CN117675666A

CN117675666A - Path calculation method, electronic device, and computer-readable storage medium

Info

Publication number: CN117675666A
Application number: CN202211041152.7A
Authority: CN
Inventors: 赵德涛; 刘毅
Original assignee: ZTE Corp
Current assignee: ZTE Corp
Priority date: 2022-08-29
Filing date: 2022-08-29
Publication date: 2024-03-08

Abstract

The present disclosure provides a path computation method, an electronic device, and a computer-readable storage medium. The path calculation method comprises the following steps: in a network in which a non-segment routing SR node exists, a segment list only comprising SR nodes is generated by utilizing a plurality of nodes from a head node to a tail node, wherein the non-SR node is a node which does not support segment routing capability, and the SR node is a node which supports segment routing capability.

Description

Path calculation method, electronic device, and computer-readable storage medium

Technical Field

The present disclosure relates to the field of communications, and in particular, to a path computation method, an electronic device, and a computer-readable storage medium.

Background

Based on Segment Routing (SR) techniques, including SR multiprotocol label switching (SR-MPLS, segment Routing Multi-Protocol Label Switching) and IPv 6Segment Routing (SRv, segment Routing IPv 6), the interior gateway protocol (IGP, internal Gateway Protocol) can dynamically calculate Segment lists (Segment lists) to provide topology-independent loop-free backup path (TI-LFA, topology Independent Loop-free Alternate) protection and Micro-loop avoidance (Micro-loop avoidance) capabilities.

In SR networks where SR nodes are not supported, according to the TI-LFA Segment List and anti-micro ring Segment List calculation techniques in the prior art, segment lists may fail to build, but in fact, segment lists satisfying the requirements are present in the SR network.

Disclosure of Invention

The present disclosure provides a path computation method, an electronic device, and a computer-readable storage medium.

In a first aspect, the present disclosure provides a path computation method, including:

in a network in which a non-segment routing SR node exists, a segment list only comprising SR nodes is generated by utilizing a plurality of nodes from a head node to a tail node, wherein the non-SR node is a node which does not support segment routing capability, and the SR node is a node which supports segment routing capability. In some embodiments, the generating a segment list comprising only SR nodes with a plurality of nodes from a head node to a tail node comprises:

determining a plurality of SR nodes in the plurality of nodes from the head node to the tail node;

generating a segment list only comprising SR nodes according to the plurality of SR nodes.

Specifically, generating a segment list including only SR nodes according to the plurality of SR nodes includes:

calculating a first path using the plurality of SR nodes according to a routing protocol;

calculating the priority of each first path;

and generating the segmentation list according to the first path with the highest priority.

In some embodiments, the generating a segment list comprising only SR nodes with a plurality of nodes from a head node to a tail node comprises:

calculating a second path using the plurality of nodes from the head node to the tail node according to the routing protocol;

calculating initial priority reference values of the second paths;

according to whether each second path comprises a non-SR node, adjusting the initial priority reference value of each second path to obtain the final priority reference value of each second path so that the final priority of the second path comprising the non-SR node is lower than the final priority of the second path not comprising the non-SR node; wherein the non-SR node is a node which does not support the segmented routing capability;

and generating the segment list according to the second path with the highest final priority.

Specifically, the priority reference value includes an overhead value inversely proportional to the priority;

the adjusting the initial priority reference value of each second path according to whether each second path includes a non-SR node, includes:

judging whether each second path comprises a non-SR node or not;

and adding a preset overhead value to a plurality of second paths comprising non-SR nodes on the basis of the initial overhead value to obtain a final overhead value, so that the final overhead value of the second paths comprising the non-SR nodes is larger than the final overhead value of the second paths not comprising the non-SR nodes.

In some embodiments, the path computation method further comprises:

and under the condition that each second path comprises a non-SR node, taking the shortest path calculated by the routing protocol as a message forwarding path.

calculating a third path using the plurality of nodes from the head node to the tail node according to the routing protocol;

judging whether each third path comprises a non-SR node or not one by one, and generating the segmentation list according to the third paths which do not comprise the non-SR node.

Specifically, the determining, piece by piece, whether each third path includes a non-SR node, and generating the segment list according to the third paths that do not include the non-SR node includes:

creating a segment list one by one according to the order of the priority of each third path from high to low until the segment list from the head node to the tail node is successfully built;

and establishing a successful segment list as the segment list only comprising the SR nodes.

Further, the path calculation method further includes:

and determining an available path to a message destination address according to the segmentation list.

In a second aspect, the present disclosure provides an electronic device comprising:

one or more processors;

a memory having one or more programs stored thereon, which when executed by the one or more processors, cause the one or more processors to implement the path computation method according to any one of the first aspects;

one or more I/O interfaces coupled between the processor and the memory configured to enable information interaction of the processor with the memory.

In a third aspect, the present disclosure provides a computer readable storage medium having stored thereon a computer program which, when executed by a processor, implements the path computation method according to any one of the first aspects.

According to the path calculation method, when the nodes which do not support Segment Routing exist in the Segment Routing network, the nodes which do not support Segment Routing can be automatically bypassed, segment List is calculated, the problems of TI-LFA and micro-loop path calculation prevention are solved, and higher reliability is provided for the network.

Drawings

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

Fig. 2 is a flowchart of one implementation of a path computation method provided by an embodiment of the present disclosure.

Fig. 3 is a flowchart of another implementation of the path computation method provided by the embodiments of the present disclosure.

Fig. 4 is a flowchart of still another implementation of the path computation method provided by the embodiments of the present disclosure.

Fig. 5 is a topological schematic diagram of a fault scenario.

Fig. 6 is a topological schematic diagram of another fault scenario.

Fig. 7 is a schematic topology diagram of a node where there is no SR support.

Fig. 8 is a schematic diagram of another topology in which there are nodes that do not support SR.

Fig. 9 is a schematic diagram of an electronic device provided in an embodiment of the disclosure.

Fig. 10 is a schematic diagram of a computer-readable storage medium provided by an embodiment of the present disclosure.

Detailed Description

It should be understood that the specific embodiments described herein are merely illustrative of the present disclosure and are not intended to limit the present disclosure.

In the following description, suffixes such as "module", "component", or "unit" for representing elements are used only for facilitating the description of the present disclosure, and have no particular meaning in themselves. Thus, "module," "component," or "unit" may be used in combination.

The method for calculating the TI-LFA backup path is described as shown in FIG. 5. Wherein the main path for node B to reach node F is the link between B and F. The method for calculating the backup path for F is as follows:

1. and calculating the shortest path after convergence.

As can be seen from fig. 5, after the link between B and F fails, the shortest path from B to F is b— > C- > D- > F.

2. The P-space is calculated.

The shortest path between the node B and the node X in the topology before the fault does not pass through a fault link, namely X is called P node, and the shortest path between the node B and the direct neighbor (such as C node) of the node B in the topology before the fault does not pass through a fault link, namely X is called extended P node.

All the P nodes form a P space. All extended P nodes make up an extended P space. For example, the C node is the P node in FIG. 5.

3. Computing Q space

The shortest path from node X to node F in the pre-failure topology is not through the failed link, then X is referred to as the Q node, and the set of X nodes is referred to as the Q space. For example, the E node is the Q node in fig. 5.

4. A backup Segment List is generated.

And selecting a P node farthest from the node B and a Q node closest to the node B on the shortest path after convergence. And constructing a backup path by link or node between the P node and the Q node.

In fig. 5, the backup path write [ Node (C), link (C- > E) ], the backup Segment List write [ Adjacent Segment identification adjacency SID (C- > E) ].

The link state database of the IGP protocol is distributed as shown in fig. 6, so that IGP may generate loops when out-of-order converges. But such loops will disappear after all devices on the forwarding path have completed convergence, and such transient loops are called Micro loops.

Taking fig. 6 as an example, the flow goes from S to D, and the shortest path is S- > R0- > R1- > R2- > R3- > D. When the links from R2 to R3 fail, a short loop is caused because each node cannot complete updating the forwarding state at the same time. If R0 updates the forwarding state earlier than R5, traffic will loop between R0 and R5 until R5 also completes the forwarding state update.

Based on Segment Routing, loop in the network can be effectively eliminated by constructing a loop-free Segment List to guide traffic to forward to a destination address and waiting for network nodes to fall back to a normal forwarding state after all network nodes complete convergence.

The calculation method of the micro-ring Segment List can use the calculation method of the TI-LFA backup Segment List.

Taking fig. 6 as an example, the flow goes from S to D, and the shortest path is S- > R0- > R1- > R2- > R3- > D. When R2 to R3 links fail, R0 senses that the links from R2 to R3 fail, a loop-free Segment List [ Node SID (R4), additive SID (R4- > R3) ] or SRv6Segment List [ additive SID (R4- > R3) ] can be constructed on the converged shortest path S- > R0- > R5- > R4- > R3- > D, traffic addressed to D is transmitted to D through Segment List temporarily, after waiting for a period of time for all nodes to complete updating of the forwarding state, segment List is withdrawn, and the traffic is forwarded according to the converged shortest path.

Therefore, the existing TI-LFA backup path and Micro-loop average path calculation method require that the equipment on the shortest IGP path is a node supporting Segment Routing. However, when the Segment Routing technology is deployed in the network, all the devices are not upgraded at the same time to support Segment Routing, so that a situation that the devices which do not support Segment Routing and the devices which support Segment Routing are co-networked together in the network is unavoidable. It can be seen from the calculation process of the TI-LFA and the anti-micro ring Segment List that in this case, in the process of generating the Segment List, the Segment List may not be generated due to the existence of a device which does not support Segment Routing on the shortest path.

As shown in fig. 7, the backup path calculated by the Node B for F is [ Node (C), link (C- > E) ], but the backup Segment List cannot be constructed because the Node C does not support Segment Routing. Resulting in failure to form TI-LFA protection. In practice there is a path [ Node (D), link (D- > E) ] that can provide protection.

As shown in fig. 8, when R2 and R3 fail, the shortest path after convergence calculated by the node R0 is R0- > R5- > R4- > R3- > D, but the node R4 does not support Segment Routing, so that a micro-ring cannot be constructed to avoid Segment List. Resulting in the inability to provide the microring avoidance function. It is in fact the presence of the path R0- > R5- > R3- > D that can provide the microring avoidance function.

Based on the analysis of the technical problems, the inventor proposes a calculation strategy for the TI-LFA backup path and the micro-ring prevention path, so that under the condition that the equipment which does not support Segment Routing and the equipment which supports Segment Routing are in the same networking, the node which does not support Segment Routing can be automatically bypassed, and the available Segment List is calculated in a best effort mode, and then the TI-LFA backup path and the micro-ring prevention path are obtained.

As a first aspect of the present disclosure, the present disclosure provides a path calculation method, as shown in fig. 1, including:

in step S100, in a network where a non-segment routing SR node exists, a segment list including only SR nodes is generated using a plurality of nodes from a head node to a tail node, wherein the non-SR node is a node that does not support segment routing capability, and the SR node is a node that supports segment routing capability.

It should be noted that, the node described in the present disclosure refers to a network element that can affect the establishment of a segment list or the forwarding of a message according to the segment list, and a switch, a wireless device, etc. of two layers in a message forwarding path do not affect the establishment of the segment list or the forwarding of the message according to the segment list, so that the node is not in the scope of the node described herein. I.e. the definition of "only SR node" cannot be negated by such network elements that do not have an impact.

It should be noted that, the fault point described in the present disclosure may be a fault point that has failed, or may be a fault point that is determined according to a network topology and may fail. Therefore, the generating the segment list according to the fault point on the main path to the tail node in the disclosure may be calculating the segment list according to the position of the fault point when the fault occurs so as to obtain the loop-free backup path; before the fault occurs, the segment list corresponding to the assumed fault points is calculated in advance according to the position of at least one assumed fault point which possibly occurs in the main path, so that the loop-free backup path is obtained, the service can be switched more quickly when the fault occurs, and the reliability of the network is improved.

It should be noted that the Segment Routing (SR) capabilities described in this disclosure include SRv capabilities and SRv6 capabilities, as well as other versions of segment routing capabilities that may occur. Correspondingly, in order to avoid excessively complicated sentences, when calculating SRv segmentation list, the SR node and the non-SR node judge whether SRv capacity is supported or not; in computing SRv the segment list, the SR node and the non-SR node determine whether SRv capabilities are supported; when calculating the segment list of other versions, the SR node and the non-SR node determine whether the segment routing capability of the other versions is supported.

In the conventional calculation process of the TI-LFA backup path and the Micro-loop availabilities path, although the Segment List can be calculated for the Micro-loop link, the calculation of the Segment List depends on the shortest path calculated by the IGP, if the shortest path exists a node which does not support Segment Routing, the available Segment List can not be calculated, and the TI-LFA and the Micro-loop availabilities can not be realized. The present disclosure addresses this problem by calculating a backup path that includes only SR nodes using a plurality of nodes from head node to tail node. The plurality of nodes may be all nodes in the network, or may be part of nodes in the network, for example, part of nodes in a multi-topology or multi-instance scenario. By calculating a plurality of nodes, a backup path only comprising SR nodes is obtained, nodes which do not support Segment Routing are automatically avoided, a Segment List is generated, and then a TI-LFA backup path and a Micro-loop average path are obtained.

The first idea of automatically avoiding non-SR nodes is to exclude non-SR nodes when computing backup paths and generating segment lists by IGP, and only SR nodes participate in the computation, thus obtaining a segment list including only SR nodes.

In some embodiments, the generating a segment list including only SR nodes using a plurality of nodes from a head node to a tail node, as shown in fig. 2, includes:

in step S210, determining a plurality of SR nodes from the head node to a plurality of nodes of the tail node;

in step S220, a segment list including only SR nodes is generated from the plurality of SR nodes.

calculating the priority of each first path;

And when the TI-LFA backup Segment List and the anti-micro ring Segment List are calculated, removing the nodes which do not support Segment Routing from the topology, and then carrying out path calculation. For example, SR-MPLS scenarios force exclusion of nodes that do not support SR-MPLS. SRv6 scenario forces exclusion of nodes that do not support SRv 6. Then, a route protocol is used to calculate a path with highest priority within a range of a plurality of SR nodes excluding non-SR nodes, for example, a route cost (cost) is calculated according to a shortest path algorithm of an IGP route protocol, the smaller the cost is, the higher the priority is, and a TI-LFA and an anti-micro ring Segment List are constructed on the basis of the IGP path with highest priority.

The method is simple and efficient, but in the calculation process, although possible paths pass through nodes which do not support Segment Routing, the generation of Segment List on the paths is not affected, and because non-SR nodes can be forcedly excluded, the paths can be possibly misexcluded.

The second idea of automatically avoiding the non-SR node is to determine whether a non-SR node exists in each backup path when each backup path is calculated by IGP, reduce the priority of the backup path passing through the non-SR node, make the priority of the backup path passing through the non-SR node lower than that of the backup path not passing through the non-SR node, and then generate a segment list according to the backup path with the highest priority.

In some embodiments, the generating a segment list including only SR nodes using a plurality of nodes from a head node to a tail node, as shown in fig. 3, includes:

in step S310, a second path is calculated using a plurality of nodes from the head node to the tail node according to the routing protocol;

in step S320, an initial priority reference value of each second path is calculated;

in step S330, according to whether each second path includes a non-SR node, the initial priority reference value of each second path is adjusted to obtain the final priority reference value of each second path, so that the final priority of the second path including the non-SR node is lower than the final priority of the second path not including the non-SR node; wherein the non-SR node is a node which does not support the segmented routing capability;

in step S340, the segment list is generated according to the second path with the highest final priority.

judging whether each second path comprises a non-SR node or not;

When the TI-LFA path and the anti-micro loop path are calculated, the priority of the path passing through the node which does not support the SR is reduced, so that when the shortest path after convergence is calculated, as long as a plurality of nodes all support the SR, the path which is preferably supported by all the nodes in the path is provided, and the path which is not preferably provided for the node which does not support the SR is not provided.

For example, path calculation is still performed by adopting an IGP shortest path tree mode, when each path is calculated, whether a non-SR node exists in the current path is judged, and if the non-SR node does not exist in the current path, the cost of the current path is normally calculated; if so, a preset cost value is added to the current path in the calculation process, so that the cost of the current path is enough to be larger than that of the current path normally calculated according to the IGP protocol. For example, the cost configured under each network element interface in the network is between 1 and 100, even if the path bypasses a plurality of network elements, the path cost will not exceed 3000, and when the current second path includes a non-SR node, a preset 100000 is added to the current second path when the path cost is calculated, and then the cost of the path is necessarily greater than the cost of all paths without the non-SR node.

It should be noted that, the added preset cost value does not modify the real configured cost under the network element and the interface, but is only added in the process of calculating the second path, and the added cost value can be understood as a penalty value of the path including the non-SR node.

In some embodiments, the path computation method further comprises:

If the paths include nodes that do not support SR, the routing protocol prefers the shortest path after convergence, and the message is still forwarded according to the shortest path.

The second approach consumes more computational power than the first approach, and when multiple paths all contain nodes that do not support SR, the method may further select a path with the least overhead among the paths to attempt to generate a Segment List.

The third idea of automatically avoiding non-SR nodes is to try to generate a segment list one by one according to the priority order of each backup path without adjusting the priority of each backup path calculated by IGP.

In some embodiments, the generating a segment list including only SR nodes using a plurality of nodes from a head node to a tail node, as shown in fig. 4, includes:

in step S410, a third path is calculated using the plurality of nodes from the head node to the tail node according to the routing protocol;

in step S420, it is determined whether each third path includes a non-SR node, and the segment list is generated according to the third paths that do not include the non-SR node.

Unlike the second approach, when calculating the priority of the third path, no penalty is added to the paths including non-SR nodes, and the priorities calculated according to the routing protocol are directly compared and ordered. For example, all possible third paths in the topology are computed by IGP shortest path tree, and irrespective of whether there are non-SR nodes in the paths, the priority is ordered according to the cost of the paths, the smaller the cost the higher the priority. When the TI-LFA and the micro-ring prevention path are calculated, if the converged optimal path cannot construct a Segment List, trying to construct the Segment List by using the suboptimal path, if the suboptimal path still cannot construct the Segment List, trying to construct the Segment List by using a suboptimal path, and so on until the Segment List is constructed or a plurality of paths are traversed.

The third concept has higher computational performance consumption than the first two concepts, but can ensure that the second concept can be constructed as long as a path capable of constructing a Segment List exists.

Further, the path calculation method further includes:

The segmented list from the head node to the tail node established by the path calculation method can be used for establishing an end-to-end available path for the service message, thereby realizing the functions of TI-LFA and micro-ring path prevention.

The following describes a specific application of the path computation method according to the first aspect of the present disclosure in an actual network topology, taking SRv6 as an example, with reference to 6 specific embodiments.

Example 1

The calculation of the TI-LFA path forces exclusion of nodes that do not support SRv.

As shown in fig. 7, where the main path of Node B to Node F is a Link between B and F, node C does not support SRv, and calculates a TI-LFA backup path for the main path Link (B- > F), the backup path may be calculated as Node D, link D- > E, excluding Node C. Thereby constructing a backup Segment List as [ Adjacent SID (D- > E) ].

Example 2

Computing the anti-micro loop path forces exclusion of nodes that do not support SRv 6.

As shown in fig. 8, the node R4 does not support SRv, when link (R2- > R3) fails, and when an anti-micro ring path is calculated for node D on R0, the R4 node is excluded, and an optimal path is obtained as R0- > R5- > R3- > D, so that an anti-micro ring SRv6Segment List is constructed as [ Adjacent SID (R5- > R3) ].

Example 3

The TI-LFA path is calculated to try to exclude nodes that do not support SRv.

As shown in FIG. 7, where the primary path for Node B to reach Node F is the Link between B and F, node C does not support SRv, when the TI-LFA backup path is calculated for the primary path Link (B- > F), there are paths [ Node [ C ], link [ C- > E ] ] and [ Node [ D ], link [ D- > E ] ], and since Node C does not support SRv6, the priority of path [ Node [ C ], link [ C- > E ] ] is lowered, and path [ Node [ D ], link [ D- > E ] ] is selected. Thereby constructing a backup Segment List of [ Adjacent SID (D- > E) ]

Example 4

Computing the anti-micro loop path best efforts excludes nodes that do not support SRv.

As shown in fig. 8, node R4 does not support SRv, when link (R2- > R3) fails, there are paths R0- > R5- > R4- > R3- > D and R0- > R5- > R3- > D when an anti-micro-ring path is calculated for node D on R0, and since R4 does not support SRv6, the priority of path R0- > R5- > R4- > R3- > D is reduced, preferably path R0- > R5- > R3- > D, thereby constructing an anti-micro-ring SRv6Segment List as [ adjar SID (R5- > R3) ].

Example 5

The TI-LFA path is calculated to try to exclude nodes that do not support SRv.

As shown in fig. 7, where the primary path for node B to reach node F is the Link between B and F, node C does not support SRv, when calculating the TI-LFA backup path for the primary path Link (b— > F):

the optimal path is [ Node [ C ], link [ C- > E ] ], but Node C in the optimal path does not support SRv6, so that a Segment List cannot be constructed, and therefore the optimal path [ Node [ C ], link [ C- > E ] ] is abandoned.

The suboptimal path is [ Node [ D ], link [ D- > E ] ], nodes on the suboptimal path all support SRv, so this path is selected as a backup path, and thus a backup Segment List is [ Adjacent SID (D- > E) ].

Example 6

As shown in fig. 8, node R4 does not support SRv, when link (R2 — > R3) fails, the anti-micro-ring path is calculated for node D on R0:

the optimal path is R0- > R5- > R4- > R3- > D, and since R4 does not support SRv6, the path R0- > R5- > R4- > R3- > D is abandoned.

The suboptimal path is R0- > R5- > R3- > D, and nodes on the path all support SRv, so that the path is selected as a backup path, and an anti-micro ring SRv6Segment List is [ Adjacent SID (R5- > R3) ].

In a second aspect, an embodiment of the present disclosure provides an electronic device, as shown in fig. 9, including:

one or more processors 501;

a memory 502 having one or more programs stored thereon, which when executed by one or more processors causes the one or more processors to implement the path computation method as in any of the first aspects above;

one or more I/O interfaces 503, coupled between the processor and the memory, are configured to enable information interaction of the processor with the memory.

Wherein the processor 501 is a device having data processing capabilities, including but not limited to a Central Processing Unit (CPU) or the like; memory 502 is a device with data storage capability including, but not limited to, random access memory (RAM, more specifically SDRAM, DDR, etc.), read-only memory (ROM), electrically charged erasable programmable read-only memory (EEPROM), FLASH memory (FLASH); an I/O interface (read/write interface) 503 is coupled between the processor 501 and the memory 502 to enable information interaction between the processor 501 and the memory 502, including but not limited to a data Bus (Bus) or the like.

In some embodiments, processor 501, memory 502, and I/O interface 503 are connected to each other and, in turn, other components of the computing device via bus 504.

In a third aspect, an embodiment of the present disclosure provides a computer readable storage medium, as shown in fig. 10, on which a computer program is stored, the computer program implementing the path calculation method of any one of the above first aspects when executed by a processor.

Those of ordinary skill in the art will appreciate that all or some of the steps of the methods, systems, functional modules/units in the devices disclosed above may be implemented as software, firmware, hardware, and suitable combinations thereof.

In a hardware implementation, the division between the functional modules/units mentioned in the above description does not necessarily correspond to the division of physical components; for example, one physical component may have multiple functions, or one function or step may be performed cooperatively by several physical components. Some or all of the physical components may be implemented as software executed by a processor, such as a central processing unit, digital signal processor, or microprocessor, or as hardware, or as an integrated circuit, such as an application specific integrated circuit. Such software may be distributed on computer readable media, which may include computer storage media (or non-transitory media) and communication media (or transitory media). The term computer storage media includes both volatile and nonvolatile, removable and non-removable media implemented in any method or technology for storage of information such as computer readable instructions, data structures, program modules or other data, as known to those skilled in the art. Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital Versatile Disks (DVD) or other optical disk storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium which can be used to store the desired information and which can be accessed by a computer. Furthermore, as is well known to those of ordinary skill in the art, communication media typically embodies computer readable instructions, data structures, program modules or other data in a modulated data signal such as a carrier wave or other transport mechanism and includes any information delivery media.

The preferred embodiments of the present disclosure have been described above with reference to the accompanying drawings, and are not thereby limiting the scope of the claims of the present disclosure. Any modifications, equivalent substitutions and improvements made by those skilled in the art without departing from the scope and spirit of the present disclosure shall fall within the scope of the claims of the present disclosure.

Claims

1. A path computation method, comprising:

in a network in which a non-segment routing SR node exists, a segment list only comprising SR nodes is generated by utilizing a plurality of nodes from a head node to a tail node, wherein the non-SR node is a node which does not support segment routing capability, and the SR node is a node which supports segment routing capability.

2. The path computation method of claim 1, wherein the generating a segment list including only SR nodes using a plurality of nodes from a head node to a tail node comprises:

3. The path computation method of claim 2, wherein generating a segment list including only SR nodes from the plurality of SR nodes comprises:

calculating the priority of each first path;

4. The path computation method of claim 1, wherein the generating a segment list including only SR nodes using a plurality of nodes from a head node to a tail node comprises:

calculating initial priority reference values of the second paths;

5. The path computation method of claim 4, wherein the priority reference value comprises an overhead value, the overhead value being inversely proportional to priority;

judging whether each second path comprises a non-SR node or not;

6. The path computation method of claim 5, wherein the path computation method further comprises:

7. The path computation method of claim 1, wherein the generating a segment list including only SR nodes using a plurality of nodes from a head node to a tail node comprises:

8. The path computation method of claim 7, wherein the determining, piece by piece, whether each third path includes a non-SR node, generating the segment list according to the third paths that do not include a non-SR node, comprises:

9. The path computation method according to any one of claims 1 to 8, wherein the path computation method further comprises:

10. An electronic device, the electronic device comprising:

one or more processors;

a memory having one or more programs stored thereon, which when executed by the one or more processors, cause the one or more processors to implement the path computation method of any of claims 1 to 9;

11. A computer readable storage medium having stored thereon a computer program which, when executed by a processor, implements the path computation method according to any one of claims 1 to 9.