CN115834463A

CN115834463A - Path calculation method, device, network controller and storage medium

Info

Publication number: CN115834463A
Application number: CN202111088571.1A
Authority: CN
Inventors: 雷文龙
Original assignee: ZTE Corp
Current assignee: ZTE Corp
Priority date: 2021-09-16
Filing date: 2021-09-16
Publication date: 2023-03-21
Also published as: WO2023040503A1

Abstract

The application provides a path calculation method, a path calculation device, a network controller and a storage medium, and relates to the field of communication. The path calculation method comprises the following steps: establishing a tunnel between a source node and a destination node, wherein the tunnel comprises a plurality of sections of sub-tunnels; acquiring an optional path of each segment of sub-tunnel and a repeat node of the optional path; and taking the repeated node as a path calculation constraint condition of the sub-tunnel with a plurality of optional paths, and performing path calculation on the sub-tunnel with the plurality of optional paths. The method is used for the tunnel path calculation process, and achieves the purpose of improving the path calculation success rate.

Description

Path calculation method, device, network controller and storage medium

Technical Field

The present invention relates to the field of communications, and in particular, to a path calculation method, an apparatus, a network controller, and a storage medium.

Background

Currently, for label switched Path calculation, a Constrained Shortest Path First (CSPF) algorithm is mostly used. If a certain path is found to be unable to pass in the path calculation process, using a trunk algorithm to process, eliminating the current path, backing back and calculating the path again, and finally calculating the shortest LSP path meeting the constraint condition.

However, in the course of rollback re-routing, when a certain path does not meet the routing requirement, the cranback algorithm may cause another path that meets the condition to be incorrectly excluded together, and finally cause the routing to fail.

Disclosure of Invention

The embodiments of the present application mainly aim to provide a path calculation method, an apparatus, a network controller, and a storage medium, which aim to improve a success rate of path calculation.

In order to achieve the above object, an embodiment of the present application provides a path calculation method, including: establishing a tunnel between a source node and a destination node, wherein the tunnel comprises a plurality of sections of sub-tunnels; acquiring an optional path of each segment of sub-tunnel and a repeat node of the optional path; and taking the repeated node as a path calculation constraint condition of the sub-tunnel with a plurality of optional paths, and performing path calculation on the sub-tunnel with the plurality of optional paths.

In order to achieve the above object, an embodiment of the present application further provides a path calculation apparatus, including:

a tunnel establishing module, configured to establish a tunnel between a source node and a destination node, where the tunnel includes multiple sub-tunnels;

the path calculation module is used for acquiring the optional path of each segment of sub-tunnel and the repeat node of the optional path;

and taking the repeated node as a path calculation constraint condition of the sub-tunnel with a plurality of optional paths, and performing path calculation on the sub-tunnel with the plurality of optional paths.

In order to achieve the above object, an embodiment of the present application further provides a network controller, including: at least one processor; and a memory communicatively coupled to the at least one processor; wherein the memory stores instructions executable by the at least one processor to enable the at least one processor to perform the path computation method described above.

To achieve the above object, an embodiment of the present application further provides a computer-readable storage medium storing a computer program, which when executed by a processor implements the path calculation method described above.

The method, the device, the network controller and the storage medium for calculating the path are used for acquiring the selectable paths of the multiple segments of sub-tunnels between the source node and the destination node and the repeated nodes of all the selectable paths, the repeated nodes are used as path calculation constraint conditions, and in the path calculation process, the repeated nodes are sequentially used as excluding nodes, namely the selectable paths containing the repeated nodes are excluded in advance during path selection, so that the success rate of path calculation is improved, and the defect that the correct path is erroneously excluded in the path calculation process of a crankback algorithm is overcome.

Drawings

One or more embodiments are illustrated by the corresponding figures in the drawings, which are not meant to be limiting.

Fig. 1 is a first flowchart of a path computation method provided in an embodiment of the present application;

fig. 2 is a schematic diagram of a network routing node topology provided by an embodiment of the present application;

fig. 3 is a second flowchart of a path calculation method provided in an embodiment of the present application;

fig. 4 is a flowchart three of a path calculation method provided in an embodiment of the present application;

fig. 5 is a fourth flowchart of a path calculation method provided by an embodiment of the present application;

fig. 6 is a schematic structural diagram of a path calculation device according to another embodiment of the present application;

fig. 7 is a schematic structural diagram of a network controller according to another embodiment of the present application.

Detailed Description

To make the objects, technical solutions and advantages of the embodiments of the present application clearer, the embodiments of the present application will be described in detail below with reference to the accompanying drawings. However, it will be appreciated by those of ordinary skill in the art that in the examples of the present application, numerous technical details are set forth in order to provide a better understanding of the present application. However, the technical solution claimed in the present application can be implemented without these technical details and various changes and modifications based on the following embodiments. The following embodiments are divided for convenience of description, and should not constitute any limitation to the specific implementation manner of the present application, and the embodiments may be mutually incorporated and referred to without contradiction.

An embodiment of the present application relates to a path calculation method, as shown in fig. 1, including:

step 101, establishing a tunnel between a source node and a destination node, wherein the tunnel comprises a plurality of segments of sub-tunnels.

Specifically, the path calculation method of the present application may be applied to an SDN controller in a Software Defined Network (SDN) Network, where the SDN controller interacts with a plurality of router devices through a communication protocol to complete path calculation and path delivery. Of course, the path calculation method of this embodiment may also be applied to network controllers in other networks.

In addition, the method for calculating the path for the tunnel according to the embodiment may be applied to various tunnels such as an SR-TE (Segment Routing-tunneling) tunnel, an SR-TP (Segment Routing-Transport Profile) tunnel, and an RSVP-TE (Resource ReSerVation Protocol-Traffic Engineering) tunnel, and may also be applied to calculation of a forwarding path for SR Policy (Segment Routing Policy).

Of course, it should be noted that before establishing the tunnel between the source node and the destination node, the network controller needs to perform tunnel configuration and obtain topology information of the entire network, for example: node number, node location, node ID, link cost, link bandwidth, and the like. And establishing the tunnel on the basis of the tunnel establishment. Such as: taking SR-TE tunnel as an example, before SR-TE tunnel IS created, it IS necessary to establish an IS-IS neighbor relationship between each routing device, and an IS-IS or BGP-LS neighbor relationship between a routing device and a controller, to implement network layer interworking, complete label distribution and network topology information collection, and send the label and the network topology information to the controller for the controller to perform path computation.

In addition, in this embodiment, a tunnel is established between the source node and the destination node, and the tunnel may be divided into multiple segments of sub-tunnels according to preset loose nodes, where the loose nodes are nodes that the tunnel must pass through. That is, it is required that a path from the source node to the destination node must pass through a preset loose node. Of course, the selection of the loose nodes is selected by the user according to the application scene and the transmission requirement. Such as: the network has 12 routing nodes (P1-P12), users designate P3 and P7 as loose nodes, a tunnel is established between a source node P1 and a destination node P12, the tunnel is divided into three sections, the first section of sub-tunnel is P1-P4, the second section of sub-tunnel is P4-P7, and the third section of sub-tunnel is P7-P12.

And 102, acquiring the optional path of each segment of the sub-tunnel and the repeated node of the optional path.

Specifically, for each segment of sub-tunnel, the optional path is obtained according to the source node and the destination node of each segment of sub-tunnel. As shown in fig. 2, fig. 2 is a schematic diagram of a network routing node topology, where numbers on links in the diagram represent link costs, and 10 routing nodes are total, and taking a source node P2, a destination node P8, and a loose node P4 as an example, a tunnel is established between the source node P2 and the destination node P8, and the tunnel is divided into two segments, where a first segment of sub-tunnel is P2-P4, and a second segment of sub-tunnel is P4-P8. As can be seen from fig. 2, for the first segment of sub-tunnels P2-P4, there are 3 alternative paths, the first alternative path L1: p2- - > P6- - > P10- - > P9- - > P3- - > P4; second optional path L2: p2- - > P1- - > P3- - > P4; third alternative path L3: p2- - > P6- - > P5- - > P4. For the second segment of sub-tunnel, there are only 1 optional path, i.e., L4: p4- - > P5- - > P6- - > P7- - > P8.

In addition, the duplicate node for acquiring the optional paths is a duplicate node for acquiring all the optional paths. I.e. all duplicate nodes between the alternative paths L1, L2, L3 and L4 are obtained. Of course, the duplicate nodes cannot contain the source node, the destination node, and the loose nodes.

And 103, taking the repeated nodes as path calculation constraint conditions of the sub-tunnels with the multiple optional paths, and performing path calculation on the sub-tunnels with the multiple optional paths.

Specifically, in this embodiment, in addition to using the duplicate node as the path computation constraint, the link cost, the link bandwidth, the link attribute, the link priority, and the like may also be used as the path computation constraint.

It should be noted that, when a constrained shortest path first CSPF algorithm is used to calculate a path at present, for multiple selectable paths between P2 and P4, an optimal path L1 (the link cost of which is 3400) is selected, and then a path of a sub-tunnel P4 to P8 is calculated, only one L4 path is found, and at this time, it is found that the entire path P2- > P6- > P10- > P9- > P3- > P4- > P5- > P6- > P7- > P8 repeatedly passes through the node P6, and the path in the tunnel cannot absolutely pass through a certain node repeatedly.

At this time. The network controller processes according to a cranback algorithm, and performs step-by-step backspacing from a tail node to eliminate interfaces or nodes, namely, the L1 path is considered to be illegal and needs to be rewarded for recalculation, and the path entry interface P3- - > P4 is deleted when the P4 node starts backspacing to the P3 node, so that the loop is prevented from being moved when the path is recalculated, and thus the selectable path L2 is caused: p2- - > P1- - > P3- - > P4 is also judged to be illegal (because the optional path L2 also passes through the path I interface P3- - > P4). Recalculating the sub-tunnel path between P2 and P4, leaving only L3, selecting an optional path L4 when calculating the sub-tunnel path between P2 and P4, and finding the whole path L3+ L4: two nodes in P2- - > P6- - > P5- - > P4- - > P5- - > P6- - > P7- - > P8 are repeatedly passed through, so that the optional path L3 is also legal. Finally, all the optional paths of the tunnel of the segment P2- - > P4 are illegal, and the calculation of the path of the whole tunnel fails.

According to the path calculation method, the optional paths of the multiple segments of sub-tunnels between the source node and the destination node and the repeated nodes of all the optional paths are obtained, the repeated nodes are used as the path calculation constraint conditions, and in the path calculation process, the repeated nodes are sequentially used as the excluding nodes, namely, the optional paths containing the repeated nodes are excluded in advance during path selection, so that the path calculation success rate is improved, and the defect that the correct paths are erroneously excluded in the path calculation process of the cranback algorithm is overcome.

An embodiment of the present application relates to a path calculation method, as shown in fig. 3, including:

step 301, a tunnel is established between a source node and a destination node, and the tunnel includes multiple segments of sub-tunnels.

Specifically, the specific implementation details of step 301 in this embodiment are substantially the same as those of step 101, and are not described herein again.

Step 302, acquiring an optional path of each segment of sub-tunnel.

And step 303, determining a common node among the multiple optional paths for all the optional paths of the whole tunnel, and taking the common node as a repeat node.

Specifically, as shown in fig. 2, taking a source node as P2, a destination node as P8, and a loose node as P4 as an example, a tunnel is established between the source node P2 and the destination node P8, and the tunnel is divided into two segments, where the first segment of sub-tunnel is P2-P4, and the second segment of sub-tunnel is P4-P8. As can be seen from fig. 2, for the first segment of sub-tunnels P2-P4, there are 3 alternative paths, the first alternative path L1: p2- - > P6- - > P10- - > P9- - > P3- - > P4; second optional path L2: p2- - > P1- - > P3- - > P4; third alternative path L3: p2- - > P6- - > P5- - > P4. For the second segment of sub-tunnel, there are only 1 optional path, i.e., L4: p4- - > P5- - > P6- - > P7- - > P8.

Further, it can be seen for all of the selectable paths L1, L2, L3, and L4 that the repetition node between the selectable path L1 and the selectable path L2 is P3, the repetition node between the selectable path L1 and the selectable path L3 is P6, the repetition node between the selectable path L1 and the selectable path L4 is P6, no repetition node between the selectable path L2 and the selectable path L3, no repetition node between the selectable path L2 and the selectable path L4, and the repetition node between the selectable path L3 and the selectable path L4 is P5, P6. Nodes P3, P5 and P6 can thus be regarded as duplicate nodes.

And step 304, taking the repeated nodes as path calculation constraint conditions of the sub-tunnels with a plurality of optional paths, and performing path calculation on the sub-tunnels with a plurality of optional paths.

Specifically, when a plurality of duplicate nodes are used as the path calculation constraint condition, the plurality of duplicate nodes are sequentially subjected to path calculation as excluded nodes. That is, the node P3 may be first used as a excluding node, and the shortest path first CSPF algorithm is used to calculate the sub-tunnel P2- - > P4, so that the L3: p2- - > P6- - > P5- - > P4. Then, the sub-tunnel of P4- - > P8 is calculated, and L4: p4- - > P5- - > P6- - > P7- - > P8. It is found that the P5 and P6 nodes are repeatedly traversed. The path computation fails. And secondly, selecting a node P6 as an excluding node, calculating the sub-tunnel P2- - > P4 by adopting a shortest path first CSPF algorithm, wherein L2 can be moved: p2- - > P1- - > P3- - > P4. Then, calculating the P4-P8 sub-tunnel, and enabling the L4: p4- - > P5- - > P6- - > P7- - > P8. At this time, it is found that all nodes in the whole path are passed only once, and the path calculation is successful according to the condition.

It should be noted that, when there are multiple duplicate nodes in the path constraint condition, the sequence when the duplicate node is specifically selected as the excluded node may be selected at will (the sequence may be P6-P3-P5 or P5-P3-P6 or P6-P5-P3, etc.), or may be according to the node number, or may be according to the preset node priority.

In addition, as shown in fig. 4, after step 304, the method further includes:

and 305, directly taking the optional path as a first sub-path of the sub-tunnel for the sub-tunnel with only one optional path.

And step 306, regarding the sub-tunnels with a plurality of optional paths, taking the path calculation result as a second sub-path.

And 307, splicing the first sub-path and the second sub-path to be used as a target path between the source node and the destination node.

Specifically, the path is directly set as the first sub-path for the sub-tunnel having only one optional path, but of course, if there are a plurality of sub-tunnels having only one optional path, the first sub-path includes a plurality of sub-paths, and if there are a plurality of sub-tunnels having a plurality of optional paths, the result of the path calculation is set as the second sub-path. And finally splicing the plurality of first sub paths and the plurality of second sub paths in sequence to obtain the target path between the source node and the destination node.

In addition, after step 307 of this embodiment, the method further includes: and issuing the target path to the tunnel.

An embodiment of the present application relates to a path calculation method, as shown in fig. 5, including:

step 501, a tunnel is established between a source node and a destination node, wherein the tunnel comprises a plurality of segments of sub-tunnels.

Specifically, the specific implementation details of step 501 in this embodiment are substantially the same as those of step 101, and are not described herein again.

And 502, acquiring the optional path of each segment of sub-tunnel, and calculating the path according to the constraint-based shortest path first algorithm and the cranback algorithm.

And step 503, when the path calculation fails, taking the node causing the failure as a repeat node.

Specifically, when the repeated nodes are obtained, the shortest path first algorithm and the cranback algorithm based on the constraint can be adopted for path calculation, when the path calculation fails, the nodes causing the failure are recorded as the repeated nodes in the second path calculation, and then the repeated nodes are used as the path calculation constraint conditions.

That is, this embodiment may supplement a path computation process as a base-preserving algorithm based on the current path computation method, and when a problem occurs in the first path computation, a processing method of removing interfaces or nodes by step back from the tail node and then recalculating is performed. But directly taking the repeated node which causes the path calculation failure last time as an excluded node to carry out path calculation again, thereby not only utilizing the path calculation result of the first path calculation, but also rapidly finishing the supplement path calculation, and preventing the repeated occurrence of the path calculation failure condition caused by the false exclusion of the trunk algorithm.

And step 504, taking the repeated nodes as path calculation constraint conditions of the sub-tunnels with the multiple optional paths, and performing path calculation on the sub-tunnels with the multiple optional paths.

Specifically, the specific implementation details of step 504 in this embodiment are substantially the same as those of

steps

103 and 304, and are not described herein again.

In addition, after the present embodiment 504, the method further includes: and for the sub-tunnel with only one optional path, directly taking the optional path as the first sub-path of the sub-tunnel. And regarding the sub-tunnel with a plurality of optional paths, taking the path calculation result as a second sub-path. And splicing the first sub-path and the second sub-path to be used as a target path between the source node and the destination node.

Specifically, the path is directly set as the first sub-path for the sub-tunnel having only one optional path, but of course, if there are a plurality of sub-tunnels having only one optional path, the first sub-path includes a plurality of sub-paths, and if there are a plurality of sub-tunnels having a plurality of optional paths, the result of the path calculation is set as the second sub-path. And finally splicing the plurality of first sub paths and the plurality of second sub paths in sequence to obtain the target path between the source node and the destination node. And the network controller acquires the target path and then sends the target path to the tunnel.

In addition, it should be understood that the above steps of the various methods are divided for clarity, and the implementation may be combined into one step or split into some steps, and the steps are divided into multiple steps, so long as the same logical relationship is included in the protection scope of the present patent; it is within the scope of the patent to add insignificant modifications to the flow or to introduce insignificant design, but not to change the core design of the flow.

Another embodiment of the present application relates to a path calculation apparatus, as shown in fig. 6, including:

a tunnel establishing module 601, configured to establish a tunnel between a source node and a destination node, where the tunnel includes multiple segments of sub-tunnels.

A path calculation module 602, configured to obtain an optional path of each segment of the sub-tunnel and a duplicate node of the optional path; and taking the repeated node as a path calculation constraint condition of the sub-tunnel with a plurality of optional paths, and performing path calculation on the sub-tunnel with the plurality of optional paths.

It should be noted that all modules involved in this embodiment are logic modules, and one logic unit may be one physical unit, may also be a part of one physical unit, and may also be implemented by a combination of multiple physical units. In addition, in order to highlight the innovative part of the present invention, a unit which is not so closely related to solve the technical problem proposed by the present invention is not introduced in the present embodiment, but this does not indicate that there is no other unit in the present embodiment.

It should be understood that the present embodiment is an apparatus embodiment corresponding to the path calculation method embodiment, and the present embodiment can be implemented in cooperation with the above embodiments. The related technical details mentioned in the above embodiments are still valid in this embodiment, and are not described herein again in order to reduce repetition. Accordingly, the related technical details mentioned in the present embodiment can also be applied in the above method embodiments.

Another embodiment of the present invention relates to a network controller, as shown in fig. 7, including: at least one processor 701; and a memory 702 communicatively coupled to the at least one processor 701; the memory 702 stores instructions executable by the at least one processor 701, and the instructions are executed by the at least one processor 701, so that the at least one processor 701 can execute the path calculation method of the above embodiment.

Where the memory and processor are connected by a bus, the bus may comprise any number of interconnected buses and bridges, the buses connecting together one or more of the various circuits of the processor and the memory. The bus may also connect various other circuits such as peripherals, voltage regulators, power management circuits, etc., which are well known in the art, and therefore, will not be described any further herein. A bus interface provides an interface between the bus and the transceiver. The transceiver may be one element or a plurality of elements, such as a plurality of receivers and transmitters, providing a means for communicating with various other apparatus over a transmission medium. The data processed by the processor is transmitted over a wireless medium via an antenna, which further receives the data and transmits the data to the processor.

The processor is responsible for managing the bus and general processing and may also provide various functions including timing, peripheral interfaces, voltage regulation, power management, and other control functions. While the memory may be used to store data used by the processor in performing operations.

Another embodiment of the present invention relates to a computer-readable storage medium storing a computer program. The computer program realizes the above-described method embodiments when executed by a processor.

That is, as can be understood by those skilled in the art, all or part of the steps in the method for implementing the above embodiments may be implemented by a program instructing related hardware, where the program is stored in a storage medium and includes several instructions to enable a device (which may be a single chip, a chip, or the like) or a processor (processor) to execute all or part of the steps of the method according to the embodiments of the present application. And the aforementioned storage medium includes: a U-disk, a removable hard disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk or an optical disk, and other various media capable of storing program codes.

It will be understood by those of ordinary skill in the art that the foregoing embodiments are specific examples of implementations of the present application and that various changes in form and details may be made therein without departing from the spirit and scope of the present application.

Claims

1. A path computation method, comprising:

establishing a tunnel between a source node and a destination node, wherein the tunnel comprises a plurality of sections of sub-tunnels;

acquiring an optional path of each segment of sub-tunnel and a repeat node of the optional path;

and taking the repeated node as a path calculation constraint condition of the sub-tunnel with a plurality of selectable paths, and performing path calculation on the sub-tunnel with the plurality of selectable paths.

2. The method according to claim 1, wherein the obtaining of the optional path of each segment of the sub-tunnel and the duplicate node of the optional path comprises:

acquiring an optional path of each segment of sub-tunnel;

and determining a common node among the multiple optional paths for all the optional paths of the whole tunnel, and taking the common node as a repeating node.

3. The path calculation method according to claim 1, wherein the obtaining of the optional path of each segment of the sub-tunnel and the duplicate node of the optional path comprises:

acquiring an optional path of each segment of sub-tunnel, and performing path calculation according to a constraint-based shortest path first algorithm and a cranback algorithm;

when the path computation fails, the node that caused the failure is treated as a duplicate node.

4. The path calculation method according to any one of claims 1 to 3, wherein after performing path calculation on the sub-tunnel having the plurality of optional paths by using the duplicate node as a path calculation constraint condition of the sub-tunnel having the plurality of optional paths, the method further comprises:

for a sub-tunnel with only one optional path, directly taking the optional path as a first sub-path of the sub-tunnel;

for the sub-tunnel with a plurality of selectable paths, taking the path calculation result as a second sub-path;

and splicing the first sub-path and the second sub-path to be used as a target path between the source node and the destination node.

5. The method according to claim 4, wherein after the splicing the first sub-path and the second sub-path as the target path between the source node and the destination node, further comprising:

and issuing the target path to the tunnel.

6. The path computation method of claim 1, wherein the path constraints further comprise at least one of: link cost, link bandwidth, link attributes, link priority.

7. The path computation method of claim 4, wherein the tunnel is an SR-TE tunnel, or an SR-TP tunnel, or an RSVP-TE tunnel.

8. A path computation apparatus, comprising:

the path calculation module is used for acquiring the selectable path of each segment of the sub-tunnel and the repeat node of the selectable path; and taking the repeated node as a path calculation constraint condition of the sub-tunnel with a plurality of selectable paths, and performing path calculation on the sub-tunnel with the plurality of selectable paths.

9. A network controller, comprising:

at least one processor; and the number of the first and second groups,

a memory communicatively coupled to the at least one processor; wherein the content of the first and second substances,

the memory stores instructions executable by the at least one processor to enable the at least one processor to perform a path computation method as claimed in any one of claims 1 to 7.

10. A computer-readable storage medium storing a computer program, wherein the computer program, when executed by a processor, implements the path computation method of any one of claims 1 to 7.