Adaptive bidirectional forwarding detection transmitting method, receiving method and device

Abstract

This application provides an adaptive bidirectional forwarding detection sending method, receiving method, and apparatus. The method includes: a first network device sending a service packet to a second network device, the service packet including an INT packet header, the INT packet header being used to carry an INT BFD control message.

Description

Technical Field

[0001] This application relates to the field of communication technology, specifically to an adaptive bidirectional forwarding detection method, receiving method, apparatus, device, and readable storage medium. Background Technology

[0002] When designing carrier networks, redundant backup link technology is typically used to protect critical applications and improve network system reliability. When a link failure occurs, network devices need to be able to quickly detect the failure and switch network traffic to the backup link to accelerate network convergence and reduce the impact of the link failure on service continuity. However, existing link failure implementations require dedicated hardware, which is complex to design and has significant implementation overhead. Summary of the Invention

[0003] This application provides an adaptive bidirectional forwarding detection sending method, receiving method, and apparatus to solve the problem that existing link faults require dedicated hardware implementation, which is complex in design and has high implementation overhead.

[0004] Firstly, an adaptive bidirectional forwarding detection sending method is provided, including:

[0005] The first network device sends a service packet to the second network device. The service packet includes an INT packet header, which is used to carry the INT BFD control message.

[0006] Optionally, the BFD control message of the INT does not implement timer negotiation and / or authentication functions.

[0007] Optionally, the service packet further includes: a bidirectional forwarding detection (BFD) packet header, the BFD packet header being used to carry standard BFD control messages, and the method further includes:

[0008] During the establishment of a bidirectional forwarding detection session, the first network device and the second network device determine whether the peer device supports adaptive bidirectional forwarding detection through the identification information field in the standard BFD control message.

[0009] Optionally, the first network device and the second network device determine whether the peer device supports adaptive bidirectional forwarding detection through the identification information field in the standard BFD control message, including:

[0010] The first network device sends a BFD DOWN control message to the second network device;

[0011] The first network device receives the BFD DOWN control message from the second network device;

[0012] The first network device sends a first BFD INIT control message to the second network device. The identification information field in the first BFD INIT control message takes a first value. When the identification information field takes a first value, it indicates that the first network device supports adaptive bidirectional forwarding detection.

[0013] The first network device receives a second BFD INIT control message from the second network device;

[0014] The first network device determines whether the value of the identification information field in the second BFD INIT control message is the first value;

[0015] If the identification information field in the second BFD INIT control message takes the first value, the first network device sends a BFD UP control message and enters adaptive mode, supporting adaptive bidirectional forwarding detection.

[0016] If the value of the identification information field in the second BFD INIT control message is not the first value, the first network device sends a BFD UP control message and enters standard mode, supporting standard bidirectional forwarding detection.

[0017] Optionally, the method further includes:

[0018] The first network device determines the transmission ratio of BFD packet header and INT packet header in the service packet based on the link rate and / or detection accuracy requirements.

[0019] Optionally, the timeout setting of the BFD control message transmission timeout timer of the INT is consistent with the timeout setting of the standard BFD control message transmission timeout timer.

[0020] Optionally, at the beginning of each transmission time interval of the transmission timeout timer, the transmission counter corresponding to the transmission timeout timer is set to 1; if an INT BFD control message is transmitted within the transmission time interval, the transmission counter is decremented by 1; if the transmission counter is 1 when the transmission time interval ends, indicating that no INT BFD control message was transmitted within the transmission time interval, a standard BFD control message is transmitted.

[0021] Optionally, the first network device sends service packets to the second network device, including:

[0022] The first network device checks whether the transmission timeout timer has expired;

[0023] If the transmission timeout timer times out, the first network device checks whether the transmission counter is 1;

[0024] If the transmit counter is 1, the first network device sends a standard BFD control message to clear the transmit timeout timer; if the transmit counter is not 1, the first network device sets the transmit counter to 1 and clears the transmit timeout timer.

[0025] If the transmission timeout timer does not time out, the first network device determines whether there is a packet to be transmitted;

[0026] If there is a packet to be sent, the first network device encapsulates an INT BFD control message in the packet to be sent, sends the INT BFD control message, and decrements the transmission counter by 1.

[0027] Secondly, an adaptive bidirectional forwarding detection receiving method is provided, including:

[0028] The second network device receives a service packet from the first network device. The service packet includes an INT packet header, which is used to carry a BFD control message for the INT packet.

[0029] Optionally, the BFD control message of the INT does not implement timer negotiation and / or authentication functions.

[0030] Optionally, the service packet further includes: a bidirectional forwarding detection (BFD) packet header, the BFD packet header being used to carry standard BFD control messages, and the method further includes:

[0031] During the establishment of a bidirectional forwarding detection session, the second network device and the first network device determine whether the peer device supports adaptive bidirectional forwarding detection through the identification information field in the standard BFD control message.

[0032] Optionally, the second network device and the first network device determine whether the peer device supports adaptive bidirectional forwarding detection through the identification information field in the standard BFD control message, including:

[0033] The second network device sends a BFD DOWN control message to the first network device;

[0034] The second network device receives the BFD DOWN control message from the first network device;

[0035] The second network device sends a third BFD INIT control message to the first network device. The identification information field in the third BFD INIT control message is set to a first value. When the identification information field is set to a first value, it indicates that the second network device supports adaptive bidirectional forwarding detection.

[0036] The second network device receives a fourth BFD INIT control message from the first network device;

[0037] The second network device determines whether the value of the identification information field in the fourth BFD INIT control message is the first value;

[0038] If the identification information field in the fourth BFD INIT control message takes the first value, the second network device sends a BFD UP control message and enters adaptive mode, supporting adaptive bidirectional forwarding detection.

[0039] If the value of the identification information field in the fourth BFD INIT control message is not the first value, the second network device sends a BFD UP control message, and the second network device enters standard mode, supporting standard bidirectional forwarding detection.

[0040] Optionally, the second network device receives service packets from the first network device, including:

[0041] The second network device determines whether the receive timeout timer has expired;

[0042] If the receive timeout timer expires, the state of the BFD state machine of the second network device will change from UP to DOWN, and the link failure will be reported to the control plane of the network device.

[0043] If the receive timeout timer does not expire, the second network device determines whether a BFD control message has been received.

[0044] If a BFD control message is received, determine whether the BFD control message type is a standard BFD control message or an INT BFD control message.

[0045] If it is a standard BFD control message, process the standard BFD control message and clear the receive timeout timer; if it is an INT BFD control message, process the INT BFD control message and clear the receive timeout timer.

[0046] Thirdly, an adaptive bidirectional forwarding detection transmitting device is provided, applied to a first network device, comprising:

[0047] The first sending module is used for the first network device to send service packets to the second network device. The service packets include an INT packet header, which is used to carry INT BFD control messages.

[0048] Thirdly, an adaptive bidirectional forwarding detection receiving device is provided, applied to a second network device, comprising:

[0049] A first receiving module is configured to receive service packets from a first network device. The service packets include an NT packet header, wherein the INT packet header is used to carry INT BFD control messages.

[0050] In this embodiment of the application, under the premise of meeting the preset detection accuracy, since some of the BFD functions can be implemented through the BFD control messages of INT, the transmission frequency of standard BFD control messages can be greatly reduced or even eliminated, thereby greatly reducing the transmission and processing overhead of standard BFD control messages, and thus eliminating the need to adopt complex hardware solutions, which can significantly reduce the implementation cost of high-speed bidirectional forwarding detection. Attached Figure Description

[0051] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0052] Figure 1 This is a schematic diagram of the BFD control message format;

[0053] Figure 2 This is a flowchart of the adaptive bidirectional forwarding detection sending method provided in the embodiments of this application;

[0054] Figure 3 This is a flowchart of the adaptive bidirectional forwarding detection receiving method provided in the embodiments of this application;

[0055] Figure 4 This is a schematic diagram of an embodiment of the present application that uses an in-band network telemetry packet with a lightweight BFD packet header;

[0056] Figure 5 This is a schematic diagram of the lightweight BFD packet header provided in the embodiments of this application;

[0057] Figure 6 This is a schematic diagram of the three-way handshake process of the adaptive BFD mode negotiation mechanism provided in the embodiments of this application;

[0058] Figure 7 This is a flowchart of the local device state transition process for the adaptive BFD mode negotiation mechanism provided in this application embodiment;

[0059] Figure 8 This is a schematic diagram of the transmission process for adaptive bidirectional forwarding detection provided in the embodiments of this application;

[0060] Figure 9This is a schematic diagram of the adaptive bidirectional forwarding detection receiving process provided in the embodiments of this application;

[0061] Figure 10 This is a schematic diagram of the adaptive bidirectional forwarding detection transmitting device provided in the embodiments of this application;

[0062] Figure 11 This is a schematic diagram of the adaptive bidirectional forwarding detection receiving device provided in the embodiments of this application;

[0063] Figure 12 This is a schematic diagram of the adaptive bidirectional forwarding detection transceiver device provided in the embodiments of this application;

[0064] Figure 13 This is a schematic diagram of the communication device provided in the embodiments of this application. Detailed Implementation

[0065] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0066] The term "comprising," and any variations thereof, used in the specification and claims of this application, is intended to cover a non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not necessarily limited to those explicitly listed, but may include other steps or units not explicitly listed or inherent to such process, method, product, or apparatus. Furthermore, the use of "and / or" in the specification and claims indicates at least one of the connected objects, such as A and / or B, indicating the inclusion of A alone, B alone, or both A and B.

[0067] In the embodiments of this application, the terms "exemplary" or "for example" are used to indicate that something is an example, illustration, or description. Any embodiment or design that is described as "exemplary" or "for example" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or design. Specifically, the use of the terms "exemplary" or "for example" is intended to present the relevant concepts in a specific manner.

[0068] It is worth noting that the technologies described in this application are not limited to Long Term Evolution (LTE) / LTE-Advanced (LTE-A) systems, but can also be used in other wireless communication systems, such as Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Orthogonal Frequency Division Multiple Access (OFDMA), Single-carrier Frequency-Division Multiple Access (SC-FDMA), and other systems. The terms "system" and "network" in this application are often used interchangeably, and the described technologies can be used with the systems and radio technologies mentioned above, as well as with other systems and radio technologies. However, the following description describes New Radio (NR) systems for illustrative purposes, and the term NR is used in most of the following description, although these technologies can also be applied to applications other than NR systems, such as 6th Generation (6G) communication systems.

[0069] In existing technologies, POS (Packet over SONET / SDH, a technology used in metropolitan area networks and wide area networks) links achieve fast fault detection through hardware detection mechanisms. However, with the increasing prevalence of high-speed Ethernet links in carrier networks, the lack of a hardware-based high-speed link fault detection mechanism has become apparent. At this point, network applications must rely on the detection mechanisms of upper-layer protocols for fault detection. However, the detection time of these upper-layer protocols is over one second, making fault detection too slow. While some routing protocols, such as Open Shortest Path First (OSPF) and Intermediate System-to-Intermediate System (IS-IS), have Fast Hello functionality to speed up detection, their detection time can only achieve an accuracy of one second, and they are only applicable to their own protocols, unable to provide fast fault detection for other protocols.

[0070] With the widespread adoption and application of next-generation 5G mobile communication technology (such as the Industrial Internet and 5G high-definition video streaming) across various vertical industries, higher demands are being placed on network reliability and service continuity. Among these, millisecond-level high-speed link fault detection is a critical requirement. The Bidirectional Forwarding Detection (BFD) protocol provides a universal, standardized, media-independent, and protocol-independent fast fault detection mechanism with the following advantages.

[0071] First, the BFD protocol can perform fault detection on any type of bidirectional forwarding path between network devices, including directly connected physical links, virtual circuits, tunnels, multi-hop routing paths, and unidirectional links.

[0072] Second, the BFD protocol can provide consistent, protocol-independent, fast fault detection times for different upper-layer application services.

[0073] Third, the BFD protocol can provide millisecond-level link failure detection speed, thereby accelerating network convergence, reducing service interruption time for network applications, and improving network reliability and availability.

[0074] The BFD protocol establishes a User Datagram Protocol (UDP) session between two network devices to detect the bidirectional forwarding path between them, serving upper-layer network applications. BFD itself does not include a neighbor discovery mechanism; instead, it relies on notifications from the upper-layer protocol it serves for neighbor discovery. After establishing a new neighbor relationship, the upper-layer protocol announces the neighbor's parameters and detection parameters (including destination and source addresses) to the BFD protocol. The BFD protocol then establishes a BFD session based on the received parameters. Once the session is established, the BFD protocol periodically and rapidly sends BFD packets. If no BFD packet is received within the detection period, it assumes a failure in the bidirectional forwarding path and notifies the upper-layer application serving the session of the failure, allowing the application to take appropriate measures.

[0075] BFD control messages are encapsulated within UDP packets. The source port number ranges from 49152 to 65535. For single-hop detection, the UDP destination port number is 3784, and for multi-hop detection, it is 4784. BFD control messages include mandatory and optional authentication parts, such as... Figure 1 As shown.

[0076] A BFD session has three states: DOWN, INIT, and UP. INIT and UP are used to establish a session, while DOWN is used to terminate the session. BFD uses a three-way handshake mechanism to establish a session. When sending a BFD control message, the sender fills in its current session state in the Sta field. The receiver then uses the Sta field of the received BFD control message and its current session state to perform state machine transitions and establish the session.

[0077] After a session is established, the detection timer is reset whenever a BFD control message is received, keeping the session in the UP state. If no BFD control message is received within the detection time, the BFD session will transition to the DOWN state and notify the upper-layer application serving the session of a failure, allowing the upper-layer application to take appropriate measures. Two network devices can negotiate the timer size by modifying the local minimum supported BFD control message transmission interval (Desired Min TX Interval) and the local minimum supported BFD control message reception interval (Required Min RX Interval) in the BFD control message, thereby changing the BFD control message transmission interval and the peer's BFD detection time.

[0078] To achieve high-speed BFD (Browser-to-Flow) communication, existing high-end network equipment uses dedicated hardware to implement the BFD protocol. For example, the Cisco ASR 9000 aggregation router uses dedicated hardware to implement the BFD protocol, with a minimum transmission interval as low as 3.3ms, supporting up to 600 BFD detection sessions. In this example, the BFD protocol overhead is described using Packets Per Second (PPS), a crucial parameter for network flow devices. If a minimum transmission interval of 3.3ms is set, and 600 bidirectional sessions are supported, the BFD protocol requires 360Kpps (packet forwarding rate), representing a significant overhead on the system. Current technical solutions all utilize dedicated hardware for this implementation.

[0079] However, existing bidirectional forwarding detection methods require dedicated hardware implementation to support high-speed BFD detection, which is complex in design and has a large implementation overhead.

[0080] See Figure 2 This application provides an adaptive bidirectional forwarding detection sending method, the specific steps of which include: step 201.

[0081] Step 201: The first network device sends a service packet to the second network device. The service packet includes an Inband Network Telemetry (INT) header, which carries the INT BFD control message.

[0082] In one embodiment of this application, the BFD control message of the INT does not implement the timer negotiation function and / or authentication function.

[0083] In one embodiment of this application, the service packet further includes: a BFD packet header, the BFD packet header being used to carry standard BFD control messages, and the method further includes:

[0084] During the establishment of a bidirectional forwarding detection session, the first network device and the second network device determine whether the peer device supports adaptive bidirectional forwarding detection through the identification information field in the standard BFD control message.

[0085] In one embodiment of this application, the first network device and the second network device determine whether the peer device supports adaptive bidirectional forwarding detection through the identification information field in the standard BFD control message, including:

[0086] The first network device sends a BFD DOWN control message to the second network device;

[0087] The first network device receives the BFD DOWN control message from the second network device;

[0088] The first network device sends a first BFD INIT control message to the second network device. The identification information field (or described as a diagnostic field (Diag field)) in the first BFD INIT control message takes a first value (e.g., any value between 9 and 31). When the identification information field takes a first value, it indicates that the first network device supports adaptive bidirectional forwarding detection.

[0089] The first network device receives a second BFD INIT control message from the second network device;

[0090] The first network device determines whether the value of the identification information field in the second BFD INIT control message is the first value;

[0091] If the identification information field in the second BFD INIT control message takes the first value, the first network device sends a BFD UP control message and enters adaptive mode, supporting adaptive bidirectional forwarding detection.

[0092] If the value of the identification information field in the second BFD INIT control message is not the first value, the first network device sends a BFD UP control message and enters standard mode, supporting standard bidirectional forwarding detection.

[0093] In one embodiment of this application, the method further includes:

[0094] The first network device determines the transmission ratio of BFD packet header and INT packet header in the service packet based on the link rate and / or detection accuracy requirements.

[0095] In one embodiment of this application, the timeout setting of the BFD control message transmission timeout timer of the INT is consistent with the timeout setting of the standard BFD control message transmission timeout timer.

[0096] In one embodiment of this application, at the beginning of each transmission time interval of the transmission timeout timer, the transmission counter corresponding to the transmission timeout timer is set to 1; if an INT BFD control message is transmitted within the transmission time interval, the transmission counter is decremented by 1; if the transmission time interval ends and the transmission counter is 1, indicating that no INT BFD control message was transmitted within the transmission time interval, then a standard BFD control message is transmitted.

[0097] In one embodiment of this application, the first network device sends service packets to the second network device, including:

[0098] The first network device checks whether the transmission timeout timer has expired;

[0099] If the transmission timeout timer times out, the first network device checks whether the transmission counter is 1;

[0100] If the transmit counter is 1, the first network device sends a standard BFD control message to clear the transmit timeout timer; if the transmit counter is not 1, the first network device sets the transmit counter to 1 and clears the transmit timeout timer.

[0101] If the transmission timeout timer does not time out, the first network device determines whether there is a packet to be transmitted;

[0102] If there is a packet to be sent, the first network device encapsulates an INT BFD control message in the packet to be sent, sends the INT BFD control message, and decrements the transmission counter by 1.

[0103] In this embodiment of the application, under the premise of meeting the preset detection accuracy, since some of the BFD functions can be implemented through the BFD control messages of INT, the transmission frequency of standard BFD control messages can be greatly reduced or even eliminated, thereby greatly reducing the transmission and processing overhead of standard BFD control messages, and thus eliminating the need to adopt complex hardware solutions, which can significantly reduce the implementation cost of high-speed bidirectional forwarding detection.

[0104] See Figure 3 This application provides an adaptive bidirectional forwarding detection receiving method, the specific steps of which include: step 301.

[0105] Step 301: The second network device receives a service packet from the first network device. The service packet includes an INT packet header, which is used to carry a BFD control message for the INT packet.

[0106] In one embodiment of this application, the BFD control message of the INT does not implement the timer negotiation function and / or authentication function.

[0107] In one embodiment of this application, the service packet further includes: a bidirectional forwarding detection (BFD) packet header, the BFD packet header being used to carry standard BFD control messages; the method further includes:

[0108] During the establishment of a bidirectional forwarding detection session, the second network device and the first network device determine whether the peer device supports adaptive bidirectional forwarding detection through the identification information field in the standard BFD control message.

[0109] In one embodiment of this application, the second network device and the first network device determine whether the peer device supports adaptive bidirectional forwarding detection through the identification information field in the standard BFD control message, including:

[0110] The second network device sends a BFD DOWN control message to the first network device;

[0111] The second network device receives the BFD DOWN control message from the first network device;

[0112] The second network device sends a third BFD INIT control message to the first network device. The identification information field in the third BFD INIT control message is set to a first value. When the identification information field is set to a first value, it indicates that the second network device supports adaptive bidirectional forwarding detection.

[0113] The second network device receives a fourth BFD INIT control message from the first network device;

[0114] The second network device determines whether the value of the identification information field in the fourth BFD INIT control message is the first value;

[0115] If the identification information field in the fourth BFD INIT control message takes the first value, the second network device sends a BFD UP control message and enters adaptive mode, supporting adaptive bidirectional forwarding detection.

[0116] If the value of the identification information field in the fourth BFD INIT control message is not the first value, the second network device sends a BFD UP control message, and the second network device enters standard mode, supporting standard bidirectional forwarding detection.

[0117] In one embodiment of this application, the second network device receives service packets from the first network device, including:

[0118] The second network device determines whether the receive timeout timer has expired;

[0119] If the receive timeout timer expires, the state of the BFD state machine of the second network device will change from UP to DOWN, and the link failure will be reported to the control plane of the network device.

[0120] If the receive timeout timer does not expire, the second network device determines whether a BFD control message has been received.

[0121] If a BFD control message is received, determine whether the BFD control message type is a standard BFD control message or an INT BFD control message.

[0122] If it is a standard BFD control message, process the standard BFD control message and clear the receive timeout timer; if it is an INT BFD control message, process the INT BFD control message and clear the receive timeout timer.

[0123] In this embodiment of the application, under the premise of meeting the preset detection accuracy, since some of the BFD functions can be implemented through the BFD control messages of INT, the transmission frequency of standard BFD control messages can be greatly reduced or even eliminated, thereby greatly reducing the transmission and processing overhead of standard BFD control messages, and thus eliminating the need to adopt complex hardware solutions, which can significantly reduce the implementation cost of high-speed bidirectional forwarding detection.

[0124] The embodiments of this application solve the problem of efficiently and cost-effectively supporting high-speed bidirectional forwarding detection in programmable switches without the need for additional design and introduction of dedicated hardware.

[0125] First, the embodiments of this application introduce an improved INT in the programmable switch, which can utilize an improved in-band network telemetry mechanism to achieve bidirectional forwarding detection (BFD) functionality, complementing the standard BFD protocol. The embodiments of this application employ in-band network telemetry packets to carry out BFD processing, effectively leveraging the network packet processing capabilities of the programmable switch consumed by actual service traffic to incidentally perform the BFD function, significantly reducing network device processing overhead compared to separately sending and processing standard BFD control messages.

[0126] Second, embodiments of this application propose an adaptive bidirectional forwarding detection method that combines in-band network telemetry-based BFD control packets (hereinafter referred to as in-band BFD control packets) and standard BFD control packets, including an improved mode negotiation mechanism and an improved adaptive transmission mechanism for BFD control packets.

[0127] 1. Bidirectional forwarding detection based on in-band network telemetry

[0128] Currently, with the rapid adoption of INT-based network measurement methods in programmable switches and routers, in-band network telemetry has become a core function of these devices. In-band network telemetry completes the testing task by inserting an in-band network telemetry packet header (INT packet header) into actual service packets. For example... Figure 4 As shown, in-band network telemetry is performed. Network device A inserts an INT header into the header of the service packet. As the service packet travels through the illustrated link to network device B, each network device along the path inserts its own measurement information into the INT header hop-by-hop. When the service packet arrives at network device B, network device B parses the measurement information from each node along the path carried in the INT header and sends it to the controller. Subsequently, network device B strips the INT header from the service packet and forwards it to downstream nodes according to its destination. This invention utilizes the mechanism of in-band network telemetry to insert a lightweight BFD header into the INT header. This allows the task of BFD detection to be performed incidentally using the service packet undergoing in-band network telemetry.

[0129] To simplify, consider a one-way detection process for BFD, where network device A sends BFD control packets and network device B receives them. The detection process from network device B to network device A is similar. In this embodiment, a lightweight BFD packet header is used to carry in-band network telemetry packets, enabling lightweight INT-based BFD control messages, such as... Figure 4As shown. Optionally, if the INT BFD control message does not implement timer negotiation and authentication functions, the lightweight packet header only includes the Vers, Diag, Sta, P, F, C, A, D, R, Detect Multi, Length, MyDiscriminator, and Your Discriminator fields, occupying a total of 96 bits in the INT packet header size, as shown. Figure 5 As shown.

[0130] Network device A will adaptively control the transmission of INT's BFD control messages and standard BFD control messages, and then analyze the adaptive transmission mechanism of INT's BFD control messages and standard BFD control messages.

[0131] 2. Adaptive bidirectional forwarding detection mode negotiation mechanism

[0132] For network device A and network device B, during the establishment of a bidirectional forwarding detection session, it is necessary to identify whether the other party supports the adaptive bidirectional forwarding detection method. In this embodiment, the diagnostic field (Diag field) in the standard BFD control message is used for differentiation. RFC5880 defines the Diag diagnostic field, which explains the reason why the BFD protocol state changes from UP to other states. Currently, nine states (0 to 8) are defined for the diagnostic field, while 9 to 31 are undefined and reserved. In this embodiment, a value from 9-31 (undefined and reserved) is selected as the identification information field for supporting the adaptive bidirectional forwarding detection method. For example, a Diag diagnostic field of 9 can be defined to indicate support for the adaptive bidirectional forwarding detection method. Based on the identification information field value and the Diag diagnostic field being 9, the three-way handshake process of the mode negotiation mechanism can be designed as follows: Figure 6 As shown. It should be noted that the value of the identification information field can be selected from 9 to 31 of the Diag diagnostic field. This application embodiment does not limit the specific value of the identification information field between 9 and 31. Figure 6 The values ​​of the Diag diagnostic field are provided as examples only. This application embodiment utilizes the diagnostic field (Diag field) of the standard BFD control message for negotiation to determine whether the peer device can support the bidirectional forwarding detection mechanism based on in-band network telemetry proposed in this application embodiment, thus completing the adaptive bidirectional forwarding detection sending and receiving process.

[0133] Assuming Figure 4 The network device A and network device B establish a BFD session, and the three-way handshake process is as follows: Figure 6 As shown. Figure 7 The state transition process in the mode negotiation mechanism of the local device (i.e., network device A) is given.

[0134] First, the local device (i.e., network device A) sends a BFD control message with the Sta field set to 1, indicating that the status of the sent BFD control message is BFD DOWN.

[0135] Second, when the local device receives the BFD DOWN control message sent by the peer device (i.e., network device B), the local device's state transitions from DOWN to INIT.

[0136] Third, the local device sends a BFD INIT control message, in which the Sta field is set to 2 and the Diag diagnostic field is set to 9.

[0137] Fourth, when the local device receives the BFD INIT control message sent by the remote device, the local device's state transitions from INIT to UP.

[0138] Fifth, the local device determines the value of the Diag diagnostic field in the received BFD INIT control message. If Diag = 9, the local device enters adaptive mode, supporting adaptive bidirectional forwarding detection. If Diag = 0, the local device enters standard mode, supporting standard bidirectional forwarding detection. Afterward, depending on the entered mode, the corresponding bidirectional forwarding detection process begins. For the peer device (i.e., network device B), the state transition process in its mode negotiation mechanism is the same and will not be elaborated here.

[0139] 3. Adaptive bidirectional forwarding detection sending process

[0140] If the adaptive bidirectional forwarding detection mode negotiation is completed and the system enters adaptive mode, then BFD control message transmission and reception are performed based on the adaptive bidirectional forwarding detection transmission mechanism. The adaptive transmission mechanism provided in this application requires determining the transmission ratio of in-band BFD control packets and standard BFD control packets based on link rate and detection accuracy requirements. Its transmission timeout timer's timeout setting is consistent with standard BFD. For example, if the BFD control message transmission interval is 10ms, then the timeout timer 1 is set to Timeout = 10ms. At the beginning of each transmission interval, the counter is set to 1; if an INT BFD control message is transmitted within the transmission interval, the counter is cleared (i.e., the counter is decremented by 1); if the counter is 1 when the transmission interval ends, it indicates that no INT BFD control message was transmitted within that transmission interval, and a standard BFD control message is transmitted. The system executes the transmission process through polling, with a polling frequency greater than the BFD transmission frequency (the BFD transmission frequency is defined as the reciprocal of the BFD transmission interval); the polling frequency is set to an integer multiple of the BFD transmission frequency.

[0141] The polling-based sending process executes as follows: Figure 8 As shown.

[0142] First, the transmit timeout timer is checked. If the transmit timer times out, the transmit counter is checked to see if it is 1. If the transmit counter is 1, it means that no INT BFD control message has been transmitted within the transmit interval. A standard BFD control message is transmitted, the transmit timeout timer is cleared, and the next transmit interval period begins, ending this round of checks. If the transmit counter is not 1 (it is 0 at this time), it means that an INT BFD control message has been transmitted within the transmit interval. The transmit counter is incremented by 1, the transmit timeout timer is cleared, and the next transmit interval period begins, ending this round of checks. If the transmit timer does not time out, the transmit buffer of the network device is checked to see if there are any service packets to be transmitted. If there are no service packets to be transmitted, the transmit buffer of the network device is checked to see if there are any service packets to be transmitted. If there are no service packets to be transmitted, the transmit buffer of the network device has service packets to be transmitted. The service packets to be transmitted are encapsulated with in-band BFD control INT header information, and the INT BFD control message is transmitted. The transmit counter is decremented by 1, so the transmit counter is now 0, ending this round of checks.

[0143] 4. Adaptive bidirectional forwarding detection receiving process

[0144] If the adaptive bidirectional forwarding detection mode negotiation concludes and the system enters adaptive mode, then BFD control message transmission and reception are performed based on the adaptive bidirectional forwarding detection transmission mechanism. The adaptive bidirectional forwarding detection reception process corresponds to the transmission process described in point 3, as follows: Figure 9 As shown.

[0145] The system executes the receive detection process via polling, with the polling frequency being an integer multiple of the standard BFD process detection frequency. The standard BFD process detection frequency is the reciprocal of the timeout period set by the receive timeout timer. The timeout period is determined based on a timer negotiation mechanism, and is the larger of the DetectMult field value in the peer's BFD control message and the larger of the required min RX Interval field on the local end and the desired min TX Interval field on the peer. Figure 7 After this round of judgment begins, the receive timeout timer is checked first. If the timer expires, the state of the BFD state machine transitions from UP to DOWN, and the link fault is reported to the network device's control plane, ending this round of judgment. If the timer has not expired, it is determined whether a BFD control message has been received; if no BFD control message has been received, this round of judgment ends; if a BFD control message has been received, it is determined whether the BFD control message type is a standard BFD control message or an INT BFD control message, and the corresponding processing procedure is followed, and the receive timeout timer is cleared, ending this round of judgment.

[0146] Under the premise of meeting the preset detection accuracy, this application embodiment can significantly reduce or even eliminate the transmission frequency of standard BFD control messages by using in-band network telemetry information to carry BFD control information, thereby significantly reducing the transmission and processing overhead of standard BFD control messages. Furthermore, it eliminates the need for complex hardware solutions, significantly reducing the implementation cost of high-speed bidirectional forwarding detection. For example, assuming the preset detection accuracy is met, using the standard BFD protocol would require sending 1000 BFD control messages per second. However, using the solution described in this invention, assuming the network device performing BFD detection also has in-band network telemetry capabilities, sending an average of 800 in-band network telemetry packets per second, these 800 in-band network telemetry packets can incidentally complete the BFD function, ideally requiring only 200 additional standard BFD control messages. By adopting this solution, the transmission frequency of standard BFD control messages can be significantly reduced.

[0147] See Figure 10 This application provides an adaptive bidirectional forwarding detection transmitting device, applied to a first network device, the device 1000 comprising:

[0148] The first sending module 1001 is used to send a service packet from the first network device to the second network device. The service packet includes an INT packet header, which is used to carry a BFD control message of INT.

[0149] In one embodiment of this application, the BFD control message of the INT does not implement the timer negotiation function and / or authentication function.

[0150] In one embodiment of this application, the service packet further includes: the BFD packet header is used to carry a standard BFD control message, and the device 1000 further includes:

[0151] The first negotiation module is used to determine, during the establishment of a bidirectional forwarding detection session, whether the peer device supports adaptive bidirectional forwarding detection by communicating with the second network device through the identification information field in the standard BFD control message.

[0152] In one embodiment of this application, the first negotiation module is further configured to:

[0153] Send a BFD DOWN control message to the second network device;

[0154] Receive the BFD DOWN control message from the second network device;

[0155] Send a first BFD INIT control message to the second network device. The identification information field in the first BFD INIT control message has a first value. When the identification information field has a first value, it indicates that the first network device supports adaptive bidirectional forwarding detection.

[0156] Receive a second BFD INIT control message from the second network device;

[0157] Determine whether the value of the identification information field in the second BFD INIT control message is the first value;

[0158] If the identification information field in the second BFD INIT control message takes the first value, then a BFDUP control message is sent to enter adaptive mode, supporting adaptive bidirectional forwarding detection.

[0159] If the value of the identification information field in the second BFD INIT control message is not the first value, then a BFD UP control message is sent to enter standard mode, supporting standard bidirectional forwarding detection.

[0160] In one embodiment of this application, the device 1000 further includes:

[0161] The determination module is used to determine the transmission ratio of BFD packet header and INT packet header in the service packet based on the link rate and / or detection accuracy requirements.

[0162] In one embodiment of this application, the timeout setting of the BFD control message transmission timeout timer of the INT is consistent with the timeout setting of the standard BFD control message transmission timeout timer.

[0163] In one embodiment of this application, at the beginning of each transmission time interval of the transmission timeout timer, the transmission counter corresponding to the transmission timeout timer is set to 1; if an INT BFD control message is transmitted within the transmission time interval, the transmission counter is decremented by 1; if the transmission time interval ends and the transmission counter is 1, indicating that no INT BFD control message was transmitted within the transmission time interval, then a standard BFD control message is transmitted.

[0164] In one embodiment of this application, the first sending module 1001: detects whether a sending timeout timer has expired; if the sending timeout timer expires, it detects whether the sending counter is 1; if the sending counter is 1, it sends a standard BFD control message to clear the sending timeout timer; if the sending counter is not 1, it sets the sending counter to 1 and clears the sending timeout timer; if the sending timeout timer has not expired, it determines whether there is a packet to be sent; if there is a packet to be sent, it encapsulates an INT BFD control message in the packet to be sent, sends the INT BFD control message, and decrements the sending counter by 1.

[0165] The apparatus provided in this application embodiment can achieve... Figure 2 The various processes implemented in the method embodiments shown achieve the same technical effects, and will not be described again here to avoid repetition.

[0166] See Figure 11 This application provides an adaptive bidirectional forwarding detection transmitting device, applied to a second network device, the device 1100 comprising:

[0167] The first receiving module 1101 is used to receive service packets from the first network device. The service packets include an INT packet header, which is used to carry BFD control messages of INT.

[0168] In one embodiment of this application, the BFD control message of the INT does not implement the timer negotiation function and / or authentication function.

[0169] In one embodiment of this application, the service packet further includes: the BFD packet header is used to carry a standard BFD control message, and the apparatus further includes:

[0170] The second negotiation module is used to determine, during the establishment of a bidirectional forwarding detection session, whether the peer device supports adaptive bidirectional forwarding detection by communicating with the first network device through the identification information field in the standard BFD control message.

[0171] In one embodiment of this application, the second negotiation module is further configured to: send a BFD DOWN control message to the first network device; receive a BFD DOWN control message from the first network device; send a third BFD INIT control message to the first network device, wherein the value of the identification information field in the third BFD INIT control message is a first value, and the value of the identification information field being the first value indicates that the second network device supports adaptive bidirectional forwarding detection; receive a fourth BFD INIT control message from the first network device; determine whether the value of the identification information field in the fourth BFD INIT control message is the first value; if the value of the identification information field in the fourth BFD INIT control message is the first value, then send a BFD UP control message to enter adaptive mode and support adaptive bidirectional forwarding detection; if the value of the identification information field in the fourth BFD INIT control message is not the first value, then send a BFD UP control message to enter standard mode and support standard bidirectional forwarding detection.

[0172] In one embodiment of this application, the first receiving module 1101 is further configured to: determine whether the receiving timeout timer has expired; if the receiving timeout timer expires, the state of the BFD state machine of the second network device is transitioned from UP to DOWN, and the link fault is reported to the control plane of the network device; if the receiving timeout timer has not expired, determine whether a BFD control message has been received; if a BFD control message is received, determine whether the BFD control message type is a standard BFD control message or an INT BFD control message; if it is a standard BFD control message, process the standard BFD control message and clear the receiving timeout timer; if it is an INT BFD control message, process the INT BFD control message and clear the receiving timeout timer.

[0173] The apparatus provided in this application embodiment can achieve... Figure 3 The various processes implemented in the method embodiments shown achieve the same technical effects, and will not be described again here to avoid repetition.

[0174] See Figure 12This application provides an adaptive bidirectional forwarding detection transceiver device. The BFD protocol control module includes a timer negotiation module and a BFD session state machine module. The timer negotiation module operates using the timer negotiation mechanism of the standard BFD protocol, consistent with RFC5880. The BFD session state machine module maintains the BFD session state and manages the transmission and reception of BFD control messages according to the aforementioned adaptive bidirectional forwarding detection mode negotiation mechanism, sending process, and receiving process. The standard BFD control message transmission and reception processing module uses the standard BFD protocol processing mode consistent with RFC5880. The INT BFD control message transmission and reception processing module uses the same INT BFD control message transmission and reception processing method as described in this application embodiment based on the in-band network telemetry-based bidirectional forwarding detection method. The functions of the transmit timeout timer module and the receive timeout module are the same as described in this application. Figure 8 and Figure 9 The corresponding timer functions are consistent throughout the process. The send counter module function is the same as... Figure 8 The timer function is consistent throughout the process.

[0175] like Figure 13 As shown, this application embodiment also provides a communication device 1300, including a processor 1301, a memory 1302, and a program or instructions stored in the memory 1302 and executable on the processor 1301. When the program or instructions are executed by the processor 1301, they implement the above-mentioned... Figure 2 or Figure 3 The various processes in the method embodiments can achieve the same technical effect. To avoid repetition, they will not be described again here.

[0176] This application embodiment also provides a readable storage medium storing a program or instructions that, when executed by a processor, implement the above-described functionality. Figure 2 or Figure 3 The various processes of the method embodiments shown can achieve the same technical effect, and will not be described again here to avoid repetition.

[0177] The processor mentioned above is the processor in the terminal described in the above embodiments. The readable storage medium includes computer-readable storage media, such as computer read-only memory (ROM), random access memory (RAM), magnetic disk, or optical disk.

[0178] The steps of the methods or algorithms described in this application can be implemented in hardware or by executing software instructions on a processor. The software instructions can consist of corresponding software modules, which can be stored in RAM, flash memory, ROM, EPROM, EEPROM, registers, hard disk, portable hard disk, read-only optical disk, or any other form of storage medium known in the art. An exemplary storage medium is coupled to the processor, enabling the processor to read information from and write information to the storage medium. Of course, the storage medium can also be a component of the processor. The processor and storage medium can be housed in an ASIC. Alternatively, the ASIC can be housed in a core network interface device. Of course, the processor and storage medium can also exist as discrete components in the core network interface device.

[0179] Those skilled in the art will recognize that, in one or more of the examples above, the functions described in this application can be implemented using hardware, software, firmware, or any combination thereof. When implemented in software, these functions can be stored in a computer-readable medium or transmitted as one or more instructions or code on a computer-readable medium. Computer-readable media include computer storage media and communication media, wherein communication media include any medium that facilitates the transfer of a computer program from one place to another. Storage media can be any available medium accessible to a general-purpose or special-purpose computer.

[0180] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of this application. It should be understood that the above description is only a specific embodiment of this application and is not intended to limit the scope of protection of this application. Any modifications, equivalent substitutions, improvements, etc., made on the basis of the technical solution of this application should be included within the scope of protection of this application.

[0181] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, embodiments of this application can take the form of entirely hardware embodiments, entirely software embodiments, or embodiments combining software and hardware aspects. Furthermore, embodiments of this application can take the form of computer program products implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0182] This application describes embodiments of methods, apparatus (systems), and computer program products according to embodiments of this application with reference to flowchart illustrations and / or block diagrams. It should be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0183] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0184] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0185] Obviously, those skilled in the art can make various modifications and variations to the embodiments of this application without departing from the spirit and scope of this application. Therefore, if these modifications and variations to the embodiments of this application fall within the scope of the claims of this application and their equivalents, this application also intends to include these modifications and variations.

Claims

1. A transmission method for adaptive bidirectional forwarding detection, characterized in that, include: The first network device sends a service packet to the second network device. The service packet includes an in-band network telemetry (INT) packet header, which is used to carry a bidirectional forwarding detection (BFD) control message for INT. The method further includes: The first network device determines the transmission ratio of BFD packet header and INT packet header in the service packet based on the link rate and / or detection accuracy requirements. The timeout setting of the BFD control message transmission timeout timer for the INT is consistent with the timeout setting of the standard BFD control message transmission timeout timer. At the start of each transmission time interval of the transmission timeout timer, the transmission counter corresponding to the transmission timeout timer is set to 1; if an INT BFD control message is transmitted within the transmission time interval, the transmission counter is decremented by 1; if the transmission time interval ends and the transmission counter is 1, indicating that no INT BFD control message was transmitted within the transmission time interval, a standard BFD control message is transmitted.

2. The method according to claim 1, characterized in that, The BFD control message of the INT does not implement timer negotiation and / or authentication functions.

3. The method according to claim 1, characterized in that, The service packet further includes: a bidirectional forwarding detection (BFD) packet header, the BFD packet header being used to carry standard BFD control messages; the method further includes: During the establishment of a bidirectional forwarding detection session, the first network device and the second network device determine whether the peer device supports adaptive bidirectional forwarding detection through the identification information field in the standard BFD control message.

4. The method according to claim 3, characterized in that, The first network device and the second network device determine whether the peer device supports adaptive bidirectional forwarding detection through the identification information field in the standard BFD control message, including: The first network device sends a BFD DOWN control message to the second network device; The first network device receives the BFD DOWN control message from the second network device; The first network device sends a first BFDINIT control message to the second network device. The identification information field in the first BFDINIT control message takes a first value. When the identification information field takes a first value, it indicates that the first network device supports adaptive bidirectional forwarding detection. The first network device receives a second BFD INIT control message from the second network device; The first network device determines whether the value of the identification information field in the second BFDINIT control message is the first value; If the identification information field in the second BFDINIT control message takes the first value, the first network device sends a BFD UP control message and enters adaptive mode, supporting adaptive bidirectional forwarding detection. If the value of the identification information field in the second BFD INIT control message is not the first value, the first network device sends a BFD UP control message and enters standard mode, supporting standard bidirectional forwarding detection.

5. The method according to claim 1, characterized in that, The first network device sends service packets to the second network device, including: The first network device checks whether the transmission timeout timer has expired; If the transmission timeout timer times out, the first network device checks whether the transmission counter is 1; If the transmit counter is 1, the first network device sends a standard BFD control message to clear the transmit timeout timer; if the transmit counter is not 1, the first network device sets the transmit counter to 1 and clears the transmit timeout timer. If the transmission timeout timer does not time out, the first network device determines whether there are packets to be transmitted. If there is a packet to be sent, the first network device encapsulates an INT BFD control message in the packet to be sent, sends the INT BFD control message, and decrements the transmission counter by 1.

6. A receiving method for adaptive bidirectional forwarding detection, characterized in that, include: The second network device receives a service packet from the first network device. The service packet includes an in-band network telemetry (INT) packet header, which is used to carry a bidirectional forwarding detection (BFD) control message for the INT. The second network device receives service packets from the first network device, including: The second network device determines whether the receive timeout timer has expired; If the receive timeout timer expires, the state of the BFD state machine of the second network device will change from UP to DOWN, and the link failure will be reported to the control plane of the network device. If the receive timeout timer does not expire, the second network device determines whether a BFD control message has been received. If a BFD control message is received, determine whether the BFD control message type is a standard BFD control message or an INT BFD control message. If it is a standard BFD control message, process the standard BFD control message and clear the receive timeout timer; if it is an INT BFD control message, process the INT BFD control message and clear the receive timeout timer.

7. The method according to claim 6, characterized in that, The BFD control message of the INT does not implement timer negotiation and / or authentication functions.

8. The method according to claim 6, characterized in that, The service packet further includes: a BFD packet header, the BFD packet header being used to carry standard BFD control messages; the method further includes: During the establishment of a bidirectional forwarding detection session, the second network device and the first network device determine whether the peer device supports adaptive bidirectional forwarding detection through the identification information field in the standard BFD control message.

9. The method according to claim 8, characterized in that, The second network device and the first network device determine whether the peer device supports adaptive bidirectional forwarding detection through the identification information field in the standard BFD control message, including: The second network device sends a BFD DOWN control message to the first network device; The second network device receives the BFD DOWN control message from the first network device; The second network device sends a third BFDINIT control message to the first network device. The identification information field in the third BFDINIT control message is set to a first value. When the identification information field is set to a first value, it indicates that the second network device supports adaptive bidirectional forwarding detection. The second network device receives a fourth BFD INIT control message from the first network device; The second network device determines whether the value of the identification information field in the fourth BFDINIT control message is the first value; If the identification information field in the fourth BFDINIT control message takes the first value, the second network device sends a BFD UP control message and enters adaptive mode, supporting adaptive bidirectional forwarding detection. If the value of the identification information field in the fourth BFD INIT control message is not the first value, the second network device sends a BFD UP control message, and the second network device enters standard mode, supporting standard bidirectional forwarding detection.

10. An adaptive bidirectional forwarding detection transmitting device, applied to a first network device, characterized in that, include: The first sending module is used to send service packets from the first network device to the second network device. The service packets include: an in-band network telemetry (INT) packet header, which is used to carry a bidirectional forwarding detection (BFD) control message for INT. The device further includes: The determination module determines the transmission ratio of BFD packet headers and INT packet headers in the service packets based on link rate and / or detection accuracy requirements. The timeout setting of the BFD control message transmission timeout timer for the INT is consistent with the timeout setting of the standard BFD control message transmission timeout timer. At the start of each transmission time interval of the transmission timeout timer, the transmission counter corresponding to the transmission timeout timer is set to 1; if an INT BFD control message is transmitted within the transmission time interval, the transmission counter is decremented by 1; if the transmission time interval ends and the transmission counter is 1, indicating that no INT BFD control message was transmitted within the transmission time interval, a standard BFD control message is transmitted.

11. A receiving device for adaptive bidirectional forwarding detection, applied to a second network device, characterized in that, include: The first receiving module is configured to receive service packets from the first network device. The service packets include: an in-band network telemetry (INT) packet header, wherein the INT packet header is used to carry a bidirectional forwarding detection (BFD) control message for the INT. The first receiving module is further used to determine whether the receiving timeout timer has timed out; If the receive timeout timer expires, the state of the BFD state machine of the second network device will change from UP to DOWN, and the link failure will be reported to the control plane of the network device. If the receive timeout timer has not expired, determine whether a BFD control message has been received. If a BFD control message is received, determine whether the BFD control message type is a standard BFD control message or an INT BFD control message. If it is a standard BFD control message, process the standard BFD control message and clear the receive timeout timer; if it is an INT BFD control message, process the INT BFD control message and clear the receive timeout timer.

12. A communication device, characterized in that, include: A processor, a memory, and a program stored in the memory and executable on the processor, wherein the program, when executed by the processor, implements the steps of the method as described in any one of claims 1 to 9.

13. A readable storage medium, characterized in that, The readable storage medium stores a program that, when executed by a processor, implements the steps of the method as described in any one of claims 1 to 9.

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