Online reconfiguration method for time-sensitive network

Abstract

The invention discloses an on-line reconfiguration method for a time-sensitive network, and the method comprises the following steps: S1, abstracting a network topology to form a directed graph; s2, determining the update time of each link according to a given shutdown time and an old traffic transmission scheme, and taking the update time as a new reference time to carry out traffic inheritance; s3, incremental scheduling is carried out, a deterministic constraint condition is established according to a scheduled transmission scheme and a current traffic attribute, and the transmission starting time is calculated by adopting network calculation; s4, after all traffic scheduling is completed, if all traffic scheduling is not completed, returning to S3; and S5, generating a GCL according to the new scheduling scheme, generating a configuration file through configuration software, and issuing the configuration file to a switch and a terminal to wait for taking effect. According to the method, the deterministic requirements of network consistency and low packet loss in a reconfiguration period can be ensured, and extremely low response time of the mechanism is selected and ensured at the earliest updating moment, so that the low-delay deterministic requirement of flow transmission is ensured; and the deterministic transmission requirement of low traffic packet loss can be ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of network data processing, and in particular to an online reconfiguration method for a time-sensitive network. Background Art

[0002] With the rapid development of the Industrial Internet of Things, industrial production lines are gradually transforming from large-scale production to customized flexible production lines. In flexible production lines, the frequent information interaction between different production equipment and the coordination requirements of the operation procedures put forward deterministic transmission requirements including low latency, low jitter, and low packet loss rate for the on-site communication network, while the traditional industrial Ethernet cannot meet this requirement due to its "best effort" service characteristics. To this end, the IEEE 802.1TSN working group proposed the Time-Sensitive Networking (TSN) technology and formulated a series of sub-standards as the basis for deterministic transmission of traffic. Among them, IEEE 802.1Qbv defines a programmable gating mechanism - Time-Aware Shaper (TAS), which uses traffic gates and gate control lists (GCL) to control the transmission of traffic in the switch port cache queue; IEEE 802.1Qcc provides a configuration model for the deployment of TSN on-end devices and switches; IEEE 802.1AS-Rev provides a basis for clock synchronization for the deployment of equipment and the forwarding of traffic on switches. At the same time, the network changes such as equipment increase and decrease, topology changes, task traffic changes caused by the constantly changing production demands in the flexible production line put forward higher requirements on the real-time reconfiguration capability of the TSN network. TSN network reconfiguration is the process of network equipment switching from the old transmission scheme to the new transmission scheme: at the downtime when the network receives the new traffic demand, all end devices stop generating old traffic. At this time, the old traffic that has been sent, that is, the legacy traffic, continues to be transmitted according to the old scheme; according to the new attributes of the traffic, the transmission time at each switch node is calculated and the corresponding new GCL configuration scheme is obtained. The time point when the overall solution is solved is the time when the new scheme is generated; finally, the GCL scheme is sent and deployed to the equipment, and each node generates and transmits new traffic according to the new configuration after the update time. Therefore, how to achieve real-time reconfiguration of the TSN network under the premise of ensuring the deterministic transmission requirements of traffic is a very challenging problem.

[0003] To solve the TSN network reconfiguration problem, two-stage reconfiguration method, sequential reconfiguration method and conflict-free constraint solving method are currently used. The first two methods focus on designing the network reconfiguration mechanism to calculate the update time, while the conflict-free constraint solving method focuses on designing the solution algorithm for the network transmission scheme after reconfiguration. Specifically, the two-stage reconfiguration method seeks the update time when the network transitions from the old state to the new state globally, but ignores the problem that the legacy traffic at the update time causes conflicts between the new and old traffic transmission schemes in the network, thereby destroying the consistency of the network reconfiguration; in order to solve the consistency problem, the sequential update method sets the network update time to the time when all old traffic transmissions are completed, thereby avoiding conflicts between legacy traffic and new traffic, but this introduces a long waiting time for the injection of new traffic, destroying the real-time nature of the reconfiguration; the conflict-free constraint solving method, under the premise of considering the coexistence of new and old traffic in the network, models the conflict-free problem between the unknown new transmission scheme and the known old transmission scheme as an integer linear programming (ILP) problem, and uses the ILP solver to obtain the new transmission scheme, but the extremely high time complexity of the solving algorithm causes a delay in the deployment of the new scheme, resulting in a large number of frame losses during the reconfiguration period, making it difficult to guarantee the deterministic requirements of the traffic.

[0004] In the prior art, the patent application number is: CN202110750997.2, and the name is: A traffic shaper token update system and method for a time-sensitive network. The specific method is: a token bucket update system is configured for the traffic shaper of the switch port cache queue. When the cache queue is empty, the number of tokens in the corresponding queue token bucket is configured and the queue is added to the empty queue pool until a new message arrives at the queue and the token bucket is updated; when the cache queue is not empty, the system updates the number of tokens in the token bucket of the relevant cache queue when the message stored in the cache queue is scheduled until the scheduling is completed. However, this method only involves the update method of the receiving port when the traffic transmission message arrives at the switch. It does not consider the network reconfiguration time node and the design of the traffic transmission plan after reconfiguration when the network parameters such as topology, routing, and traffic change. It cannot guarantee the real-time nature of network reconfiguration and the deterministic transmission of traffic in the network; the patent application number is: CN202310917826.3, and the name is: TSN device reconfiguration method. The specific method is: when a new TSN device is connected, the new topology structure and business flow requirements are determined by obtaining the old TSN device adjacency table and business controller traffic information, and then the GCL is generated based on the scheduling period, time slot frame length, sending order, and protection band, and the YANG model and NETCONFIG protocol are used to implement configuration distribution. However, this distributed configuration method simply establishes the configuration process, and does not involve the design of the specific update time, the configuration effective time, and the detailed design of the GCL of each port. It cannot guarantee the consistency of reconfiguration and the deterministic transmission requirements of the traffic after reconfiguration; the patent application number is: 202210184833.2, and the name is: A network configuration management method for TSN switches. The specific approach is: when a new TSN device is connected, the new device is discovered through broadcasting and the new global topology and traffic information are obtained. The central controller uses the traffic information to realize joint optimization of routing scheduling, determine the transmission path and GCL of each traffic, and send them to the switch. However, this method does not consider the conflict between new traffic and legacy traffic during network reconfiguration. At the same time, the GCL generation scheme does not consider the frame isolation of data frames from different traffic in terms of transmission time, resulting in conflicts in the transmission of different data frames, and the deterministic transmission requirements of traffic during reconfiguration cannot be guaranteed; the patent application number is: CN201810661209.0, and the name is: Virtual network reconfiguration method based on taboo search for SDN. The specific approach is: for the virtual network update problem with congested nodes, according to the network node priority, the taboo search algorithm is used to determine the mapping of virtual nodes to physical nodes after the network update according to the remaining CPU resources. However, this method only establishes a mapping scheme for updated nodes, without considering the updated traffic transmission path and the configuration of the GCL of each node, and cannot guarantee the deterministic requirements of updated traffic transmission.

[0005] Therefore, how to design a reconfiguration mechanism to ensure the consistency and real-time performance of the network during the reconfiguration process, and design relevant reconfiguration algorithms based on this mechanism to obtain the transmission plan after network reconfiguration at a lower time cost to ensure the certainty of traffic transmission, is an urgent problem to be solved. Technical personnel in this field are committed to developing an online reconfiguration method for time-sensitive networks. Summary of the invention

[0006] In view of the above-mentioned defects of the prior art, the technical problems to be solved by the present invention are:

[0007] In the time-sensitive network, there is a lack of a reconfiguration mechanism that can guarantee network consistency and real-time performance. The lack of consistency guarantee causes conflicts between the newly registered traffic and the legacy traffic in the network when the time-sensitive network is reconfigured, causing data frame loss in the switching node or introducing extremely high queuing waiting delays, which cannot meet the low-latency and low-packet-loss requirements of the traffic. The lack of real-time performance causes extremely high waiting time when the traffic is injected into the network, which cannot guarantee the low-latency requirements of traffic transmission.

[0008] In time-sensitive networks, there is a lack of efficient and fast transmission solution algorithms that can ensure the determinism of traffic transmission after reconfiguration. The extremely high time complexity of the existing solution algorithms results in the reconfiguration calculation time from the downtime to the new solution generation time being much longer than the downtime response time. The new transmission solution cannot be issued and deployed at the update time, resulting in a large number of data frames being lost after the new traffic starts to be injected at the update time, which destroys the deterministic transmission requirement of low traffic loss.

[0009] To achieve the above object, the present invention provides an online reconfiguration method for a time-sensitive network, the method comprising the following steps:

[0010] S1: abstract the network topology of the terminal devices, switches and links in the network to form a directed graph;

[0011] S2: Determine the link update time of each switch according to the downtime time given by the system and the old traffic transmission plan, use this as the new reference time, and perform traffic inheritance according to the reference time;

[0012] S3: Incremental scheduling, establishes deterministic constraints based on the scheduled transmission scheme and current traffic attributes, and uses network calculation to calculate the start transmission time;

[0013] S4: According to the determined scheduling order of the incremental algorithm, until all traffic scheduling is completed, if not completed, return to step S3;

[0014] S5: Generate GCL according to the new scheduling plan, and generate a configuration file through the configuration software and send it to the switch and terminal to wait for it to take effect;

[0015] Furthermore, the terminal device and the switch in step S1 are abstracted as nodes, and the link is abstracted as a directed edge;

[0016] Further, the difference between the downtime time described in step S2 and the update time is the current link downtime response time;

[0017] Furthermore, the update time is expressed by the following formula:

[0018] First, the old transmission scheme is used to calculate the traffic frame sequence numbers left in the network after the downtime ρ of different switch links takes effect, that is, the frames that have been sent from the source node but have not yet reached the destination node, which specifically satisfy the following formula:

[0019]

[0020] Where F represents the flow set, Indicates flow rate f i At the injection time of the source node, Indicates the current flow rate f i The last frame number left in the network after the downtime takes effect;

[0021] Link V1-V 00 There is the first frame of the legacy flow f1, and no subsequent link needs to wait for the frame to be transmitted. Then the update time of each switch link that the frame passes through is obtained:

[0022]

[0023] Where ε represents the link set, Represents the current link τ k Update time, l i Indicates the traffic frame length, and B indicates bandwidth;

[0024] Furthermore, the scheme inheritance of the traffic in step S2 is expressed by the following formula:

[0025]

[0026] In the formula, R i Indicates flow rate f i The set of links passed through;

[0027] It also includes calculating the network reconfiguration super period according to the traffic cycle information. The super period is represented by C, which is obtained by the least common multiple of all traffic cycles, that is:

[0028] C=LCM(p i );

[0029] Further, the deterministic constraints in step S3 include a deadline constraint, a frame sequence constraint and a frame isolation constraint;

[0030] The deadline constraint is that the end-to-end delay of each traffic frame from the source node to the destination node should not exceed the maximum allowed delay, which is expressed by the formula:

[0031]

[0032] In the formula, Indicates the start transmission time on the last hop link;

[0033] The frame sequence constraint is that the transmission time of the same data frame on the previous switch link should be less than the transmission time on the next switch link, which is expressed by the formula:

[0034]

[0035] In the formula, H i Indicates the total number of links that the current traffic passes through. Indicates that the source node sends a link, Indicates that traffic is on the link The start time of transmission;

[0036] The frame isolation constraint is that the frames of any two flows do not overlap in the transmission interval of the same link, which is expressed by the formula:

[0037]

[0038] Where C represents the super period, which is obtained by the lowest common divisor of all traffic periods, that is, C = LCM (p i );

[0039] Furthermore, the scheduling order of the incremental algorithm is sorted according to the traffic cycle and deadline information:

[0040] First, sort by cycle, that is, for flow f i and f i+1 ;

[0041] If p i >p i+1 , then the flow f i Sort in stream f i+1 Before, if f i <f i+1 , then the flow f i Sort in stream f i+1 after;

[0042] If p i =p i+1, then sort by deadline, if d i <d i+1 , then the flow f i Sort in stream f i+1 Before, if d i >d i+1 , then the flow f i Sort in stream f i+1 after;

[0043] If d i =d i+1 , then manually determine the sorting results according to actual needs;

[0044] Furthermore, the incremental scheduling in step S3 is to calculate the transmission scheme of the new traffic that is not inherited in an incremental solution manner, flow by flow and link by link, according to the constraint conditions and the sorting result;

[0045] Furthermore, in one round of incremental scheduling, all links from the source node to the destination node are traversed, and the switch residual service curve and link cumulative service curve are established for the current link, and the worst delay is calculated using the network calculation method and used as the start transmission time of the next link. The switch residual service curve is expressed by the formula as follows:

[0046]

[0047] In the formula, represents the link τ at time t k The arrival curve, represents the link τ at time t k The service curve, represents the link τ at time t k Remaining service capacity curve;

[0048] Furthermore, the link τ k The worst delay is the maximum horizontal distance between the arrival curve and the service curve, which is expressed by the following formula:

[0049]

[0050] The start transmission time of the next link is the sum of the start transmission time of the current link and the worst delay of the current link, thereby obtaining the transmission plan for all new traffic.

[0051] The present invention proposes an online reconfiguration method for time-sensitive networks. By designing a network asynchronous reconfiguration mechanism, the network update time can be determined according to the actual downtime of each link to realize asynchronous reconfiguration of the network. By ensuring that the legacy traffic is transmitted before the update time, packet loss is avoided, and the deterministic requirements of network consistency and low packet loss during reconfiguration are guaranteed. The earliest update time selection ensures an extremely low response time of this mechanism, thereby ensuring the low-latency deterministic requirements of traffic transmission. At the same time, the update time also provides a reference time for the subsequent solution of new solutions; by designing an incremental reconfiguration transmission solution solution algorithm based on network calculation, the update time of each link calculated by the aforementioned mechanism is used as the reference time for solving the new transmission solution. First, the transmission solution of some new traffic is obtained by the inheritance judgment method, reducing the amount of data required to solve the new solution. Then, the incremental scheduling method is adopted to schedule each traffic one by one, and the high computational complexity of solving all unknown quantities at the same time is avoided in a step-by-step iterative manner from the local optimum to the global optimum. Finally, when solving the new solution, this algorithm converts the inter-frame conflict judgment with extremely high computational complexity into the worst-case delay solution based on network calculation, and realizes the solution with linear time complexity, avoiding the exponential time complexity brought by the conflict judgment. Therefore, by reducing the computational complexity of the solution algorithm, the algorithm can achieve extremely low time complexity, avoiding the problem that the new transmission solution cannot be issued and deployed after the downtime response time ends, and ensuring the deterministic transmission requirements of low packet loss. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 A schematic diagram of the architecture of the online reconfiguration method of the present invention;

[0053] Figure 2 A topological structure diagram of a time-sensitive network system of the present invention;

[0054] Figure 3 A directed graph of network topology after modeling of the present invention;

[0055] Figure 4 It is a schematic diagram of the scheme inheritance strategy of the present invention;

[0056] Figure 5 This is a schematic diagram of the worst-case delay calculated by the network calculation of the present invention. DETAILED DESCRIPTION

[0057] The following describes several preferred embodiments of the present invention with reference to the drawings in the specification, so that the technical content is clearer and easier to understand. The present invention can be embodied in many different forms of embodiments, and the protection scope of the present invention is not limited to the embodiments mentioned in the text.

[0058] In the drawings, components with the same structure are indicated by the same numerical reference numerals, and components with similar structures or functions are indicated by similar numerical reference numerals. The size and thickness of each component shown in the drawings are arbitrarily shown, and the present invention does not limit the size and thickness of each component. In order to make the illustration clearer, the thickness of the components is appropriately exaggerated in some places in the drawings.

[0059] The present invention provides an online reconfiguration method for a time-sensitive network, and the architecture diagram of the online reconfiguration method is as follows: Figure 1 As shown, the following steps are included:

[0060] S1: abstract the network topology of the terminal devices, switches and links in the network to form a directed graph;

[0061] S2: Determine the link update time of each switch according to the downtime time given by the system and the old traffic transmission plan, use this as the new reference time, and perform traffic inheritance according to the reference time;

[0062] S3: Incremental scheduling, establishes deterministic constraints based on the scheduled transmission scheme and current traffic attributes, and uses network calculation to calculate the start transmission time;

[0063] S4: According to the determined scheduling order of the incremental algorithm, until all traffic scheduling is completed, if not completed, return to step S3;

[0064] S5: Generate GCL according to the new scheduling plan, and generate a configuration file through the configuration software and send it to the switch and terminal to wait for it to take effect.

[0065] In a more specific embodiment, the present invention designs a network asynchronous reconfiguration mechanism and an incremental reconfiguration transmission scheme solving algorithm based on network calculation.

[0066] First, the network asynchronous reconfiguration mechanism calculates the earliest update time on the switching node by analyzing the distribution of legacy traffic in the network. The legacy traffic transmission is completed before the update time to ensure the consistency of reconfiguration; asynchronous update times are configured for different switching nodes to reduce the waiting time for new traffic to be injected into the network and ensure the real-time reconfiguration.

[0067] The network asynchronous reconfiguration mechanism includes the following steps:

[0068] 1.1: The network topology of the terminal devices, switches and links in the network is abstracted to form a directed graph. All terminal devices and switch devices are abstracted as nodes, and the unidirectional links between devices are abstracted as directed edges. The network system topology structure and data routing information of this embodiment are as follows: Figure 2As shown in Figure 1, the TSN network consists of 6 terminal devices and 4 switch nodes. Each terminal device can be used to send and receive traffic. Each switch connects the end device and other switches for traffic transfer. All links are full-duplex links. The corresponding abstracted network topology directed graph and data flow transmission path are shown in Figure 1. Figure 3 shown.

[0069] 1.2: Determine the update time of each switch link according to the downtime given by the system and the old traffic transmission scheme. The difference between the update time and the downtime is the current link downtime response time. In this example, the downtime time ρ of all links is given to be 0.5ms, the length of all data frames is 1250Byte, and the bandwidth of all links is B=100Mbps. The cycles of the three flows under the old transmission scheme are {p1=2ms, p2=4ms, p3=8ms}, and the start transmission time of each hop of the switch is {O1:{V 00 -V1:0,V1-V 00 :1ms},O2=:{V 01 -V1:1ms,V1-V2:2ms,V2-V 02 :3ms},O3:{V 02 -V2:1ms,V2-V3:2ms,V3-V 03 :3ms}}, as shown in Table 1:

[0070] Table 1 Old transmission scheme

[0071]

[0072] When the network downtime is 0.5ms, the old transmission scheme is first used to calculate the traffic frame sequence numbers of different switch links left in the network after the downtime ρ takes effect, that is, the frames that have been sent from the source node but have not yet reached the destination node. Specifically, the following formula is satisfied:

[0073]

[0074] Where F represents the flow set, Indicates flow rate f i At the injection time of the source node, Indicates the current flow rate f i The last frame sequence number left in the network after the downtime takes effect. In this example, link V1-V 00 There is the first frame of the legacy flow f1, and no subsequent link needs to wait for the frame to be transmitted. Then the update time of each switch link that the frame passes through is obtained:

[0075]

[0076] Where ε represents the link set, Represents the current link τ k Update time, l i Indicates the traffic frame packet length, and B indicates bandwidth. In this example, at 0.5ms, the legacy frame in the network is the first frame of f1, so the update time of each link that f1 passes through is the time when the current link completes transmission, and the update time of the other links is the downtime. The time from the start of data frame transmission to the completion of transmission is 0.1ms, and finally, except for the directed link V1-V 01 Except for the update time of 1.1ms, the update time of other links is 0.5ms.

[0077] Secondly, the incremental reconfiguration transmission scheme solution algorithm based on network calculation, on the basis of the aforementioned reconfiguration mechanism, converts the inter-frame conflict judgment with exponential time complexity into delay calculation through network calculation method, and obtains the reconfigured transmission scheme with linear complexity, which greatly reduces the calculation time of the reconfiguration scheme and reduces the data frame loss during the solution of the new transmission scheme, thus ensuring the deterministic transmission requirements.

[0078] The incremental reconfiguration transmission solution algorithm based on network calculation includes the following steps:

[0079] 2.1: Under the condition that the route remains unchanged, the transmission scheme of whether the new traffic can inherit the old traffic is determined according to the update time of each link. The strategy diagram is as follows: Figure 4 As shown. If in the old transmission scheme, the start transmission time of the traffic on the links it passes through is later than the update time of the link, then the traffic can inherit the old transmission scheme. The judgment formula for scheme inheritance is:

[0080]

[0081] Where R i Indicates flow rate f i The set of links that the traffic passes through. In this example, traffic 2 and 3 can both inherit the old solution.

[0082] 2.2: Calculate the network reconfiguration supercycle based on the traffic cycle information. Let C represent the supercycle, which is obtained from the least common multiple of all traffic cycles, that is:

[0083] C=LCM(p i )

[0084] In this example, the super period is the least common multiple of 2ms, 4ms, and 8ms, that is, 8ms.

[0085] 2.3: Establish a series of deterministic constraints on link transmission and terminal equipment when transmitting new traffic based on the update time of each link, including deadline constraints, frame sequence constraints, and frame isolation constraints. The key constraints are:

[0086] 2.3.1: Deadline constraint: Each traffic frame is calculated from the time it is sent from the source node, and the end-to-end delay to the destination node should not exceed the maximum allowed delay. In this example, the periods of the four new flows are {p1 * =2ms,p2 * =4ms,p3 * =8ms,p4 * =8ms}, the maximum allowable delays are {d1 * =6ms,d2 * =12ms,d3 * =24ms,d4 * =24ms}, that is, the following formula should be satisfied:

[0087]

[0088] In the formula Indicates the start time of transmission on the last hop link.

[0089] 2.3.2: Frame sequence constraint: the transmission time of the same data frame on the previous switch link should be less than the transmission time on the next switch link, that is, it satisfies the following formula:

[0090]

[0091] Where H i Indicates the total number of links that the current traffic passes through. Indicates that the source node sends a link, Indicates that traffic is on the link The start time of the transmission.

[0092] 2.3.3: Frame isolation constraint: the frames of any two flows do not overlap in the transmission interval of the same link, that is, the following formula should be satisfied:

[0093]

[0094] Where C represents the super period, which is obtained by the lowest common divisor of all traffic periods, that is, C = LCM (p i ). In this example, the super period is 8ms.

[0095] 2.4: Sort the traffic set to be scheduled according to the traffic cycle and deadline information to determine the scheduling order of the incremental algorithm. First, sort by cycle, that is, for flow f i and f i+1 ,

[0096] 2.4.1: If p i >p i+1 , then the flow f i Sort in stream f i+1Before, if f i <f i+1 , then the flow f i Sort in stream f i+1 after;

[0097] 2.4.2: If p i =p i+1 , then sort by deadline. If d i <d i+1 , then the flow f i Sort in stream f i+1 Before, if d i >d i+1 , then the flow f i Sort in stream f i+1 after;

[0098] 2.4.3: If d i =d i+1 , the sorting results are manually determined according to actual needs.

[0099] 2.5: According to the constraints in the third step and the sorting results in the fourth step, the transmission plan for the new traffic that has not been inherited is calculated flow by flow and link by link in an incremental solution manner. When scheduling, the incremental algorithm extracts a data flow from the traffic set in each round and only calculates the transmission plan for the current flow. For the traffic for which a new transmission plan has been generated, its transmission plan is considered to be known and added to the frame isolation constraint of the current traffic scheduling. In each round of scheduling, all links passed from the source node to the destination node are traversed, and the switch residual service curve and link cumulative service curve are established for the current link. The worst delay is calculated using the network calculation method and used as the start transmission time of the next link. The switch residual service curve can be obtained as follows:

[0100]

[0101] In the formula, represents the link τ at time t k The arrival curve, represents the link τ at time t k The service curve, represents the link τ at time t k Remaining service capacity curve. Service curve, arrival curve and worst-case delay diagram are shown in Figure 5 Link τ k The worst delay is the maximum horizontal distance between the arrival curve and the service curve, as shown in the following formula:

[0102]

[0103] The start transmission time of the next link is the sum of the start transmission time of the current link and the worst delay of the current link. Thus, the transmission plan for all new traffic is obtained. In this example, the new transmission plan is shown in Table 2. Flow 1 that cannot inherit the old plan and the newly added flow 4 both generate new plans.

[0104] Table 2 New transmission scheme

[0105]

[0106] 2.6: Generate GCL based on the generated new traffic scheduling scheme, and generate corresponding configuration files for terminal devices and switch ports through relevant configuration software. Finally, the configuration software is sent to the device and takes effect after the update time.

[0107] The preferred specific embodiments of the present invention are described in detail above. It should be understood that ordinary technicians in the field can make many modifications and changes based on the concept of the present invention without creative work. Therefore, all technical solutions that can be obtained by technicians in the technical field based on the concept of the present invention through logical analysis, reasoning or limited experiments on the basis of the prior art should be within the scope of protection determined by the claims.

Claims

1. An online reconfiguration method for a time-sensitive network, characterized in that: The method comprises the following steps: S1: abstract the network topology of the terminal devices, switches and links in the network to form a directed graph; S2: Determine the link update time of each switch according to the downtime time given by the system and the old traffic transmission plan, use this as the new reference time, and perform traffic inheritance according to the reference time; S3: Incremental scheduling, establishes deterministic constraints based on the scheduled transmission scheme and current traffic attributes, and uses network calculation to calculate the start transmission time; S4: According to the determined scheduling order of the incremental algorithm, until all traffic scheduling is completed, if not completed, return to step S3; S5: Generate GCL according to the new scheduling plan, and generate a configuration file through the configuration software and send it to the switch and terminal to wait for it to take effect.

2. The online reconfiguration method for a time-sensitive network according to claim 1, characterized in that: In step S1, the terminal devices and switches are abstracted as nodes, and the links are abstracted as directed edges.

3. The online reconfiguration method for a time-sensitive network according to claim 1, characterized in that: The difference between the downtime time described in step S2 and the update time is the current link downtime response time.

4. The online reconfiguration method for a time-sensitive network according to claim 3, characterized in that: The update time is expressed by the formula as follows: First, the old transmission scheme is used to calculate the traffic frame sequence numbers left in the network after the downtime ρ of different switch links takes effect, that is, the frames that have been sent from the source node but have not yet reached the destination node, which specifically satisfy the following formula: In the formula, F represents the flow set, Indicates flow rate f i At the injection time of the source node, Indicates the current flow rate f i The last frame number left in the network after the downtime takes effect; Link V1-V 00 There is the first frame of the legacy flow f1, and no subsequent link needs to wait for the frame to be transmitted. Then the update time of each switch link that the frame passes through is obtained: Where ε represents the link set, Represents the current link τ k Update time, l i Indicates the traffic frame length, and B indicates bandwidth.

5. The online reconfiguration method for a time-sensitive network according to claim 4, characterized in that: The scheme inheritance of the flow in step S2 is expressed by the following formula: In the formula, R i Indicates flow rate f i The set of links passed through; It also includes calculating the network reconfiguration super period according to the traffic cycle information. The super period is represented by C, which is obtained by the least common multiple of all traffic cycles, that is: C=LCM(p i )。 6. The online reconfiguration method for a time-sensitive network according to claim 5, characterized in that: The deterministic constraints in step S3 include a deadline constraint, a frame sequence constraint, and a frame isolation constraint; The deadline constraint is that the end-to-end delay of each traffic frame from the source node to the destination node should not exceed the maximum allowed delay, which is expressed by the formula: In the formula, Indicates the start transmission time on the last hop link; The frame sequence constraint is that the transmission time of the same data frame on the previous switch link should be less than the transmission time on the next switch link, which is expressed by the formula: In the formula, H i Indicates the total number of links that the current traffic passes through. Indicates that the source node sends a link, Indicates that traffic is on the link The start time of transmission; The frame isolation constraint is that the frames of any two flows do not overlap in the transmission interval of the same link, which is expressed by the formula: Where C represents the super period, which is obtained by the lowest common divisor of all traffic periods, that is, C = LCM (p i ).

7. The online reconfiguration method for a time-sensitive network according to claim 6, characterized in that: The scheduling order of the incremental algorithm is sorted according to the traffic cycle and deadline information: First, sort by cycle, that is, for flow f i and f i+1 ; If p i >p i+1 , then the flow f i Sort in stream f i+1 Before, if f i <f i+1 , then the flow f i Sort in stream f i+1 after; If p i =p i+1 , then sort by deadline, if d i <d i+1 , then the flow f i Sort in stream f i+1 Before, if d i >d i+1 , then the flow f i Sort in stream f i+1 after; If d i =d i+1 , the sorting results are manually determined according to actual needs.

8. The online reconfiguration method for a time-sensitive network according to claim 7, characterized in that: The incremental scheduling in step S3 is to calculate the transmission scheme of the new traffic that is not inherited on a flow-by-flow and link-by-link basis in an incremental solution manner according to the constraint conditions and the sorting results.

9. The online reconfiguration method for a time-sensitive network according to claim 8, characterized in that: In the incremental scheduling, in one round of scheduling, all the links passed from the source node to the destination node are traversed, and the switch residual service curve and the link cumulative service curve are established for the current link. The worst delay is calculated by the network calculation method and used as the start transmission time of the next link. The switch residual service curve is expressed by the formula as follows: In the formula, represents the link τ at time t k The arrival curve, represents the link τ at time t k The service curve, represents the link τ at time t k Remaining service capacity curve.

10. The online reconfiguration method for a time-sensitive network according to claim 8, characterized in that: The link τ k The worst delay is the maximum horizontal distance between the arrival curve and the service curve, which is expressed by the following formula: The start transmission time of the next link is the sum of the start transmission time of the current link and the worst delay of the current link, thereby obtaining the transmission plan for all new traffic.

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