CN112804143B

CN112804143B - Route protection method based on CCN (content-centric networking) network, router and Internet

Info

Publication number: CN112804143B
Application number: CN202110374904.0A
Authority: CN
Inventors: 李涛; 张晨; 汪硕; 黄韬
Original assignee: Network Communication and Security Zijinshan Laboratory
Current assignee: Network Communication and Security Zijinshan Laboratory
Priority date: 2021-04-08
Filing date: 2021-04-08
Publication date: 2021-07-02
Anticipated expiration: 2041-04-08
Also published as: CN112804143A

Abstract

The invention discloses a route protection method based on a CCN (central control network), a router and the Internet.A forwarding module, a route switching module and a route management module are configured at each route node of the CCN, the route management module is in communication connection with a controller of a network, and a standby PIT (packet Internet protocol) route is stored in the route switching module; in the normal state of the main path, the routing node forwards data through the main route, and the standby PIT route does not form a forwarding route; when the main path is abnormal, the routing node on the alternative path starts a node protection mode or a link protection mode. The invention designs the route switching module, and the route switching module decides whether to send the forwarding plane or not in the process of sending the forwarding plane by the control plane, thereby realizing the uninterrupted data transmission based on the mode and the method of node protection and link protection, improving the safety and the reliability of data transmission, and realizing the functions of upgrading the version of the uninterrupted equipment of the existing network and the like.

Description

Route protection method based on CCN (content-centric networking) network, router and Internet

Technical Field

The invention relates to the technical field of communication, in particular to a CCN network-based route protection method, a router and the Internet.

Background

With the explosion of internet services, the center of gravity of user interest is shifted from the storage location of information to the information itself, and a network communication model with information as the center, i.e., ICN, becomes a focus of much attention. The core idea of the ICN is to use an information naming mode to replace the traditional IP address-centric network communication model, thereby facilitating content search and content acquisition for users, and realizing the evolution from IP address-centric forwarding to content-centric forwarding. The NDN is a network architecture which adopts name routing and caches content through a router, so that data transmission can be faster, and the retrieval efficiency of the content can be improved. An example of a specific implementation of NDN is the content centric network proposed by Van Jacobson et al of Parlot research center (PARC) of Schleman corporation, CCN for short.

The CCN routing node completes data forwarding through 3 important data structures, namely a Forwarding Information Base (FIB), a Pending Interest Table (PIT) and a content cache base (CS). The FIB records the next hop interface of the current node to the content providing node, which is equivalent to the FIB in the IP network, and the FIB is automatically generated by the routing protocol and is a basis for forwarding the interest packet. Unlike IP forwarding, NDN forwarding allows a set of forwarding outlets, not limited to one. The PIT is used for recording the content name of the forwarded but unresponsive interest packet and the source interface thereof, so that the corresponding data packet can accurately reach the requester, and when the response data packet is forwarded by using a PIT entry or the PIT entry exceeds a threshold value, the entry is deleted. The CS is used to store the cache content of the routing node, similar to the cache in the IP router, but adopts a cache replacement policy different from the IP, and the router will periodically update the information cached by the CS, and perform continuous caching for the data router requested by the hotspot, and delete the data router from the cache for the data router that times out.

For a traditional NDN network, when a client requester requests content, an interest packet is first broadcast, and after the interest packet reaches a routing node, the following steps are performed:

1. the router inquires the CS according to the content name in the interest packet, if the CS contains the requested data packet, the router directly returns a copy of the data packet to the source interface of the interest packet, and discards the satisfied interest packet;

2. otherwise, the query is continued in the PIT, and if the content name entry exists in the PIT, it indicates that the same interest packet has been received and forwarded before, but a return result is not obtained, and the source interface of the interest packet needs to be accessed into the interface list corresponding to the PIT, and the interest packet is discarded at the same time. When the corresponding data packet returns, replying a copy of the data to the corresponding interface according to the interface list, and storing the data packet in the CS to meet the potential future request;

3. if the CS and the PIT do not have the result, the FIB is searched, if the corresponding content name entry is found in the FIB, the node receives the interest packet for the first time, the interest packet is forwarded according to an interface list (an interface which does not contain the interest packet) of the FIB, and a new entry is added in the PIT;

4. if there is no result in any of the three structures CS, PIT and FIB, it indicates that there is no relevant matching route, and the node cannot process this interest packet and then discards or floods it.

When the interest packet reaches the node cached with the corresponding request data, a data packet containing the data name and the data content and the sender signature is returned to the request node along the original path. It should be noted that the interest packet and the data packet do not carry a host or an interface address (e.g., an IP address), the interest packet is routed to the holder of the data according to the name of the data to be requested, and the data packet is reversely transmitted to the requester of the data through the state information established when the interest packet passes through each node.

The router is relatively simple to process the data packet, and when the data packet arrives at the routing node, the data packet is firstly searched in the CS according to the content name field of the data packet. If the data packet exists in the CS, the data packet is discarded; if not in CS, look up in PIT. If the corresponding entry exists in the PIT, forwarding the data to all interfaces of the matched entry of the PIT, and caching the content into the CS; if there is no matching entry in the PIT, the packet is discarded.

The above prior art has the following disadvantages:

(1) the interface failure causes the data message to be unable to reach: in the traditional CCN, after a data packet reaches a routing node, a PIT route is searched, and the data packet is forwarded out through an interface according to the request of the PIT route. However, if the PIT requests to enter the interface, an interface failure, such as a device failure or an interface drop, occurs at this time, which inevitably causes the loss of the data packet along the way, and particularly, in the case that the data packet reaches the last hop device, the entire network resource is basically transmitted, but cannot be delivered, which inevitably causes the waste of the network resource.

(2) The fault tolerance mechanism is deficient, and the user experience is poor: the failure of some devices causes the failure of the device cache CS and the PIT route, which causes the convergence of the SDN/FIB route, but it is a disaster for the sent PIT route and the data packet that is being returned according to the PIT route, and data loss inevitably occurs due to the failure of the device midway, and after the FIB convergence is finished, the user needs to resend the PIT route to make a request for corresponding content, which is not favorable for the user friendly experience.

(3) The online upgrading can not be realized without interrupting the flow: the existing CCN is designed based on an unprotected link channel, so that the whole CCN equipment cannot be upgraded on line continuously, and after the re-convergence of the SDN/FIB is needed in the upgrading process, a user initiates a PIT request again to complete a secondary request after the routing convergence.

Disclosure of Invention

The technical purpose is as follows: aiming at the defects in the prior art, the invention discloses a routing protection method based on a CCN network, a router and the Internet, and aims to provide a CCN protection channel of a node and a link.

The technical scheme is as follows: in order to achieve the technical purpose, the invention adopts the following technical scheme:

a route protection method based on a CCN network is characterized in that a forwarding module, a switching module and a route management module are configured at each route node of the CCN network, the route management module is in communication connection with a controller of the CCN network, PIT main and standby routes are stored in the route switching module in advance, and the PIT main and standby routes comprise a PIT main route and a PIT standby route;

in a normal state, data are forwarded through a main path formed by a PIT main route, and a PIT standby route is stored in a route switching module; when the main path is abnormal, the alternative path formed by the PIT standby route forwards data, the routing node on the alternative path starts a node protection mode or a link protection mode, and each routing node executes the following steps:

(1) the forwarding module senses the fault of the neighbor node and reports the fault to the route switching module;

(2) the route switching module issues the PIT standby route stored in advance to a forwarding plane, the PIT standby route enters an alternative path, and the route switching module reports the path abnormal information to the route management module;

(3) the route management module searches for the next available PIT master/slave route, and after calculation and integration, the next available PIT master/slave route is issued to the route switching module;

if the next available PIT master/standby route cannot be searched in the route management module, reporting the latest node fault to the controller, triggering the controller to perform FIB route calculation, obtaining the next available FIB master/standby route and issuing the next available FIB master/standby route to the route management module; the routing management module generates a next available PIT master/slave route again based on the next available FIB master/slave route; the FIB main and standby routes comprise an FIB main route and an FIB standby route;

(4) and the route switching module receives and stores the next available PIT main and standby route sent by the route management module and is used for fast switching when the next abnormity occurs.

Specifically, when a node needing to be protected exists on a main path, a controller searches a previous hop routing node and an optimal next hop routing node of the node needing to be protected according to a link topology structure, and issues an FIB (FIB-based FIB) main-standby route to the previous hop routing node; generating a PIT main and standby route aiming at the PIT request according to the FIB main and standby route;

when the node to be protected is not abnormal, the data is forwarded through a main path formed by a PIT main route, and the PIT standby route is stored in a route switching module; when the node to be protected is abnormal, the optimal next hop routing node is switched to a node protection mode after sensing the abnormality, and enters an alternative path bypassing the node to be protected;

and after the controller comprehensively calculates, the controller sends the next available FIB main/standby route to the routing nodes on the alternative path again for the next quick switching of the fault again.

Specifically, when a path is abnormal and a link to be protected is generated, each network node in the link to be protected reports power-off information to the controller and then powers off;

after discovering the broken link of the main path, the controller calculates an alternative path and sends a switching instruction to each routing node on the alternative path;

after receiving the switching instruction, each routing node on the alternative path switches to a link protection mode, triggers route switching, issues the PIT standby route stored in the route switching module to a forwarding plane, and enters the alternative path bypassing the link to be protected;

after the main path is recovered to normal, each network node in the link to be protected reports a state to the controller, the controller is triggered to perform FIB (focused ion beam) calculation, the controller reestablishes the PIT main/standby route according to the requirement on the route node on the main path, and synchronously updates the PIT main/standby route in each route node on the alternative path.

Specifically, each routing node of the CCN network is provided with a primary routing request interface and a backup routing interface, the primary routing request interface corresponds to a PIT primary route, and the backup routing interface corresponds to a PIT backup route.

Specifically, when the abnormal condition is a network node fault, a node protection mode is started, the routing node with the fault is sensed on the main path, the routing switching module is triggered to send the standby path table, the main routing request interface is closed, and the standby routing interface is opened; each routing node on the alternative path triggers a routing switching module to send a standby path table by the flow;

and when the abnormal condition is that more than one network node needs to be powered off to upgrade the version, a link protection mode is started, the routing node receiving the switching instruction on the alternative path triggers the routing switching module to send a standby path table, the main routing request interface is closed, and the standby routing interface is opened.

Specifically, the route protection method is applied to an SDN scenario, where an SDN controller is adopted by a controller, or is applied to a distributed routing scenario.

A CCN router, comprising:

the routing management module is used for calculating the next available PIT master/slave route or receiving the next available FIB master/slave route sent by the network controller, generating the next available PIT master/slave route again based on the next available FIB master/slave route, and sending the next available PIT master/slave route to the routing switching module; the FIB main and standby routes comprise an FIB main route and an FIB standby route, and the PIT main and standby routes comprise a PIT main route and a PIT standby route;

the route switching module is used for storing the PIT standby route in advance, receiving link fault information, quickly switching the CCN router to the PIT standby route to realize packet loss prevention, asynchronously informing the CCN route management module of triggering the convergence of the route and updating the PIT main and standby routes;

the forwarding module is used for sensing the fault of the neighbor node in the link and transmitting the fault information to the CCN routing switching module; the forwarding module has a CCN forwarding function and stores a PIT interest table, an FIB routing table and a CS storage table.

Specifically, the CCN router includes a normal mode, a node protection mode, and a link protection mode, and in the normal state, the router forwards data through a primary path formed by a PIT primary route, and a PIT backup route does not form a forwarding route; when the main path is abnormal, the router forwards data through an alternative path formed by a PIT standby route, the router on the alternative path starts a node protection mode or a link protection mode, and each router executes the following steps:

(2) the route switching module issues the PIT standby route stored in advance to a forwarding plane, enters an alternative path, enables equipment data to be transmitted in a continuous flow mode, and reports the path abnormal information to the route management module;

if the next available PIT master/slave route cannot be searched in the route management module, reporting the latest node fault to the controller, triggering the FIB calculation route of the controller again, then sending the next available FIB master/slave route to the route management module, and generating the next available PIT master/slave route again based on the next available FIB master/slave route;

Specifically, the router is provided with a main routing request interface and a standby routing interface, the main routing request interface corresponds to a PIT main route, and the standby routing interface corresponds to a PIT standby route; and the trigger route switching module is used for closing the main route request interface and opening the standby route interface when the router is abnormal in the main path, and issuing the PIT standby route stored in advance to the forwarding plane.

An internet, characterized by: the CCN router comprises a controller and the CCN router which is configured at each network node.

Has the advantages that: compared with the prior art, the invention has the following technical effects:

(1) the CCN network continuously upgrades the flow: the invention designs a node protection and link protection mode, and can realize the uninterrupted flow of single equipment or the failure of the whole link or the upgrading.

(2) And (3) CCN network node fault protection: for the CCN, the failure of a single equipment node is unavoidable, the failure of unimportant nodes can be tolerated, but the failure on a core node inevitably causes the large-area breakdown of the CCN, so that corresponding node protection can be deployed in a deployment network.

(3) Protection of CCN networks against link failure: the CCN has the upgrading of multiple devices or the disconnection of multiple devices, the traditional upgrading or the failure of multiple nodes on a link cannot solve the problem as much as possible through node protection, and the disconnection of the current network flow is inevitably brought. The invention provides a link protection mode and a method, which are based on end-to-end protection of the whole link, and design of a route switching module.

Drawings

Fig. 1 is a schematic network structure diagram of the application of the route protection method based on the CCN network of the present invention.

Fig. 2 is a schematic diagram of a route protection method in a node protection state according to the present invention;

fig. 3 is a schematic diagram of a route protection method in a link protection state according to the present invention.

Detailed Description

The technical solution of the present invention will be described in detail below with reference to the accompanying drawings.

1. Modular design

Based on CCN traditional route design, a route switching module is newly developed, and the basic functions of the route switching module are to store PIT backup routes in advance, sense the backup routes after forwarding link failure and quickly switch the backup routes to realize forwarding without packet loss and then asynchronously inform a CCN route management module to trigger the convergence of the routes; as shown in fig. 1, the basic steps are as follows:

step 1: the CCN forwarding module senses the fault of the neighbor node and reports the fault to the CCN route switching module; the CCN route switching module rapidly issues the standby PIT route stored in advance to a forwarding plane, and continuous stream transmission of equipment data forwarding is guaranteed. The CCN forwarding module has a CCN forwarding function and stores a PIT interest table, an FIB routing table and a CS storage table, wherein the FIB routing is the forwarding routing of the interest packet, the PIT routing is the request routing formed by the interest packet along the FIB, the routing is used for forwarding the content packet for use, and the PIT request table is used for sending the interest packet and returning and searching the content packet for use. The CS table is a storage table entry of the CCN.

Step 2: the CCN route switching module reports the path abnormal information to the CCN route management module, the CCN route management module completes calculation and integration of new main and standby routes, and then sends the new main and standby PIT routes to the CCN route switching module, wherein the new main and standby routes are next available main and standby routes; in general, the main and standby routes are integrated in advance in the CCN route management module, and as long as the main link or node failure information is received, the CCN route management module immediately issues the standby route and reports the abnormal information to the controller; the controller recalculates a new available primary/secondary route because the previous backup route has already been issued, all previous backup routes are converted into primary routes by the controller, and then the controller calculates a new backup route, i.e. the next available primary/secondary route, and synchronously issues the new primary/secondary route to the CCN route management module.

The CCN route management module is a module newly developed based on the CCN route module and is responsible for storing and issuing the CCN main and standby routes, and if the CCN route management module does not find the main and standby routes after receiving the report of the switching module information, the CCN route management module triggers the controller to calculate the corresponding main and standby routes and issue the corresponding main and standby routes to the CCN route management module, and then the step 3 needs to be performed.

And step 3: if the CCN route management module cannot find a new main/standby PIT route, namely the next available main/standby route, the CCN route management module reports the latest node fault to the controller, triggers the controller to re-FIB calculation route, and then sends the main/standby FIB route to the CCN route management module. If the FIB route changes because of the information reporting and calculating, the controller needs to generate a corresponding FIB route and send the FIB route to the CCN forwarding module.

2. Node protection

The method is performed in an SDN-based scene, and is similar to the SDN-based scene in a distributed routing scene.

As shown in fig. 2, assuming that the network manager considers that the CCN router 2 needs node protection, the network manager issues the configuration to the SDN controller, and the SDN controller searches for the previous CCN router 1 of the CCN router 2 and the optimal next hop router 3 in the topology according to the link topology; and issuing the FIB main route and the standby route to the CCN router 1, wherein the route form is shown in the table 1.

TABLE 1

That is, a primary and secondary route for Prefix is formed, for the PIT request, the request needs to be made according to the primary and secondary route, and the PIT route as shown in fig. 3 is generated along the way, wherein the CCN1-CCN2-CCN3 normally issues the forwarding plane of the CCN router along the main route, and the CCN1-CCN4-CCN3 standby route does not form a forwarding route, but is placed in a newly developed route switching module of the CCN device; for example, for the CCN3 device, there are two request interfaces formed, that is, Requesting Faces and Requesting Back Faces, respectively, the controller informs interface No. 5 that the interface is a standby interface, and the CCN3 router stores the PIT route corresponding to the interface in the route switching module.

The handover procedure is as follows: as shown in fig. 2, it is assumed that the CCN router 2 fails, the CCN router 3 senses that the neighbor interface No. 4 Down is dropped, and then informs the route switching module of the device, and the route switching module triggers fast PIT route switching to switch the request interface of the PIT request route to the interface No. 5, and at the same time, deletes the interface No. 4 from which the Down has dropped, and issues a new PIT route table to the forwarding plane; then, a route switching module informs an SDN controller of the abnormal condition of equipment through a route management module, slow convergence of the route is triggered, then data flow is accessed to a CCN router 4 through a No. 5 interface of the CCN3 router, the alternative path is formally entered, then the flow activates a route switching module of the alternative path to quickly issue a PIT forwarding route, meanwhile, the switching module informs the route management module, and then the SDN controller of the link switching condition is informed, after the SDN controller performs comprehensive calculation, a new FIB main and standby route, namely the next available FIB main and standby route, is issued to the route management module again, and the main and standby PIT routes, namely the next available PIT main and standby route, are generated again based on the FIB route, and the next fault quick switching is waited.

In the invention, when the route management module can not find the standby route, or when switching occurs and the standby route in the CCN route management module is used, the controller recalculates the standby route and sends the standby route to the CCN route management module.

3. Link protection

For link protection, i.e. providing the whole end-to-end path protection function, the deployment of protection links in the network deployment plan is required. As shown in FIG. 3, CCN1- - -CCN2- - -CCN3 is taken as a main path, and CCN4- - -CCN5 is taken as an alternative path. The PIT routing table and the FIB routing table formed along the way are the same as the normal routing table. And storing the PIT and FIB routing tables on the alternative paths in the routing switching module and not issuing the forwarding plane, and issuing the forwarding plane by the PIT and FIB routing tables of the main path.

Assuming that a user initiates a Prefix resource request to a server, data will be upgraded by multiple devices in a reply process, and the whole handover process is as follows:

1. suppose that the CCN1 router, the CCN2 router and the CCN3 router are powered off and upgraded at the same time; the method comprises the steps of reporting equipment power-off information to an SDN controller, and then powering off and upgrading;

2. the SDN controller finds that the main link is broken, the flow needs to be switched to a standby link, and finds that CCN4- - -CCN5 is an alternative path from a user to a server Prefix resource through calculation, namely, switching instructions are issued to CCN4 and CCN5, namely, the CNN4 and CNN5 main link down are informed;

3. after receiving the switching instruction, the CCN4 and CCN5 route switching modules trigger the switching of the routes and issue the PIT route table stored in the route switching module to a forwarding plane;

4. in the process of replying the server data packet, because the CCN3 router is powered off, the device such as the exchanger and the like is automatically switched to the CCN5 router and then the data packet is forwarded according to the issued PIT route.

5. After the upgrade is completed, the CCN1 router, the CCN2 router and the CCN3 router notify the SDN controller of the equipment state, and the SDN controller is triggered to calculate the route again;

6. the SDN controller reestablishes PIT routing tables on CCN1, CCN2 and CCN3 routers according to requirements, synchronously deletes PIT forwarding routes of CCN4 and CCN5, and CCN4 and CCN5 store corresponding PIT routes in the route switching module, namely store the next available primary and standby PIT routes in the route switching module. Thus, the flow of the end-to-end link is not cut off in the upgrading process.

The PIT route and the FIB route both comprise main and standby routes, and in the node protection networking, the main and standby routes only need to be stored in the CCN1, namely the last hop equipment of the node protection. The main and standby routes are stored in the route management module and the forwarding module of the CCN 1; in the link protection networking, because two separate lines are used, all the table entry storage is consistent with the normal path, and only the alternative path PIT route cannot issue the forwarding plane and needs to wait for the controller to notify the issue. That is, the main switch is triggered to switch by abnormal time such as interface down on the CCN3, but the backup path table is issued by the traffic trigger switch module on the devices such as CCN4 and CCN1 of the alternative paths, or the issuance is controlled by the controller in a unified way, and the controller issuance efficiency is not as fast as the traffic trigger switch, but the traffic trigger has the condition of false switch. In the link protection networking, each device issues a normal FIB route, and generates a PIT route based on a request message. And the controller end indicates that the route is a standby PIT route in the route management module through the identification and does not send a forwarding plane. The FIB route is normally issued.

The invention relates to a design of a standby table entry of a PIT (packet intermediate transport) routing table of a CCN (central control network), which designs a routing switching module, wherein the routing switching module decides whether to send a forwarding plane or not in the process of sending the forwarding plane by a control plane. The invention introduces the design idea of data uninterrupted flow into the CCN network, realizes the data uninterrupted flow based on the mode and the method of node protection and link protection, the node protection is designed aiming at the fault of a single device, the link protection is designed aiming at end-to-end, but is not limited to the point, for example, the segmented link protection idea, namely, a part of the path with heavier load is separated from the end-to-end link protection, and the invention is also one of the ideas of the invention.

The characters referred to in part in the present invention have the following meanings:

ICN: information centralized Networking, Information-Centric network communication model.

NDN: named Data Networking, a type that employs name routing, through routers to cache content network architectures.

CCN: content-centralized Networking, Content-Centric Networking.

FIB: forwarding Information Base, Forwarding Information Base.

PIT: pending Interest Table.

CS: content Store, Content cache library.

SDN: software Defined Network, Software Defined Network.

The above description is only of the preferred embodiments of the present invention, and it should be noted that: it will be apparent to those skilled in the art that various modifications and adaptations can be made without departing from the principles of the invention and these are intended to be within the scope of the invention.

Claims

1. A route protection method based on a CCN network is characterized in that a forwarding module, a switching module and a route management module are configured at each route node of the CCN network, the route management module is in communication connection with a controller of the CCN network, PIT main and standby routes are stored in the route switching module in advance, and the PIT main and standby routes comprise a PIT main route and a PIT standby route;

if the next available PIT master/slave route cannot be searched in the route management module, reporting the latest node fault to the controller, triggering the controller to perform FIB route calculation, obtaining the next available FIB master/slave route and issuing the next available FIB master/slave route to the route management module, and generating the next available PIT master/slave route again by the route management module based on the next available FIB master/slave route; the FIB main and standby routes comprise an FIB main route and an FIB standby route;

2. The CCN network-based route protection method according to claim 1, wherein: when a node needing to be protected exists on the main path, the controller searches a previous hop routing node and an optimal next hop routing node of the node needing to be protected according to the link topology structure, issues an FIB main/standby route to the previous hop routing node, and generates a PIT main/standby route aiming at the PIT request along the FIB main/standby route;

3. The CCN network-based route protection method according to claim 1, wherein: when the path is abnormal and a link needing to be protected is generated, each network node in the link needing to be protected reports power-off information to the controller and then is powered off;

4. A CCN network based route protection method according to any one of claims 1 to 3, characterized in that: each routing node of the CCN is provided with a main routing request interface and a standby routing interface, the main routing request interface corresponds to a PIT main route, and the standby routing interface corresponds to a PIT standby route.

5. The CCN network-based route protection method according to claim 4, wherein: when the abnormal condition is a network node fault, starting a node protection mode, sensing a routing node with the fault on the main path, triggering a routing switching module to send a standby path table, closing a main routing request interface and opening a standby routing interface; each routing node on the alternative path triggers a routing switching module to send a standby path table by the flow;

6. The CCN network-based route protection method according to claim 4, wherein: the route protection method is applied to an SDN scene, and the SDN controller is adopted by the controller, or is applied to a distributed route scene.

7. A CCN router, comprising:

8. A CCN router according to claim 7, wherein: the CCN router comprises a normal mode, a node protection mode and a link protection mode, and in the normal state, the router forwards data through a main path formed by a PIT main route, and the PIT standby route does not form a forwarding route; when the main path is abnormal, the router forwards data through an alternative path formed by a PIT standby route, the router on the alternative path starts a node protection mode or a link protection mode, and each router executes the following steps:

9. A CCN router according to claim 8, wherein: the router is provided with a main routing request interface and a standby routing interface, the main routing request interface corresponds to a PIT main route, and the standby routing interface corresponds to a PIT standby route; and the trigger route switching module is used for closing the main route request interface and opening the standby route interface when the router is abnormal in the main path, and issuing the PIT standby route stored in advance to the forwarding plane.

10. An internet, characterized by: comprising a controller and a CCN router according to any of claims 7 or 8 arranged at respective network nodes.