, a virtual machine, a home gateway device, an OLT device, or a terminal entity.

In addition, the domain of the intermediate path between the Relay device (including "Relay1/Relay2/…/Relay n") and the Gateway device (including "Gateway1/Gateway 2/…/Gateway m") does not support multicast capability by default, and multicast traffic is encapsulated into unicast traffic by Relay and sent to the Gateway device by this segment.

Optionally, in the implementation shown in fig. 5, the parity group may also need to be configured with the parity attribute of the relay device's own MAC address (or determined based on a user input instruction, or otherwise).

Optionally, in the implementation shown in fig. 5, a keep-alive mechanism between relay devices needs to be configured, that is, BFD, NQA, etc. are configured to ensure that whether other relay devices are reachable through a route can be timely perceived.

In one possible implementation, the unicast address of the first network device is the same as the unicast address of the third network device; or, the anycast address of the first network device is the same as the anycast address of the third network device. Specifically, since the destination address of the first packet is the unicast address (or the anycast address) of the first network device, in the case that the unicast address of the first network device is the same as the unicast address of the third network device (or the anycast address of the first network device is the same as the anycast address of the third network device), the routing path between the third network device and the second network device is ensured to be connected. In other words, after the first network device sends a redirect message to the third network device indicating to process the request to join the AMT network, to ensure that a subsequent third network device can communicate with the second network device based on the switched-on routing path.

In one possible implementation manner, after the first network device receives the first packet sent by the second network device in step S101, the first network device may determine that the first network device is a relay device (or root node) closest to the second network device; in step S102, the first network device may generate a redirection message based on the first message, that is, the first network device reconstructs the first message into a new AMT redirection message, and sends the new AMT redirection message to the third network device, where the redirection message includes all the key data in the first message, which may play a role of the first message. In other words, the redirection message sent by the first network device in step S102 is used to indicate to the third network device to process the request sent by the second network device to join the AMT network.

The first message received by the first network device in step S101 and the redirect message sent by the first network device in step S102 will be described below based on the examples shown in fig. 6a and 6b, respectively.

As shown in fig. 6a, the redirect message includes the following fields:

version (Version, V): v defaults to 0 to indicate the version of the AMT protocol;

Message Type (Type): the value of the Type is 1; the method comprises the steps of indicating the Type of an AMT message, and determining the message as a discovery message based on 'type=1' after the first network equipment receives the Type of message;

reserved (Reserved): reserving a field;

discovery code (Discovery Nonce): for verification.

As shown in fig. 6b, the redirect message includes the following fields:

message Type (Type): any value other than the value of Type 0-7, for example, the value shown in FIG. 6b is 8; the method comprises the steps of indicating the Type of the AMT message, and determining that the message is an AMT redirection message based on 'type=8' after other network equipment (such as third network equipment) receives the Type of the message;

source UDP Port number (Source UDP Port): a UDP port number on the gateway device (e.g., the second network device) for receiving a response from the relay device;

reserved (Reserved): reserving a field;

source IP address (Source IP Address): an interface IP address on the gateway device (e.g., the second network device) for receiving a response from the relay device;

discovery code (Discovery Nonce): for verification.

Based on the implementation shown in fig. 6a and fig. 6b, compared with the first packet, the redirect packet has at least two fields, i.e. the source UDP port number and the address information of the source IP address, added to indicate the address of the second network device; and enabling a subsequent third network device to process the request of the second network device to join the AMT network based on the address of the second network device.

It should be understood that the present application is not limited to the values of the number of bytes (or the number of bits) of the different fields and the sequence between the different fields in the frame formats shown in fig. 6a to 6b, and the values of the number of bytes (or the number of bits) of the different fields and the sequence between the different fields in the frame formats shown in fig. 6a to 6b are only one implementation example. The values of the byte numbers (or bit numbers) of the different fields in the frame formats shown in fig. 6a to 6b may be other values, and the sequence between the different fields in the frame formats shown in fig. 6a to 6b may be other field sequences, which is not limited herein. In addition, the different fields in the frame formats shown in fig. 6a to 6b may all be implemented independently.

In one possible implementation manner, in the implementation process of step S102, the first network device may trigger to perform sending the redirection packet to the third network device based on various implementation manners, which will be described below.

In a first implementation manner, in step S102, the process of sending the redirection packet to the third network device by the first network device includes: and the first network equipment sends the redirection message to the third network equipment when the processing capacity of the first network equipment reaches a threshold value.

Specifically, when the first network device determines that the processing capability of the first network device reaches a threshold, the first network device sends a redirection message for indicating to process a request for joining the AMT network to a third network device, so that the third network device processes the request for joining the AMT network by the second network device based on the redirection message. Thus, the condition that the network is unstable due to the overload of the processing load of the first network device can be avoided.

Illustratively, after the first network device receives the first packet sent by the second network device in step S101, the first network device may determine that the first network device is a relay device (or root node) closest to the second network device; after that, the first network device may determine whether the processing capability of the first network device reaches a threshold, and if so, the first network device generates a redirection message based on the first message, and sends the redirection message to the third network device in step S102.

Optionally, when the first network device determines that the processing capability of the first network device does not reach the threshold, the first network device may send a response packet of the first packet to the second network device, so that the second network device joins the AMT network based on the response packet of the first packet, without performing the implementation procedure of step S102.

It should be appreciated that the processing capability of the first network device may be represented by a variety of parameters, such as cpu usage, port bandwidth usage, etc., without limitation. In addition, the first network device may determine the "threshold" in a variety of ways, for example, the first network device factory pre-configures the threshold, the first network device determines the threshold based on a user input instruction, the first network device determines the threshold based on indication information of a multicast source of the AMT network, or the threshold may be determined in other ways, which is not limited herein.

In a second implementation manner, in step S102, the process of sending the redirection packet to the third network device by the first network device includes: and the first network equipment sends the redirection message to the third network equipment when the attribute corresponding to the second network equipment is not matched with the attribute corresponding to the first network equipment.

Specifically, when the first network device determines that the attribute corresponding to the second network device does not match the attribute corresponding to the first network device, the first network device sends a redirection message for indicating to process a request for joining the AMT network to the third network device, so that the third network device matching the attribute corresponding to the second network device processes the request for joining the AMT network by the second network device. Therefore, when a plurality of network devices (including the first network device and the third network device) exist in the AMT network, the load sharing of the plurality of network devices is divided by the attribute difference of the network devices, so that the load balancing of the plurality of network devices is realized to a certain extent, and the occurrence of unstable network caused by overload of a certain network device is reduced.

Illustratively, the attribute corresponding to the second network device includes a parity corresponding to an address of the second network device; the attributes corresponding to the first network device include attributes corresponding to the parity. Specifically, the attribute corresponding to the second network device may be represented by parity corresponding to the address of the second network device, and because the first message received by the first network device includes the address of the second network device, the first network device determines the attribute corresponding to the second network device based on the first message, which is easy to implement.

As an implementation example, as shown in fig. 7, for a relay device in an AMT network, a first network device that is a "relay-odd device" and a third network device that is a "relay-even device" are included; the implementation process of the first network device may include:

the relay-odd device responds to the discover message with the gateway source address being an odd address, and if the relay-odd device receives the discover message with the source address being an even address, the relay-odd device copies a copy of the message and redirects the copy to the relay-even device.

Optionally, the relay-odd device delays the X second reply or not.

Further alternatively, X may have a value of 1 to 3.

As another implementation example, as shown in fig. 7, for a relay device in an AMT network, a first network device that is a "relay-even device" and a third network device that is a "relay-odd device" are included; the implementation process of the first network device may include:

the relay-even device responds to the discover message with the gateway source address being an even address, and if the relay-even device receives the discover message with the source address being an odd address, the relay-even device copies a copy of the message and redirects the copy to the relay-odd device. Optionally, the relay-even device delays the X second reply or not.

In a third implementation manner, in step S102, the process of sending the redirection packet to the third network device by the first network device includes: and when the attribute corresponding to the second network equipment is not matched with the attribute corresponding to the first network equipment and the processing capacity of the first network equipment reaches a threshold value, the first network equipment sends the redirection message to the third network equipment.

Specifically, when the first network device determines that the attribute corresponding to the second network device does not match the attribute corresponding to the first network device, and the first network device determines that the processing capability of the first network device reaches a threshold, the first network device sends a redirection message for indicating to process a request for joining the AMT network to the third network device, so that the third network device matching the attribute corresponding to the second network device processes the request for joining the AMT network by the second network device. Therefore, on one hand, the situation that the network is unstable due to the fact that the processing load of the first network device is too heavy can be avoided, on the other hand, under the condition that a plurality of network devices (including the first network device, the third network device and the like) exist in the AMT network, the load sharing of the network devices is divided through the difference of the attributes of the network devices, the load balancing of the network devices is achieved to a certain extent, and the situation that the network is unstable due to the fact that the load of a certain network device is too heavy is reduced.

It should be understood that in the second and third implementations described above, the "parity corresponding to an address" may specifically indicate that the address is an "odd" attribute in the case where the value of the last bit (or the first bit, the second bit.) in the address is odd; and indicates that the last bit (or first, second) in the address has an even value, the address is an "even" attribute. The "attribute corresponding to the parity" may be an attribute determined by negotiating with each other in advance between a plurality of network devices (including the first network device and the third network device) in the AMT network, may be an attribute preconfigured by a factory of the plurality of network devices in the AMT network, may be an attribute determined by the plurality of network devices in the AMT network based on their addresses, or may be an attribute determined by other means, and is not limited herein.

In one possible implementation, before the first network device sends the redirection packet to the third network device in step S102, the method further includes: the first network device determines that the third network device route is reachable, and the first network device sends the redirect message to the third network device in step S102.

Specifically, if the first network device determines that the route of the third network device is reachable, the first network device sends the redirect message to the third network device in step S102, so as to ensure that after the first network device sends the redirect message to the third network device, the third network device can process a request of joining the AMT network by the second network device.

It should be appreciated that in the embodiment of the present application, the case where the route of the third network device is not reachable includes at least one of a failure of the third network device, a failure of a routing link between the third network device and the second network device, a failure of a routing link between the third network device and the first network device, or other cases. Further description will be provided below in connection with several implementation examples.

In one implementation example, the determining, by the first network device, that the third network device route is reachable includes: the first network device sends a keep-alive message and receives a response to the keep-alive message within a first time period.

Specifically, after the first network device sends the keep-alive message, if the first network device receives a response of the keep-alive message within a first time period, the first network device determines that a route of a third network device is reachable, and expects that the third network device can process a request of joining the AMT network by the second network device.

Illustratively, this implementation example one may also be referred to as determining whether an ip route is withdrawn. The different relay devices (including the first network device and the third network device) can communicate with each other depending on the opposite end route, and both of them issue routes for uniquely identifying the address of the device, ip addresses of commonly used local loop (loopback) interfaces are issued, and when the routes are issued, interfaces connected with the lack multicast capability network can be associated, and when the interfaces connected with the lack multicast capability network fail, the routes are also withdrawn. Therefore, when the third network device fails or the route with the lack multicast capability network is not reachable, the first network device can determine that the opposite route is not reachable (e.g., is not in place or is not operational) by sensing the route withdrawal of the third network device; conversely, the third network device may also determine that the peer route is not reachable (e.g., is out of place or inoperable) by perceiving the route withdrawal set by the first network.

Implementing example two, the process of determining, by the first network device, whether the third network device is reachable by the route includes: the first network device transmits a network quality analysis (network quality analysis, NQA) probe message and receives a response to the NQA probe message within a second time period.

Specifically, after sending the NQA probe packet, if the first network device receives a response to the NQA probe packet within a first time period, the first network device determines that a route of a third network device is reachable, and predicts that the third network device can process a request of joining the AMT network by the second network device.

Illustratively, the determination of whether the ip route is withdrawn in implementation example one above relies on convergence of the route, which is generally slow to perceive. While in implementation example two, NQA detection may reach fault awareness on the order of milliseconds (ms). Similar to implementation example one, different relay devices (including the first network device and the third network device) issue routes that uniquely identify the device address to the outside, and interfaces connected to the lack multicast capability network may be associated when issuing routes. Different relay devices mutually use NQA to detect whether the opposite end fails, the NQA can achieve ms-level detection, and when the complete machine of the opposite end fails and the route from the local end to the opposite end is not withdrawn at the control layer, the opposite end does not answer the NQA detection, and the local end can also sense that the route of the opposite end is unreachable (or called failure).

Implementing example three, the process of the first network device determining that the third network device route is reachable includes: the first network device sends a bidirectional forwarding detection (bidirectional forwarding detection, BFD) message and receives a response to the BFD message for a third duration.

Specifically, after the first network device sends the BFD packet, if the first network device receives a response to the BFD packet within a first time period, the first network device determines that a route of a third network device is reachable, and predicts that the third network device can process a request that the second network device join the AMT network.

For example, different relay devices (including the first network device and the third network device) are mutually deployed to the BFD detection of the opposite end, and the BFD detection (BFD track) is connected to the interface of the lack multicast capability network, when the whole machine of the opposite end fails or when the interface connected to the lack multicast capability network fails, the home end cannot receive the BFD response message of the opposite end, and because the BFD can achieve ms-level detection, the opposite end route can be quickly perceived as unreachable (or as failure).

S103, the third network equipment sends a response message.

In this embodiment, after receiving the redirection message in step S103, the third network device generates a response message corresponding to the request for joining the AMT network based on the redirection message. In step S103, the third network device sends the response message, and correspondingly, the second network device receives the response message in step S103. Wherein the response message includes an address of the third network device.

In one possible implementation manner, before the third network device sends a response packet corresponding to the request for joining the AMT network to the second network device in step S103, the method further includes: the third network device determines that the attribute corresponding to the third network device matches the attribute corresponding to the second network device.

Specifically, when the third network device determines that the attribute corresponding to the third network device matches the attribute corresponding to the second network device, the third network device sends a response message corresponding to the request for joining the AMT network to the second network device, so as to process the request for joining the AMT network by the second network device. Therefore, when a plurality of network devices (including the first network device and the third network device) exist in the AMT network, the load sharing of the plurality of network devices is divided by the attribute difference of the network devices, so that the load balancing of the plurality of network devices is realized to a certain extent, and the occurrence of unstable network caused by overload of a certain network device is reduced.

Optionally, the attribute corresponding to the second network device includes parity corresponding to an address of the second network device, and the attribute corresponding to the third network device includes an attribute corresponding to the parity. Specifically, the attribute corresponding to the second network device may be represented by parity corresponding to the address of the second network device, and because the redirection packet received by the third network device includes the address of the second network device, the attribute corresponding to the second network device is clear by the first network device based on the first packet, which is easy to implement.

It should be understood that the attribute corresponding to the second network device and the attribute corresponding to the third network device may also be implemented in other manners, and specific reference may be made to the description in step S102, which is not repeated herein.

In one possible implementation, after the first network device receives the first packet from the second network device in step S101, the method further includes: after the fourth duration, the first network device sends a response message corresponding to the request to join the AMT network to the second network device, where the response message includes an address of the first network device. Specifically, after the fourth duration, the first network device sends a response message corresponding to the request to join the AMT network to the second network device, so that in a case where the third network device cannot process the request (for example, the third network device is overloaded, the third network device fails, the third network device cannot be routed), the second network device can still join the AMT network through the first network device, and further, the stability of the network is improved.

Illustratively, the fourth duration may be a duration on the order of seconds, e.g., the fourth duration has a value of 1 to 3 seconds.

Thus, for the second network device, after the second network device sends the first packet for indicating to request to join the AMT network in step S101, the second network device may receive n response packets corresponding to the request to join the AMT network, that is, the second network device receives one or more response packets corresponding to the request to join the AMT network. Under the condition that the value of n is larger than 1, that is, under the condition that n response messages are a plurality of response messages, the second network device can join the AMT network through a plurality of network devices based on the plurality of response messages. Therefore, compared with the implementation mode that a single network device processes the request of joining the AMT network of the second network device, the situation that the AMT network is easily caused to be cut off when the single network device has faults occurs, the success rate of joining the AMT network of the second network device can be improved because the second network device can join the AMT network through a plurality of network devices based on the response messages, and the network stability can be improved.

Optionally, for the second network device, after step S103, the method further includes: the second network device sends a first request message, wherein the first request message corresponds to a first response message, and the first response message is a response message received first in the n response messages. Specifically, the second network device may further send a first request message corresponding to a first response message received first in the n response messages, where in a case where the value of n is greater than 1, that is, in a case where the n response messages are multiple response messages, the second network device may send the first request message corresponding to the first response message received first in the multiple response messages, so as to facilitate fast joining in the multicast network based on the first request message, so as to improve communication efficiency.

Further optionally, after the second network device sends the first request packet, the method further includes: and when the second network equipment determines that the response message of the first request message is not received after the preset duration threshold, the second network equipment sends a second request message, wherein the second request message corresponds to other response messages except the first response message in the response messages. Specifically, when the second network device determines that the response message of the first request message is not received after the preset duration threshold, the second network device sends other response messages corresponding to the response messages except the first response message, so that the second network device can also join the AMT network based on other response messages under the condition that the second network device cannot join the AMT network based on the first request message, and the success rate of joining the AMT network by the second network device is improved.

Based on the above technical solution, after the first network device receives the first packet of the second network device for requesting to join the AMT network in step S101, the first network device sends a redirect packet for instructing to process the request for joining the AMT network to the third network device in step S102, so that the third network device processes the request for joining the AMT network by the second network device based on the redirect packet in step S103. Thus, compared to an implementation in which the first network device processes a request for the second network device to join the AMT network after receiving the request; in the implementation process, the implementation manner of processing the request of joining the AMT network by the second network device by the third network device can reduce the occurrence of transmission interruption in the AMT network, so as to improve the network stability.

In addition, in the implementation process, load sharing among different Relay devices in the AMT network can be realized, and the method is particularly suitable for scenes of more gateway devices, higher multicast forwarding pressure and protection requirements on the Relay devices. The application improves the mechanism and rules in the AMT architecture, provides a novel and stable load sharing scheme, can well ensure the stability of the performance of the relay equipment and the node protection of the relay equipment, and further improves the network quality and stability.

The embodiments of the present application are described above in terms of methods, and the communication device provided by the embodiments of the present application is described below in terms of devices.

Referring to fig. 8, an embodiment of the present application provides a communication apparatus 800, which can implement the functions of the communication apparatus (including the first network device, the second network device, or the third network device) in the above method embodiment, so that the beneficial effects of the above method embodiment can also be implemented.

The communication apparatus 800 includes a receiving unit 801 and a transmitting unit 802.

In the case where the communication apparatus 800 is used to realize the function of the first network device in the foregoing embodiment, the communication apparatus 800 includes the following implementation procedure.

The receiving unit 801 is configured to receive a first packet from a second network device, where the first packet is used to request the AMT network, and the first packet includes an address of the second network device;

the sending unit 802 is configured to send a redirection packet to a third network device, where the redirection packet is used to indicate to process a request to join the AMT network, and the redirection packet includes an address of the second network device.

In a possible implementation manner, the sending unit 802 is configured to send the redirection packet to the third network device when the processing capability of the first network device reaches a threshold.

In a possible implementation manner, the sending unit 802 is configured to send the redirection packet to the third network device when the attribute corresponding to the second network device does not match the attribute corresponding to the first network device.

In a possible implementation manner, the sending unit 802 is configured to send the redirection packet to the third network device when the attribute corresponding to the second network device does not match the attribute corresponding to the first network device, and the processing capability of the first network device reaches a threshold.

In one possible implementation, the attribute corresponding to the second network device includes parity corresponding to an address of the second network device; the attributes corresponding to the first network device include attributes corresponding to the parity.

In a possible implementation, the apparatus further includes a processing unit 803; the sending unit 802 is further configured to send the redirect message to the third network device when the processing unit 803 is configured to determine that the third network device route is reachable.

In a possible implementation manner, the sending unit 802 is further configured to send a keep-alive packet, and the determining, by the processing unit 803, that the third network device route is reachable includes: when the receiving unit 801 receives a response of the keep-alive message within a first time period, it determines that the third network device route is reachable.

In a possible implementation manner, the sending unit 802 is further configured to send an NQA probe packet, and the determining, by the processing unit 803, that the third network device route is reachable includes: when the receiving unit 801 receives a response of the NQA message in the second period, it determines that the third network device route is reachable.

In a possible implementation manner, the sending unit 802 is further configured to send a BFD packet, and the determining, by the processing unit 803, that the third network device route is reachable includes: when the receiving unit 801 receives the response of the BFD packet in the third duration, it determines that the third network device route is reachable.

In a possible implementation manner, the sending unit 802 is further configured to send, after the fourth time period threshold, a response packet to the second network device, where the response packet corresponds to the request to join the AMT network, and the response packet includes an address of the first network device.

In one possible implementation, the unicast address of the first network device is the same as the unicast address of the third network device; or, the anycast address of the first network device is the same as the anycast address of the third network device.

In one possible implementation manner, the first network device and the third network device are both relay devices in the AMT network or devices serving as a root in the AMT network, and the second network device is a gateway device in the AMT network or a device serving as a leaf in the AMT network.

In the case where the communication apparatus 800 is used to realize the function of the second network device in the foregoing embodiment, the communication apparatus 800 includes the following implementation procedure.

The sending unit 802 is configured to send a first packet, where the first packet is used to indicate that the AMT network is requested to be added, and the first packet includes address information of the second network device; the receiving unit 801 is configured to receive n response messages corresponding to the request to join the AMT network, where n is greater than or equal to 1.

In a possible implementation manner, the sending unit 802 is further configured to send a first request packet, where the first request packet corresponds to a first response packet, and the first response packet is a response packet that is received first in the n response packets.

In a possible implementation manner, the apparatus further includes a processing unit 803, where the sending unit 802 is further configured to send a second request packet when the processing unit 803 determines that the response packet of the first request packet is not received after the preset duration threshold, where the second request packet corresponds to response packets other than the first response packet in the plurality of response packets.

In one possible implementation, the second network device is a gateway device in the AMT network or a device in which the AMT network acts as a leaf.

In the case where the communication apparatus 800 is used to realize the function of the third network device in the foregoing embodiment, the communication apparatus 800 includes the following implementation procedure.

The receiving unit 801 is configured to receive a redirection packet from a first network device, where the redirection packet is used to indicate to process a request for joining the AMT network, and the redirection packet includes an address of a second network device;

The sending unit 802 is configured to send a response packet corresponding to the request for joining the AMT network to the second network device, where the response packet includes an address of the third network device.

In a possible implementation, the apparatus further includes a processing unit 803; the sending unit 802 is further configured to send a response packet corresponding to the request for joining the AMT network to the second network device when the processing unit 803 determines that the attribute corresponding to the third network device matches the attribute corresponding to the second network device.

In one possible implementation, the attribute corresponding to the second network device includes a parity corresponding to an address of the second network device, and the attribute corresponding to the third network device includes an attribute corresponding to the parity.

In one possible implementation, the unicast address of the third network device is the same as the unicast address of the first network device; or, the anycast address of the third network device is the same as the anycast address of the first network device.

It should be noted that, for the content of the information execution process of each unit of the communication device 800, reference may be specifically made to the description in the foregoing method embodiment of the present application, and the description is omitted here.

The embodiment of the application also provides a communication device 900, referring to fig. 9, and fig. 9 is a schematic structural diagram of the communication device 900 according to the embodiment of the application.

Optionally, the communication apparatus 900 performs the functions of the first network device in fig. 4 and related embodiments; wherein the communication apparatus 1000 and the communication apparatus 1100 perform the functions of the second network device and the third network device in fig. 4 and the related embodiments, respectively.

Optionally, the communication apparatus 900 performs the functions of the second network device in fig. 4 and related embodiments; wherein the communication apparatus 1000 and the communication apparatus 1100 perform the functions of the first network device and the third network device in fig. 4 and related embodiments, respectively.

Optionally, the communication apparatus 900 performs the functions of the third network device in fig. 4 and related embodiments; wherein the communication apparatus 1000 and the communication apparatus 1100 perform the functions of the first network device and the second network device in fig. 4 and related embodiments, respectively.

The communication device 900 shown in fig. 9 comprises a memory 902 and at least one processor 901.

Alternatively, the processor 901 may implement the method in the above embodiment by reading the instructions stored in the memory 902, or the processor 901 may implement the method in the above embodiment by internally stored instructions. In the case where the processor 901 implements the method in the above-described embodiment by reading the instructions held in the memory 902, the instructions for implementing the method provided in the above-described embodiment of the present application are held in the memory 902.

Optionally, at least one processor 901 is one or more CPUs, or is a single core CPU, or may be a multi-core CPU.

Further optionally, the at least one processor 901 may be further configured to execute the implementation procedure corresponding to the processing unit 803 in the foregoing embodiment shown in fig. 8, and achieve corresponding beneficial effects, which are not described herein.

The memory 902 includes, but is not limited to, RAM, ROM, EPROM, flash memory, or optical memory, among others. The memory 92 stores instructions of the operating system.

After the program instructions stored in the memory 902 are read by the at least one processor 901, the communication device performs the corresponding operations in the foregoing embodiments.

Optionally, the communication device shown in fig. 9 further comprises a network interface 903. The network interface 903 may be a wired interface, such as an FDDI, GE interface; the network interface 903 may also be a wireless interface. The network interface 903 is used to perform data transceiving in fig. 4 and related embodiments.

Further optionally, the network interface 903 may be further configured to perform the implementation procedure corresponding to the receiving unit 801 and the sending unit 802 in the foregoing embodiment shown in fig. 8, and achieve corresponding beneficial effects, which are not described herein.

It should be understood that the network interface 903 has a function of receiving data and transmitting data, a function of "receiving data" and a function of "transmitting data" may be integrated in the same transceiver interface, or a function of "receiving data" and a function of "transmitting data" may be implemented in different interfaces, which are not limited herein. In other words, the network interface 903 may include one or more interfaces for implementing functions of "receiving data" and "transmitting data".

After the processor 901 reads the program instructions in the memory 902, the other functions that can be executed by the communication device 900 are described in the foregoing method embodiments.

Optionally, the communication device 900 further comprises a bus 904, and the processor 901 and the memory 902 are typically connected to each other through the bus 904, but may be connected to each other in other manners.

Optionally, the communication apparatus 900 further comprises an input/output interface 905, where the input/output interface 905 is configured to connect with an input device, and receive relevant configuration information input by a user or other devices capable of linking with the communication apparatus 900 through the input device. Input devices include, but are not limited to, a keyboard, touch screen, microphone, and the like.

The communication device 900 provided by the embodiment of the present application is configured to perform the method performed by the communication device (the first network device or the server) provided by the above embodiments of the method, and achieve the corresponding beneficial effects.

For example, in the case where the communication apparatus 900 performs the functions of the first network device in fig. 4 and related embodiments; after receiving the first message from the communication apparatus 1000, the communication apparatus 900 sends a redirect message to the communication apparatus 1100, where the redirect message is used to instruct to process the request to join the AMT network, and the redirect message includes the address of the second network device. Thereafter, the communication apparatus 1100 transmits, to the communication apparatus 1000, a response message corresponding to the request to join the AMT network based on the redirection message, the response message including the address of the third network device. Thus, compared to an implementation in which communication device 900 processes a request for communication device 1000 to join the AMT network after receiving the request; in this implementation, the implementation of processing a request by the communication device 1100 to join the AMT network by the communication device 1000 may reduce the occurrence of transmission breaks in the AMT network to improve network stability.

As another example, in the case where the communication apparatus 900 performs the function of the second network device in fig. 4 and related embodiments; after the communication device 900 transmits the first message to the communication device 1000, the communication device 900 receives n response messages transmitted from the communication device 1100 (and the communication device 1000 if present), where n is greater than or equal to 1. Therefore, compared to the implementation manner in which a single communication device (i.e., the communication device 1000 that receives the first message) processes the request of the communication device 900 to join the AMT network, the case that the single communication device has a fault easily causes the AMT network to be disconnected in transmission, because the communication device 900 can join the AMT network through a plurality of communication devices based on the plurality of response messages, the success rate of the communication device 900 joining the AMT network can be improved, so as to improve the network stability.

As another example, in the case where the communication apparatus 900 performs the function of the third network device in fig. 4 and related embodiments; the communication device 900 receives a redirect message from the communication device 1000, where the redirect message is used to instruct to process a request to join the AMT network; thereafter, the communication apparatus 900 transmits a response message corresponding to the request to join the AMT network, including the address of the third network device, to the communication apparatus 1100 based on the redirection message. Thus, compared to an implementation in which communication apparatus 1000 processes a request for communication apparatus 1100 to join the AMT network after receiving the request; in this implementation, the implementation of processing a request by communication device 900 for communication device 1100 to join the AMT network may reduce the occurrence of transmission breaks in the AMT network to improve network stability.

The specific implementation of the communication device shown in fig. 9 may refer to the descriptions in the foregoing method embodiments, and will not be described in detail herein.

The embodiment of the application also provides a communication system, which is shown in fig. 10, and fig. 10 is a schematic diagram of the communication system according to the embodiment of the application. As shown in fig. 10, the present application relates to a first network device, a second network device and a third network device, which can be applied to an AMT network. Among other things, the AMT network may include a multicast source (e.g., "source" in fig. 10) and a multicast receiver (e.g., "receiver" in fig. 10). In fig. 10, the first network device and the third network device may be relay devices in an AMT network. Optionally, other relay devices are also included in the AMT network. In fig. 10, the second network device may be a gatewy device in an AMT network. Optionally, other gateway devices are also included in the AMT network.

As an implementation example, in the communication system shown in fig. 10, when the first network device, the second network device, and the third network device apply the methods related to the foregoing embodiments, after the first network device receives the first packet from the second network device, the first network device sends a redirect packet to the third network device, where the redirect packet is used to indicate to process a request to join the AMT network, and the redirect packet includes an address of the second network device. Thereafter, the third network device sends a response message corresponding to the request to join the AMT network based on the redirection message Wen Xiang to the second network device, the response message including an address of the third network device. Thus, compared to an implementation in which the first network device processes a request for the second network device to join the AMT network after receiving the request; in this implementation, the implementation of the third network device processing the request of the second network device to join the AMT network may reduce the occurrence of transmission interruption in the AMT network, so as to improve network stability.

It should be understood that, in the communication system shown in fig. 10, the first network device, the second network device and the third network device may also apply other methods related to the foregoing embodiments and achieve corresponding technical effects, which are not described herein.

In the several embodiments provided in the present application, it should be understood that the disclosed systems, devices, and methods may be implemented in other manners. For example, the apparatus embodiments described above are merely illustrative, e.g., the division of the units is merely a logical function division, and there may be additional divisions when actually implemented, e.g., multiple units or components may be combined or integrated into another system, or some features may be omitted or not performed. Alternatively, the coupling or direct coupling or communication connection shown or discussed with each other may be an indirect coupling or communication connection via some interfaces, devices or units, which may be in electrical, mechanical or other form.

The above embodiments are only for illustrating the technical solution of the present application, and not for limiting the same; although the application has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit of the application.

Claims

1. A method of multicast joining, the method being applied to an automated multicast tunnel AMT network, comprising:

the method comprises the steps that first network equipment receives a first message from second network equipment, wherein the first message is used for requesting to join the AMT network and comprises an address of the second network equipment;

the first network device sends a redirection message to a third network device, where the redirection message is used to instruct to process a request for joining the AMT network, and the redirection message includes an address of the second network device.

2. The method of claim 1, wherein the first network device sending the redirect message to a third network device comprises:

and the first network equipment sends the redirection message to the third network equipment when the processing capacity of the first network equipment reaches a threshold value.

3. The method of claim 1, wherein the first network device sending the redirect message to a third network device comprises:

and the first network device sends the redirection message to the third network device when the attribute corresponding to the second network device is not matched with the attribute corresponding to the first network device.

4. The method of claim 1, wherein the first network device sending the redirect message to a third network device comprises:

and when the attribute corresponding to the second network device is not matched with the attribute corresponding to the first network device and the processing capacity of the first network device reaches a threshold value, the first network device sends the redirection message to the third network device.

5. The method according to claim 3 or 4, wherein,

the attribute corresponding to the second network device comprises parity corresponding to an address of the second network device;

the attributes corresponding to the first network device include attributes corresponding to the parity.

6. The method according to any one of claims 1 to 5, wherein before the first network device sends the redirect message to a third network device, the method further comprises:

and the first network equipment determines that the route of the third network equipment is reachable, and the first network equipment sends the redirection message to the third network equipment.

7. The method of claim 6, wherein the first network device determining that the third network device route is reachable comprises:

The first network device sends a keep-alive message and receives a response of the keep-alive message within a first time period.

8. The method of claim 6, wherein the first network device determining whether the third network device is reachable by a route comprises:

the first network device sends a network quality analysis NQA probe message and receives a response to the NQA probe message within a second duration.

9. The method of claim 6, wherein the first network device determining that the third network device route is reachable comprises:

and the first network equipment sends a Bidirectional Forwarding Detection (BFD) message, and receives a response of the BFD message within a third duration.

10. The method according to any of claims 1 to 9, wherein after the first network device receives the first message from the second network device, the method further comprises:

and after the fourth duration, the first network device sends a response message corresponding to the request to join the AMT network to the second network device, wherein the response message comprises the address of the first network device.

11. The method according to any one of claims 1 to 10, wherein,

The unicast address of the first network device is the same as the unicast address of the third network device; or alternatively, the first and second heat exchangers may be,

the anycast address of the first network device is the same as the anycast address of the third network device.

12. The method according to any one of claims 1 to 11, wherein,

the first network device and the third network device are both relay devices in the AMT network or devices serving as roots in the AMT network, and the second network device is gateway devices in the AMT network or devices serving as leaves in the AMT network.

13. A method of multicast joining, the method being applied to an automated multicast tunnel AMT network, comprising:

the third network equipment receives a redirection message from the first network equipment, wherein the redirection message is used for indicating to process a request for joining the AMT network, and the redirection message comprises an address of the second network equipment;

and the third network equipment sends a response message corresponding to the request for joining the AMT network to the second network equipment, wherein the response message comprises the address of the third network equipment.

14. The method of claim 13, wherein before the third network device sends a response message corresponding to the request to join the AMT network to the second network device, the method comprises:

And the third network equipment determines that the attribute corresponding to the third network equipment is matched with the attribute corresponding to the second network equipment.

15. The method of claim 14, wherein the attribute corresponding to the second network device comprises a parity corresponding to an address of the second network device, and wherein the attribute corresponding to the third network device comprises an attribute corresponding to the parity.

16. The method according to any one of claims 13 to 15, wherein,

the unicast address of the third network device is the same as the unicast address of the first network device; or alternatively, the first and second heat exchangers may be,

the anycast address of the third network device is the same as the anycast address of the first network device.

17. The method according to any one of claims 13 to 16, wherein,

18. A communication device, characterized in that the communication device is arranged in a first network equipment in an automatic multicast tunnel AMT network, and comprises a receiving unit and a transmitting unit;

The receiving unit is configured to receive a first packet from a second network device, where the first packet is used to request the AMT network, and the first packet includes an address of the second network device;

the sending unit is configured to send a redirection packet to a third network device, where the redirection packet is used to instruct to process a request for joining the AMT network, and the redirection packet includes an address of the second network device.

19. The apparatus of claim 18, wherein the device comprises a plurality of sensors,

the sending unit is configured to send the redirection packet to the third network device when the processing capability of the first network device reaches a threshold.

20. The apparatus of claim 18, wherein the device comprises a plurality of sensors,

the sending unit is configured to send the redirection packet to the third network device when the attribute corresponding to the second network device does not match the attribute corresponding to the first network device.

21. The apparatus of claim 18, wherein the device comprises a plurality of sensors,

the sending unit is configured to send the redirection packet to the third network device when the attribute corresponding to the second network device does not match the attribute corresponding to the first network device and the processing capability of the first network device reaches a threshold.

22. The apparatus of claim 20 or 21, wherein the device comprises a plurality of sensors,

23. The apparatus according to any one of claims 18 to 22, further comprising a processing unit;

the sending unit is further configured to send the redirection packet to the third network device when the processing unit determines that the route of the third network device is reachable.

24. The apparatus of claim 23, wherein the device comprises a plurality of sensors,

the sending unit is also used for sending keep-alive messages;

the processing unit configured to determine that the third network device route is reachable includes: and when the receiving unit receives the response of the keep-alive message in the first time period, determining that the route of the third network equipment is reachable.

25. The apparatus of claim 23, wherein the device comprises a plurality of sensors,

the sending unit is also used for sending network quality analysis NQA detection messages;

the processing unit configured to determine that the third network device route is reachable includes: and when the receiving unit receives the response of the NQA message in the second time period, determining that the route of the third network equipment is reachable.

26. The apparatus of claim 23, wherein the device comprises a plurality of sensors,

the sending unit is also used for sending a Bidirectional Forwarding Detection (BFD) message;

the processing unit determining that the third network device route is reachable includes: and when the receiving unit receives the response of the BFD message within a third duration, determining that the route of the third network equipment is reachable.

27. The device according to any one of claims 18 to 26, wherein,

the sending unit is further configured to send, after the fourth time length threshold, a response packet corresponding to the request to join the AMT network to the second network device, where the response packet includes an address of the first network device.

28. The device according to any one of claims 18 to 27, wherein,

29. The device according to any one of claims 18 to 28, wherein,

30. A communication device, characterized in that the communication device is arranged in a third network equipment in an automatic multicast tunnel AMT network, and comprises a receiving unit and a sending unit;

31. The apparatus of claim 30, further comprising a processing unit;

the sending unit is configured to send a response packet corresponding to the request for joining the AMT network to the second network device when the processing unit determines that the attribute corresponding to the third network device matches the attribute corresponding to the second network device.

32. The apparatus of claim 31, wherein the device comprises a plurality of sensors,

the attribute corresponding to the second network device comprises parity corresponding to an address of the second network device, and the attribute corresponding to the third network device comprises an attribute corresponding to the parity.

33. The device according to any one of claims 30 to 32, wherein,

34. The device according to any one of claims 30 to 33, wherein,

35. A communication system comprising a communication device according to any of claims 18 to 29 and a communication device according to any of claims 30 to 34.