WO2023273838A1

WO2023273838A1 - Method and apparatus for establishing session on basis of bfd technology, and network device and computer storage medium

Info

Publication number: WO2023273838A1
Application number: PCT/CN2022/098219
Authority: WO
Inventors: 何志远
Original assignee: 中兴通讯股份有限公司
Priority date: 2021-06-29
Filing date: 2022-06-10
Publication date: 2023-01-05
Also published as: CN115550249A

Abstract

A method and apparatus for establishing a session on the basis of BFD technology, and a network device and a computer storage medium. The method comprises: performing basic configuration detection on a BFD session, and adding the BFD session, which has passed the detection, to a link establishment queue (S100); when the BFD session in the link establishment queue fails to be established, moving the BFD session, which has failed to be established, into a delayed link establishment queue (S200); and starting a delay timer for the BFD session, which has failed to be established, and when the delay timer ends, moving the BFD session, which has failed to be established, into the link establishment queue (S300).

Description

Method, device, network equipment and computer storage medium for establishing session based on BFD technology

Cross References to Related Applications

This application is based on a Chinese patent application with application number 202110726338.5 and a filing date of June 29, 2021, and claims the priority of this Chinese patent application. The entire content of this Chinese patent application is hereby incorporated by reference into this application.

technical field

The embodiments of the present application relate to the technical field of IP network communication, and in particular, relate to a method, device, network device, and computer storage medium for establishing a session based on the BFD technology.

Background technique

For bidirectional forwarding detection (Bidirectional Forwarding Detection, BFD) session establishment, the configuration check is usually performed before the session enters the link establishment queue. Only the sessions that pass the check can enter the link establishment queue, so as to avoid sessions with missing basic configurations entering the link establishment queue, which wastes Link building resources. Secondly, the concurrent establishment mechanism is usually used when establishing a session, that is, there will be multiple sessions established at the same time. For example, 10 sessions can be established at the same time. If all 10 sessions are established at the same time, start from the link establishment queue Move out, and then establish the last 10 sessions in the queue. Configuration checking, concurrent establishment, and faster message exchange can all speed up the establishment of BFD sessions on the device. However, when there are a large number of failed sessions in the link establishment queue (session establishment failures may be The situation cannot be found by checking the basic configuration on the local side), the newly generated sessions will be queued behind these sessions, and wait for these sessions to fail to be established again before they can be traversed and start to establish sessions, especially for sessions that are successfully established normally and occasionally fail In this case, the session cannot quickly restore the state, because the invalid session will be added to the end of the link establishment queue when it is established again, which is equivalent to a newly added session for link establishment.

Therefore, in the field of IP network communication technology, especially the network where a large number of BFD sessions are deployed, it is sensitive to network failures. However, due to reasons such as network cutover, there will be a large number of BFD sessions that fail to be established on the device. Operators expect new sessions to be established quickly, or After restarting the device, it is expected that the sessions on the device can quickly reach a steady state, or that the sessions that frequently fluctuate can be suppressed to a certain extent.

Contents of the invention

The following is an overview of the topics described in detail in this article. This summary is not intended to limit the scope of the claims.

Embodiments of the present application provide a method, device, network device, and computer storage medium for establishing a session based on the BFD technology.

In the first aspect, the embodiment of the present application provides a method for establishing a session based on BFD technology, including: performing basic configuration detection on the BFD session, and adding the BFD session that passes the detection to the link establishment queue; when the BFD session in the link establishment queue If the establishment fails, move the failed BFD session to the delayed link-building queue; start a delay timer for the BFD session that failed to establish, and when the delay timer expires, the BFD session that failed to establish Move to the link establishment queue.

In the second aspect, the embodiment of the present application provides a device for establishing a session based on BFD technology, including: a detection module configured to perform basic configuration detection on the BFD session, and add the BFD session that passes the detection to the link establishment queue; session establishment The module is configured to attempt to establish BFD sessions in the order of the BFD sessions in the link-building queue. When the BFD sessions in the link-building queue fail to be established, the failed BFD sessions will be moved to the delayed link-building queue, and at the same time, the The BFD session that fails to be established starts a delay timer, and when the delay timer expires, the BFD session that fails to be established is moved to the link establishment queue.

In a third aspect, the embodiment of the present application provides a network device, including a processor, a memory, and a communication bus; the communication bus is configured to realize connection and communication between the processor and the memory; the processor is configured to be It is configured to execute one or more computer programs stored in the memory, so as to implement the method for establishing a session based on the BFD technology as described in the first aspect.

In the fourth aspect, the embodiment of the present application also provides a computer-readable storage medium, the computer-readable storage medium stores computer-executable instructions, and the computer-executable instructions are used to make a computer execute the A method for establishing a session based on BFD technology.

Additional features and advantages of the application will be set forth in the description which follows, and, in part, will be obvious from the description, or may be learned by practice of the application. The objectives and other advantages of the application will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.

Description of drawings

The accompanying drawings are used to provide a further understanding of the technical solution of the present application, and constitute a part of the description, and are used together with the examples of the application to explain the technical solution of the application, and do not constitute a limitation to the technical solution of the application.

Fig. 1 is a schematic diagram of routing deployment of the communication network involved in this application;

Fig. 2 is a schematic diagram of BFD session establishment in one embodiment of the present application;

FIG. 3 is a flowchart of a method for establishing a session based on BFD technology provided by an embodiment of the present application;

FIG. 4 is a flowchart of a method for processing BFD session oscillation in a method for establishing a session based on BFD technology provided by an embodiment of the present application;

FIG. 5A is a schematic diagram of an initial session queue in a method for establishing a session based on BFD technology provided by an embodiment of the present application;

FIG. 5B is a schematic diagram of queue changes during link establishment in a method for establishing a session based on BFD technology provided by an embodiment of the present application;

FIG. 5C is a schematic diagram of a new session queue change in a method for establishing a session based on BFD technology provided by an embodiment of the present application;

FIG. 5D is a schematic diagram of queue changes when the timer expires in the method for establishing a session based on the BFD technology provided by an embodiment of the present application;

FIG. 6A is a schematic diagram of a queue in which there are a large number of failed session establishments in the prior art;

FIG. 6B is a schematic diagram of a queue in which there are a large number of failed session establishments in one embodiment of the present application;

FIG. 7 is a schematic structural diagram of a device for establishing a session based on BFD technology provided by an embodiment of the present application;

FIG. 8 is a schematic structural diagram of a device for establishing a session based on BFD technology provided by an embodiment of the present application;

Fig. 9 is a schematic structural diagram of a network device provided by an embodiment of the present application.

detailed description

In order to make the purpose, technical solution and advantages of the present application clearer, the present application will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the present application, not to limit the present application.

As shown in Figure 1, there will be a large number of router devices (routers) in the communication network, and one device (Router5 in Figure 1) can communicate with multiple devices. For non-direct connection) connectivity, a large number of BFD sessions can be manually configured on the device, or BFD sessions can be dynamically created through the routing protocols supported by the router device (such as open shortest path first\border network management protocol, etc.), so that when the link fails , BFD can quickly detect, and then trigger the routing (communication path) switching in the network (for example, the path of 5->7 can be 5->6->7, or 5->9>10->7, if the default It is the former, when a link failure between 5-6 is detected, the communication path can be switched to the latter), reducing packet loss caused by link failure and speeding up network stability.

BFD is a technology for link detection by sending detection packets quickly (in milliseconds). Before link detection, a session needs to be established, which is usually called session state negotiation. Link detection is performed after the session state is up. . The process of BFD session state negotiation is shown in Figure 2. There are four states: down, init, up, and admindown. The first three states are commonly used, and down is the initial state. The process of session establishment (link establishment) is as follows: the BFD sessions on device A and device B send mutual BFD down packets; after receiving the down packets from the peer, they switch the state to the init state. The state of the message remains unchanged, and continue to send down messages; the session in the init state sends the init message of BFD; the session in the init state switches to up (established successfully) after receiving the init message, and if the init message is not received after the timeout After the session state is switched, it is down (failure to establish); after the session state is switched to up, the establishment process ends, and then the link detection is performed.

Therefore, three packet exchanges are required to successfully establish a BFD session, and the state transition is: down->init->up. The interval for sending messages is 3-5 seconds according to the agreement, and the time for a successful session establishment process is about 6-10 seconds. Usually three attempts are made to establish a session. The maximum time for such a session to be established is 30 seconds. At the same time, it can be seen that the session that can be established will complete the establishment process quickly, while the session that fails to be established will take a long time to establish a link. However, under normal circumstances, the newly generated session will be added behind the original series of sessions, and there are sessions that will fail to be established in this series of sessions. In this case, the newly added session will wait for these The failed session establishment can only be attempted after repeated establishment failures, which will easily result in low efficiency of session establishment. At the same time, in some cases, a BFD session that has been successfully established originally jumps to a failure (down) state due to a fault, and the BFD session with this situation is called an oscillating BFD session. The reason for the flapping BFD session may be that the network packet is congested and the link itself is normal, or the link is frequently abnormal due to attacks. A BFD session that flaps due to the latter is called a frequently flapping BFD session. For temporarily invalid BFD sessions, they can be re-established with a high probability after entering the link establishment queue, and their status quickly returns to up. However, for frequently-oscillated BFD sessions, there is a high probability that they will still fail to be re-established. Therefore, those skilled in the art generally expect that newly added BFD sessions and temporarily invalidated BFD sessions can be quickly attempted to be established, and the establishment of failed BFD sessions and frequently oscillating BFD sessions are suppressed from attempting to be established.

Based on this, the embodiments of the present application propose a method, device, network device, and computer storage medium for establishing a session based on the BFD technology. Newly added BFD sessions can be established first, and BFD sessions that have failed to be established can be delayed, so that sessions can be quickly established in the case of large capacity and complex configurations, and the device can quickly enter a stable state. When the device is running stably, the BFD session can be recovered quickly when the BFD session fluctuates occasionally. When the device is attacked and the BFD session fluctuates frequently, the frequent flapping can be suppressed by delaying the link establishment of the frequently fluctuating BFD session.

Referring to FIG. 3 , an embodiment of the present application provides a method for establishing a session based on the BFD technology, which includes but is not limited to the following steps S100 , S200 and S300 .

Step S100, perform basic configuration detection on the BFD session, and add the BFD session that passes the detection to the link establishment queue;

Step S200, when the BFD session in the chain-building queue fails to be established, move the failed BFD session to the delayed chain-building queue;

Step S300, start a delay timer for the BFD session that failed to be established, and move the BFD session that failed to be established to the link establishment queue when the delay timer expires.

Referring to FIG. 5A , the BFD sessions that pass the detection are added to the link establishment queue. For example, the initial n BFD sessions are sequentially queued in the link establishment queue and waiting to be established. At this time, the delay queue is empty. Referring to FIG. 5B , the above step S200 is executed, the sessions S1 and S3 are successfully established and removed from the queue, and the sessions S2 and S4 fail to be established, respectively start a delay timer t1 and t2 and move into the delay queue. Referring to FIG. 5C , the newly added session Sn+1 is added to the end of the link establishment queue before the corresponding timer of the session in the delay queue expires. Referring to FIG. 5D , the above step S300 is executed, the timer of session S2 in the delay queue expires, the timer is removed and removed from the delay queue, and added to the end of the link establishment queue.

In some embodiments of the present application, in step S300, the BFD session that fails to be established is moved to any position in the link establishment queue, which may be the front, middle or end of the link establishment queue.

The method for establishing a session based on the BFD technology in the embodiment of the present application has a good effect on the situation where there are a large number of sessions that fail to be established in the communication network. With reference to Fig. 6A, in some situations in this field, for the session that fails to establish, it is to constantly go back to queue up and try to rebuild in the link building queue usually, at this moment, newly added session Sn+n will be added to the failed session (Sn+1, Sn +6.....) to wait for the establishment later, so that the newly added session cannot be established quickly. In the embodiment of this application, since the sessions that failed to be established before are in the delay queue, and the respective timers have not expired, the link establishment queue is empty at this time, and the newly added session Sn+n will enter the link establishment queue directly Start establishing a session.

In some embodiments of the present application, the duration of the delay timer may be a fixed value or a random value. The use of random values helps the sessions that failed to establish links to be dispersed in the delay queue, preventing a large number of failed sessions from entering the delay queue and being removed from the delay queue and entering the link establishment queue at the same time, thereby ensuring that the status of a large number of BFD sessions is quickly stabilized.

In some embodiments of the present application, referring to FIG. 4, in the above step S200, after the successfully established BFD session is removed from the link establishment queue, further includes:

S210, monitor the state of the successfully established BFD session, if the successfully established BFD session fails due to a fault, mark it as a temporarily invalid BFD session, add the temporarily invalid BFD session to the link establishment queue and record the temporarily invalid session The number of chain building times;

S220. When the number of link establishment times exceeds the threshold, mark the temporarily invalidated BFD session as a frequently oscillating BFD session, and move the frequently oscillating BFD session to a delayed link establishment queue;

S230. Start a delay timer for the frequently oscillating BFD session, and move the frequently oscillating BFD session in the delayed link establishment queue to the link establishment queue when the delay timer expires.

In the above-mentioned embodiment, by setting the threshold value of failure times, the oscillating BFD sessions are classified into temporarily invalid BFD sessions and frequently oscillating BFD sessions. Try to build. In some examples, when a temporarily invalidated BFD session is added to the link establishment queue, it is inserted at the front of the link establishment queue, which is conducive to faster re-establishment of a session temporarily invalidated due to an external failure.

Through the above-mentioned steps in the embodiment of the present application, a method for establishing a session based on BFD technology is realized, which breaks the principle of equal session establishment, gives priority to the establishment of newly added BFD sessions, and delays the establishment of BFD sessions that have failed in previous attempts, so that large-capacity , In the case of complex configurations, the session is quickly established, and the device quickly enters a steady state. When the device is running stably, the BFD session can be recovered quickly when the BFD session fluctuates occasionally. When the device is attacked and the BFD session fluctuates frequently, the frequent flapping can be suppressed by delaying the link establishment of the frequently fluctuating BFD session.

The embodiment of the present application also provides a device for establishing a session based on BFD technology. Referring to FIG. 7, the device includes:

The detection module 71 is configured to perform basic configuration detection on the BFD session, and add the BFD session passed through to the link establishment queue;

The session establishment module 72 is configured to try to establish according to the order of the BFD sessions in the link-building queue, if the establishment is successful, the BFD sessions that are successfully established will be removed from the link-building queue, and if the establishment fails, the BFD sessions that have failed to be established will be moved to In the delayed link establishment queue, a delay timer is enabled for the BFD sessions that fail to be established. When the delay timer expires, the BFD sessions that fail to be established will be moved to the link establishment queue.

In some embodiments of the present application, referring to FIG. 8 , the device for establishing a session based on BFD technology further includes a monitoring module 73 and a marking module 74,

Wherein, the monitoring module 73 is configured to monitor the state of the successfully established BFD session, if the successfully established BFD session fails due to failure, the marking module 74 is configured to mark it as a temporarily invalid BFD session, and the session establishing module 72 will The temporarily invalidated BFD session is added to the link establishment queue and the number of link establishment times of the temporarily invalidated session is recorded. In some examples, when the number of link establishment times of the temporarily invalidated BFD session reaches a threshold, the marking module 74 further marks the temporarily invalidated BFD session as a frequently oscillating BFD session, and the session establishment module 72 is configured to move the frequently oscillating BFD session to In the delayed link establishment queue, a delay timer is enabled for frequently flapping BFD sessions. When the delay timer expires, the frequently flapped BFD sessions in the delayed link establishment queue are moved to the link establishment queue. By setting the threshold of the number of failures, the flapping BFD sessions are classified into temporary failure BFD sessions and frequent flapping BFD sessions, so that the temporary failure BFD sessions can be quickly restored and the BFD sessions that are frequently flapping are delayed from trying to establish again. In some examples, when a temporarily invalidated BFD session is added to the link establishment queue, it is inserted at the front of the link establishment queue, which is conducive to faster re-establishment of a session temporarily invalidated due to an external failure.

Through the device for establishing sessions based on BFD technology in the embodiment of the present application, the principle of equal session establishment is broken, newly added BFD sessions are established first, and BFD sessions that have failed to be established are delayed, so that in the case of large capacity and complex configuration The session is established quickly, and the device quickly enters a steady state. When the device is running stably, the BFD session can be recovered quickly when the BFD session fluctuates occasionally. When the device is attacked and the BFD session fluctuates frequently, the frequent flapping can be suppressed by delaying the link establishment of the frequently fluctuating BFD session.

The embodiment of the present application also provides a network device, including at least one processor and a memory for communicating with the at least one processor; the memory stores instructions that can be executed by at least one processor, and the instructions are executed by at least one processor Executing, so that at least one processor can execute the aforementioned method for establishing a session based on the BFD technology.

Referring to FIG. 9 , it is taken as an example that a processor 910 and a memory 920 in a network device 900 may be connected through a bus. The memory 920, as a non-transitory computer-readable storage medium, can be used to store non-transitory software programs and non-transitory computer-executable programs. In addition, the memory 920 may include a high-speed random access memory, and may also include a non-transitory memory, such as at least one magnetic disk memory, a flash memory device, or other non-transitory solid-state storage devices. In some implementations, the memory 920 includes memory that is remotely located relative to the processor 910, and these remote memories may be connected to the network device 900 through a network. Examples of the aforementioned networks include, but are not limited to, the Internet, intranets, local area networks, mobile communication networks, and combinations thereof.

Those skilled in the art can understand that the device structure shown in FIG. 9 does not constitute a limitation to the network device 900, and may include more or less components than shown in the figure, or combine some components, or arrange different components.

The embodiment of the present application also provides a computer-readable storage medium, the computer-readable storage medium stores computer-executable instructions, and the computer-executable instructions are executed by one or more processors, for example, by the Execution by one processor 910 can make the above-mentioned one or more processors execute the method for controlling the reflective smart surface in the above-mentioned method embodiment, for example, execute the above-described steps S100 to S300 in FIG. 3 , and the method in FIG. 4 Method step S210 to step S230.

The method for establishing a session based on the BFD technology provided by the embodiment of the present application has at least the following beneficial effects: Breaking the principle of equal session establishment, giving priority to establishing newly added BFD sessions, and delaying the establishment of BFD sessions that have failed attempts, so that in large capacity, In the case of complex configurations, the session is quickly established, and the device quickly enters a steady state. When the device is running stably, the BFD session can be recovered quickly when the BFD session fluctuates occasionally. When the device is attacked and the BFD session fluctuates frequently, the frequent flapping can be suppressed by delaying the link establishment of the frequently fluctuating BFD session.

The device embodiments described above are only illustrative, and the units described as separate components may or may not be physically separated, that is, they may be located in one place, or may be distributed to multiple network units. Part or all of the modules can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

Those skilled in the art can understand that all or some of the steps and systems in the methods disclosed above can be implemented as software, firmware, hardware and an appropriate combination thereof. Some or all of the physical components may be implemented as software executed by a processor, such as a central processing unit, digital signal processor, or microprocessor, or as hardware, or as an integrated circuit, such as an application-specific integrated circuit . Such software may be distributed on computer readable media, which may include computer storage media (or non-transitory media) and communication media (or transitory media). As known to those of ordinary skill in the art, the term computer storage media includes both volatile and nonvolatile media implemented in any method or technology for storage of information, such as computer readable instructions, data structures, program modules, or other data. permanent, removable and non-removable media. Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile disk (DVD) or other optical disk storage, magnetic cartridges, tape, magnetic disk storage or other magnetic storage devices, or can Any other medium used to store desired information and which can be accessed by a computer. In addition, as is well known to those of ordinary skill in the art, communication media typically embodies computer readable instructions, data structures, program modules, or other data in a modulated data signal such as a carrier wave or other transport mechanism, and may include any information delivery media .

The above is the description of the embodiments of the present application, but the present application is not limited to the above-mentioned embodiments. Those skilled in the art can also make various equivalent deformations or replacements without violating the spirit of the present application. These equivalent Any modification or substitution is within the scope defined by the claims of the present application.

Claims

A method for establishing a session based on BFD technology, the method comprising:

Check the basic configuration of the BFD session, and add the BFD session that passes the test to the link establishment queue;

When the establishment of the BFD session in the link creation queue fails, move the failed BFD session to the delayed link establishment queue; and

A delay timer is started for the BFD session that fails to be established, and when the delay timer expires, the BFD session that fails to be established is moved to the link establishment queue.
The method for establishing a session based on BFD technology according to claim 1, further comprising:

Monitor the state of the successfully established BFD session, if the successfully established BFD session fails due to a fault, mark it as a temporarily invalid BFD session, add the temporarily invalid BFD session to the link establishment queue and record the temporarily invalid The number of times a BFD session is established.
The method for establishing a session based on BFD technology according to claim 2, further comprising:

When the number of link building times exceeds the threshold, the temporarily invalidated BFD session is marked as a frequently oscillating BFD session, and the frequently oscillating BFD session is moved to the delayed link building queue;

A delay timer is started for the frequently oscillating BFD session, and when the delay timer expires, the frequently oscillating BFD session in the delayed link establishment queue is moved to the link establishment queue.
The method for establishing a session based on BFD technology according to claim 2, wherein adding the temporarily invalidated BFD session to the link establishment queue includes:

Insert the temporarily invalidated BFD session into the head of the link establishment queue.
The method for establishing a session based on BFD technology according to claim 1, wherein the delay time of the delay timer is a fixed value or a random value.
The method for establishing a session based on BFD technology according to claim 1, wherein, when the delay timer expires, the BFD session that fails to be established is moved to any position in the link establishment queue.
A device for establishing a session based on BFD technology, comprising:

The detection module is configured to perform basic configuration detection on the BFD session, and add the BFD session that passes the detection to the link establishment queue;

The session establishment module is configured to attempt to establish the BFD sessions in the sequence of the link establishment queue. When the BFD sessions in the link establishment queue fail to be established, the failed BFD sessions will be moved to the delayed link establishment queue. The BFD session that fails to be established starts a delay timer, and when the delay timer expires, the BFD session that fails to be established is moved to the link establishment queue.
The device for establishing a session based on BFD technology according to claim 7, further comprising:

monitoring module; and

markup module,

Wherein, the monitoring module is configured to monitor the state of the successfully established BFD session, if the successfully established BFD session fails due to a fault, the marking module is configured to mark it as a temporarily invalid BFD session, the The session establishment module adds the temporarily invalidated BFD session to the link establishment queue and records the number of link establishment times of the temporarily invalidated session.
The device for establishing a session based on BFD technology according to claim 7, wherein,

When the number of link establishment times exceeds the threshold, the marking module marks the temporarily invalidated BFD session as a frequently oscillating BFD session, and the session establishment module is configured to move the frequently oscillating BFD session to a delayed link establishment queue Start a delay timer for the frequently oscillating BFD session, and move the frequently oscillating BFD session in the delayed link establishment queue to the link establishment queue when the delay timer expires.
The device for establishing a session based on BFD technology according to claim 8, wherein,

The session establishment module is configured to insert the temporarily invalidated BFD session into the front of the link establishment queue.
A network device, including a processor, a memory, and a communication bus;

The communication bus is configured to implement connection communication between the processor and the memory;

The processor is configured to execute one or more computer programs stored in the memory, so as to implement the method for establishing a session based on the BFD technology according to any one of claims 1 to 6.
A computer-readable storage medium, the computer-readable storage medium stores computer-executable instructions, and the computer-executable instructions are used to enable a computer to execute the BFD technology-based establishment according to any one of claims 1 to 6. method of the session.