CN105763607A - Subscription content acquisition method, equipment and system - Google Patents

Abstract

A subscription content acquisition method, device and system are used to solve the problem that if the subscription node is not online when the root node sends new content to the subscription node, the new content sent by the root node will not be received. The method includes: the intermediate node receives the first request message sent by the subscribing node; the intermediate node determines that the first entry for processing the first part of content is stored, and the intermediate node updates the first entry according to the content carried in the first request message; The first entry includes the identifier of the first part of the content; the intermediate node receives the second part of the content sent by the backup node; the second part of the content includes the first content with the first serial number, and the first part of the content is a subset of the second part of the content; The intermediate node sends the second part of content to the subscribing node according to the routing information included in the updated first entry.

Description

Method, device and system for acquiring subscription content

technical field

The present invention relates to the communication field, and in particular to a method, device and system for acquiring subscribed content.

Background technique

Currently, in an Information-centric Networking (ICN), users can subscribe to content they are interested in. For example, in ICN, depending on the content, multiple meeting nodes (Rendezvousnode, RN) can be set up, or it can also be called the root node. Different RNs can store different content. For example, some RNs can store sports content. , some RNs can store financial content subscriptions, etc. Generally speaking, when content providers have new content, they will push new content to the corresponding RN. When a user wants to subscribe to relevant content, he can subscribe to the corresponding RN. In this way, after the RN receives the content published by the content provider, it can push it to all users who subscribe to the relevant content.

For example, please refer to Figure 1A, both Node 1 and Node 2 have subscribed to the content of sports in the meeting node, then after the message provider (such as node 3 in Figure 1A) pushes the new content of sports to the meeting node , and the nodes can send these new contents to node 1 and node 2 respectively. Of course, FIG. 1A is a relatively simple diagram, and there may be some intermediate nodes between the nodes shown in FIG. 1A , which are not shown in FIG. 1A .

However, in the current subscription process, if the subscriber is not online when the RN sends new content to the subscriber, the subscriber may not receive the subscribed content. After the subscriber goes online again, the RN will not submit the subscription again. The user sends content that has already been sent before, so the loss of information will occur. Taking Figure 1A as an example, if node 2 is not online when the meeting node sends new content to node 1 and node 2, node 2 cannot receive this part of the new content.

Contents of the invention

Embodiments of the present invention provide a subscription content acquisition method, device and system, which are used to solve the problem that if the subscription node is not online when the root node sends new content to the subscription node, the new content sent by the root node will not be received.

In the first aspect, a first method for obtaining subscribed content is provided, the method includes: an intermediate node receives a first request message sent by a subscribing node for obtaining the subscribed first part of content, and the intermediate node determines to store the first part of content for processing the first entry, the intermediate node updates the first entry according to the content carried in the first request message. Afterwards, the intermediate node receives the second part of content sent by the backup node, and the intermediate node sends the second part of content to the subscribing node according to the routing information from the intermediate node to the subscribing node included in the updated first entry. Wherein, the first request message carries a first serial number, the first serial number is the serial number of the first content included in the first part of content, and the first serial number is the sequence with the smallest value among the serial numbers of the contents included in the first part of content No. The first entry includes an identifier of the first part of content. The second portion of content includes first content with a first serial number, the first portion of content being a subset of the second portion of content.

In the embodiment of the present invention, if the subscribing node does not receive certain content, the subscribing node may send a request message (for example, a first request message) for obtaining the content, and the first request message may carry the information of this part of the content The smallest serial number in the serial number, so that the subscribing node can receive this part of the content, so that even if the subscribing node is offline, it can re-request the lost content after going online, or even if the subscribing node does not receive part of the subscription due to network abnormalities and other reasons Content, you can also re-request to obtain the content in the future, so as to avoid the loss of content as much as possible.

With reference to the first aspect, in a first possible implementation of the first aspect, the intermediate node updates the first entry according to the content carried in the first request message, which may be implemented in the following manner: the intermediate node judges that the first entry includes Whether the value of the sequence number is less than or equal to the value of the first sequence number, if the value of the sequence number included in the first entry is less than or equal to the value of the first sequence number, the intermediate node adds the intermediate node to the subscribing node in the first entry routing information to obtain the updated first entry, and the intermediate node discards the first request message.

If the value of the sequence number included in the first entry is less than or equal to the value of the first sequence number, the intermediate node may determine that the content requested by the first request message is a subset of the content requested by the first entry, and the intermediate node The content requested by the first request message can be obtained only by adding the routing information from the intermediate node to the subscribing node in the first entry, without forwarding the first request message, saving transmission resources.

In combination with the first aspect, in the second possible implementation of the first aspect, the intermediate node updates the first entry according to the content carried in the first request message, which can be implemented as follows: the intermediate node judges the sequence included in the first entry Whether the value of the number is less than or equal to the value of the first serial number, if the value of the serial number included in the first entry is greater than the value of the first serial number, the intermediate node will update the value of the serial number included in the first entry to the first The value of a sequence number, and the routing information from the intermediate node to the subscribing node is added to the first entry to obtain the updated first entry. Then, after the intermediate node updates the first entry according to the content carried in the first request message, the intermediate node may forward the first request message to the backup node.

That is, if the value of the sequence number included in the first entry is greater than the value of the first sequence number, indicating that the content requested by the first request message is more than that requested by the first entry, the intermediate node can modify the first table The sequence number in the item, and forward the first request message to the backup node, so that the content requested by the first request message can be obtained. In this way, there is no need to add a new entry, and the subsequent forwarding of the content requested by the first request message can be completed by directly using the first entry.

With reference to the first aspect or the first possible implementation manner or the second possible implementation manner of the first aspect, in a third possible implementation manner of the first aspect, the intermediate node receives the first possible implementation manner sent by the backup node. After the second part of content, the intermediate node may also determine that the serial number with the smallest value among the serial numbers of the contents included in the second part of content is equal to the serial number included in the updated first entry.

If the serial number with the smallest value among the serial numbers of the contents included in the second part of content is equal to the serial number included in the updated first entry, the intermediate node can determine that the second part of the content is included in the updated first entry. The content of the request, so that the intermediate node forwards the second part of the content to the subscribing node, otherwise the intermediate node can discard the second part of the content, in this way the accuracy of the forwarded content can be improved.

With reference to the first aspect, in a fourth possible implementation of the first aspect, the first request message also carries a second serial number, the second serial number is the serial number of the second content included in the first part of content, and the second serial number The number is the serial number with the largest value among the serial numbers of the contents included in the first part of content.

In addition to the first sequence number, the first request message may also carry the second sequence number, so that the subscribing node can clearly indicate what content is needed, so that the received content can better meet the requirements of the subscribing node.

Combining the first aspect or any of the first possible implementation manner to the fourth possible implementation manner of the first aspect, in the fifth possible implementation manner of the first aspect, in the middle After the node receives the first request message sent by the subscribing node for obtaining the subscribed first part of the content, the intermediate node can also query whether the first part of the content is stored locally. If the first part of the content is not stored locally, the intermediate node queries whether it is stored The first entry used to process the first part of content.

In combination with the fifth possible implementation of the first aspect, in the sixth possible implementation of the first aspect, after the intermediate node inquires whether the first part of content is stored locally, if the first part of content is stored locally, the intermediate node The first part of content can be sent to subscribing nodes.

That is, after the intermediate node receives the first request message, it can first query locally whether the first part of the content requested by the first request message is stored locally. If the content is stored locally, the intermediate node can directly send the locally stored first part of the content to For subscribing nodes, there is no need to go through the following process, which saves the process of obtaining subscription content, improves the efficiency of obtaining subscription content, and saves transmission resources. If the content is not stored locally, the intermediate node can continue the following process to try to ensure that the subscribing node can obtain the first part of the content.

Combining the first aspect or any one of the first possible implementation manner to the sixth possible implementation manner of the first aspect, in the seventh possible implementation manner of the first aspect, in the middle Before the node updates the first entry according to the content carried in the first request message, the intermediate node can also determine whether the value of the third sequence number included in the first entry is less than or equal to the value of the first sequence number, and whether the value of the third sequence number included in the first entry Whether the value of the fourth sequence number included is greater than or equal to the value of the second sequence number, if the value of the third sequence number included in the first entry is less than or equal to the value of the first sequence number, and the value of the first sequence number included in the first entry The value of the fourth sequence number is greater than or equal to the value of the second sequence number, the intermediate node adds the routing information from the intermediate node to the subscribing node in the first entry, obtains the updated first entry, and the intermediate node discards the first request message. Wherein, the first entry includes a third sequence number and a fourth sequence number, the third sequence number is the sequence number with the smallest value among the sequence numbers of the content requested by the first entry, and the fourth sequence number is the sequence number requested by the first entry. The serial number with the highest value among the serial numbers of the requested content.

That is, in addition to the first request message can carry two sequence numbers, the entry stored in the intermediate node can also include two sequence numbers, then, the first entry includes two sequence numbers, and the first request message carries On the premise that two serial numbers are provided, the intermediate node can judge whether the content requested by the first request message is a subset of the content requested by the first entry, and if so, the intermediate node only needs to add The routing information from the intermediate node to the subscribing node can then forward the obtained content to the subscribing node, without forwarding the first request message downwards, saving transmission resources.

With reference to the seventh possible implementation of the first aspect, in the eighth possible implementation of the first aspect, if the value of the third serial number included in the first entry is greater than the value of the first serial number and/or Or the value of the fourth sequence number included in the first entry is smaller than the value of the second sequence number, the intermediate node creates a second entry, and the second entry includes the identification of the first part of the content, the first sequence number, and the second sequence number , and routing information from the intermediate node to the subscribing node, the intermediate node may forward the first request message to the backup node.

That is, if the content requested by the first request message is not a subset of the content requested by the first entry, the intermediate node needs to re-establish the entry for the first request message, that is, the second entry, so that the Get the content of the first part.

With reference to the first aspect, in the ninth possible implementation of the first aspect, after the intermediate node receives the first request message sent by the subscribing node for obtaining the subscribed first part of content, if it is determined that the The first entry of the first part of the content, the intermediate node can also create a second entry, the second entry includes the identifier of the first part of the content, the first serial number, and the routing information from the intermediate node to the subscribing node, and the intermediate node can set the The first request message is forwarded to the backup node.

That is, if the first entry is not stored, the intermediate node can newly create an entry for the first request message, that is, a second entry, so that the first part of content can be acquired more accurately.

With reference to the ninth possible implementation manner of the first aspect, in the tenth possible implementation manner of the first aspect, the second entry further includes a second sequence number carried in the first request message, and the second sequence number is the serial number of the second content included in the first part of content, and the second serial number is the serial number with the largest value among the serial numbers of the contents included in the first part of content.

If the first request message also carries the second sequence number, the intermediate node may also add the second sequence number to the second entry when creating the second entry, so as to realize a more accurate request.

In a second aspect, a second method for obtaining subscribed content is provided. The method includes: a subscribing node sends a first request message for obtaining the subscribed first part of content, and the subscribing node receives the second part of content. Wherein, the first request message carries a first serial number, the first serial number is the serial number of the first content included in the first part of content, and the first serial number is the sequence with the smallest value among the serial numbers of the contents included in the first part of content number, the second part of content includes the first content with the first serial number, and the first part of content is a subset of the second part of content.

For example, the subscribing node may lose part of the subscribed content due to offline or network anomalies, and the subscribing node only needs to send the first request message to obtain the subscribed content, which is relatively simple.

With reference to the second aspect, in the first possible implementation of the second aspect, the first request message also carries a second serial number, the second serial number is the serial number of the second content included in the first part of the content, and the second serial number The number is the serial number with the largest value among the serial numbers of the contents included in the first part of content.

In addition to carrying the first sequence number, the first request message may also carry the second sequence number, so that the requested content is more accurate and more in line with the requirements of the subscribing nodes.

With reference to the first possible implementation of the second aspect, in the second possible implementation of the second aspect, before the subscribing node sends the first request message for acquiring the subscribed first part of content, the subscribing node may It is determined that the sequence numbers of the two most recently received contents are not consecutive.

That is, if the subscribing node determines that the sequence numbers of the two newly received contents are not consecutive, the subscribing node may determine that part of the content is lost, and in this case, the subscribing node may send a first request message to request to obtain the missing content.

In combination with the second aspect or the first possible implementation manner or the second possible implementation manner of the second aspect, in the third possible implementation manner of the second aspect, after the subscribing node receives the second part of content, subscribe The node judges whether the serial number with the smallest value among the serial numbers of the contents included in the second part of content is smaller than the first serial number, if the serial number with the smallest value among the serial numbers of the contents included in the second part of content is smaller than the first serial number number, the subscribing node can delete at least one content in the second part of content. Wherein, the serial number with the smallest value in at least one content is the serial number with the smallest value among the serial numbers of the contents included in the second part of content, and the serial number with the largest value in at least one content is the first serial number minus 1.

That is, the subscribing node can delete content that is duplicated with previously received content from the received content, saving storage space.

In a third aspect, an intermediate node is provided, and the intermediate node includes: a memory for storing instructions; a communication interface for receiving a first request message sent by a subscribing node for obtaining the subscribed first part of content; the first request The message carries a first serial number, the first serial number is the serial number of the first content included in the first part of content, and the first serial number is the serial number with the smallest value among the serial numbers of the contents included in the first part of content; the processor, An instruction for executing memory storage, determining that the first entry for processing the first part of the content is stored, then updating the first entry according to the content carried in the first request message; the first entry includes the identifier of the first part of the content; communicating The interface is used to receive the second part of the content sent by the backup node; the second part of the content includes the first content with the first serial number, and the first part of the content is a subset of the second part of the content; the communication interface is used to The routing information from the intermediate node to the subscribing node included in the first entry sends the second part of content to the subscribing node.

With reference to the third aspect, in a first possible implementation manner of the third aspect, the processor may be configured to update the first entry according to the content carried in the first request message, including: determining the sequence number included in the first entry Whether the value is less than or equal to the value of the first sequence number, if the value of the sequence number included in the first entry is less than or equal to the value of the first sequence number, add the route from the intermediate node to the subscribing node in the first entry information, obtain the updated first entry, and discard the first request message.

With reference to the third aspect, in a second possible implementation manner of the third aspect, the processor is configured to update the first entry according to the content carried in the first request message, including: judging whether the value of the sequence number included in the first entry is Less than or equal to the value of the first serial number; if the value of the serial number included in the first entry is greater than the value of the first serial number, update the value of the serial number included in the first entry to the value of the first serial number, The routing information from the intermediate node to the subscribing node is added to the first entry to obtain an updated first entry. The communication interface is further configured to: forward the first request message to the backup node after the processor updates the first entry according to the content carried in the first request message.

With reference to the third aspect or the first possible implementation of the third aspect or the second possible implementation of the third aspect, in a third possible implementation of the third aspect, the processor is further configured to: receive at the communication interface the After the second part of content, it is determined that the serial number with the smallest value among the serial numbers of the contents included in the second part of content is equal to the serial number included in the updated first entry.

With reference to the third aspect, in a fourth possible implementation of the third aspect, the first request message also carries a second serial number, the second serial number is the serial number of the second content included in the first part of content, and the second serial number It is the serial number with the largest value among the serial numbers of the contents included in the first part of content.

In combination with the third aspect or any possible implementation manner of the first possible implementation manner to the fourth possible implementation manner of the third aspect, in a fifth possible implementation manner of the third aspect, the processor further Used for: after the communication interface receives the first request message sent by the subscribing node for obtaining the subscribed first part of the content, query whether the first part of the content is stored locally; if the first part of the content is not stored locally, then query whether the user It is used to process the first entry of the first part of content.

With reference to the fifth possible implementation of the third aspect, in a sixth possible implementation of the third aspect, the processor is further configured to: if the first part of content is stored locally, send the first part of content to the Subscribe to a node.

In combination with the third aspect or any possible implementation manner of the first possible implementation manner to the sixth possible implementation manner of the third aspect, in a seventh possible implementation manner of the third aspect, the processor further It is used to: before updating the first entry according to the content carried in the first request message, determine whether the value of the third sequence number included in the first entry is less than or equal to the value of the first sequence number, and the first entry Whether the value of the fourth serial number included in is greater than or equal to the value of the second serial number. The processor is configured to update the first entry according to the content carried in the first request message, including: if the value of the third sequence number included in the first entry is less than or equal to the value of the first sequence number, and the value included in the first entry The value of the fourth sequence number is greater than or equal to the value of the second sequence number, and the routing information from the intermediate node to the subscribing node is added to the first entry to obtain the updated first entry, and the first request message is discarded. Wherein, the first entry includes a third sequence number and a fourth sequence number, the third sequence number is the sequence number with the smallest value among the sequence numbers of the content requested by the first entry, and the fourth sequence number is the sequence number requested by the first entry. The serial number with the highest value among the serial numbers of the requested content.

With reference to the seventh possible implementation of the third aspect, in an eighth possible implementation of the third aspect, the processor is further configured to: if the value of the third sequence number included in the first entry is greater than the value of the first sequence number and/or the value of the fourth sequence number included in the first entry is less than the value of the second sequence number, and a second entry is established, the second entry includes the identification of the first part of the content, the first sequence number , the second serial number, and routing information from the intermediate node to the subscribing node, and the communication interface is further configured to forward the first request message to the backup node.

With reference to the third aspect, in a ninth possible implementation manner of the third aspect, the processor is further configured to: after the communication interface receives the first request message sent by the subscribing node for acquiring the subscribed first part of content, determine that the Store the first entry for processing the first part of content, then create a second entry, the second entry includes the identifier of the first part of content, the first serial number, and the routing information from the intermediate node to the subscribing node, and the communication interface It is also used to forward the first request message to the backup node.

With reference to the ninth possible implementation manner of the third aspect, in a tenth possible implementation manner of the third aspect, the second entry further includes a second sequence number carried in the first request message, and the second sequence number is The serial number of the second content included in the part of content, the second serial number is the serial number with the largest value among the serial numbers of the contents included in the first part of content.

In a fourth aspect, a subscription node is provided, the subscription node includes: a memory for storing instructions, a processor for executing the instructions stored in the memory, generating a first request message for obtaining the subscribed first part of content, and communicating An interface, configured to send the first request message, and also configured to receive the second part of content. Wherein, the first request message carries a first serial number, the first serial number is the serial number of the first content included in the first part of content, and the first serial number is the sequence with the smallest value among the serial numbers of the contents included in the first part of content number, the second part of content includes the first content with the first serial number, and the first part of content is a subset of the second part of content.

With reference to the fourth aspect, in the first possible implementation of the fourth aspect, the first request message also carries a second serial number, the second serial number is the serial number of the second content included in the first part of the content, and the second serial number The number is the serial number with the largest value among the serial numbers of the contents included in the first part of content.

With reference to the first possible implementation of the fourth aspect, in a second possible implementation of the fourth aspect, the subscribing node further includes a memory and a processor, where the memory is used to store instructions, and the processor is used to execute memory storage Before the communication interface sends the first request message for acquiring the subscribed first part of content, it is determined that the sequence numbers of the two newly received contents are not consecutive.

With reference to the fourth aspect or the first possible implementation manner or the second possible implementation manner of the fourth aspect, in a third possible implementation manner of the fourth aspect, the subscribing node further includes a memory and a processor, wherein, The memory is used to store instructions, and the processor is used to execute the instructions stored in the memory. After the communication interface receives the second part of the content, it is judged whether the serial number with the smallest value among the serial numbers of the contents included in the second part of the content is smaller than the first serial number, If the serial number with the smallest value among the serial numbers of the contents included in the second part of content is smaller than the first serial number, at least one content in the second part of content is deleted. Wherein, the serial number with the smallest value in at least one content is the serial number with the smallest value among the serial numbers of the contents included in the second part of content, and the serial number with the largest value in at least one content is the first serial number minus 1.

In a fifth aspect, a content subscription system is provided, and the system includes an intermediate node and a backup node. The intermediate node is configured to receive the first request message sent by the subscribing node for acquiring the subscribed first part of content, determine that the first entry for processing the first part of content is stored, and then update the content according to the content carried in the first request message The first entry. The second part of content sent by the backup node is received, and the second part of content is sent to the subscribing node according to the routing information from the intermediate node to the subscribing node included in the updated first entry. Wherein, the first request message carries a first serial number, the first serial number is the serial number of the first content included in the first part of content, and the first serial number is the sequence with the smallest value among the serial numbers of the contents included in the first part of content number, the first entry includes the identifier of the first part of content, the second part of content includes the first content with the first serial number, and the first part of content is a subset of the second part of content. The backup node is used to obtain the second part of the content, and send the second part of the content to the subscribing node through the intermediate node.

Among them, the content stored in the backup node can come from the root node. After receiving the content published by the content providing node, the root node can set a unique serial number for each content received according to the local time, and can set the content and The serial numbers of the content are sent to the backup node, so that the backup node can save the content and the serial number of the content. When the subscribing node requests the content, the backup node can send the requested content and the serial number of the requested content to Subscribe to a node.

In a sixth aspect, another intermediate node is provided, and the intermediate node may include a functional unit for executing the method in the first aspect.

In a seventh aspect, another subscribing node is provided, and the subscribing node may include a functional unit for executing the method of the second aspect.

In an eighth aspect, an embodiment of the present invention provides a computer storage medium for storing computer software instructions for the above-mentioned intermediate node, which includes a program designed for the intermediate node to execute the above-mentioned aspect.

In a ninth aspect, an embodiment of the present invention provides a computer storage medium for storing computer software instructions used by the above-mentioned subscribing node, which includes a program designed for the subscribing node to execute the above aspect.

In the embodiment of the present invention, if the subscribing node does not receive some content, the subscribing node can send a first request message, and the first request message can carry a part of the serial number of this part of the content, so that the subscribing node can receive this part Therefore, even if the subscribing node is offline, it can re-request for the lost content after going online, or even if the subscribing node does not receive part of the subscription content due to network abnormalities, etc., it can re-request the content in the future to avoid content loss as much as possible Condition.

In the present invention, the names of intermediate nodes, subscribing nodes and backup nodes do not limit the devices themselves, and these devices may appear with other names in actual implementation. As long as the functions of each device are similar to those of the present invention, they fall within the scope of the claims of the present invention and their equivalent technologies.

These or other aspects of the present invention will be more clearly understood in the description of the following embodiments.

Description of drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the accompanying drawings required in the embodiments of the present invention. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For Those of ordinary skill in the art can also obtain other drawings based on these drawings without making creative efforts.

FIG. 1A is a schematic diagram of an ICN network;

FIG. 1B is a structural diagram of an ICN network provided by an embodiment of the present invention;

FIG. 2 is a schematic diagram of an implementation manner of an intermediate node provided by an embodiment of the present invention;

FIG. 3 is an interaction diagram of a method for acquiring subscribed content provided by an embodiment of the present invention;

FIG. 4 is an interaction diagram of another content subscription method provided by an embodiment of the present invention;

FIG. 5 is a possible structural block diagram of an intermediate node provided by an embodiment of the present invention;

Fig. 6 is a possible structural block diagram of a subscribing node provided by an embodiment of the present invention.

detailed description

In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments It is a part of embodiments of the present invention, but not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without creative efforts fall within the protection scope of the embodiments of the present invention.

The techniques described herein can be used in communication systems that route based on information content, such as Information-centric Networking (ICN) systems, and other such communication systems or future evolved systems.

In the following, some terms used in the embodiments of the present invention are explained to facilitate the understanding of those skilled in the art.

1) ICN is one of the future Internet architectures. Compared with the traditional Internet Protocol (Internet Protocol, IP) network, the routing of ICN is routing based on information content. Under the ICN, an Interest message can be used to request content, and a Data message can be used to send the requested content, that is, the Data message can carry data, and the Data message itself can be regarded as a data packet.

2) The subscription node (Subscriber) in the ICN may be implemented by a physical machine (such as a server), or may also be implemented by a virtual machine, and is used for subscribing to corresponding content.

3) The root node in the ICN, including, for example, the RN, can receive content published by a content publisher (Publisher), where the content publisher can also be called a content publishing node. In the embodiment of the present invention, the RN can set a serial number for each content according to the time when each content is received, so that each content can uniquely correspond to a serial number, and the phenomenon of out-of-sequence between various contents can be avoided. Among the content provided by the content publisher received by the RN, some of the content may be the content subscribed by the subscribing node, so the RN can actively send the content subscribed by the subscribing node to the subscribing node. The root node may be implemented by a physical machine (such as a server), or may also be implemented by a virtual machine.

4) The backup node in the ICN, for example, includes a Broker (intermediary server) node, which may be a backup node for all content published by each content publisher in the network. For example, the backup node can also act as a content subscriber, that is, it can also serve as a subscription node to subscribe content to all RNs in the network. After the RN receives the content provided by the content publisher, it can set a serial number for the content, and then can Send the received content and the set serial number to the backup node, and the backup node can save the content after receiving the content pushed by RN. The backup node may be implemented by a physical machine (such as a server), or may also be implemented by a virtual machine.

5) The intermediate nodes in the ICN may include nodes located between the subscribing node and the RN (or backup node), nodes located between the content providing node and the RN, and nodes located between the backup node and the RN node, etc.

6) A terminal device is a device that provides voice and/or data connectivity to a user, and may include, for example, a handheld device with a wireless connection function, or a processing device connected to a wireless modem. The terminal device can communicate with the core network via a radio access network (Radio Access Network, RAN), and exchange voice and/or data with the RAN. The terminal equipment may include UE, wireless terminal equipment, mobile terminal equipment, subscriber unit (SubscriberUnit), subscriber station (SubscriberStation), mobile station (MobileStation), mobile station (Mobile), remote station (RemoteStation), access point (AccessPoint , AP), remote terminal device (RemoteTerminal), access terminal device (AccessTerminal), user terminal device (UserTerminal), user agent (UserAgent), or user equipment (UserDevice), etc. For example, it may include mobile phones (or "cellular" phones), computers with mobile terminal equipment, dedicated terminal equipment in NB-IoT, portable, pocket, handheld, computer built-in or vehicle-mounted mobile devices. For example, Personal Communication Service (Personal Communication Service, PCS) phone, cordless phone, Session Initiation Protocol (SIP) phone, Wireless Local Loop (Wireless Local Loop, WLL) station, Personal Digital Assistant (Personal Digital Assistant, PDA) and other devices.

7) The terms "system" and "network" in the embodiments of the present invention may be used interchangeably. "Multiple" means two or more. "And/or" describes the association relationship of associated objects, indicating that there may be three types of relationships, for example, A and/or B may indicate: A exists alone, A and B exist simultaneously, and B exists independently. In addition, the character "/", unless otherwise specified, generally indicates that the associated objects before and after are in an "or" relationship.

Some principles and system architecture diagrams involved in the solution of the embodiment of the present invention are introduced below.

In order to support the basic content request and content transmission of ICN, the following three basic tables can be maintained in the intermediate node, and the intermediate node can use the following three tables to complete the routing of Interest messages and the forwarding of Data messages.

1. A forwarding information base (Forwarding information Base, FIB), used to route Interest messages to potential matching data sources. The <content name prefix, interface list> tuple can be stored in the FIB, and can be queried by the longest match method. For example, the subscribing node requests relevant content through the Interest message, and the Interest can carry the prefix of the name of the content to be requested, for example, a possible prefix is /Sports, then the intermediate node can know the Interest by querying the FIB after receiving the Interest message The interface through which the message should be forwarded is equivalent to knowing which data source the content requested by the Interest message is located in. For example, after the intermediate node receives the Interest message, it can determine that the Interest message should be forwarded through interface 1 by querying the FIB. Interface 1 corresponds to It is RN1. The information in the FIB can be updated automatically through manual configuration or name-based routing protocols.

2. The pending request table (PendingInterestTable, PIT), which is used to save the upstream inbound interface information of the content requester (subscribing node), so as to ensure that when the content requested by the subscribing node arrives, the intermediate node can correctly send the content sent to the subscribing node. Generally, according to different prefixes, a prefix can correspond to a PIT entry. After the content to be requested is forwarded to the subscribing node, the intermediate node can delete the PIT entry that matches the content. The PIT entry of the content, the intermediate node can delete it through the timeout mechanism, so as to save the storage space of the intermediate node as much as possible, and also free up the PIT entry for more Interest messages.

In addition, the PIT entries can be aggregated. For example, the intermediate node first receives the Interest message 1 sent by the subscription node 1. The prefix of the content name carried by the Interest message 1 is prefix 1, and the intermediate node creates a PIT entry for the prefix 1. The PIT entry includes prefix 1, and includes uplink interface information of subscribing node 1. Afterwards, the intermediate node receives the Interest message 2 sent by the subscribing node 2. The prefix of the name of the content carried by the Interest message 2 is also prefix 1, so it is considered that the content requested by the two subscribing nodes is the same, and the intermediate node does not need to be an Interest message. 2 Create a PIT entry again, and directly add the uplink interface information of the subscribing node 2 to the PIT entry created for prefix 1, and there is no need to forward Interest message 2, for example, Interest message 2 can be discarded, which can reduce the number of subsequent nodes The number of received Interest messages also saves transmission resources. For the aggregated PIT entry, after the intermediate node receives the requested content, the intermediate node may respectively send the content to the subscribing nodes corresponding to the multiple uplink interface information included in the PIT entry.

3. The content warehouse table (ContentStore, CS), the content requested by the subscribing node, the intermediate node passing through can choose to cache, and the CS table can store the information of the content cached by the intermediate node. In this way, when a new subscription node requests content, the intermediate node can directly obtain the relevant content from the cache instead of obtaining the content from the original content provider (such as RN), which reduces the process of obtaining content and improves the efficiency of obtaining content .

After the intermediate node receives the Interest message, the process is as follows:

First the intermediate node can look up the CS table. If the content requested by the Interest message is found in the CS table, the intermediate node can obtain the content from the cache of the intermediate node, forward the content through the interface that received the Interest message, and discard the Interest message at the same time, without further Forwarding backwards, the processing ends. If the content requested by the Interest message is not found in the CS table, the intermediate node determines that the content requested by the Interest message is not cached locally, and the intermediate node can search the PIT. If the content requested by the Interest message is found in the PIT If the prefix of the name matches the PIT entry, it means that other Interest messages with the same content as the Interest message request have been forwarded before and are waiting for the content, then the intermediate node can send the received current Interest message to the incoming interface Information is added to the PIT entry, and the Interest information is discarded at the same time, and the processing ends. If no PIT entry matching the prefix of the name of the content requested by the Interest message is found in the PIT, the intermediate node can search the FIB, and if a match is found in the FIB with the prefix of the name of the content requested by the Interest message prefix, the intermediate node creates a new PIT entry according to the prefix of the name of the content requested by the Interest message and the inbound interface information of the Interest message, and the name of the PIT entry is the content of the Interest message. The prefix of the name, the requested (Requested) information in the PIT entry is the inbound interface information of the Interest message, and then the intermediate node can forward the Interest message to the next hop node through the FIB. And if no prefix matching the prefix of the name of the content requested by the Interest message is found in the FIB, the Interest message is discarded, and the processing is determined to fail.

Corresponding to the processing method of the Interest message, if the intermediate node receives the Data message, the processing flow of the Data message is as follows:

The intermediate node can search the PIT, and if a PIT table entry matching the prefix of the name of the content included in the Data message is found in the PIT, the intermediate node can forward the Data message to all Interest messages recorded in the PIT table entry In addition, the intermediate node can cache the content included in the Data message, and record the cached content information in the CS table, so that when other nodes request the content again, the content can be directly sent to the requesting node.

The above describes the general processing methods for Interest messages and Data messages in ICN, and the subscription process in ICN is introduced below.

For example, the subscribing node subscribes to relevant content by sending a Subscribe message, and the Subscribe message may carry the prefix of the name of the content to be subscribed (for example, it may be the prefix of the name of the content to be subscribed), such as the Subscribe message carried in the The name of the content to subscribe to is prefixed with /Sports. The Subscribe message reaches the root node through the intermediate node. For the intermediate node along the way, after receiving the Subscribe message, if there is no locally stored subscription table (SubscriptionTable, ST) matching the prefix of the name of the content requested by the Subscribe message , then an ST table matching the prefix of the name of the content requested by the Subscribe message can be generated, the prefix of the name of the content requested by the Subscribe message and the inbound interface information of the Subscribe message can be recorded in the ST, and passed through the FIB The Subscribe message is forwarded to the next hop node. For the intermediate node, after receiving the Subscribe message, if the ST table matching the prefix of the name of the content requested by the Subscribe message has been stored locally, the intermediate node does not need to forward the Subscribe message to the next hop node, Instead, the incoming interface information of the Subscribe message can be directly added to the existing ST, and the Subscribe message can be discarded.

Among them, ST can be regarded as "standing query (standing query)", because the PIT entry will be deleted after one query. For subscription content, the subscription node may only need to subscribe once, and as long as there is a content update, the root node will You can actively push content to subscribing nodes. If you use PIT entries, subsequent pushes cannot be performed. Therefore, ST can be used in this case. ST can also be similar to PIT entries, and can include the name of the corresponding content. The prefix and the incoming interface information of the subscribing node, and different from the PIT entry, the ST can be stored for a long time, so that each time the content is pushed, it can be forwarded according to the ST.

The following describes the subscription process in ICN with reference to FIG. 1B. FIG. 1B is a possible system architecture diagram in the embodiment of the present invention. The system architecture diagram takes ICN as an example. Of course, the embodiment of the present invention is not limited to the application in ICN.

For example, the subscribing node 1 subscribes related content to the root node by sending a Subscribe message 1, for example, the prefix of the name of the content requested to subscribe carried in the Subscribe message 1 is /Sports. The Subscribe message 1 passes through the intermediate node 1, and the intermediate node 1 determines that no ST that matches /Sports is stored locally (if the prefix of the name of the content included in the ST is the same as /Sports, it is considered that the ST matches /Sports, and the ST matches the Subscribe message 1), then the intermediate node 1 can create an ST, wherein, the prefix of the name of the content included in the ST (for example, in the ST, the prefix of the name of the content is represented by name) as / Sports, and the inbound interface information including the Subscribe message 1 are, for example, 0. Meanwhile, the intermediate node 1 searches for the local FIB and forwards the Subscribe message 1 to the intermediate node 3 . Alternatively, the Subscribe message 1 passes through the intermediate node 1, and the intermediate node 1 determines that the ST that matches /Sports has been stored locally, then the intermediate node 1 does not need to create a new ST, but can directly use the incoming interface information of the Subscribe message 1 (for example, The information of port 0 in FIG. 1B) is added to the existing ST, and the Subscribe message 1 can be discarded.

If the Subscribe message 1 is forwarded to the intermediate node 3, after receiving the Subscribe message 1, the intermediate node 3 can perform a similar process to that of the intermediate node 1. For example, the intermediate node 3 also generates a new ST and sends the Subscriber message 1 forwarded to the root node.

For example, the subscribing node 2 subscribes to the root node through the Subscribe message 2 to the same content as the content subscribed by the subscribing node 1 (for example, the prefix of the content subscribed by the subscribing node 2 is also /Sports), then the Subscribe message 2 reaches the intermediate node 2 , the intermediate node 2 can perform a processing method similar to that of the intermediate node 1, for example, the intermediate node 2 also generates a new ST, and forwards the Subscribe message 2 to the next hop node, that is, to the intermediate node 3. After receiving the Subscribe message 2, the intermediate node 3 determines that the ST that matches the prefix of the content name carried by the Subscribe message 2 has been stored locally, and then the intermediate node 3 can add the incoming interface information of the Subscribe message 2 to the Subscribe message 2. In ST, for example, the incoming interface of the Subscribe message 2 is port 1 in the figure, the intermediate node 3 does not need to forward the Subscribe message 2 to the root node, for example, the intermediate node 3 can discard the Subscribe message 2.

After the root node receives the Subscribe message 1, if there is an updated content associated with the prefix of the content name carried by the Subscribe message 1, the root node can send the updated content to the intermediate node 3 in the form of a Data message, and the intermediate node 3 receives it. After the Data message, it is determined that the ST that matches the prefix of the name of the content carried by the Data message (that is, the prefix of the name of the content carried by the Subscribe message 1) is locally stored, then the intermediate node 3 can send the Data message to the The incoming interface indicated by the ST is, for example, port 1 and port 2 in Figure 1B. After the intermediate node 1 receives the Data message, it can send the Data message to the subscribing node 1 by querying the local ST. Similarly, After receiving the Data message, the intermediate node 2 can send the Data message to the subscribing node 2 by querying the local ST. In this way, content subscription is realized.

In addition, when the content provider (for example, the content provider node in FIG. 1B ) has new content to publish, the content provider node can send a Publish (Publish) message 1, and the Publish message 1 can carry the name of the corresponding root node and all The name of the published content (the name of the content carried in the message can be understood as the prefix of the name of the content, or can be understood as the prefix of the name of the content), such as the name of the root node carried in the Publish message 1 and the published content The name of the Publish may be /RNName/Sports/football, and of course, the published content itself may also be carried in the Publish message 1 . The Publish message 1 is sent to the root node through the FIB of the intermediate node 4. After receiving the Publish message 1, the root node can delete the RNName carried in the Publish message 1, that is, delete the name of the root node, and obtain the Publish message 2. The root node You can continue to push the Publish message 2 to all subscribing nodes that subscribe to the content through the locally saved ST, which is equivalent to pushing the content published by the Publish message 1 to all subscribing nodes that subscribe to the content. For example, the root node can send the Publish message 2 to the backup node and the intermediate node 3 respectively. After receiving the Publish message 2, the intermediate node 3 determines that the prefix of the name of the content carried by the Publish message 2 is locally stored (that is, the Subscribe message 1 The prefix of the name of the content carried) matches the ST, then the intermediate node 3 can send the Publish message 2 to the incoming interface indicated by the ST, for example, port 1 and port 2 in Figure 1B, then the intermediate node 1 After receiving the Publish message 2, the Publish message 2 can be sent to the subscription node 1 by querying the local ST. Similarly, after the intermediate node 2 receives the Publish message 2, it can query the local ST to send the Publish message 2. Message 2 is sent to subscribing node 2. In this way, content subscription is realized.

There is a problem in this process: for example, when the root node sends the Publish message 2 to the subscribing node 2, the subscribing node 2 is offline, or for example, when the root node sends the Publish message 2 to the subscribing node 2, there may be a network abnormality, the subscribing node 2 may not be able to receive the content carried in the Publish message 2, resulting in incomplete subscribed content. The solutions provided by the embodiments of the present invention are introduced below to solve this problem. Firstly, the device provided by the embodiment of the present invention is introduced.

Optionally, a content subscription system is provided. The content subscription system may include an intermediate node and a backup node. Refer to FIG. 1B. An implementation of the intermediate node may be the intermediate node shown in FIG. One implementation manner may be the backup node shown in FIG. 1B, wherein the backup node may receive the content with the serial number from the root node, and one implementation manner of the root node may be the root node shown in FIG. 1B. In addition, the "intermediate node" and "backup node" here are just names, and the names themselves do not limit the device.

Optionally, the intermediate nodes included in the content subscription system may be implemented in the form of a router or the like, or may also be implemented in the form of the computer device (or system) in FIG. 2 .

FIG. 2 is a schematic diagram of computer equipment provided by an embodiment of the present invention. The computer device 200 includes at least one processor 201 , a communication bus 202 , a memory 203 and at least one communication interface 204 .

The processor 201 may be a general-purpose central processing unit (CPU), a microprocessor, an application-specific integrated circuit (Application-Specific Integrated Circuit, ASIC), or one or more integrated circuits for controlling program execution of the present invention.

Communication bus 202 may include a path for communicating information between the components described above. The communication interface 204 uses any device such as a transceiver for communicating with other devices or communication networks, such as Ethernet, Radio Access Network (RAN), and Wireless Local Area Networks (Wireless Local Area Networks, WLAN).

The memory 203 may be a read-only memory (read-only memory, ROM) or other types of static storage devices that can store static information and instructions, a random access memory (random access memory, RAM) or other types of dynamic storage that can store information and instructions The device can also be an Electrically Erasable Programmable Read-Only Memory (EEPROM), a Compact Disc Read-Only Memory (CD-ROM) or other optical disc storage, optical disc storage (including compact discs, laser discs, optical discs, Digital Versatile Disc, Blu-ray Disc, etc.), magnetic disk storage medium or other magnetic storage device, or any other medium capable of carrying or storing desired program code in the form of instructions or data structures and accessible by a computer, but not limited to this. The memory can exist independently and be connected to the processor through the bus. Memory can also be integrated with the processor.

Wherein, the memory 203 is used to store the application program code for executing the solution of the present invention, and the execution is controlled by the processor 201 . The processor 201 is used to execute application program codes stored in the memory 203 .

In a specific implementation, as an embodiment, the processor 201 may include one or more CPUs, for example, CPU0 and CPU1 in FIG. 2 .

In a specific implementation, as an embodiment, the computer device 200 may include multiple processors, such as the processor 201 and the processor 208 in FIG. 2 . Each of these processors may be a single-core (single-CPU) processor or a multi-core (multi-CPU) processor. A processor herein may refer to one or more devices, circuits, and/or processing cores for processing data (eg, computer program instructions).

In a specific implementation, as an embodiment, the computer device 200 may further include an output device 205 and an input device 206 . Output device 205 communicates with processor 201 and can display information in a variety of ways. For example, the output device 205 may be a liquid crystal display (liquid crystal display, LCD), a light emitting diode (light emitting diode, LED) display device, a cathode ray tube (cathoderay tube, CRT) display device, or a projector (projector), etc. The input device 206 communicates with the processor 201 and can accept user input in various ways. For example, the input device 206 may be a mouse, a keyboard, a touch screen device, or a sensing device, among others.

The above computer device 200 may be a general computer device or a special computer device. In a specific implementation, the computer device 200 can be a desktop computer, a portable computer, a network server, a personal digital assistant (PDA), a mobile phone, a tablet computer, a wireless terminal device, a communication device, an embedded device, or a similar structure in FIG. 2 device of. The embodiment of the present invention does not limit the type of the computer device 200 .

The intermediate node in the content subscription system can be realized by the device shown in FIG. 2 , and one or more software modules are stored in the memory of the intermediate node. The intermediate node can realize the software module through the program code in the processor and the memory, and realize the process of requesting the subscription content.

Optionally, the backup node in the content subscription system may also be implemented by a computer device (or system). For example, when the backup node is implemented by a computer device (or system), continue to refer to FIG. 2 .

Optionally, a subscribing node is also provided. Referring to FIG. 1B , an implementation manner of the subscribing node may be the subscribing node shown in FIG. 1B . In addition, the "subscribing node" here is just a name, and the name itself does not limit the device.

Optionally, the subscribing node may also be implemented by means of a computer device (or system). For example, when the subscribing node is implemented by means of a computer device (or system), reference may continue to FIG. 2 .

Through the above-mentioned system and equipment, the content subscription solution provided by the embodiment of the present invention can be realized. Even if the subscription node loses some subscribed content due to reasons such as the subscription node is offline or the network quality is poor, the subscription node can also make a new request. Try to ensure that the subscribing nodes can get relatively complete subscription content.

Before introducing the content subscription method provided by the embodiment of the present invention, first introduce several improvement points proposed by the embodiment of the present invention:

Improvement point 1: The root node sets the serial number for each content published by the content providing node in turn according to the local time. Each content can uniquely correspond to a serial number, and the root node can push the content carrying the serial number to the subscribing node and backup node. When the subscribing node goes online again after being offline, it can directly send the prefix of the name of the content it subscribed to and the serial number of the last received content before going offline to the backup node, and the backup node can send the subscribing node offline. Published content is resent to subscribing nodes. Because all content is uniformly numbered by the root node, the content that the backup node determines to be sent is the same as the content requested by the subscribing node, avoiding confusion due to the fact that the content does not have a serial number (for example, the content actually requested by the subscribing node content 1, content 2 and content 3, but the clock of the subscribing node is not synchronized with the clock of the backup node. If the content does not have a serial number, the backup node may think that the subscribing node requests content 3, content 2 and content 4, resulting in Sending errors. That is, because there is no unified clock, the time when the backup node and the subscription node receive the same content is not synchronized, and there may be out-of-order phenomena).

Improvement point 2: Add corresponding fields in the Interest message, for example, you can add a field for indicating that the Interest message is to reacquire the subscribed content, for example, this field can be expressed as Get_Loss_Pub_Msg, for example, this field can occupy 1 bit, if The value of Get_Loss_Pub_Msg is 1, which indicates that the Interest message is used to reacquire the subscribed content, or indicates that the Interest message is used to obtain the previously unreceived subscribed content. For example, a field for carrying the sequence number of the last related content received by the subscribing node may also be added (or this field may also be used to carry the sequence number of the first content that the subscribing node requests to reacquire, the sequence number of the first content The sequence number with the smallest value among the sequence numbers of all content requested by the subscribing node), for example, this field may be expressed as Seq_min, and the length of this field may be determined by the length of the sequence number. For example, a field for carrying the serial number of the second content requested by the subscribing node to be reacquired may also be added. The field can be expressed as Seq_max, and the length of this field can be determined by the length of the sequence number.

Wherein, if Get_Loss_Pub_Msg is carried in the Interest message, Seq_min needs to be carried at least, and Seq_max can also be carried optionally. If the Interest message carries Get_Loss_Pub_Msg and Seq_min, but does not carry Seq_max, or although Seq_max is carried, but the value of Seq_max is empty (Null), it indicates that the Interest message requests to obtain the content whose sequence number is Seq_min and the sequence number is located in All the content after Seq_min (or may not include the content with the sequence number Seq_min), then the backup node determines to send the content with the sequence number Seq_min and all the content with the sequence number after Seq_min to the subscribing node (or may not send the sequence content whose serial number is Seq_min), otherwise, if the Interest message carries Seq_max, and the value of Seq_max is not Null, it indicates that the Interest message requests to obtain all the content whose serial number is between Seq_min and Seq_max (including the content whose serial number is Seq_max content, which may also include the content whose sequence number is Seq_min, or may not include the content whose sequence number is Seq_min), then the backup node determines to send all the content whose sequence number is between Seq_min and Seq_max to the subscribing node.

Among them, if the subscribing node is offline and then online again, the Interest message sent by the subscribing node can carry Get_Loss_Pub_Msg and Seq_min, optionally, it can carry Seq_max or not, if it carries Seq_max, the value of Seq_max can be Null, Or it may not be Null.

If the subscribing node is always online, but some subscription content is not received or lost due to some reasons (such as network abnormality, etc.), then optionally, the Interest message sent by the subscribing node can carry Get_Loss_Pub_Msg, Seq_min and Seq_max, and the value of Seq_max is not Null, so that the subscribing node can obtain the required content more accurately.

Improvement point 3: Optimize PIT entries. For example, a new field may be added to the PIT entry to indicate that the PIT entry is to reacquire the subscription content. For example, this field may be represented as Notify, and the value of the Notify field may be the value of Get_Loss_Pub_Msg in the Interest message, for example This field can occupy 1 bit. If the value of Notify is 1, it indicates that the PIT entry is used to retrieve the subscribed content, or indicates that the PIT entry is used to obtain the previously unreceived subscribed content. For example, a field for carrying the sequence number of the last relevant content received by the subscribing node may also be added in the PIT entry (or this field may also be used to carry the sequence number of the first content that the PIT entry requests to reacquire. , the sequence number of the first content is the sequence number with the smallest value among the sequence numbers of all the contents requested by the PIT entry), for example, this field can be expressed as Seq_min, and the length of this field can be determined by the length of the sequence number. For example, a field for carrying the serial number of the second content requested to be reacquired by the PIT entry may also be added, where the serial number of the second content is the sequence with the largest value among the serial numbers of all the content requested by the PIT entry number, for example, this field can be expressed as Seq_max, and the length of this field can be determined by the length of the sequence number.

When a large number of subscription nodes obtain the same subscription content at the same time, if all the Interest messages sent by these subscription nodes are forwarded to the backup node, it will cause a large burden on the backup node, and may even cause the backup node to fail. By optimizing PIT entries, Interest messages can be aggregated. For example, for Interest messages requesting the same content, you only need to add the corresponding inbound interface information in the PIT entry, and there is no need to forward the Interest message, saving transmission resources. It also reduces the burden on backup nodes.

Improvement point 4: A field for indicating whether to obtain the requested content from an intermediate node along the way is added to the Interest message, for example, the field is expressed as Get_Content_from_Origin. For example, this field can occupy 1 bit. If the value of Get_Content_from_Origin is 1, it is determined not to obtain the requested content from the intermediate nodes along the way. If the value of Get_Content_from_Origin is 0, or the Interest message does not carry Get_Content_from_Origin, it is determined that Get the requested content from the passed intermediate nodes.

For example, if the value of Seq_max carried by the subscribing node in the Interest message is Null, or the value of Seq_max is not carried in the Interest message, the subscribing node may carry Get_Content_from_Origin in the Interest message, and set the value of Get_Content_from_Origin to 1. Because the upper limit to be obtained by the subscribing node is uncertain at this time, and the backup node stores the complete content, so the backup node can send the complete content to the subscribing node, and the intermediate node may only cache part of the content. If the node is obtained, the obtained content may be incomplete, so in this case, you can choose not to obtain the content from the intermediate node.

For example, if the value of Seq_max carried by the subscribing node in the Interest message is not Null, the subscribing node can carry Get_Content_from_Origin in the Interest message, and the value of Get_Content_from_Origin can be set to 1 or 0, because at this time the subscription The upper and lower limits that a node needs to obtain are clear. If the intermediate node caches the content, it can be obtained from the intermediate node to reduce the time and steps required to obtain the content. If the intermediate node does not cache the content, it can be obtained from the backup node. , so as to ensure that the required content can be obtained as much as possible.

In order to have a better understanding of the above improvements, the following describes the method provided by the embodiment of the present invention in conjunction with the accompanying drawings, which can be understood based on the architecture of FIG. 1B . The following is divided into two examples for introduction.

example 1:

See Figure 3.

1. When the content providing node has new content to publish, it can send the new content to the root node through the Publish message 1. For example, the Publish message 1 may carry the name of the root node and the identifier of the published content, for example, the identifier of the published content may include a prefix of the name of the published content, such as /RNName/sports.

2. After the root node receives the Publish message 1, it can parse the Publish message 1 to obtain the published content carried in it. The root node can number the received content in sequence according to the local time, for example, it can set the sequence number for the received content in sequence according to the local time .

3. The root node pushes the content to all subscribing nodes that have subscribed to the content. For example, the root node can send Publish message 2 to the backup node and subscribing node 1 to push the content. Among them, the Publish message 2 carries the published new content, and also carries the serial number set by the root node for each content. However, for example, the subscribing node 1 is offline, so the Publish message 2 cannot be received.

Among them, after the root node receives the Publish message 1, it can delete the name of the root node carried in the Publish message 1, that is, delete the RNName, and the root node can add the serial number set for the content carried in the Publish message 1 to the Publish message 1 , for example, the Publish message 1 with the RNName deleted and the sequence number added is called Publish message 2.

4. After receiving the Publish message 2, the backup node can save the content carried in the Publish message 2 and the serial numbers corresponding to these contents. For example, a backup node can be backed up by a database.

5. The subscribing node 1 goes online again, and sends a first request message, which is used to request to reacquire previously pushed content, for example, the first request message is used to request to obtain the first part of content. For example, the first request message can be implemented by an Interest message, and the first request message can include:

(1)/The name of the backup node/the identifier of the subscribed content to be acquired, wherein, for example, the identifier of the content to be acquired may include the prefix of the name of the content to be acquired, or the identifier of the content to be acquired may also include Other information of the content, for example, may include the complete name of the content to be acquired. Because the backup node saves relatively complete content, the subscribing node can request from the backup node;

(2) The first serial number, for example, the first serial number can be the serial number of the first content included in the first part of content, and the serial number of the first content is the smallest among the serial numbers of the contents included in the first part of content The sequence number, for example, the first sequence number is carried in the Seq_min field in the Interest message. Wherein, the first content may be, for example, the last subscription content received by the subscription node 1 , or the first content may be the first subscription content not received by the subscription node 1 . Since subscriber 1 has just gone online in Example 1, it may be necessary to obtain all the lost content, so the value of Seq_max carried in the Interest message can be Null, or the Interest message can not carry Seq_max;

(3) A field used to indicate that the Interest message is to reacquire the subscribed content, for example, this field may be expressed as Get_Loss_Pub_Msg; wherein, this field is optional, that is, the first request message may or may not carry this field field;

(4) A field used to indicate whether to obtain the requested content from an intermediate node along the way. For example, this field is expressed as Get_Content_from_Origin. For example, the value of Get_Content_from_Origin is 1, indicating that the content is not obtained from the intermediate node and needs to be obtained from the backup node. Get content. Wherein, this field is optional, that is, this field may or may not be carried in the first request message. Optionally, if this field is not carried in the first request message, the field of the requested content may not be obtained from the intermediate nodes along the way by default, or the field of the requested content may be obtained from the intermediate nodes along the way by default , which can be preset as required.

6. The intermediate node receives the Interest message through the communication interface 204, and the intermediate node can make a comprehensive judgment and decide whether to forward the Interest message through the processor 201 according to the prefix and serial number of the content name carried in the Interest message. Optionally, the judgment process is as follows:

1) Since the value of Get_Content_from_Origin carried in the Interest message is 1, the processor 201 does not need to query the CS table, that is, it does not need to obtain the content from the local cache. Then the intermediate node queries the local PIT through the processor 201 to determine whether a PIT entry matching the prefix of the content name carried in the Interest message is stored, that is, whether a PIT entry for processing the first part of content is stored. According to whether the PIT entry for processing the first part of the content is stored, the following is divided into two branches to introduce:

Branch 1: If the intermediate node finds the PIT entry matching the prefix of the content name carried by the Interest message through the processor 201 (for example, the PIT entry can be called the first entry), and the first entry If the value of the included Seq_max is Null, or the first entry does not include Seq_max, the intermediate node may use the processor 201 to update the first entry according to the content carried in the first request message. For example, the intermediate node may use the processor 201 to update the first entry in the following manner:

(i) Optionally, if the value of Seq_min carried in the Interest message is greater than or equal to the value of Seq_min recorded in the first entry, the intermediate node can add The routing information from the intermediate node to the subscribing node 1 obtains the updated first entry. For example, the routing information from the intermediate node to the subscribing node 1 may include the incoming interface information of the Interest message. In addition, the intermediate node does not need to forward the Interest message to the next-hop node through the communication interface 204, for example, the Interest message can be discarded through the processor 201, reducing the amount of data to be sent and saving transmission resources.

(ii) Or, optionally, if the value of Seq_min carried in the Interest message is smaller than the value of Seq_min recorded in the first entry, the intermediate node may update the value of Seq_min in the first entry through the processor 201 Take a value, for example, update the value of Seq_min in the first entry to the value of Seq_min carried in the Interest message, and the intermediate node can add the intermediate node to the subscription through the processor 201 in the Requested field in the first entry The routing information of node 1, for example, the routing information from the intermediate node to the subscribing node 1 may include the incoming interface information of the Interest message, so as to obtain the updated first entry. In addition, in this case, besides updating the first entry, the intermediate node can also forward the Interest message to the next-hop node through the communication interface 204 .

Branch 2: If the intermediate node does not find a PIT entry matching the prefix of the content carried by the Interest message, the intermediate node can add a new PIT entry through the processor 201, for example, the newly added PIT entry can be called is the second entry. The prefix of the name of the content included in the second entry is the prefix of the name of the content carried in the Interest message, and the notify field included in the second entry is used to indicate that the PIT entry is used to reacquire the subscribed content, and the second entry The value of Seq_min included is the value of Seq_min carried in the Interest message, the value of Seq_max included in the second table item is the value of Seq_max carried in the Interest message, and the routing information included in the second table item is the intermediate node to The routing information of subscribing node 1, for example, the routing information may include the inbound interface information of subscribing node 1, and the inbound interface information of subscribing node 1 is the inbound interface information of the Interest message, for example, the routing information included in the second entry is the Incoming interface information of the Interest message. In addition, the intermediate node forwards the Interest message to the next-hop node through the communication interface 204 .

7. The intermediate node forwards the Interest message to the next-hop node through the communication interface 204 . Example 1 Take this as an example, then it is possible to realize the i-th case of branch 1 in step 6, or it is possible to realize the case of branch 2 in step 6.

8. After receiving the Interest message, the backup node sends a Data message, which carries the second part of the content.

Wherein, after receiving the Interest message, the backup node determines all subscription content after the sequence number corresponding to the value of Seq_min carried in the Interest message, that is, determines the second part of the content, and carries the determined second part of the content in the Data message.

Wherein, the prefix of the name of the requested content can be carried in the Data message, and Seq_min can also be carried. The value of Seq_min is the same as the value of Seq_min carried in the Interest message. Optionally, Seq_max can be carried or Seq_max may not be carried. If Seq_max is carried in the Data message, the value of Seq_max can be the same as the value of Seq_min carried in the Interest message, for example, Null, or the value of Seq_max can be the median value of the sequence numbers corresponding to all the contents carried in the Data message The value of the largest sequence number. Of course, the Data message may also carry the content requested by the Interest message.

9. After the intermediate node receives the Data message sent by the backup node through the communication interface 204, the processor 201 according to the local PIT entry (at this time, the PIT entry may be the updated first entry, or may also be the first entry). Seq_min in the second entry) determines whether to forward the Data message or discard the Data message (of course, the premise is that the prefix of the name of the content included in the PIT entry matches the prefix of the name of the content carried in the Data message). Optionally, the judgment process is as follows:

If the value of Seq_min in the Data message is equal to the value of Seq_min recorded in the local PIT entry, the intermediate node can forward the Data message to the next hop node through the communication interface 204, otherwise the intermediate node can pass the processor 201 discards the Data message, that is, if the second part of the content carried by the Data message is a subset of the first part of the content, the intermediate node can forward the Data message to the next-hop node through the communication interface 204, otherwise the intermediate node can pass the Processor 201 discards the Data message. For example, in Example 1, the intermediate node determines to forward the Data message to the next-hop node through the communication interface 204 as an example, and the next-hop node of the intermediate node is, for example, the subscribing node 1 .

10. The intermediate node forwards the Data message to the next-hop node through the communication interface 204 .

11. The subscribing node 1 receives the Data message and parses the Data message to obtain the second part of the content carried in the Data message. The subscribing node 1 can compare the value of Seq_min carried by the Data message (that is, the value of the sequence number with the smallest value among the sequence numbers of the contents included in the second part of the content) with the value of Seq_min previously requested by itself (that is, the value of the first sequence number value) to determine whether duplicate content has been received. For example, if the value of Seq_min carried in the Data message is smaller than the value of Seq_min previously requested by the subscription node 1, then the subscription node 1 determines that it has received duplicate content, and the subscription node 1 can delete the duplicate content from the second part of the content , to save storage space. For example, if the value of Seq_min carried in the Interest message sent by the subscribing node 1 is 10, and the value of Seq_min carried in the received Data message is 2, the processor 203 can determine that the content with sequence numbers 2-9 is repeated reception It can be deleted. It can be seen that the sequence number with the largest value in the content deleted by subscription node 1 is the first sequence number minus 1.

Example 1 is an example of subscribing node 1 going online after being offline. The following introduces example 2. In example 2, subscribing node 1 is always online, but due to network abnormalities and other reasons, some subscribed content is not received. Subscribing node 1 can be based on The continuity of the serial numbers of the content received by itself, and re-acquire the content that has not been received.

Example 2:

See Figure 4. Among them, steps 1-4 in Figure 4 can refer to Figure 3, and the introduction of these steps can refer to Example 1, wherein, in Step 3 in Example 1, subscription node 1 cannot receive Publish message 2 because it is offline, and Example 2 In step 3 of , subscribing node 1 cannot receive Publish message 2 due to network abnormalities and other reasons. The other different steps in Example 2 are described below.

5. The subscribing node 1 may determine that the content whose sequence number is between the first sequence number (for example, num1) and the second sequence number (for example, numN) is lost.

For example, due to network abnormalities and other reasons, the subscribing node 1 does not receive the content whose sequence number is between the first sequence number (for example, num1) and the second sequence number (for example, numN), where N is greater than 1 integer. For example, after the subscribing node 1 receives the content with the serial number num0, and then receives the content with the serial number numN+1, since the serial numbers of the received content are discontinuous, the subscribing node 1 can determine that some subscription content is lost, That is, it can be determined that the content between num1 and numN (including num1 and numN) has not been received.

6. The subscribing node 1 may send a first request message to the backup node to request to obtain the content whose serial number is between num1-numN, for example, the content whose serial number is between num1-numN may be called the first part of content. For example, the first request message can be realized by an Interest message, and the Interest message can carry the following content, for example:

(1)/The name of the backup node/Identification of the content of the first part. Wherein, the identification of the first part of content may include, for example, a prefix of the name of the first part of content;

(2) Seq_min, whose value is, for example, num1, and Seq_max, whose value is, for example, numN.

(3) A field used to indicate that the Interest message is to reacquire the subscribed content, for example, this field may be expressed as Get_Loss_Pub_Msg. Wherein, this field is optional, that is, this field may or may not be carried in the first request message.

(4) Get_Content_from_Origin. Wherein, this field is optional, that is, the Interest message can choose to carry Get_Content_from_Origin or not carry Get_Content_from_Origin, if it carries Get_Content_from_Origin, the value of Get_Content_from_Origin can be 0, indicating that the content can be obtained from the intermediate node.

7. The intermediate node receives the Interest message through the communication interface 204, and the processor 201 determines whether to forward the Interest message according to the prefix, Seq_min, and Seq_max of the name of the requested content carried in the Interest message. Optionally, the judgment process is as follows:

1) Because the Interest message does not carry Get_Content_from_Origin, or the value of Get_Content_from_Origin carried is 0, then the intermediate node queries the local CS table through the processor 201, if it is found in the CS table that the Interest message requested to obtain is locally cached Content, that is, cached content whose serial number is between num1 and numN, the intermediate node can obtain the content from the cache through the processor 201, carry the content in the Data message, and send it to the subscribing node 1 through the communication interface 204 , then what the intermediate node sends to the subscribing node 1 at this time is the first part of the content, and the processing ends. If the intermediate node inquires in the CS table and determines that the content requested by the Interest message is not cached locally, the intermediate node queries the local PIT through the processor 201 to determine whether a PIT entry for processing the first part of content is stored. According to whether the PIT entry for processing the first part of the content is stored, the following is divided into two branches to introduce:

Branch 1: Optionally, if the intermediate node finds the first entry, where the prefix of the content name included in the first entry matches the Interest message, and the value of the third serial number included in the first entry Less than or equal to the value of the first sequence number, and the value of the fourth sequence number included in the first entry is greater than or equal to the value of the second sequence number, that is, the [Seq_min, Seq_max] carried in the Interest message is the [Seq_min, Seq_max] included in the second entry. Seq_min, Seq_max], the intermediate node determines that the first entry is the stored PIT entry for processing the first part of the content, then the intermediate node can add the routing information from the intermediate node to the subscription node 1 through the processor 201 In the second entry, the routing information may include, for example, the inbound interface information of the Interest. In addition, the intermediate node does not need to forward the Interest message to the next-hop node through the communication interface 204, for example, the Interest message can be discarded through the processor 201 to save transmission resources.

Branch 2: Or, optionally, if the intermediate node does not find a PIT entry whose prefix of the name of the included content matches the Interest message, or although it finds that the prefix of the name of the included content matches the Interest message PIT entry, but the value of the third sequence number included in the PIT entry is greater than the value of the first sequence number and/or the value of the fourth sequence number included in the PIT entry is smaller than the value of the second sequence number, that is, the The [Seq_min, Seq_max] carried by the Interest message is not a subset of the [Seq_min, Seq_max] included in the PIT entry, then the intermediate node determines that the PIT entry for processing the first part of the content is not stored, and the intermediate node can pass the processor 201 A newly added PIT entry, for example, a newly added PIT entry may be called a second entry. The prefix of the name of the content included in the second entry is the prefix of the name of the content carried in the Interest message, and the notify field included in the second entry is used to indicate that the PIT entry is used to reacquire the subscribed content, and the second entry The value of Seq_min included is the value of Seq_min carried in the Interest message, the value of Seq_max included in the second entry is the value of Seq_max carried in the Interest message, and the routing information included in the second entry can be an intermediate node Routing information to the subscribing node 1, for example, the routing information may include the incoming interface information of the Interest message. The intermediate node may forward the Interest message to the next-hop node through the communication interface 204 .

8. The intermediate node forwards the Interest message to the next-hop node through the communication interface 204 . Example 2 takes this as an example, then in this case, it is possible to realize the case of branch 2 of step 7.

9. After receiving the Interest message, the backup node determines the first sequence number (ie num1) corresponding to the value of Seq_min carried by the Interest message and the second sequence number (ie num1) corresponding to the value of Seq_max carried by the Interest message ( That is, all subscription content between numN) (which may include the content with the serial number num1 and the content with the serial number numN), that is, determine the second part of the content, carry the determined second part of the content in the Data message, and Send the Data message. In Example 2, the second part of content may be the same as the first part of content.

Among them, the Data message can carry the prefix of the name of the requested content, and can also carry Seq_min and Seq_max. The value of Seq_min is num1, and the value of Seq_max is numN. Of course, the Data message can also carry the value requested by the Interest message. specific content.

10. After the intermediate node receives the Data message sent by the backup node through the communication interface 204, it uses the processor 201 according to the local PIT entry (the PIT entry can be the updated first entry, or it can also be the second table entry). Item) in Seq_min and Seq_max decide whether to forward the Data message or discard the Data message (of course, the premise is that the prefix of the name of the content included in the PIT entry matches the prefix of the name of the content carried in the Data message). Optionally, the judgment process is as follows:

If the value of Seq_min in the Data message is equal to the value of Seq_min recorded in the local PIT entry, and the value of Seq_max in the Data message is equal to the value of Seq_max recorded in the local PIT entry, then the intermediate The node can forward the Data message to the next-hop node through the communication interface 204 , otherwise, the intermediate node can discard the Data message through the processor 201 . For example, in Example 2, the intermediate node determines to forward the Data message to the next-hop node through the communication interface 204 as an example, and the next-hop node is, for example, the subscribing node 1 .

11. The intermediate node forwards the Data message to the next-hop node through the communication interface 204 .

12. The subscribing node 1 receives the Data message, so that the subscribing node 1 obtains the second part of content.

The following describes the equipment provided by the embodiments of the present invention with reference to the accompanying drawings.

Referring to FIG. 5 , based on the same inventive concept, an intermediate node is provided, and the intermediate node may include a receiving unit 501 , a processing unit 502 and a sending unit 503 .

In practical applications, the physical device corresponding to the receiving unit 501 may include the communication interface 204 in FIG. 2 , the physical device corresponding to the processing unit 502 may be the processor 201 in FIG. 2 , and the physical device corresponding to the sending unit 503 may include the The communication interface 204 in. It can be considered that, among the communication interfaces 204 in FIG. Each communication interface 204 can realize both the function of the receiving unit 501 and the function of the sending unit 503 .

The intermediate node may be used to execute the methods described in FIGS. 3-4 above, and may be, for example, the aforementioned intermediate node. Therefore, for the functions realized by the units in the intermediate node, etc., reference may be made to the description in the method part above, and details will not be repeated.

Referring to FIG. 6 , based on the same inventive concept, a subscription node is provided, and the subscription node may include a receiving unit 601 and a sending unit 602 . Optionally, the subscribing node may further include a processing unit 603, which is also shown in FIG. 6 .

In practical applications, the physical device corresponding to the receiving unit 601 may include the communication interface 204 in FIG. 2 , the physical device corresponding to the processing unit 603 may be the processor 201 in FIG. 2 , and the physical device corresponding to the sending unit 602 may include the The communication interface 204 in. It can be considered that among the communication interfaces 204 in FIG. 2, some communication interfaces 204 realize the function of the receiving unit 601, and some communication interfaces 204 realize the function of the sending unit 602, or it can be considered that among the communication interfaces 204 in FIG. Each communication interface 204 can realize both the function of the receiving unit 601 and the function of the sending unit 602 .

The subscribing node may be used to execute the methods described above in FIGS. 3-4 , for example, may be the subscribing node as described above. Therefore, for the functions realized by the units in the subscribing node, etc., reference may be made to the description in the previous method part, and details will not be repeated.

In the embodiment of the present invention, if the subscribing node does not receive certain content, the subscribing node may send a request message (for example, a first request message) for obtaining the content, and the first request message may carry the information of this part of the content The smallest serial number in the serial number, so that the subscribing node can receive this part of the content, so that even if the subscribing node is offline, it can re-request the lost content after going online, or even if the subscribing node does not receive part of the subscription due to network abnormalities and other reasons Content, you can also re-request to obtain the content in the future, so as to avoid the loss of content as much as possible.

An embodiment of the present invention also provides a computer storage medium for storing computer software instructions for the above-mentioned intermediate node, which includes a program designed for the intermediate node to execute the above-mentioned aspects.

The embodiment of the present invention also provides another computer storage medium, which is used to store the computer software instructions used by the above-mentioned subscribing node, which includes a program designed for the subscribing node to execute the above aspect.

In the present invention, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are only illustrative. For example, the division of the units or units is only a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components can be Incorporation may either be integrated into another system, or some features may be omitted, or not implemented. In another point, the mutual coupling or direct coupling or communication connection shown or discussed may be through some interfaces, and the indirect coupling or communication connection of devices or units may be in electrical or other forms.

The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place, or may be distributed to multiple network units. Part or all of the units can be selected according to actual needs to implement the embodiments of the present invention.

Each functional unit in the embodiment of the present invention may be integrated into one processing unit, or each unit may also be an independent physical module.

If the integrated unit is realized in the form of a software function unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on such an understanding, all or part of the technical solutions of the present invention may be embodied in the form of software products, which are stored in a storage medium and include instructions to enable a computer device (which may be a personal computer, A server, or a network device, etc.) or a processor (processor) executes all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage media include: Universal Serial Bus flash drives (Universal Serial Bus flash drives), mobile hard disks, ROMs, RAMs, magnetic disks or optical disks, and other media that can store program codes.

As mentioned above, the above embodiments are only used to introduce the technical solutions of the present invention in detail, but the descriptions of the above embodiments are only used to help understand the methods of the embodiments of the present invention, and should not be construed as limitations on the embodiments of the present invention. Changes or substitutions that can be easily imagined by those skilled in the art should fall within the protection scope of the embodiments of the present invention.

Claims (30)

1. a subscribed content acquisition methods, it is characterised in that including:

Intermediate node receives subscribes to the first request message for obtaining ordered Part I content that node sends；Described first request message carries First ray number, and described First ray number is the serial number of the first content that described Part I content includes, the serial number that the serial number intermediate value of the described First ray number each content included by described Part I content is minimum；

Described intermediate node determines the first list item stored for processing described Part I content, then described intermediate node asks the first list item described in the content update that carries of message according to described first；Described first list item includes the mark of described Part I content；

Described intermediate node receives the described the second part that backup node sends；Described the second part includes the described first content with described First ray number, and described Part I content is the subset of described the second part；

Described the second part to the routing iinformation of described subscription node, is sent to described subscription node according to the described intermediate node that includes of the first list item after updating by described intermediate node.

2. the method for claim 1, it is characterised in that described intermediate node asks the first list item described in the content update that carries of message according to described first, including:

Described intermediate node judges that the value of the serial number that described first list item includes is whether less than or equal to the value of described First ray number；

If the value of the serial number that described first list item includes is less than or equal to the value of described First ray number, described intermediate node adds the described intermediate node routing iinformation to described subscription node in described first list item, obtain the first list item after described renewal, and described intermediate node abandons described first request message.

3. the method for claim 1, it is characterised in that

Described intermediate node asks the first list item described in the content update that carries of message according to described first, including:

Described intermediate node judges that the value of the serial number that described first list item includes is whether less than or equal to the value of described First ray number；

If the value of the serial number that described first list item includes is more than the value of described First ray number, the value of the serial number that described first list item is included by described intermediate node is updated to the value of described First ray number, described first list item adds the described intermediate node routing iinformation to described subscription node, obtains the first list item after described renewal；

After the first list item described in the content update that described intermediate node carries according to described first request message, also include:

Described intermediate node asks message to be transmitted to described backup node by described first.

4. the method as described in as arbitrary in claim 1-3, it is characterised in that after described intermediate node receives the described the second part that backup node sends, also include:

Described intermediate node determines the serial number that the minimum serial number of the serial number intermediate value of each content that described the second part includes includes equal to the first list item after described renewal.

5. the method for claim 1, it is characterized in that, described first request message also carries the second serial number, described second serial number is the serial number of the second content that described Part I content includes, and described second serial number is the serial number that the serial number intermediate value of each content included by described Part I content is maximum.

6. the method as described in as arbitrary in claim 1-5, it is characterised in that intermediate node receive subscribe to that node sends for obtain ordered Part I content the first request message after, also include:

Described intermediate node inquires about whether this locality stores described Part I content；

If this locality does not store described Part I content, then whether the inquiry of described intermediate node stores the first list item for processing described Part I content.

7. method as claimed in claim 6, it is characterised in that described method also includes:

If locally stored described Part I content, described Part I content is sent to described subscription node by described intermediate node.

8. the method as described in as arbitrary in claim 1-7, it is characterised in that

Before the first list item described in the content update that described intermediate node carries according to described first request message, also include:

Described intermediate node determines that the value of the 3rd serial number that described first list item includes is whether less than or equal to the value of described First ray number, and whether the value of the 4th serial number that includes of described first list item is be more than or equal to the value of described second serial number；Wherein, described first list item includes described 3rd serial number and described 4th serial number, described 3rd serial number is the serial number that the serial number intermediate value of the requested content of described first list item is minimum, and described 4th serial number is the serial number that the serial number intermediate value of the requested content of described first list item is maximum；

Described intermediate node asks the first list item described in the content update that carries of message according to described first, including:

If the value of the 3rd serial number that described first list item includes is less than or equal to the value of described First ray number, and the value of the 4th serial number that includes of described first list item is be more than or equal to the value of described second serial number, described intermediate node adds the described intermediate node routing iinformation to described subscription node in described first list item, obtain the first list item after described renewal, and described intermediate node abandons described first request message.

9. method as claimed in claim 8, it is characterised in that described method also includes:

If the value of the 4th serial number that the value of the 3rd serial number that described first list item includes includes more than the value of described First ray number and/or described first list item is less than the value of described second serial number, described intermediate node sets up the second list item, and described second list item includes the mark of described Part I content, described First ray number, described second serial number and the described intermediate node routing iinformation to described subscription node；

Described intermediate node asks message to be transmitted to described backup node by described first.

10. the method for claim 1, it is characterised in that after intermediate node receives and subscribes to the first request message being used for obtaining ordered Part I content that node sends, also include:

Described intermediate node determines described first list item not stored for processing described Part I content, then described intermediate node sets up the second list item, and described second list item includes the mark of described Part I content, described First ray number and the described intermediate node routing iinformation to described subscription node；

Described intermediate node asks message to be transmitted to described backup node by described first.

11. method as claimed in claim 10, it is characterized in that, described second list item also includes carrying asks the second serial number in message described first, described second serial number is the serial number of the second content that described Part I content includes, and described second serial number is the serial number that the serial number intermediate value of each content included by described Part I content is maximum.

12. a subscribed content acquisition methods, it is characterised in that including:

Subscribe to node and send the first request message for obtaining ordered Part I content；Described first request message carries First ray number, and described First ray number is the serial number of the first content that described Part I content includes, the serial number that the serial number intermediate value of the described First ray number each content included by described Part I content is minimum；

Described subscription node receives the second part；Described the second part includes the described first content with described First ray number, and described Part I content is the subset of described the second part.

13. method as claimed in claim 12, it is characterized in that, described first request message also carries the second serial number, described second serial number is the serial number of the second content that described Part I content includes, and described second serial number is the serial number that the serial number intermediate value of each content included by described Part I content is maximum.

14. method as claimed in claim 13, it is characterised in that before subscribing to the first request message that node sends for obtaining ordered Part I content, also include:

Described subscription node determines that the serial number of two contents of up-to-date reception is discontinuous.

15. the method as described in as arbitrary in claim 12-14, it is characterised in that after described subscription node receives the second part, also include:

Described subscription node judges that whether the minimum serial number of the serial number intermediate value of each content that described the second part includes is less than described First ray number；

If the minimum serial number of the serial number intermediate value of each content that described the second part includes is less than described First ray number, at least one content in the second part described in described subscription knot removal；The serial number that the minimum serial number intermediate value that serial number is each content that described the second part includes of at least one content intermediate value described is minimum, the maximum serial number of at least one content intermediate value described is that described First ray number subtracts 1.

16. an intermediate node, it is characterised in that including:

Receive unit, subscribe to, for receiving, the first request message for obtaining ordered Part I content that node sends；Described first request message carries First ray number, and described First ray number is the serial number of the first content that described Part I content includes, the serial number that the serial number intermediate value of the described First ray number each content included by described Part I content is minimum；

Processing unit, for determining the first list item stored for processing described Part I content, then asks the first list item described in the content update that message carries according to described first；Described first list item includes the mark of described Part I content；

Described reception unit, is additionally operable to receive the described the second part that backup node sends；Described the second part includes the described first content with described First ray number, and described Part I content is the subset of described the second part；

Transmitting element, for according to the described intermediate node that includes of the first list item after updating to the routing iinformation of described subscription node, described the second part is sent to described subscription node.

17. intermediate node as claimed in claim 16, it is characterised in that described processing unit is used for the first list item according to the described first content update asking message to be carried, including:

Judge that the value of the serial number that described first list item includes is whether less than or equal to the value of described First ray number；

If the value of the serial number that described first list item includes is less than or equal to the value of described First ray number, described first list item adds the described intermediate node routing iinformation to described subscription node, obtain the first list item after described renewal, and abandon described first request message.

18. intermediate node as claimed in claim 16, it is characterised in that

Described processing unit for asking the first list item described in the content update that carries of message according to described first, including: judge that the value of the serial number that described first list item includes is whether less than or equal to the value of described First ray number；If the value of the serial number that described first list item includes is more than the value of described First ray number, the value of the serial number included by described first list item is updated to the value of described First ray number, described first list item adds the described intermediate node routing iinformation to described subscription node, obtains the first list item after described renewal；

Described transmitting element is additionally operable to: after the first list item described in the content update that described processing unit carries according to described first request message, ask message to be transmitted to described backup node by described first.

19. the intermediate node as described in as arbitrary in claim 16-18, it is characterised in that described processing unit is additionally operable to:

After described reception unit receives the described the second part that backup node sends, it is determined that the serial number that the minimum serial number of the serial number intermediate value of each content that described the second part includes includes equal to the first list item after described renewal.

20. intermediate node as claimed in claim 16, it is characterized in that, described first request message also carries the second serial number, described second serial number is the serial number of the second content that described Part I content includes, and described second serial number is the serial number that the serial number intermediate value of each content included by described Part I content is maximum.

21. the intermediate node as described in as arbitrary in claim 16-20, it is characterised in that described processing unit is additionally operable to:

After described reception unit receives and subscribes to the first request message being used for obtaining ordered Part I content that node sends, whether inquiry this locality stores described Part I content；

If this locality does not store described Part I content, then inquire about the first list item whether stored for processing described Part I content.

22. intermediate node as claimed in claim 21, it is characterised in that described processing unit is additionally operable to:

If locally stored described Part I content, then by described communication interface, described Part I content is sent to described subscription node.

23. the intermediate node as described in as arbitrary in claim 16-22, it is characterised in that

Described processing unit is additionally operable to: before the first list item described in the content update carried according to described first request message, determine that the value of the 3rd serial number that described first list item includes is whether less than or equal to the value of described First ray number, and whether the value of the 4th serial number that includes of described first list item is be more than or equal to the value of described second serial number；Wherein, described first list item includes described 3rd serial number and described 4th serial number, described 3rd serial number is the serial number that the serial number intermediate value of the requested content of described first list item is minimum, and described 4th serial number is the serial number that the serial number intermediate value of the requested content of described first list item is maximum；

Described processing unit is used for the first list item according to the described first content update asking message to be carried, including: if the value of the 3rd serial number that includes of described first list item is less than or equal to the value of described First ray number, and the value of the 4th serial number that includes of described first list item is be more than or equal to the value of described second serial number, described first list item adds the described intermediate node routing iinformation to described subscription node, obtain the first list item after described renewal, and abandon described first request message.

24. intermediate node as claimed in claim 23, it is characterised in that

Described processing unit is additionally operable to: if the value of the 4th serial number that includes more than the value of described First ray number and/or described first list item of the value of the 3rd serial number that described first list item includes is less than the value of described second serial number, setting up the second list item, described second list item includes the mark of described Part I content, described First ray number, described second serial number and the described intermediate node routing iinformation to described subscription node；

Described transmitting element is additionally operable to: ask message to be transmitted to described backup node by described first.

25. intermediate node as claimed in claim 16, it is characterised in that

Described processing unit is additionally operable to: after described reception unit receives and subscribes to the first request message being used for obtaining ordered Part I content that node sends, determine described first list item not stored for processing described Part I content, then setting up the second list item, described second list item includes the mark of described Part I content, described First ray number and the described intermediate node routing iinformation to described subscription node；

Described transmitting element is additionally operable to: ask message to be transmitted to described backup node by described first.

26. intermediate node as claimed in claim 25, it is characterized in that, described second list item also includes carrying asks the second serial number in message described first, described second serial number is the serial number of the second content that described Part I content includes, and described second serial number is the serial number that the serial number intermediate value of each content included by described Part I content is maximum.

27. one kind is subscribed to node, it is characterised in that including:

Transmitting element, for sending the first request message for obtaining ordered Part I content；Described first request message carries First ray number, and described First ray number is the serial number of the first content that described Part I content includes, the serial number that the serial number intermediate value of the described First ray number each content included by described Part I content is minimum；

Receive unit, be used for receiving the second part；Described the second part includes the described first content with described First ray number, and described Part I content is the subset of described the second part.

28. subscribe to node as claimed in claim 27, it is characterized in that, described first request message also carries the second serial number, described second serial number is the serial number of the second content that described Part I content includes, and described second serial number is the serial number that the serial number intermediate value of each content included by described Part I content is maximum.

29. subscribe to node as claimed in claim 28, it is characterized in that, described subscription node also includes processing unit, for send the first request message for obtaining ordered Part I content at described transmitting element before, it is determined that the serial number of two contents of up-to-date reception is discontinuous.

30. the subscription node as described in as arbitrary in claim 27-29, it is characterised in that described subscription node also includes processing unit, is used for:

Receive after the second part at described reception unit, it is judged that whether the minimum serial number of the serial number intermediate value of each content that described the second part includes is less than described First ray number；

If the minimum serial number of the serial number intermediate value of each content that described the second part includes is less than described First ray number, delete at least one content in described the second part；The serial number that the minimum serial number intermediate value that serial number is each content that described the second part includes of at least one content intermediate value described is minimum, the maximum serial number of at least one content intermediate value described is that described First ray number subtracts 1.