CN115801547A - Transition method and device for automatic protection switching APS state machine - Google Patents

Abstract

The application discloses a transition method and a transition device of an automatic protection switching APS state machine, which relate to the technical field of communication. The method comprises the following steps: determining the state of an APS state machine as a first state; the APS state machine is transitioned from a first state to a second state. Wherein the first state is an invalid state in the current APS mode and the second state is an valid state in the current APS mode.

Description

Transition method and device for automatic protection switching APS state machine

Technical Field

The present application relates to the field of communications technologies, and in particular, to a transition method and apparatus for an Automatic Protection Switching (APS) state machine.

Background

The g.8031 standard protocol is an ethernet APS protocol, and for a network node (or a network node configured with an APS function) running the APS protocol, the APS protocol defines an APS state machine of the network node, that is, a certain state of the APS state machine of the network node running the APS protocol is represented by a combination of values of several fields, such as a state, a protection type (protection type), a requested signal (requested signal), a bridged signal (bridged signal), and a bridged type (bridged type).

However, only a part of all the combination results obtained by combining the values of the field segments is a valid combination result, the state indicated by the valid combination result is the valid state of the APS state machine, the other part of the combination results is invalid, and the state indicated by the invalid combination result is the invalid state of the APS state machine.

In the current APS protocol, only a transition policy of an active state of an APS state machine is defined, but a transition policy of an inactive state is not defined, which results in that when the current state of the APS state machine of a network node running the APS protocol is an inactive state, the network node cannot perform state transition on the current state of the APS state machine according to an APS state switching request, so that the network node jumps out of the current inactive state, and thus the APS state machine of the network node hangs up. As a result, the APS functionality of a network node is impaired, which in turn leads to impairment of the traffic transmitted by that network node.

Disclosure of Invention

The application provides a transition method and a transition device of an APS state machine, which can avoid the phenomenon of hanging up of the APS state machine of a communication device, and further ensure that the communication device can normally transmit service flow.

In order to achieve the above purpose, the present application provides the following technical solutions:

in a first aspect, the present application provides a method for transitioning an APS state machine, the method performed by a first communication device. The method comprises the following steps: the state of the APS state machine is determined to be a first state. The APS state machine is transitioned from a first state to a second state. Wherein the first state is an invalid state in the current APS mode and the second state is an valid state in the current APS mode.

According to the transition method of the APS state machine provided by the application, the first communication device can rapidly jump out of the current invalid state (for example, the update period of the APS state machine state with the duration of 3.3ms specified by the APS protocol), so that the phenomenon that the APS state machine is hung up by the first communication device is avoided, and the first communication device can be further ensured to normally transmit the traffic.

In a possible design, the second state is a state indicated by an APS state switching request.

In another possible design, the APS state switching request is an APS state switching request with the highest execution priority in the at least one APS state switching request received by the first communications device. The at least one APS state switching request includes at least one of an APS state switching request issued by a control layer of the first communication device, an APS state switching request generated by the first communication device according to the detected state of the communication link, and an APS state switching request carried in an APS message sent by the second communication device to the first communication device.

Through the two implementation manners, that is, when the first communication device obtains the APS state switching request, the APS state machine of the first communication device can be rapidly changed from the invalid state (for example, the update period of the APS state machine state specified by the APS protocol is 3.3 ms) to the second state based on the state (i.e., the second state) indicated by the APS state switching request, so that the phenomenon that the APS state machine is hung up in the first communication device is avoided, and the first communication device can normally transmit the traffic flow.

In another possible design, the APS patterns include 1+1 unidirectional cut-back pattern, 1+1 unidirectional non-cut-back pattern, 1+1 bidirectional cut-back pattern, 1+1 bidirectional non-cut-back pattern, 1:1 bidirectional cut-back pattern, and 1:1 bidirectional non-cut-back pattern.

In another possible design, the determining that the state of the APS state machine is the first state includes: and determining that the state of the APS state machine is a first state according to the value of the field for indicating the state of the APS state machine.

Specifically, the first communication device may determine that the state of the APS state machine is the first state according to a value of a field indicating the state of the APS state machine and a preset APS state machine invalid state set.

In another possible design, when the APS mode is 1+1 unidirectional non-switchback mode and the second state is a protection locked LO state indicated by an APS state switch request, the transitioning the APS state machine from the first state to the second state includes: the state of the APS state machine is transitioned from the first state to the LO state.

In another possible design, when the APS mode is 1+1 bidirectional non-switchback mode and the second state is an SF _ W state indicating an APS state switch request, the transitioning the APS state machine from the first state to the second state includes: the state of the APS state machine is transitioned from the first state to the SF _ W state.

In another possible design, when the APS mode is 1+1 bidirectional non-switchback mode and the second state is an NR state indicated by an APS state switch request, the transitioning the APS state machine from the first state to the second state includes: the state of the APS state machine is transitioned from the first state to the NR state.

Through the several possible implementation manners, the method provided by the application realizes that the APS state machine of the first communication device is changed from the invalid state to the valid state under different APS modes, namely, the phenomenon that the APS state machine is hung up on the first communication device is avoided, and the first communication device can further ensure that the first communication device can normally transmit the service flow.

In a second aspect, the present application provides a communication device.

In one possible design, the communication device is configured to perform any one of the methods provided in the first aspect. The present application may divide the functional modules of the communication device according to any one of the methods provided by the first aspect. For example, the functional blocks may be divided for the respective functions, or two or more functions may be integrated into one processing block. For example, the present application may divide the communication apparatus into a determination unit, a transition unit, and the like according to functions. The above description of possible technical solutions and beneficial effects executed by each divided functional module may refer to the technical solutions provided by the first aspect or the corresponding possible designs thereof, and will not be described herein again.

In another possible design, the communication device includes: one or more processors and a transmission interface through which the one or more processors receive or transmit data, the one or more processors being configured to invoke program instructions stored in a memory to cause a communication device to perform any of the methods provided by the first aspect and any of its possible designs.

In a third aspect, the present application provides a computer-readable storage medium comprising program instructions which, when executed on a computer or processor, cause the computer or processor to perform any of the methods provided by the first aspect and any of its possible implementations.

In a fourth aspect, the present application provides a computer program product comprising a computer program that, when run on a processor, implements part or all of the operations of the method provided by the first aspect or any one of the possible implementations of the first aspect.

It is understood that any one of the apparatuses, computer storage media, computer program products, or chip systems provided above can be applied to the corresponding methods provided above, and therefore, the beneficial effects achieved by the apparatuses, the computer storage media, the computer program products, or the chip systems can refer to the beneficial effects in the corresponding methods, and are not described herein again.

In the present application, the names of the above-mentioned communication means do not limit the devices or functional modules themselves, which may appear by other names in actual implementations. Insofar as the functions of the respective devices or functional modules are similar to those of the present application, they fall within the scope of the claims of the present application and their equivalents.

Drawings

Fig. 1 is a schematic hardware structure diagram of a communication device according to an embodiment of the present disclosure;

fig. 2 is a schematic diagram of a network structure according to an embodiment of the present application;

fig. 3 is a schematic flowchart of a transition method of an APS state machine according to an embodiment of the present disclosure;

fig. 4 is a schematic structural diagram of a communication device according to an embodiment of the present application;

FIG. 5 is a schematic structural diagram of a signal bearing medium for bearing a computer program product according to an embodiment of the present application.

Detailed Description

In the embodiments of the present application, words such as "exemplary" or "for example" are used to mean serving as an example, instance, or illustration. Any embodiment or design described herein as "exemplary" or "e.g.," is not necessarily to be construed as preferred or advantageous over other embodiments or designs. Rather, use of the word "exemplary" or "such as" is intended to present relevant concepts in a concrete fashion.

In the embodiments of the present application, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or to implicitly indicate the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present application, the meaning of "a plurality" is two or more unless otherwise specified. The term "at least one" in this application means one or more,

the APS protocol is a protocol for implementing automatic protection switching. The basic principle of the APS protocol is: when there are multiple communication paths from point to point, backups may be formed between the multiple communication paths. If the communication path in use is defined as a working path, the other backup communication path is defined as a protection path. When the initially selected working channel fails, the APS protocol can enable the network node to quickly switch to other protection channels for transmitting traffic.

In the APS protocol, the states of APS state machines of network nodes running the APS protocol are defined by several fields, such as state, protection type, requested signal, bridged signal, and bridged type.

As shown in table 1, table 1 shows a detailed description of various fields in the APS protocol for defining the state of an APS state machine of a network node running the APS protocol:

TABLE 1

In practical applications, the APS modes supported by the network node running the APS protocol include: 1+1 unidirectional backcut pattern, 1+1 unidirectional non-backcut pattern, 1+1 bidirectional backcut pattern, 1+1 bidirectional non-backcut pattern, 1:1 bidirectional backcut pattern, and 1:1 bidirectional non-backcut pattern. Wherein each APS mode can be represented by A, B, D, R of the protection type field in table 1. Wherein, a represents APS, B represents bridging, D represents direction, r represents reverse, and the specific meanings of A, B, D, R are shown in table 1.

For example, 1+1 unidirectional cut-back pattern can be represented by combination of values 1001 of A, B, D, R in protection type field. It should be understood that in any APS mode, the value of a in the protection type field is 1.

The 1+1 mode represents permanent bridging, and specifically represents that two network nodes directly transmit traffic through a working path and a protection path at the same time. 1:1 mode represents a non-permanent bridge, specifically representing that only one of the working path and the protection path can transmit traffic.

The unidirectional mode indicates that only one end network node operates the APS protocol on two network nodes communicating with each other, i.e., only one end network node has APS function. The bidirectional mode means that two network nodes which communicate with each other run the APS protocol, i.e. both network nodes which communicate with each other have APS functionality.

The switching-back mode refers to that after the fault of the working channel is recovered, the flow is switched back to the working channel from the protection channel for transmission. The non-switching mode means that even if the failure of the working channel is recovered, the flow is still transmitted through the protection channel until the failure of the protection channel, and then the flow is transmitted through the working channel.

Based on the definitions of the fields in table 1, the APS protocol may represent a certain state of the APS state machine of the network node running the APS protocol by a combination of values of the fields state, protection type, requested signal, bridged signal, and bridged type. However, as can be seen from table 1, when the values of the fields state, protection type, requested signal, bridged signal, and bridged type are all combined in an arrangement, the combination results are very large. In practice, only a part of the combination results indicate that the states of the APS state machines are reasonably valid in one or more APS modes, i.e., the states of the part of the combination results are valid states of the APS state machines, while the states of the APS state machines of the rest of the combination results are not reasonable/valid in some APS modes or any APS modes, i.e., the states of the rest of the combination results are invalid states of the APS state machines.

For example, if the APS mode is 1+1 unidirectional non-switchback mode, the state is not WTR in the APS mode. Therefore, in the APS mode, if the state in the combined result indicating the states of the APS state machines is WTR, the state of the APS state machine is an invalid state.

Next, the invalid states of the APS state machines in the above 6 APS modes are shown in tables 2 to 7.

In tables 2 to 7, the following are shown:

"X" represents an unlimited value, i.e., X can be 0 or 1;

the value in parentheses for each state in the "state" column is the encoded value defined for that state by the APS protocol. For example, for the state RR, 2 in RR (2) is the value of code 0010 defined by the APS protocol for the RR state;

"INV" is invalid (invalid), indicating an undefined state in the APS protocol, and it should be understood that if the value of the undefined state field is included in the combined result, the state indicated by the combined result is an invalid state of the APS state machine.

It should be noted that the first columns in tables 2 to 7 are APS modes indicated by values of the protection type field. The value combinations of each horizontal row in tables 2-7 can be used to indicate the invalid state of the APS state machine.

Referring to table 2, table 2 shows the invalid state of the APS state machine in which the APS mode is 1+1 unidirectional non-wraparound mode.

Taking the case that the state = NR (0) in the combined result, that is, the value of the state field is 0000: in this case, the value of the bridged signal should be 1. Therefore, when the bridged signal in the combined result takes a value of 0, the state represented by the combined result is the invalid state of the APS state machine regardless of whether the requested signal in the combined result takes a value of 0 or 1 (i.e., X).

Taking the case that the state = DNR (1) in the combined result, that is, the value of the state field is 0001 as an example: in this case, when the value of the requested signal and the bridged signal in the combination result is both 1, the state indicated by the combination result is the valid state of the APS state machine. Therefore, for the requested signal and the bridged signal in the combined result, when one of the values is 0, the state represented by the combined result is the invalid state of the APS state machine regardless of whether the other value is 0 or 1 (i.e., X).

Taking the case that the state = RR (2) in the combined result, that is, the value of the state field is 0010: in this case, since the RR state does not occur when the APS mode is 1+1 unidirectional non-switchback mode, when the APS mode is 1+1 unidirectional non-switchback mode, the state field value in the combination result is 0010, and the state indicated by the combination result is an invalid state of the APS state machine regardless of whether the value of the requested signal and the bridged signal is 0 or 1 (i.e., X).

Taking the case that the state = EXER (4) in the combined result, that is, the value of the state field is 0100: in this case, since the EXER state occurs only when the APS mode is the bidirectional mode in practical use. Therefore, when the APS mode is 1+1 unidirectional non-cut back mode, the state field in the combined result is 0100, and the state indicated by the combined result is invalid state of the APS state machine regardless of whether the requested signal and the bridged signal are 0 or 1 (i.e., X).

Taking the state = WTR (5) in the combined result, that is, the value of the state field is 0101 as an example: in this case, the WTR state is a state indicating that the network node switches to the protection path due to a failure of the working path when transmitting traffic, and the network node switches back the traffic to the working path again when the failure of the working path is recovered. Therefore, when the APS mode is the 1+1 unidirectional non-switchback mode, the state field in the combined result is 0101, the queued signal and bridged signal in the combined result are 0 or 1 (i.e. X), and the states represented by the combined result are both invalid states of the APS state machine.

Taking the state = SF _ W (11) in the combined result, that is, the value of the state field is 1011 as an example: in this case, the SF _ W status indicates that the working path of the network node transmitting the traffic is faulty, i.e. the network node is currently transmitting the traffic through the protection path. That is, in the SF _ W state, the value of the request signal must be 1 (i.e., there is traffic on the protection path). Therefore, when the value of the request signal in the combination result is 0, the state represented by the combination state is the invalid state of the APS state machine regardless of whether the bridged signal is 0 or 1 (i.e., X). In addition, since traffic should be transmitted on the protection path in the 1+1 mode, the bridged signal value in the 1+1 mode needs to be 1. Therefore, when the value of the bridged signal in the combination result is 0, the state represented by the combination state is the invalid state of the APS state machine regardless of whether the value of the request signal is 0 or 1 (i.e., X).

For the case that the state field in the combination result takes other values, the details are not repeated here.

TABLE 2

Similarly, table 3 shows the invalid state of the APS state machine for which the APS mode is 1+1 unidirectional cut-back mode:

TABLE 3

Similarly, table 4 shows the invalid state of the APS state machine for APS mode being 1+1 bidirectional non-wrapping mode:

TABLE 4

Similarly, table 5 shows the invalid state of the APS state machine for APS mode being 1+1 bidirectional switchback mode:

TABLE 5

Similarly, table 6 shows the invalid states of the APS state machine for which the APS mode is 1:1 bidirectional switchback mode:

TABLE 6

Similarly, table 7 shows the invalid state of the APS state machine for APS mode being 1:1 bidirectional non-wrapping mode:

TABLE 7

Currently, the APS protocol defines the transition rule of the effective state of the APS state machine of the network node running with the APS protocol in different APS modes, so as to implement the automatic protection switching when the network node transmits traffic under various fault scenarios.

Taking the APS mode as 1+1 unidirectional non-switchback mode as an example, the transition rule specified by the APS protocol is shown in table 8:

the second column and the third column in table 8 indicate the active states of the current APS state machines of the network node, and the first column in table 8 is the number of each current active state (e.g., A, C, D, E …). The second row on the right side of the third column in table 8 represents the APS state switching request acquired by the network node. The first row on the right side of the third column in table 8 indicates the number of each APS state switch request (e.g., a, b, c, d, e …). It should be understood that the first, second and third columns in table 8 may be referred to as a horizontal row header and the first and second rows to the right of the third column in table 8 may be referred to as a vertical row header.

Here, the execution priorities of the APS state switching requests with numbers a, b, c, d, and e … are sequentially lower, that is, the APS state switching request with number a has the highest execution priority, and the APS state switching request with number n has the lowest execution priority.

In table 8, "MS _ P" indicates manual switching to the protection path (i.e., the protection path is active and the working path is standby), and "MS _ W" indicates manual switching to the working path (i.e., the working path is active and the protection path is standby). In Table 8, "r" represents a requested signal and "b" represents a bridged signal. "SF _ W restoration" in table 8 indicates that the working path is being restored from the SF state (i.e., work receivers from SF), "SF _ P restoration" indicates that the protection path is being restored from the SF state (i.e., protection receivers from SF), "SD _ W restoration" indicates that the working path is being restored from the SD state (i.e., work receivers from SD), "SD _ P restoration" indicates that the protection path is being restored from the SD state (i.e., protection receivers from SD).

The area shown by the black bold line frame in table 8 indicates the next target state shown by the intersection of the horizontal line and the vertical line, which is obtained by the network node according to the obtained APS state switching request shown by the vertical line header in the current valid state shown by the horizontal line header. Here, the arrowed number, e.g., "→ C", shown at the cross point indicates that the state of the APS state machine of the network node will jump from the currently active state to the state corresponding to the number pointed by the arrow, e.g., the state of "C" (i.e., the APS state where state is LO, r is 0, and b is 1). It can be seen that the state corresponding to the number pointed by the arrow is the next target state obtained by the network node according to the obtained APS state switching request. The "O" shown in the cross point indicates that the current valid state is kept unchanged, or it can be understood that the next target state obtained by the network node according to the obtained APS state switching request is still the current valid state. The "N/A" shown at the cross point indicates that this is not the case.

Referring to table 8, taking the current valid state as the valid state with number E in table 8 (i.e. the APS state with state SF _ W and r and b both having value 1) as an example:

if the APS state switching request acquired by the network node is the APS state switching request (i.e., LO state switching request) numbered a in table 8, it can be seen that the state field in the state of the APS state machine indicated by the APS state switching request numbered a is LO. As can be seen from table 1, the priority of the LO is higher than that of SF _ W, so that the network node changes the state of the APS state machine from the currently active state, which is numbered E, to the state, which is numbered C, of which the state is LO, in response to the APS state switching request. That is, as shown in the intersection "→ C" between the horizontal line where the number E is located and the vertical line where the number a is located in table 8, in the current valid state with the number E, the next target state obtained by the network node according to the APS state switching request with the number a is the state of the APS state machine with the number C pointed by the arrow.

If the APS state switching request acquired by the network node is an APS state switching request numbered c (i.e., an SF _ W state switching request), it can be seen that a state field in the state of the APS state machine indicated by the APS state switching request numbered c is SF _ W. This situation will not usually occur because the state field of the currently active state is SF _ W. That is, as shown in the intersection "N/a" between the horizontal line with the number E and the vertical line with the number c in table 8, in the currently valid state with the number E, the situation that the network node acquires the APS state switching request with the number c does not usually occur.

If the APS state switching request acquired by the network node is an APS state switching request numbered g (i.e., an SD _ W state switching request), it can be seen that a state field in the state of the APS state machine indicated by the APS state switching request numbered g is SD _ W. As can be seen from table 1, the priority of SD _ W is lower than that of SF _ W, so the network node does not respond to the APS state switching request, i.e. the network node keeps the current active state unchanged. That is, as shown in the intersection "O" between the horizontal line with the number E and the vertical line with the number g in table 8, when the network node acquires the APS state switching request with the number g in the current valid state with the number E, the network node keeps the state of the APS state machine with the number E unchanged.

It can be seen that, when the priority of the state indicated by the APS state switching request acquired by the network node is higher than the priority of the state of the current valid state of the APS state machine, the current valid state is transitioned to a state where the state is the state with higher priority indicated by the APS state switching request. And when the priority of the state indicated by the APS state switching request acquired by the network node is lower than the priority of the state in the current effective state, maintaining the current effective state unchanged. Based on this, the transition rules shown in table 8 are not described in detail.

TABLE 8

However, as can be seen from the above, a plurality of invalid states of the APS state machine (invalid states as shown in tables 2 to 7) are included in each APS mode. When the current state of the APS state machine of a network node running an APS protocol is an invalid state due to a hardware or software failure of the network node, the network node cannot jump out of the invalid state based on the transition rule shown in table 8, so that an APS state machine of the network node hangs up, that is, the APS function of the network node is damaged, and thus, the traffic flow transmitted by the network node is damaged.

Based on this, the embodiment of the present application provides a transition method for an APS state machine, based on which a network node running an APS protocol can quickly transition from an invalid state to an valid state in a current APS mode when the current state of the APS state machine is an invalid state, that is, the network node is quickly tripped out of the invalid state of the APS state machine, thereby avoiding a phenomenon that the APS state machine is hung up at the network node, and further ensuring that the network node can normally transmit traffic.

The APS protocol may be an ethernet APS protocol or a Multi Protocol Label Switching (MPLS) APS protocol, which is not limited herein.

The embodiment of the present application further provides a communication device, where the communication device is configured to execute the transition method of the APS state machine, and the communication device may be any network node running the APS protocol on a traffic transmission path, or a functional component of the network node (for example, a board, a line card, a chip, and the like, which is not limited thereto). The network node may be, for example, a general-purpose computer, a routing device, or the like, or may also be a server, which is not specifically limited in this application embodiment.

Referring to fig. 1, fig. 1 shows a hardware structure diagram of a communication apparatus provided in an embodiment of the present application. As shown in fig. 1, the communication device 10 operates with the APS protocol, and the communication device 10 may include a processor 11, a main memory (main memory) 12, a storage medium 13, a communication interface 14, and a bus 15. The processor 11, the main memory 12, the storage medium 13, and the communication interface 14 may be connected by a bus 15.

The processor 11 is a control center of the communication device 10, and may be a Central Processing Unit (CPU), and the processor 11 may also be other general-purpose processors, digital Signal Processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, graphics Processing Units (GPUs), neural Network Processing Units (NPUs), tensor Processing Units (TPUs), or artificial intelligence (artificial intelligence) chips. As one example, processor 11 may include one or more CPUs, such as CPU 0 and CPU 1 shown in FIG. 1. In addition, the number of processor cores in each processor is not limited in the present application.

The main memory 12 is used for storing program instructions, and the processor 11 may implement the transition method of the APS state machine provided by the embodiment of the present application by executing the program instructions in the main memory 12.

In one possible implementation, the main memory 12 may exist independently of the processor 11. Main memory 12 may be coupled to processor 11 via bus 15 for storing data, instructions, or program code. The processor 11 can implement the transition method of the APS state machine provided by the embodiment of the present application when calling and executing the instructions or program codes stored in the main memory 12.

In another possible implementation, the main memory 12 may also be integrated with the processor 11.

The storage medium 13 may be either volatile memory or nonvolatile memory, or may include both volatile and nonvolatile memory. The volatile memory may be a read-only memory (ROM), a Programmable ROM (PROM), an Erasable PROM (EPROM), an electrically Erasable EPROM (EEPROM), or a flash memory. Volatile memory can be Random Access Memory (RAM), which acts as external cache memory. By way of example, and not limitation, many forms of RAM are available, such as static random access memory (static RAM, SRAM), dynamic Random Access Memory (DRAM), synchronous Dynamic Random Access Memory (SDRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), enhanced synchronous SDRAM (ESDRAM), synchronous Link DRAM (SLDRAM), and direct rambus RAM (DR RAM). The nonvolatile memory includes: storage Class Memory (SCM), solid State Drive (SSD), hard Disk Drive (HDD), and the like. The storage level memory may be, for example, a non-volatile memory (NVM), a phase-change memory (PCM), an access memory (AEP), or the like.

A communication interface 14, configured to connect the communication apparatus 10 with another device (e.g., an opposite-end device) through a communication network, where the communication network may be an ethernet network, a Radio Access Network (RAN), a Wireless Local Area Network (WLAN), or the like. The communication interface 14 may comprise a receiving unit for receiving data/messages and a transmitting unit for transmitting data/messages.

The bus 15 may be an Industry Standard Architecture (ISA) bus, a peripheral component interconnect express (PCIe), a compute express link (CXL), a Peripheral Component Interconnect (PCI) bus, an Extended ISA (EISA) bus, or the like. The bus may be divided into an address bus, a data bus, a control bus, etc. For ease of illustration, only one thick line is shown in FIG. 1, but it is not intended that there be only one bus or one type of bus.

It should be noted that the configuration shown in fig. 1 is not intended to limit the communication device 10, and that the communication device 10 may include more or less components than those shown in fig. 1, or some components may be combined, or a different arrangement of components than those shown in fig. 1, in addition to those shown in fig. 1.

The embodiment of the present application further provides a network architecture, where when traffic is transmitted between two network nodes in the network architecture, at least two communication paths for transmitting the traffic are included. One of the at least two communication paths for transmitting traffic may be used as a working path, and a communication path other than the working path among the at least two communication paths for transmitting traffic may be used as a protection path.

It should be noted that at least one of the two network nodes may be operated with the APS protocol. The communication apparatus shown in fig. 1 may be a network node operating an APS protocol in the two network nodes, or may be a functional component of a network node operating an APS protocol in the two network nodes, which is not limited in this respect.

As shown in fig. 2, fig. 2 is a schematic diagram illustrating a network structure 20 according to an embodiment of the present disclosure. The network architecture 20 includes 5 network nodes for transmitting traffic, which are a network node 21, a network node 22, a network node 23, a network node 24, and a network node 25. Two communication paths exist between the network node 21 and the network node 25, which are respectively a path 1: network node 21-network node 22-network node 25, and route 2: network node 21-network node 23-network node 24-network node 25. Where path 1 may be a working path for transporting traffic between network node 21 and network node 25, and path 2 may be a protection path for transporting traffic between network node 21 and network node 25.

Wherein at least one of network node 21 and network node 25 may operate with the APS protocol. The communication device shown in fig. 1 may be a network node operating an APS protocol in the network node 21 and the network node 25, or may be a functional component of a network node operating an APS protocol in the network node 21 and the network node 25, which is not limited thereto.

The transition method of the APS state machine according to the embodiment of the present application will be described below with reference to the accompanying drawings.

Referring to fig. 3, fig. 3 is a flowchart illustrating a transition method of an APS state machine according to an embodiment of the present application, where the method may be performed by the communication device shown in fig. 1. The method may comprise the steps of:

s101, the first communication device determines that the state of the APS state machine is a first state, and the first state is an invalid state in the current APS mode.

Specifically, the first communication device may determine that the current state of the APS state machine is the first state in the current APS mode based on values of fields in the current state of the APS state machine and the invalid states of the APS state machine summarized in tables 2 to 7.

It should be understood that the first communication device may be pre-provisioned with a set of APS state machine invalid states as shown in tables 2-7. Alternatively, the first communication apparatus may connect to communicate with a device in which the APS state machine invalid state set shown in tables 2 to 7 is preset, so that the first communication apparatus can determine that the current state of the APS state machine is an invalid state in the current APS mode by communicating with the device.

For detailed descriptions of the invalid state of the APS state machine and the APS mode, reference may be made to the above description, which is not described herein again.

S102 (optional), the first communication device determines the APS state switching request.

Specifically, the first communication device determines an APS state switching request of a current preset period. The preset period refers to a period in which the first communication device periodically updates the state of the APS state machine. The current APS protocol provides for this preset period to be 3.3ms.

The APS state switching request of the current preset period determined by the first communication device is the state switching request with the highest execution priority in at least one APS state switching request acquired by the first communication device in the preset period. Here, the execution priority of the at least one APS state switching request may refer to the description of the execution priority of the APS state switching request shown in table 8, which is not described herein again.

The at least one APS state switching request includes an APS state switching request issued by a control layer of the first communication device, an APS state switching request generated by the first communication device according to a detected state of a communication link (including a working path and a protection path), and at least one APS state switching request in the APS state switching requests carried in an APS message sent by the second communication device to the first communication device.

Optionally, the first communication device detects the state of the communication link, for example, the state of the communication link may be detected by an operation, administration and maintenance (OAM) technology of the ethernet, which is not limited in this embodiment of the present application.

For example, as shown in table 8, the APS state switching request issued by the control layer of the first communication device may be at least one of an "LO" state switching request with a number a, an "FC" state switching request with a number b, an "MS _ P" state switching request with a number k, an "MS _ W" state switching request with a number l, an "clear" state switching request with a number m, or an "EXER" state switching request with a number n.

Further exemplarily, as shown in table 8, the APS state switching request generated by the first communication device according to the detected state of the communication link and the APS state switching request carried in the APS message sent by the second communication device and received by the first communication device may be, for example, at least one of an "SF _ W" state switching request numbered e, an "SF _ W recovery" state switching request numbered d, an "SF _ P" state switching request numbered e, an "SF _ P recovery" state switching request numbered f, an "SD _ W" state switching request numbered g, an "SD _ W recovery" state switching request numbered h, an "SD _ P" state switching request numbered i, and an "SD _ P recovery" state switching request numbered j.

In a possible implementation manner, the first communication device may determine, as the APS state switching request in the current preset period, the state switching request having the highest execution priority in the at least one APS state switching request acquired in the current preset period.

In another possible implementation manner, when the first communication device does not acquire any APS state switching request in the current preset period, the first communication device may determine, as the APS state switching request in the current preset period, the APS state switching request determined by the preset period that is before the current preset period and closest to the current preset period.

S103, the first communication device changes the state of the APS state machine from the first state to the second state, where the second state is an active state in the current APS mode.

Specifically, the first communication device may transition the state of the APS state machine from the first state to the second state when the preset period comes. That is to say, with the method provided in the embodiment of the present application, the first communication device can implement that the APS state machine jumps out of the invalid state at most 3.3ms, thereby avoiding the phenomenon that the APS state machine is hung up by the first communication device, and further ensuring that the first communication device can normally transmit the traffic.

In one possible implementation, the second state may be a preset valid state of the APS state machine in the current APS mode, and the preset valid state may be any valid state of the APS state machine in the current APS mode.

For example, in connection with table 1, the preset valid state may be a valid state including a state field having the lowest priority (i.e., the state is NR), i.e., the preset valid state may be a valid state in which the state field is NR.

It can be seen that in this case, as long as the first communication device determines that the current state of the APS state machine is an invalid state (i.e., a first state), the first communication device can directly transition the state of the APS state machine from the first state to the preset valid state (i.e., a second state) upon arrival of the current preset period.

Taking the preset valid state as the valid state with the state field NR (for example, the state numbered a in table 8) as an example, when the first communication device determines that the current state of the APS state machine is the first state (for example, any one of the invalid states shown in table 2), the first communication device may directly transition the state of the APS state machine from the first state to the state numbered a in table 8 when the current preset period arrives.

In this case, taking the current APS mode as 1+1 unidirectional non-switchback mode and the preset valid state as the valid state with the state field NR (i.e., the state numbered a in table 8) as an example, table 9 shows transition rules for the first communication device to make a state transition when the current state of the APS state machine is invalid when every preset period arrives, in combination with table 2 and table 8, as shown in table 9, table 9 shows 1+1 unidirectional non-switchback mode.

It can be seen that when the first communication device determines that the current state of the APS state machine is an invalid state, such as the invalid state shown in any one of columns 1-3 of table 9, at the time the current preset period arrives, the first communication device can directly transition the state of the APS state machine from the current invalid state to the preset valid state numbered a in table 8 (as shown by → a in the area of the black bold line in table 10).

It is to be understood that the invalid states shown in columns 1-3 of Table 9 are invalid states in Table 2.

TABLE 9

In another possible implementation manner, the second state may be a valid state of the APS state machine indicated by the APS state switching request determined by the first communication device at S102.

It should be understood that, as shown in table 8, the LO state switch request with number a indicates that the valid state of the APS state machine is the valid state with number C. And b, the FS state switching request indicates that the valid state of the APS state machine is the valid state D. And c, indicating that the valid state of the APS state machine is the valid state of the number E. SF _ P state switch request, numbered e, indicates that the valid state of APS state machine is valid state numbered F. And g, the SD _ W state switching request indicates that the valid state of the APS state machine is the valid state of P. And the SD _ P state switching request with the number i indicates that the valid state of the APS state machine is the valid state with the number Q. And the MS _ P state switching request with the number k indicates that the valid state of the APS state machine is the valid state with the number G. And the MS _ W state switching request with the number l indicates that the valid state of the APS state machine is the valid state with the number H.

Optionally, as shown in table 8, the SF _ W recovery state switching request with the number d, the SF _ P recovery state switching request with the number f, the SD _ W recovery state switching request with the number h, the SD _ P recovery state switching request with the number j, the clear state switching request with the number m, and the EXER state switching request with the number n may set the valid state of the APS state machine indicated by the request to be the valid state with the number a, which is not limited to this.

In this way, taking the example that the APS state switching request determined by the first communication device in S102 is the "SF _ W" state switching request with the number E shown in table 8, when the current preset period arrives, the first communication device may transition the invalid state (i.e., the first state) of the APS state machine to the valid state (i.e., the second state) with the number E in table 8.

Taking the example that the current APS mode is 1+1 unidirectional non-switchback mode, in combination with table 2 and table 8, as shown in table 10, table 10 shows a transition rule for performing state transition on the current invalid state of the APS state machine based on the APS state switching request determined in each preset period when the first communication device arrives at each preset period in 1+1 unidirectional non-switchback mode.

It can be seen that, when the current preset period arrives, when the first communication device determines that the current state of the APS state machine is an invalid state, for example, an invalid state shown in any one of rows 1 to 3 in table 9, the first communication device transitions the APS state machine from the current invalid state to a valid state indicated by the APS switching request shown in rows 2 to 3 on the right side of the third column in table 10 (e.g., a valid state corresponding to the number pointed by the arrow in the black bold line area in table 10).

It will be appreciated that the invalid states shown in columns 1-3 of Table 10 are the invalid states shown in Table 2. The numbers indicated by the arrows in the black bold line regions in table 10 are the numbers of the valid states in table 8.

Watch 10

In this way, the first communication device can quickly jump out of the invalid state of the APS state machine based on the transition rule as shown in table 9 or table 10.

In summary, the present application provides a transition method of an APS state machine, which defines a transition rule of an invalid state of the APS state machine, so that when a current state of the APS state machine of a first communication device is an invalid state, the first communication device can quickly jump out from the current invalid state (for example, an update period of the state of the APS state machine specified by a protocol and having a duration of 3.3 ms), thereby avoiding an APS state machine hang-up phenomenon occurring in the first communication device, and further ensuring that the first communication device can normally transmit traffic.

The scheme provided by the embodiment of the application is mainly introduced from the perspective of a method. To implement the above functions, it includes hardware structures and/or software modules for performing the respective functions. Those of skill in the art would readily appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as hardware or combinations of hardware and computer software. Whether a function is performed as hardware or computer software drives hardware depends upon the particular application and design constraints imposed on the solution. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present application.

In the embodiment of the present application, the communication apparatus may be divided into the functional modules according to the method example, for example, each functional module may be divided according to each function, or two or more functions may be integrated into one processing module. The integrated module can be realized in a hardware mode, and can also be realized in a software functional module mode. It should be noted that, in the embodiment of the present application, the division of the module is schematic, and is only one logic function division, and there may be another division manner in actual implementation.

As shown in fig. 4, fig. 4 is a schematic structural diagram of a communication device 40 according to an embodiment of the present application. The communication device 40 may be used to perform the above-described transition method of the APS state machine, such as for performing the method shown in fig. 3. The communication device 40 may include a determination unit 41 and a transition unit 42.

A determining unit 41, configured to determine that the state of the APS state machine is the first state. And a transition unit 42, configured to transition the state of the APS state machine from the first state to the second state. Wherein the first state is an invalid state in the current APS mode and the second state is an valid state in the current APS mode.

As an example, in conjunction with fig. 3, the determination unit 41 may be configured to perform S101, and the transition unit 42 may be configured to perform S103.

Optionally, the second state is a state indicated by the APS state switching request.

Optionally, the APS state switching request is an APS state switching request with the highest execution priority in at least one APS state switching request received by the communication device 40. The at least one APS state switching request includes at least one of an APS state switching request issued by a control layer of the communication device 40, an APS state switching request generated by the communication device 40 according to the detected state of the communication link, and an APS state switching request carried in an APS message received by the communication device 40.

Optionally, the determining unit 41 is specifically configured to determine, according to a value of a field used for indicating a state of the APS state machine, that the state of the APS state machine is the first state.

As an example, in connection with fig. 3, the determining unit 41 may be configured to perform S101.

Optionally, the APS modes include 1+1 unidirectional cut back mode, 1+1 unidirectional non-cut back mode, 1+1 bidirectional cut back mode, 1+1 bidirectional non-cut back mode, 1:1 bidirectional cut back mode, and 1:1 bidirectional non-cut back mode.

Optionally, when the APS mode is 1+1 unidirectional non-loopback mode and the second state is a protection locked LO state indicated by the APS state switching request, the transition unit 42 is specifically configured to transition the state of the APS state machine from the first state to the LO state.

As an example, in connection with fig. 3, the transition unit 42 may be configured to perform S103.

Optionally, when the APS mode is 1+1 bidirectional non-switchback mode, and the second state is an SF _ W state in which the working path indicated by the APS state switching request fails, the transition unit 42 is specifically configured to transition the state of the APS state machine from the first state to the SF _ W state.

As an example, in connection with fig. 3, the transition unit 42 may be configured to perform S103.

Optionally, when the APS mode is 1+1 bidirectional non-switchback mode and the second state is an NR state indicated by the APS state switch request, the transition unit 42 is specifically configured to transition the state of the APS state machine from the first state to the NR state.

As an example, in connection with fig. 3, the transition unit 42 may be configured to perform S103.

For the detailed description of the above alternative modes, reference may be made to the foregoing method embodiments, which are not described herein again. In addition, for any explanation and beneficial effect description of the communication device 40 provided above, reference may be made to the corresponding method embodiment described above, and details are not repeated.

As an example, in connection with fig. 1, the functions implemented by the determining unit 41 and the transition unit 42 in the communication device 40 may be implemented by the processor 11 in fig. 1 executing the program code in the main memory 12 in fig. 1.

Fig. 5 illustrates a schematic structural diagram of a signal bearing medium for bearing a computer program product, which is provided by the embodiment of the present application, the signal bearing medium is used for storing the computer program product or storing a computer program for executing a computer process on a computing device.

As shown in fig. 5, signal bearing medium 50 may include one or more program instructions that, when executed by one or more processors, may provide the functions or portions of the functions described above with respect to fig. 3. Thus, for example, one or more features described with reference to S101-S103 of FIG. 3 may be undertaken by one or more instructions associated with the signal bearing medium 50. Further, the program instructions in FIG. 5 also describe example instructions.

In some examples, signal bearing medium 50 may comprise a computer readable medium 51, such as, but not limited to, a hard disk drive, a Compact Disc (CD), a Digital Video Disc (DVD), a digital tape, a memory, a read-only memory (ROM), a Random Access Memory (RAM), or the like.

In some embodiments, the signal bearing medium 50 may comprise a computer recordable medium 52 such as, but not limited to, memory, read/write (R/W) CDs, R/W DVDs, and the like.

In some implementations, the signal bearing medium 50 may include a communication medium 53, such as, but not limited to, a digital and/or analog communication medium (e.g., a fiber optic cable, a waveguide, a wired communications link, a wireless communication link, etc.).

The signal bearing medium 50 may be conveyed by a wireless form of communication medium 53, such as a wireless communication medium conforming to the IEEE 1902.11 standard or other transport protocol. The one or more program instructions may be, for example, computer-executable instructions or logic-implementing instructions.

In some examples, a communication device such as that described with respect to fig. 3 may be configured to provide various operations, functions, or actions in response to being programmed by one or more of computer readable medium 51, computer recordable medium 52, and/or communication medium 53.

It should be understood that the arrangements described herein are for illustrative purposes only. Thus, those skilled in the art will appreciate that other arrangements and other elements (e.g., machines, interfaces, functions, orders, and groupings of functions, etc.) can be used instead, and that some elements may be omitted altogether depending upon the desired results. In addition, many of the described elements are functional entities that may be implemented as discrete or distributed components or in conjunction with other components, in any suitable combination and location.

In the above embodiments, the implementation may be wholly or partially realized by software, hardware, firmware, or any combination thereof. When implemented using a software program, may be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. The processes or functions according to the embodiments of the present application are generated in whole or in part when the instructions are executed on and by a computer. The computer may be a general purpose computer, a special purpose computer, a network of computers, or other programmable device. The computer instructions may be stored on a computer readable storage medium or transmitted from one computer readable storage medium to another computer readable storage medium, for example, the computer instructions may be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wire (e.g., coaxial cable, fiber optic, digital Subscriber Line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.). Computer-readable storage media can be any available media that can be accessed by a computer or can comprise one or more data storage devices, such as servers, data centers, and the like, that can be integrated with the media. The usable medium may be a magnetic medium (e.g., a floppy disk, a hard disk, a magnetic tape), an optical medium (e.g., a DVD), or a semiconductor medium (e.g., a Solid State Disk (SSD)), among others.

In some embodiments, the methods disclosed in embodiments of the present application may be implemented as computer program instructions encoded on a computer-readable storage medium in a machine-readable format or encoded on other non-transitory media or articles of manufacture.

The above description is only for the specific embodiments of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present invention, and all the changes or substitutions should be covered within the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims (19)

1. A method for transition of an automatic protection switching, APS, state machine, the method performed by a first communication device, the method comprising:

determining that the state of an APS state machine is a first state, wherein the first state is an invalid state in a current APS mode;

transitioning the APS state machine from the first state to a second state, the second state being an active state in the APS mode.

2. The method of claim 1,

the second state is the state indicated by the APS state switching request.

3. The method according to claim 2, wherein the APS state switching request is an APS state switching request with the highest execution priority among the at least one APS state switching request received by the first communications device;

the at least one APS state switching request includes at least one of an APS state switching request issued by the first communication device control layer, an APS state switching request generated by the first communication device according to the detected state of the communication link, and an APS state switching request carried in an APS message sent by the second communication device to the first communication device.

4. The method of any of claims 1-3, wherein determining the state of the APS state machine as the first state comprises:

and determining that the state of the APS state machine is a first state according to the value of the field for indicating the state of the APS state machine.

5. The method of any of claims 1-4, wherein the APS modes comprise 1+1 unidirectional switchback mode, 1+1 unidirectional non-switchback mode, 1+1 bidirectional switchback mode, 1+1 bidirectional non-switchback mode, 1:1 bidirectional switchback mode, and 1:1 bidirectional non-switchback mode.

6. The method of claim 5, wherein when the APS mode is the 1+1 unidirectional non-switchback mode and the second state is a protection locked LO state indicated by the APS state switch request, the transitioning the APS state machine from the first state to a second state comprises:

transitioning the APS state machine from the first state to the LO state.

7. The method of claim 5 or 6, wherein when the APS mode is the 1+1 bidirectional non-rollback mode and the second state is a working path failure (SF _ W) state indicated by the APS state switch request, the transitioning the APS state machine from the first state to the second state comprises:

transitioning the APS state machine from the first state to the SF _ W state.

8. The method of any of claims 5-7, wherein when the APS mode is the 1+1 bidirectional non-switchback mode and the second state is a No Request (NR) state indicated by the APS state switch request, the transitioning the APS state machine from the first state to the second state comprises:

transitioning the APS state machine from the first state to the NR state.

9. A communications apparatus, comprising:

the determining unit is used for determining that the state of the APS state machine is a first state, and the first state is an invalid state in the current APS mode;

a transition unit to transition the APS state machine from the first state to a second state, the second state being an active state in the APS mode.

10. The apparatus according to claim 9, wherein the second state is a state indicated by an APS state switching request.

11. The communication device according to claim 10, wherein the APS state switching request is an APS state switching request with the highest execution priority among the at least one APS state switching request received by the communication device;

the at least one APS state switching request includes at least one of an APS state switching request issued by the control layer of the communication device, an APS state switching request generated by the communication device according to the detected state of the communication link, and an APS state switching request carried in an APS message received by the communication device.

12. The communication device according to any of claims 9-11,

the determining unit is specifically configured to determine, according to a value of a field indicating a state of the APS state machine, that the state of the APS state machine is the first state.

13. The communication device of any of claims 9-12, wherein the APS modes comprise 1+1 unidirectional switchback mode, 1+1 unidirectional non-switchback mode, 1+1 bidirectional switchback mode, 1+1 bidirectional non-switchback mode, 1:1 bidirectional switchback mode, and 1:1 bidirectional non-switchback mode.

14. The communication apparatus according to claim 13, wherein when the APS mode is the 1+1 unidirectional non-switchback mode, the second state is a protection lock LO state indicated by the APS state switch request;

the transition unit is specifically configured to transition the APS state machine from the first state to the LO state.

15. The communication apparatus according to claim 13 or 14, wherein when the APS mode is the 1+1 bidirectional non-switchback mode, the second state is a working path failure SF _ W state indicated by the APS state switch request;

the transition unit is specifically configured to transition the APS state machine from the first state to the SF _ W state.

16. A communication device according to any of claims 13-15, wherein when the APS mode is the 1+1 bidirectional non-switchback mode, the second state is the no request NR state indicated by the APS state switch request;

the transition unit is specifically configured to transition the APS state machine from the first state to the NR state.

17. A communications apparatus, comprising:

a memory storing program instructions;

at least one processor configured to execute the program instructions to cause the communication device to perform the method of any of claims 1-8.

18. A computer-readable storage medium, characterized in that the computer-readable storage medium comprises program instructions, which, when run on a computer or a processor, cause the computer or the processor to carry out the method of any one of claims 1-8.

19. A computer program product, characterized in that it comprises a program which, when executed by a processor, carries out the method of any one of claims 1-8.

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