WO2015043257A1

WO2015043257A1 - Link setup method, system, and computer storage medium in distributed cdn system

Info

Publication number: WO2015043257A1
Application number: PCT/CN2014/080588
Authority: WO
Inventors: 于荣国; 熊勤
Original assignee: 中兴通讯股份有限公司
Priority date: 2013-09-27
Filing date: 2014-06-24
Publication date: 2015-04-02
Also published as: CN104519080A; CN104519080B

Abstract

Disclosed are a link setup method, system, and computer storage medium in a distributed CDN system. The method comprises: a management layer obtaining data information of a control layer, and obtaining data information of each node at a capability layer; the management layer allocating, to each node at the capability layer according to the obtained data information, a control layer that each node at the capability layer belongs to; and the control layer setting up a communications link to each node at the capability layer based on the data information.

Description

Chain building method, system and computing product storage medium for distributed CDN system

The present invention relates to the field of multimedia services, and in particular to a chain construction method, system and computer storage medium for a distributed CDN system. Background technique

With the rapid development of communication technologies, the continuous improvement of network bandwidth and the widespread application of global cloud computing technologies, the number of Internet users has increased rapidly. IPTV (interactive network TV) technology has been rapidly promoted, and has begun to be started by major operators around the world. Large-scale adoption and deployment. In particular, the implementation of the current "three networks integration" policy provides a spurt development opportunity for China's emerging Content Delivery Network (CDN) industry.

The growth of CDN business volume and its industrial chain has put forward higher requirements for CDN management, control layer and capability layer equipment. The goal will gradually develop towards ultra-large capacity, security and stability, and flexible networking. Large-scale networking technology needs to be broken. In the distributed CDN system under the CDN large-scale software architecture, to achieve the flexibility and efficiency of large-scale node management, the CDN management and control capabilities have higher and more reliable requirements. In order to improve the robustness of the system, the management and control layers of the CDN are often set to the silent (dual-center) mode or the active/standby mode. This has a higher flexibility in building the chain when the CDN is switched. Claim.

Taking the networking of the CDN system as an example, the current CDN network element mainly uses a bottom-up approach to establish a communication link between network elements. The establishment of the signaling network and the media network topology are both solidified and do not have to be The ability to control, the flexibility is poor, so in the dual-center solution of the media positioning system MLSS (management, also known as CDN Manager) in the previous architecture, when modifying the topology of the MLSS signaling network, it needs to be in the capability layer. A large number of switching operations are performed on the node, and the engineering operation is complicated and difficult, and the risk is large, and it is difficult to automatically switch the link. Large-scale soft on CDN Under the framework of the structure, this drawback will become more prominent.

For the problem that the link in the distributed CDN system in the related art cannot be automatically switched, an effective solution has not been proposed yet. Summary of the invention

The embodiment of the invention provides a method, a system and a computer storage medium for constructing a distributed CDN system, which can solve the problem that the link cannot be automatically switched in the distributed CDN system.

The embodiment of the present invention provides a method for establishing a distributed CDN system, where the method includes: the management layer acquires data information of the control layer, and acquires data information of each node of the capability layer; the management layer according to the acquired data information, Each node of the capability layer is assigned a home control layer; the control layer establishes a communication link to each node of the capability layer based on the foregoing data information.

Preferably, the management layer acquiring the data information of the control layer includes: the management layer adds the data information of the control layer by using a WEB module control layer management interface; where the data information of the control layer includes a control layer Identification, module number, office number.

Preferably, the management layer acquiring the data information of each node of the capability layer includes: the management layer adds data information of each node of the capability layer by using a WEB module node management interface, where the data information of the node includes a node. Identification, node signaling IP, signaling port, module number, office number, and link-building mode information.

Preferably, the control layer establishes a communication link to each node of the capability layer based on the data information, where: the control layer synchronizes data information of the management layer, and selects, from the data information, the control attributed to the control Data information of the nodes of the layer; storing the data information of the selected node in the node link list; and the control layer establishes a communication link to each node of the capability layer according to the node link list.

Preferably, the method further includes: the control layer monitoring the link list of the node in real time; when the monitoring finds that the link list of the node changes, the control layer creates or closes a changed link. The embodiment of the present invention further provides a link establishing system, where the system includes a management layer, a capability layer, and a control layer, where: the management layer includes: an information acquiring module, configured to acquire data information of the control layer, and obtain the foregoing The data module of each node of the capability layer is configured to allocate, according to the acquired data information, a control layer for each node of the capability layer; the control layer includes: a chain building module, configured to perform the foregoing according to the foregoing data information Each node of the capability layer establishes a communication link.

Preferably, the information acquiring module includes: a first acquiring unit, configured to add data information of the control layer by using a WEB module control layer management interface; wherein, the data information of the control layer includes a control layer identifier, a module number , bureau number.

Preferably, the information acquiring module includes: a second acquiring unit, configured to add data information of each node of the capability layer by using a WEB module node management interface, where the data information of the node includes a node identifier, a node signaling IP address , signaling port, module number, office number, and link-building mode information.

Preferably, the chain building module includes: a table building unit configured to synchronize data information of the management layer, and select, from the data information, data information of a node belonging to the control layer; The data information of the node is stored in the node link list; the chain-building unit is configured to establish a communication link to each node of the capability layer according to the node link list.

Preferably, the control layer further includes: a monitoring module configured to monitor the link list of the node in real time; and a processing module configured to: when the monitoring module finds that the link list of the node changes, newly or close the changed link.

The embodiment of the invention further provides a computer storage medium, wherein the computer storage medium stores computer executable instructions, and the computer executable instructions are used to execute the chain construction method of the CDN system described above.

According to the embodiment of the present invention, the management layer acquires the data information of the control layer, and acquires the data information of each node of the capability layer; the management layer is the each section of the capability layer according to the acquired data information. The point is assigned a home control layer; the above control layer establishes a communication link to each node of the capability layer based on the above data information, and solves the problem that the link cannot be automatically switched in the distributed CDN system in the related art, thereby realizing the large CDN Under the scale software architecture, the control layer software flexibly manages the topology of the capability layer nodes and the simplification of the capability layer configuration. When the topology of the signaling network changes, automatic switching of the link between the control layer software and the capability layer node can be achieved, and the impact on the service function is minimized. At the same time, it can also meet the rapid expansion of the CDN system and large-scale expansion.

The above description is only an overview of the technical solutions of the present invention, and the technical means of the present invention can be more clearly understood, and can be implemented in accordance with the contents of the specification, and the above and other objects, features and advantages of the present invention can be more clearly understood. Specific embodiments of the invention are set forth below. DRAWINGS

1 is a flowchart of a method for establishing a distributed CDN system according to an embodiment of the present invention; FIG. 2 is a structural block diagram of a chain building system according to an embodiment of the present invention;

3 is a system architecture diagram of a CDN reverse chain construction according to an embodiment of the present invention; FIG. 4 is a schematic flowchart of a CDN reverse chain construction method according to an embodiment of the present invention. detailed description

The embodiment of the present invention provides a method and system for establishing a distributed CDN system. The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It is understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

The technical solution of the present invention relates to the field of multimedia services in a telecommunication network such as IPTV, video surveillance, mobile streaming media, and the like, and particularly relates to a network control method in a distributed CDN system in a large-scale networking mode in a converged CDN service system.

This embodiment provides a method for establishing a distributed CDN system. FIG. 1 is a flowchart of a method for establishing a distributed CDN system according to an embodiment of the present invention. As shown in FIG. 1, the method includes the following steps: Step S102 - step S106 ): Step S102, the management layer acquires data information of the control layer, and acquires data information of each node of the capability layer;

Step S104: The management layer allocates a belonging control layer to each node of the capability layer according to the acquired data information.

Step S106: The control layer establishes a communication link to each node of the capability layer based on the foregoing data information.

Through the foregoing method, the management layer acquires the data information of the control layer, and acquires the data information of each node of the capability layer; the management layer allocates a belonging control layer to each node of the capability layer according to the acquired data information; the control layer is based on the foregoing data. The information is used to establish a communication link to each node of the capability layer, which solves the problem that the link in the distributed CDN system cannot be automatically switched in the related art, thereby realizing the control layer software to the capability layer node topology under the CDN large-scale software architecture. Flexible management and simplification of the capability layer configuration. When the topology of the signaling network changes, the automatic switching of the link between the control layer software and the capability layer node can be achieved, and the impact on the service function is minimized. It also meets the rapid expansion of CDN systems and large-scale expansion.

Preferably, the control layer establishes a communication link to each node of the capability layer based on the data information, where: the control layer synchronizes data information of the management layer, and filters data information of a node belonging to the control layer from the data information. And storing the data information of the selected node in the node link list; the control layer establishes a communication link to each node of the capability layer according to the node link list.

Preferably, the method further includes: the control layer monitoring the link list of the node in real time; when the monitoring finds that the link list of the node changes, the control layer newly changes or closes the changed link.

The technical problem to be solved by the technical solution of the present invention is to provide a networking control method in a distributed CDN system, which is used to implement flexible management of the capability layer node topology of the control layer software under the CDN large-scale software architecture, and Simplification of the capability layer configuration. When the topology of the signaling network changes, the automatic switching of the link between the control layer software and the capability layer node can be realized, and the service function will be performed. The impact of functions such as content distribution, channel creation, and program recording can be minimized; it can also meet the rapid expansion of CDN systems and large-scale expansion.

According to the embodiment of the present invention, the networking control method in the distributed CDN system is compared with the traditional control method of the CDN networking, and the control method described in the embodiment of the present invention may be referred to as a reverse chain-building method. The system from the building chain method can be divided into a management layer, a capability layer and a control layer. The system implementing the reverse chain building method can include a CDNWEB module, a management data module, a management database module, a control layer data module, Control layer database module, control layer communication module. The individual modules are described in detail below.

The CDNWEB module is configured as an entry for the CDN management layer data configuration, and performs CDN system resource configuration and delivery, such as: communication information of each node of the capability layer, control layer network element information, control layer of the node belonging, etc.; Add, modify, or delete; also configured to display the interface of business data.

The management data module is configured to cooperate with the control layer data module to complete the data synchronization function, and synchronize the system resource configuration information added by the management layer to each control layer in the entire network. Meanwhile, when the management data configuration changes, Real-time data updates between management software and control layer software.

The management database module is configured to save all the resource configuration data sent by the management layer, and collect the capability layer node performance data reported by the control layer software, and the service processing result. The main configuration is page data presentation of the CDNWEB module and data synchronization between the management software and the control layer software. It can also be configured as the management software to cache the upper layer service instructions, which are read and distributed by the management layer to the control layer software.

Control layer network management module: Configured to add, delete, and modify the control layer basic configuration. At the same time, management communication information such as management IP, module number, and office number can be configured for each network element of the control layer.

Control layer data module: configured to cooperate with the management data module to implement data synchronization. The basic data delivered by the management layer is saved in the control layer database module to perform normal operation of the business function.

The control layer database module is configured to provide an access interface to all the business processes of the control layer, and save or update the basic configuration and service data delivered by the management layer and the control layer data; The service instruction of the node is periodically read and distributed by the control layer service process to each node of the capability layer, and receives the processing result of the capability layer node; and is configured to notify the specified module when the data of the control layer changes, and keep the data in real time. Update.

Control layer communication module: Configured to manage the communication link between the control layer and each layer. After the control layer communication module is started, the communication and establishment chain information of the management layer and the capability layer are automatically read from the control layer database module, and the communication link is established actively with the management layer and the capability layer. At the same time, the communication module will also monitor the communication link information in the control layer database module in real time. Once the link information changes, the communication module will immediately open or close the changed link to ensure the link is correct and unobstructed.

The capability layer node is configured to establish a chain with the software of the control layer, and receive the service instructions (such as content distribution, channel creation, program recording, etc.) delivered by the control layer to store the media content. Report the service processing result and node performance data; and provide CDN media services to users.

The following describes a method for implementing reverse chain construction in a distributed CDN large-scale networking through a specific embodiment, and is also compatible with the previous chain-building mode, and mainly includes the following steps:

In the control layer network management, add management communication information for each control layer software, including management IP, module number, office number, etc., and data is written into each control layer database;

The control layer communication module periodically queries the control layer database, reads the management communication link information, and actively establishes a signaling link to the management software. At the same time, the communication module also monitors the management communication link information in the database in real time, once the information When a change occurs, the communication module will immediately open or close the changed link to ensure the correct and smooth link.

The management layer adds the data of each node of the capability layer through the WEB module node management interface, including the node identifier, node signaling IP, signaling port, module number, office number, and link establishment mode. Information such as building a chain or building a chain in reverse; here, the forward building chain represents the ability layer to actively build a chain to the control layer.

(Traditional CDN chain building method), reverse chain construction means that the control layer actively builds a chain of capabilities. The capability layer can consist of one or more nodes.

Based on the above description, preferably, in the embodiment, the management layer acquires the data information of each node of the capability layer, where the management layer adds the data information of each node of the capability layer by using the WEB module node management interface, where the node is The data information includes a node identifier, a node signaling IP, a signaling port, a module number, a station number, and a link establishment mode information.

The management layer adds the information of each control layer of the CDN through the WEB module control layer management interface, including the control layer identifier, module number, and office number. Management is unique and there can be multiple control layers.

Based on the above description, preferably, in the embodiment, the management layer acquires the data information of the control layer, where: the management layer adds the data information of the control layer by using a WEB module control layer management interface; wherein, the data of the foregoing control layer The information includes the control layer identifier, module number, and office number.

The management layer controls the relationship interface through the WEB module node to assign a control layer to each node of the capability layer. One node belongs to one control layer, different nodes can belong to the same control layer, and one control layer can control hundreds of capability layer nodes.

The CDNWEB module data is added, triggering data synchronization. Through the data synchronization mechanism between the management data module and the control layer data module, the management software configures the system resource configuration information (capability layer node information, control layer information, capability layer node attribution information). ) Full synchronization to each network element of the control layer. When the resource configuration information changes, real-time data synchronization is maintained between the management software and the control layer software.

The control layer software reads the synchronized data information, and selects the node data in the jurisdiction of the control layer. According to the chain-building mode, the node data that needs to be reverse-chained is stored in the node link list of the control layer. Node data to the built-in chain is not saved in this list. When the signaling network topology occurs When the data synchronization is triggered again, the node link list of each control layer is updated in real time.

The control layer communication module periodically scans the database, reads the node link list, and actively establishes a communication link to each node software of the capability layer. At the same time, the communication module also monitors the link list information in the database in real time. Once the list information changes, the communication module will immediately create or close the changed link to ensure the correct and smooth link.

For a node that is being chained, the control layer waits for the capability layer node to initiate a link establishment request. In the CDN reverse chain building system constructed by the method disclosed in the embodiment, the management software configuration data and the synchronization mechanism with the control layer software are used to generate a node link list, and the operation method is simple and efficient, and the product is improved. The software of the control layer actively establishes a signaling link to the software of each node of the capability layer according to the link list of the capability layer node, thereby realizing the flexible management of the topology; breaking through the conventional chain-building mode in the CDN system (positive It is compatible with both forward chain construction and reverse chain construction. From the capability layer, the chain construction method is more flexible, reliable and practical. More importantly, when the topology of the signaling network is modified, the automatic switching between the control layer and the capability layer link is realized, which simplifies the engineering operation and minimizes the impact on the service; Componentization with the control layer greatly enhances the CDN's large-scale networking and rapid capacity expansion.

Corresponding to the chain-building method described in the foregoing embodiment, this embodiment provides a chain-building system, which is used to implement the chain-building method of the distributed CDN system according to the embodiment of the present invention, and FIG. 2 is implemented according to the present invention. The structural block diagram of the example of the chain-building system, as shown in Figure 2, the chain-building system includes the management layer, the capability layer, and the control layer. The structure is described in detail below.

The management layer includes: an information obtaining module 10, configured to acquire data information of the foregoing control layer, and obtain data information of each node of the capability layer; and an allocation module 12 configured to allocate one node to each node of the capability layer according to the acquired data information. Attributable control layer;

The control layer includes: a chain building module 20 configured to establish a communication link to each node of the capability layer according to the foregoing data information. Through the foregoing embodiment, the management layer acquires the data information of the control layer, and acquires the data information of each node of the capability layer; the management layer allocates a belonging control layer to each node of the capability layer according to the acquired data information; the foregoing control layer is based on the foregoing The data information is used to establish a communication link to each node of the capability layer, which solves the problem that the link in the distributed CDN system cannot be automatically switched in the related art, thereby realizing the control layer software to the capability layer node extension under the CDN large-scale software architecture. Park's flexible management and simplification of the capability layer configuration. When the topology of the signaling network changes, automatic switching of the link between the control layer software and the capability layer node can be achieved, and the impact on the service function is minimized. At the same time, it can also meet the rapid expansion of the CDN system and large-scale expansion.

Preferably, the information acquiring module 10 includes: a first acquiring unit, configured to add data information of the control layer by using a WEB module control layer management interface; wherein, the data information of the control layer includes a control layer identifier, a module number, and a local number.

Preferably, the information acquiring module 10 includes: a second acquiring unit, configured to add data information of each node of the capability layer by using a WEB module node management interface, where the data information of the node includes a node identifier, a node signaling IP, and a letter Let the port, module number, office number, and link-building mode information.

Preferably, the chain building module 20 includes: a table building unit configured to synchronize data information of the management layer, and filter data information of a node belonging to the control layer from the data information; The information is stored in the node link list; the chain building unit is configured to establish a communication link to each node of the capability layer according to the node link list.

Preferably, the control layer further includes: a monitoring module 30 configured to monitor the link list of the node in real time; and the processing module 40 configured to: when the monitoring module finds that the link list of the node changes, newly or close the changed link .

In practical applications, the above-mentioned chain-building system may be disposed on multiple servers, and in response, each module in the above-mentioned chain-building system may be in a corresponding server.

The technical solution of the embodiment of the present invention will be described in more detail below with reference to the accompanying drawings and embodiments. Bright.

FIG. 3 is a system architecture diagram of a CDN reverse chain construction according to an embodiment of the present invention. As shown in FIG. 3, this embodiment provides a CDN reverse chain-based system, including a CDN management layer server. Marked as CDNM, CDN Manager), one or more CDN Control Layer Servers (labeled CDNC, CDN Control), one or more CDN Capability Layer Node Devices (ie CDN nodes, labeled NODE in the figure). The CDN management layer server also includes a CDNWEB module (CDNWEB Management Layer Data (ML-D), Management Layer Database (ML-DB); the CDN control layer server also includes a control layer network management system ( NetNumen N31, referred to as N31), Control Layer Data (CL-D), Control Layer Database (CL-DB), Control Layer Communication (CL-COM) .

4 is a schematic flowchart of a method for reverse chain building of a CDN according to an embodiment of the present invention. As shown in FIG. 4, the process includes the following steps (step S401-step S414):

Step S401: Add a control layer CDNC network element to the N31 network management system, and add management information of the management CDNM to each CDNC network element through the network management, mainly including the signaling IP, the module number, the office number, and the port of the CDNM, and the data is directly written. The database CL-DB of each CDNC network element;

Step S402: The communication module CL-COM of each CDNC network element periodically scans the table in the CL-DB to read the communication establishment information of the CDNM.

Step S403: Each CDNC network element of the control layer actively establishes a communication link to the management CDNM; if the CDNM communication information in the CL-DB table changes, the CL-COM immediately closes or updates the changed link to ensure the effective link. The road is correct and unobstructed.

Step S404: Add the communication data (one or more) of each NODE of the capability layer through the management layer CDNWEB, and the data (one or more) of each CDNC network element of the control layer. At the same time, it is also possible to establish a affiliation relationship between each NODE and CDNC, as well as business dependencies between NODEs and the like. The data is directly written into the management layer ML-DB, and the version information of the corresponding table is also updated, and the data in the table is marked as being changed.

Step S405: The management data is added, the CDNWEB triggers data synchronization, and sends a data change notification to the management data module ML-D, and the change notification carries the latest version information of each data table.

Step S406: The management data module ML-D broadcasts the message to the data module CL-D of all CDNC network elements after receiving the data change notification.

Step S407: The data module CL-D of each CDNC network element queries the data version information in the CLDB, and compares with the version number of the notification, and starts the data synchronization process.

Step S408: Each CDNC network element decides whether to send a data synchronization request to the ML-D according to the table version information acquired by the CL-D, and which tables are synchronized.

Step S409: The ML-D receives the data synchronization request from each CDNC network element, returns a data synchronization response to the CD-D module of each CDNC, and carries the data synchronization FTP information.

Step S410: After receiving the data synchronization response returned by the CDNM, the CL-D obtains the latest data from the FTP address specified by the CDNM, and writes the data into the CD-DB database of the CDNC.

Step S411: The communication module CL-COM of each CDNC network element periodically scans the node communication information table in the CL-DB to obtain the node communication information that needs to be reversely built.

Step S412: The CL-COM of each CDNC network element actively sends a link establishment request to all capability layers NODE belonging to the CDNC to establish a communication link between the CDNC and the NODE.

Step S413: The CL-DB of the CDNC network element has a data change notification function. Through CL-DB, the CL-COM real-time monitoring of the link list information of the node is realized. When the communication information of the node changes, the CL-DB of each CDNC network element notifies the corresponding communication module CL-COM.

Step S414: After receiving the data change notification, the CL-COM queries the node communication information table in the control layer CL-DB to obtain the latest communication information of the node belonging to the CDNC and requiring reverse link establishment. According to the latest list information, create or close a changed link to ensure the effective link. Correct and smooth.

The technical advantage of the embodiment of the present invention is that: the software of the control layer actively establishes a signaling link to the software of each node of the capability layer according to the link list of the capability layer node, and implements flexible management of the topology; When the topology of the network is changed, the changed link can be newly created or closed by modifying the information of the node belonging to the control layer in the management layer, thereby eliminating the need to perform a large number of switching operations on each node of the capability layer, thereby simplifying the engineering operation; It also facilitates the rapid access of batch nodes when the capability layer is expanded on a large scale.

In this embodiment, the management CDNM and the control layer CDNC are deployed in the entire architecture as a module MLSS (Media Location Srevice System). MLSS directly manages and controls multiple nodes. In this embodiment, it is divided into two different components: the management CDNM and the control layer CDNC, which are independently deployed, which greatly enhances the capacity expansion of the CDN system. This improvement and modification may increase the utility of the invention, but are also within the scope of the invention.

While the preferred embodiments of the present invention have been disclosed for purposes of illustration, those skilled in the art will recognize that various modifications, additions and substitutions are possible, and the scope of the invention should not be limited to the embodiments described above.

Claims

claims

1. A link building method for a distributed content distribution network CDN system. The method includes: the management layer obtains data information of the control layer, and obtains data information of each node of the capability layer; the management layer obtains data information based on the obtained data information, Assign a belonging control layer to each node in the capability layer;

The control layer establishes communication links to each node of the capability layer based on the data information.

2. The method of claim 1, wherein the management layer obtaining the data information of the control layer includes:

The management layer adds the data information of the control layer through the WEB module control layer management interface; wherein the data information of the control layer includes a control layer identification, a module number, and a station number.

3. The method according to claim 1, wherein the management layer obtaining the data information of each node of the capability layer includes:

The management layer adds data information of each node of the capability layer through the WEB module node management interface. The data information of the node includes node identification, node signaling IP, signaling port, module number, office number and link establishment. Mode information.

4. The method of claim 1, wherein, based on the data information, the control layer establishing communication links to each node of the capability layer includes:

The control layer synchronizes the data information of the management layer, selects the data information of the nodes belonging to the control layer from the data information, and stores the data information of the selected nodes in the node link. within the list;

The control layer establishes communication links to each node of the capability layer according to the node link list.

5. The method of claim 4, wherein the method further includes:

The control layer monitors the node link list in real time;

When monitoring finds that the node link list changes, the control layer creates or closes the changed link.

6. A link building system, the system includes a management layer, a capability layer and a control layer; the management layer includes: an information acquisition module configured to acquire data information of the control layer and acquire each node of the capability layer data information;

The allocation module is configured to allocate a belonging control layer to each node of the capability layer based on the obtained data information;

The control layer includes: a link building module configured to establish communication links to each node of the capability layer based on the data information.

7. The system of claim 6, wherein the information acquisition module includes: a first acquisition unit configured to add data information of the control layer through the WEB module control layer management interface; wherein, the control layer The data information includes control layer identification, module number, and station number.

8. The system of claim 6, wherein the information acquisition module includes: a second acquisition unit configured to add data information of each node of the capability layer through a WEB module node management interface, Data information includes node identification, node signaling IP, signaling port, module number, office number and link establishment mode information.

9. The system of claim 6, wherein the link building module includes:

The table building unit is configured to synchronize the data information of the management layer, filter out the data information of the nodes belonging to the control layer from the data information, and save the data information of the selected nodes in the node chain. in the road list;

The link establishment unit is configured to establish communication links to each node in the capability layer according to the node link list.

10. The system of claim 9, wherein the control layer further includes:

A monitoring module configured to monitor the node link list in real time;

The processing module is configured to create or close the changed link when the monitoring module discovers that the node link list has changed.

11. A computer storage medium, which stores computer executable instructions, and the computer executable instructions are used to execute the construction of the distributed content distribution network CDN system according to any one of claims 1 to 5. chain method.