WO2016070670A1 - 一种跨域路径的计算方法及装置 - Google Patents

一种跨域路径的计算方法及装置 Download PDF

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WO2016070670A1
WO2016070670A1 PCT/CN2015/087561 CN2015087561W WO2016070670A1 WO 2016070670 A1 WO2016070670 A1 WO 2016070670A1 CN 2015087561 W CN2015087561 W CN 2015087561W WO 2016070670 A1 WO2016070670 A1 WO 2016070670A1
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domain
path
pce
cross
intra
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French (fr)
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盛伟
卢刚
李晓建
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中兴通讯股份有限公司
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  • This paper relates to, but is not limited to, the path computation technology in the field of communication. Specifically, it is a calculation method and device for a cross-domain path.
  • the node set belonging to the common address management scope or following the same path calculation rule in the MPLS/GMPLS network is divided into one domain (DOMAIN), and the large-scale network is connected by the inter-domain link.
  • the domain consists of each domain having at least one PCE, managing intra- and inter-domain traffic data, and calculating end-to-end TE-LSP paths.
  • Figure 1 is a 4-domain MPLS-TE/GMPLS network topology diagram.
  • the nodes on the ring dotted line represent domain boundary nodes (including nodes N11, N12, N13, N14 of domain 1, and nodes N21, N22, N23, N24 of domain 2, N25, node N31, N32, N33, N34 of domain 3, nodes N41, N42, N43, N44 of domain 4, PCE1, PCE2, PCE3, and PCE4 are one of domain 1, domain 2, domain 3, and domain 4, respectively.
  • the domain PCE server is connected to the primary PCE, maintains the traffic database, and is responsible for the path calculation of the domain node request.
  • the intra-domain traffic data managed by each domain PCE is kept secret.
  • the single-domain sub-PCE cannot obtain the intra-domain information of other domains, and cannot calculate the intra-domain paths of other domains. Therefore, any single-domain PCE cannot independently complete the inter-domain end-to-end.
  • the TE-LSP path calculation requires multi-domain PCE collaboration to splicing the path segments in the local domain calculated by each domain PCE into a complete cross-domain path.
  • the PCEs interact with each other according to the PCEP (Path Computation Unit Communication Protocol) message defined by the RFC5440 protocol.
  • PCEP Path Computation Unit Communication Protocol
  • Method 1 A multi-PCE domain-by-domain computing cross-domain path method based on the RFC5152 protocol.
  • the first domain PCE receives the calculation of the inter-domain path request, calculates the inter-domain path route and returns the source node, and the inter-domain routing node establishes the inter-domain path according to the RSVP-TE (Resource Reservation Protocol-Traffic Engineering) protocol, along the inter-domain route.
  • the PATH signaling is transmitted, and the inter-domain path reserved resource is calculated.
  • the source node and the domain inbound boundary node request the local PCE to calculate the intra-domain path route, and transmit the PATH signaling along the intra-domain route to calculate the intra-domain path.
  • the path reserves resources.
  • the destination node After receiving the PATH signaling, the destination node returns RESV signaling reversely along the inter-domain and intra-domain routes, and allocates path resources at each node to complete the establishment of the inter-domain path.
  • the first node SRC receives the cross-domain path request from the first node SRC to the destination node DST, and requests the PCE1 to calculate the inter-domain path.
  • the PCE1 calculates the optimal domain according to the inter-domain routing policy in the inter-domain topology.
  • the inter-path route is: SRC, node BN_EX1, node BN_EN2, node BN_EX2, node BN_EN3, DST, the calculation result returns SRC, message flow (1), PATH signaling is transmitted along the inter-domain route, and SRC, BN_EN2, BN_EN3 receive the domain After the PATH signaling, PCE1, PCE2, and PCE3 are respectively requested to calculate the intra-domain path routing of domain 1, domain 2, and domain 3. See message flows (2), (5), and (8), and the intra-domain PATH signaling is along the domain. The path reserving the path resources in domain 1, domain 2, and domain 3, see message flows (3), (6), and (9).
  • the destination node DST After receiving the PATH message, the destination node DST reversely returns the RESV signaling along the cross-domain path. To allocate the path resource in the inter-domain domain, see message flow (10), the first node SRC receives the RESV signaling, and completes the cross-domain path establishment.
  • the method path calculation is included in the path establishment process, and the cross-domain path calculated by the first domain PCE is divided into intra-domain path segments, along the inter-domain path PATH signaling direction, and the intra-domain PCE calculates the intra-domain path routing, along the intra-domain path PATH. Let each node calculate the reserved path resource. This method can only calculate one cross-domain path at a time. Although the calculation time is small, the calculation success rate is low. If the path calculation fails in any domain, the cross-domain path calculation fails. The failure backtracking recalculation is complicated and calculated. Cross-domain paths are not necessarily optimal across the entire network.
  • Method 2 Reverse Recursive Path Computation (BRPC) method based on RFC5441 protocol.
  • the first domain PCE receives the calculation of the inter-domain path request, calculates the optimal domain sequence according to the inter-domain routing policy, and sends the BRPC path calculation request message from the first domain PCE to the downstream domain PCE until the tail domain PCE receives the BRPC path calculation request message.
  • the tail domain PCE calculates the shortest path tree (VSPT) from the tail domain to the destination node, and returns the domain VSPT to the upstream domain PCE, and the upstream domain PCE calculates The VSPT of the local domain inbound node passing the downstream domain VSPT to the destination node continues to return the VSPT calculation result to the upstream domain PCE. Only the first domain PCE receives the downstream domain VSPT, and calculates the shortest path from the source node to the destination node as the cross-domain. Path calculation result.
  • VSPT shortest path tree
  • PCE1 receives the cross-domain path request from compute node N11 to node N32, calculates the optimal domain sequence domain 1, domain 2, and domain 3.
  • PCE1 sends a BRPC calculation request to PCE2, and PCE2 sends a BRPC calculation to PCE3.
  • the request PCE3 calculates VSPT (domain 3), returns to PCE2, PCE2 calculates VSPT (domain 2), and returns to PCE1, PCE1 calculates VSPT (domain 1), that is, the optimal cross-domain path from N11 to N32.
  • the method traverses all the inter-domain paths and selects the optimal cross-domain path result.
  • the calculation success rate is high, but the calculation efficiency is poor.
  • Each domain PCE is required to calculate all the intra-domain path segments in sequence.
  • Method 3 A cross-domain path calculation method for a hierarchical PCE architecture based on the RFC6805 protocol.
  • the path calculation unit is divided into two levels of the parent and child PCE.
  • the sub-PCE maintains the intra-domain topology information, and the inter-domain topology information is saved to the parent PCE.
  • the parent PCE maintains the inter-domain topology information, which reduces the size of the inter-domain topology information and improves the topology convergence and path. Calculate the speed.
  • the parent and child PCEs jointly calculate the inter-domain path, and the parent PCE calculates the inter-domain path route of the inter-domain path in the inter-domain topology.
  • the inter-domain route scheduling sub-PCE calculates all the intra-domain path segments in parallel, and the parent PCE calculates the successful intra-domain path. In the segment, splicing and selecting the optimal cross-domain path.
  • PCE1, PCE2, PCE3, and PCE4 are four sub-domain PCEs. After receiving the cross-domain path calculation request from N11 to N32 of PCE1, the parent PCE calculates all four spans in the inter-domain topology.
  • PCE requests the sub-PCE to calculate all the intra-domain path segments: PCE1 calculates the two intra-domain paths from N11 to N13, N11 to N14 in domain 1, and PCE2 calculates N25 to N22 in domain 2, Two intra-domain paths from N25 to N24, PCE3 calculates two intra-domain paths from N31 to N32 and N33 to N32 in domain 3.
  • PCE4 calculates two intra-domain paths from N41 to N43 and N44 to N43 in domain 4. All sub-PCEs will be in the domain. The path calculation result returns to the parent PCE, and the parent PCE selects the optimal cross-domain path for calculation.
  • each domain sub-PCE calculates all intra-domain path segments in parallel, the parent PCE
  • the splicing and selection of the optimal inter-domain path is computationally efficient.
  • this method is only applicable to a simple inter-domain topology network.
  • the number of path segments in the domain to be calculated increases and the computational efficiency decreases.
  • the number of intra-domain paths calculated by the sub-PCE is reduced by limiting the number of inter-domain path routes calculated by the parent PCE, but the computational success rate may be reduced because the parent PCE does not hit the optimal cross-domain path route.
  • the embodiment of the invention provides a new cross-domain path calculation solution to solve the technical problem of further improving the calculation efficiency while ensuring the success rate of the cross-domain path calculation.
  • the embodiment of the invention provides a method for calculating a cross-domain path, including:
  • the parent path calculation unit PCE calculates an optimal domain sequence according to the inter-domain routing policy
  • the parent PCE scheduling sub-PCE calculates all intra-domain path routes in parallel on the calculated domain sequence
  • the parent PCE calculates an optimal intra-domain path according to the sub-PCE to calculate an optimal cross-domain path
  • the parent PCE requests the sub-PCE to calculate the intra-domain path segment reserved resources of the selected cross-domain path in parallel;
  • the parent PCE After all the sub-PCE reserved path resources are successful, the parent PCE returns the selected cross-domain path as the cross-domain path calculation result.
  • the method further includes:
  • the parent PCE sets the domain as a fault domain; when the domain is a tail domain of the domain sequence and the number of domains in the domain sequence is greater than 2, The parent PCE sets the upstream domain of the domain as a fault domain; when the domain is the first domain of the domain sequence and the domain in the domain sequence When the number of the parent PCE is greater than 2, the parent PCE sets the downstream domain of the domain as the fault domain; the parent PCE recalculates the optimal domain sequence and performs subsequent operations after excluding the fault domain that is set;
  • the parent PCE returns a cross-domain path and the result of the calculation is a failure.
  • the parent PCE calculates a successful intra-domain path according to the sub-PCE to select an optimal cross-domain path, including:
  • the parent PCE associates the intra-domain path in which the sub-PCE calculation is successful with the abstract link, and sets the intra-domain path metric target to an abstract link metric target, and deletes the abstract link corresponding to the intra-domain path that fails to be calculated;
  • the parent PCE constructs a cross-domain path calculation topology by using the abstract link and the inter-domain link, and calculates all the cross-domain paths arranged according to the path metric target value according to the inter-domain routing policy;
  • the parent PCE selects the current optimal cross-domain path.
  • the method further includes:
  • the next optimal cross-domain path is selected according to the path metric target value, and the sub-PCE performs parallel calculation of the intra-domain path segment reserved resources of the selected inter-domain path.
  • the parent PCE scheduling sub-PCE calculates all the intra-domain path routes in parallel, including:
  • the parent PCE traverses the inter-domain links of each domain and the upstream and downstream domains according to the calculated domain sequence order, and determines the inbound boundary node group and the outbound boundary node group of each sub-domain respectively; creating the inbound boundary node and the outbound boundary node Inter-m*n intra-area path calculation request, m is the number of inbound boundary nodes, n is the number of outbound boundary nodes, the first domain inbound boundary node group only contains the source node, and the tail domain outbound boundary node group only contains the sink nodes;
  • the parent PCE sends the intra-domain path computation request to each sub-PCE.
  • the embodiment of the present invention further provides a cross-domain path computing device, which is disposed in the parent path computing unit PCE.
  • the device includes:
  • the domain sequence calculation module is configured to calculate an optimal domain sequence according to an inter-domain routing policy
  • a scheduling module configured to schedule sub-PCEs to calculate all intra-domain path routes in parallel on the calculated domain sequence
  • a requesting module configured to request the sub-PCE to calculate a resource reserved for the intra-domain path segment of the selected cross-domain path in parallel;
  • the result is returned to the module, and is set to return the selected cross-domain path as the cross-domain path calculation result after all the sub-PCEs reserve the path resource successfully.
  • the device further includes:
  • the fault domain setting module is configured to set the domain as the fault domain if the domain is the intermediate domain of the domain sequence, if the domain is the domain of the domain sequence, and if the domain is the tail domain of the domain sequence If the number of domains in the domain sequence is greater than 2, the upstream domain of the domain is set as the fault domain; if the domain is the first domain of the domain sequence and the number of domains in the domain sequence is greater than 2, then Setting a downstream domain of the domain as a fault domain; if the domain is a first domain of the domain sequence and only two domains exist in the domain sequence, or the domain is a tail domain of the domain sequence and the domain sequence is There are only two domains, indicating that the result return module returns a cross-domain path calculation result as a failure;
  • the fault domain elimination module is configured to re-start the domain sequence calculation module to calculate an optimal domain sequence after excluding the fault domain that is set.
  • the selecting module is configured to implement an optimal cross-domain path in the intra-domain path selection according to the sub-PCE calculation by:
  • the intra-domain path metric target is set to an abstract link metric target, and the abstract link corresponding to the intra-domain path in which the calculation fails is deleted; using the abstract link and the inter-domain chain
  • the requesting module is further configured to: when the selected cross-domain path fails to reserve resources, select the next optimal cross-domain path according to the path metric target value, request the sub-PCE to perform parallel calculation of the selected cross The intra-domain path segment of the domain path reserves resources.
  • the scheduling module is configured to perform parallel calculation of all intra-domain path routes by scheduling the sub-PCE on the calculated domain sequence by:
  • An embodiment of the present invention provides a computer storage medium, where the computer storage medium stores computer executable instructions, and the computer executable instructions are used to execute the foregoing method.
  • the cross-domain path calculation scheme proposed by the embodiment of the present invention is based on the hierarchical PCE architecture.
  • the sub-PCEs calculate the intra-domain path segments that constitute the inter-domain path in parallel, and the intra-domain path routing and resource pre-preparation.
  • the calculation is separated, which reduces the calculation range of the domain and the calculation of the path resources in the reserved domain, improves the calculation efficiency, and can better satisfy the network application.
  • the embodiment of the present invention introduces a fault domain backtracking algorithm to ensure that the cross-domain path is calculated in the entire network, and the calculation success rate is improved.
  • FIG. 1 is a diagram showing an example of an MPLS-TE/GMPLS network topology
  • FIG. 2 is a schematic diagram of a multi-PCE domain-by-domain computing cross-domain path
  • FIG. 3 is a schematic diagram of calculating a cross-domain path by a BRPC method
  • FIG. 4 is a schematic diagram of a cross-domain path for computing a hierarchical PCE architecture
  • FIG. 5 is a schematic flowchart diagram of a method for calculating a cross-domain path according to an embodiment of the present invention
  • FIG. 6 is a flowchart of a method for cooperatively calculating a cross-domain path between a parent and a child PCE in an example of an embodiment of the present invention
  • FIG. 7 is a schematic diagram of a computing device of a cross-domain path set in a parent path computing unit PCE according to an embodiment of the present invention.
  • Figure 8 (a) is a schematic diagram of a domain sequence in an embodiment of the present invention.
  • FIG. 8(b) is a schematic diagram of a domain boundary node group in an embodiment of the present invention.
  • FIG. 8(c) is a schematic diagram of a cross-domain path calculation topology in the embodiment of the present invention.
  • FIG. 8(d) is a schematic diagram of a cross-domain path selected in the embodiment of the present invention.
  • FIG. 8(e) is a schematic diagram of a cross-domain path for completing resource allocation in an embodiment of the present invention.
  • FIG. 9( a ) is a second schematic diagram of a cross-domain path calculation topology in an embodiment of the present invention.
  • FIG. 9(b) is a second schematic diagram of the cross-domain path selected in the embodiment of the present invention.
  • FIG. 9(c) is a second schematic diagram of a cross-domain path for completing resource allocation in an embodiment of the present invention.
  • FIG. 10(a) is a third schematic diagram of a cross-domain path calculation topology in the embodiment of the present invention.
  • Figure 10 (b) is a second schematic diagram of the domain sequence in the first embodiment of the present invention.
  • Figure 10 (c) is a second schematic diagram of a domain boundary node group in the embodiment of the present invention.
  • Figure 10 (d) is the third of the path topology in the embodiment of the present invention.
  • Figure 10 (e) is a third schematic diagram of the cross-domain path selected in the embodiment of the present invention.
  • FIG. 10(f) is a third schematic diagram of a cross-domain path in which resource allocation is completed in an embodiment of the present invention.
  • a cross-domain path calculation method as shown in FIG. 5, includes:
  • the parent path calculation unit PCE calculates an optimal domain sequence according to the inter-domain routing policy
  • the parent PCE scheduling sub-PCE calculates all intra-domain path routes in parallel on the calculated domain sequence
  • the parent PCE calculates an optimal intra-domain path according to the sub-PCE to calculate an optimal cross-domain path
  • the parent PCE requests the sub-PCE to calculate the intra-domain path segment reserved resources of the selected cross-domain path in parallel;
  • the parent PCE After all the sub-PCE reserved path resources are successful, the parent PCE returns the selected cross-domain path as the cross-domain path calculation result.
  • the embodiment of the present invention is based on a hierarchical PCE architecture, starting from an optimal domain sequence, traversing and calculating all cross-domain path routes on the domain sequence, and multiple sub-PCEs in parallel computing domain path segment routing and reserving designated cross-domain path resources, reducing sub-PCE Serial calculation and reservation of path resources in redundant domains improve computational efficiency.
  • the method may further include:
  • the parent PCE sets the domain as a fault domain; when the domain is a tail domain of the domain sequence and the number of domains in the domain sequence is greater than 2, The parent PCE sets the upstream domain of the domain as the fault domain; when the domain is the first domain of the domain sequence and the number of domains in the domain sequence is greater than 2, the parent PCE sets the downstream domain of the domain. a fault domain; the parent PCE recalculates the optimal domain sequence and performs subsequent operations after excluding the fault domain that is set;
  • the parent PCE returns a cross-domain path and the result of the calculation is a failure.
  • the fault domain backtracking algorithm is used to recalculate the domain sequence, and the entire network calculates the cross-domain path to ensure the calculation success rate.
  • the parent PCE calculates a successful intra-domain path according to the sub-PCE to select an optimal cross-domain path, including:
  • the parent PCE associates the intra-domain path in which the sub-PCE calculation is successful with the abstract link, and sets the intra-domain path metric target to an abstract link metric target, and deletes the abstract link corresponding to the intra-domain path that fails to be calculated;
  • the parent PCE constructs a cross-domain path calculation topology by using the abstract link and the inter-domain link, and calculates all cross-domain paths arranged according to the path metric target value according to the inter-domain routing policy;
  • the parent PCE selects the current optimal cross-domain path.
  • the inter-domain routing policy may be specified in advance or selected according to related technologies.
  • the method may further include: if the selected cross-domain path reserves the resource fails, selecting the next best cross-domain path according to the path metric target value, requesting the sub-PCE to perform the parallel calculation of the selected cross-domain The in-domain path segment of the path reserves resources.
  • the calculating, by the parent PCE scheduling sub-PCE, all the intra-domain path routes in the calculated domain sequence may include:
  • the parent PCE traverses the inter-domain links of each domain and the upstream and downstream domains according to the calculated domain sequence order, and determines the inbound boundary node group and the outbound boundary node group of each sub-domain respectively; creating the inbound boundary node and the outbound boundary node Inter-m*n intra-area path calculation request, m is the number of inbound boundary nodes, n is the number of outbound boundary nodes, the first domain inbound boundary node group only contains the source node, and the tail domain outbound boundary node group only contains the sink nodes;
  • the parent PCE sends the intra-domain path computation request to each sub-PCE.
  • a parent-child PCE collaboratively calculates a cross-domain path flow, and only describes a sub-PCE calculation flow, and a parent-child PCE collaborative message flow.
  • the cooperation message between the parent and the child PCE adopts the RFC5440 protocol PCEP message format, and the parent-child PCE cooperation message is as follows:
  • InterPath_REQ the cross-domain path calculation request message sent by the first domain sub-PCE to the parent PCE, and the PCReq message type
  • IntraPath_REQ multiple intra-domain path calculation request messages sent by the parent PCE to the sub-PCE, PCReq message type
  • IntraPath_RSP the sub-PCE returns multiple intra-domain path calculation result messages to the parent PCE, and the PCRep message type;
  • IntraAlloc_RSP The sub-PCE returns the reserved path resource result message in the specified domain to the parent PCE, and the PCNtf message type;
  • the parent PCE calculation process is as follows:
  • Step 101 The parent PCE receives the InterPath_REQ message of the first domain sub-PCE cross-domain path calculation request, or calculates a new fault domain, and the fault domain is calculated, and the optimal domain sequence is calculated according to the inter-domain routing policy.
  • Step 102 If the domain sequence calculation fails, step 115 is performed, and the cross-domain path calculation fails, and if successful, step 103 is performed;
  • Step 103 The parent PCE traverses the inter-domain link between each domain and the upstream and downstream domains according to the calculated sequence of the domain sequence, and determines the entry and exit boundary node group.
  • the i-th sub-domain entry and exit boundary node group is described as follows:
  • the first domain inbound boundary node group only contains the source node
  • the tail domain outbound boundary node group only contains the sink node, creating an intra-domain path calculation request between the inbound and outbound boundary nodes, and the intra-domain path becomes an inter-domain abstract link for constructing the inter-domain path, and the above description is created.
  • Step 104 The parent PCE requests each sub-PCE to calculate an intra-domain path route, and sends an IntraPath_REQ message to the sub-PCEs of all domains in the domain sequence.
  • Step 105 The parent PCE receives the intra-domain path response IntraPath_RSP message returned by the sub-PCE, if all the intra-domain path calculation fails, step 106 is performed, if each sub-PCE of the domain sequence can calculate at least one intra-domain path execution step 108;
  • Step 106 After the parent domain PCE uses the fault domain backtracking algorithm to determine the location of the path calculation failure subdomain in the domain sequence in all the domains, perform the following processing:
  • step 115 is performed, if the downstream domain is not the tail domain, and the downstream domain is set as the fault domain, step 107 is performed;
  • step 115 is performed, if it is not the first domain, the upstream domain is set as the fault domain, and step 107 is performed;
  • Step 107 The parent PCE adds the failure domain to the fault domain sequence, and returns to step 101, that is, backtracking and recalculating the new domain sequence, and calculating the cross-domain path;
  • Step 108 follows the in-domain data privacy principle, according to the RFC5220 protocol, the IntraPath_RSP message received by the parent PCE, and the ERO of the path in the successful domain is calculated in the Path-Key format, and the parent PCE will calculate the path Path-Key corresponding to the domain in success.
  • the abstract link association, the intra-domain path metric object is set to an abstract link metric target, and the abstract link corresponding to the path within the domain where the calculation fails is deleted;
  • Step 109 The parent PCE determines whether the IntraPath_RSP message of the sub-PCE of all domains in the domain sequence is received. If not, the process proceeds to step 109, and waits for the receiving domain sub-PCE to calculate the response. If all are received, step 110 is performed;
  • Step 110 Construct a cross-domain path calculation topology by using an inter-domain abstract link and an inter-domain link, and use an appropriate path algorithm according to the inter-domain routing policy to calculate all cross-domain paths arranged in the order of the path metric target value;
  • Step 111 Select the current optimal cross-domain path, determine whether it is successful, if it fails, perform step 115, return cross-domain path calculation failure, if successful, perform step 112;
  • Step 112 The requesting sub-PCE calculates an intra-domain path reserved resource of the selected optimal cross-domain path, and sends an IntraAlloc_REQ message to the sub-PCE.
  • Step 113 Receive the sub-PCE reserved resource response IntraAlloc_RSP message, and determine whether the sub-PCE reserves the path resource in the domain successfully. If the cross-domain path is deleted or marked as unavailable, perform step 111, that is, select the next best. The cross-domain path calculates the reserved resource, if successful, step 114;
  • Step 114 Determine whether the selected cross-domain path completes the reserved intra-path path segment resource. If not, go to step 113 and wait for the sub-PCE to reserve the resource response message. If yes, go to step 115 to return to the inter-domain path.
  • Step 115 Return the inter-domain path calculation result InterPath_RSP message to the sub-PCEs of all domains, and end the parent PCE calculation process.
  • Step 201 The first domain sub-PCE receives the cross-domain path calculation request of the source node, and sends a cross-domain path calculation request InterPath_REQ message to the parent PCE, thereby triggering step 101;
  • Step 202 The sub-PCE receives the m*n intra-domain path calculation request sent by the parent PCE.
  • IntraPath_REQ message selects an appropriate path algorithm, calculates the route of the optimal path in the m*n domain, uses the Path-Key format to generate the ERO information of the path in the successful domain, and sends an IntraPath_RSP message to the parent PCE.
  • Step 203 The sub-PCE receives the IntraAlloc_REQ message of the reserved intra-domain path resource request sent by the parent PCE, invokes the reserved resource algorithm to calculate the intra-domain path node and the link reserved resource, and returns the reserved intra-domain path resource result to the parent PCE.
  • Step 204 The sub-PCE receives the InterPath_RSP message of the cross-domain path calculation result sent by the parent PCE, and releases the intra-domain path data that is not selected in the domain.
  • Step 205 Determine whether the sub-PCE is the first domain sub-PCE of the cross-domain path, if not, end the sub-PCE calculation process, and if yes, go to step 206;
  • Step 206 Return the cross-domain path calculation result to the source node, and end the sub-PCE calculation process.
  • An embodiment of the present invention provides a computer storage medium, where the computer storage medium stores computer executable instructions, and the computer executable instructions are used to execute the foregoing method.
  • a cross-domain path computing device is disposed in a parent path computing unit PCE; the device includes:
  • the domain sequence calculation module is configured to calculate an optimal domain sequence according to an inter-domain routing policy
  • a scheduling module configured to schedule sub-PCEs to calculate all intra-domain path routes in parallel on the calculated domain sequence
  • a requesting module configured to request the sub-PCE to calculate a resource reserved for the intra-domain path segment of the selected cross-domain path in parallel;
  • the result is returned to the module, and is set to return the selected cross-domain path as the cross-domain path calculation result after all the sub-PCEs reserve the path resource successfully.
  • the device may further include:
  • the fault domain setting module is configured to set the domain as the fault domain if the domain is the intermediate domain of the domain sequence, if the domain is the domain of the domain sequence, and if the domain is the tail domain of the domain sequence If the number of domains in the domain sequence is greater than 2, the upstream domain of the domain is set as the fault domain; if the domain is the first domain of the domain sequence and the number of domains in the domain sequence is greater than 2, then Setting a downstream domain of the domain as a fault domain; if the domain is a first domain of the domain sequence and only two domains exist in the domain sequence, or the domain is a tail domain of the domain sequence and the domain sequence is There are only two domains, indicating that the result return module returns a cross-domain path calculation result as a failure;
  • the fault domain elimination module is configured to re-start the domain sequence calculation module to calculate an optimal domain sequence after excluding the fault domain that is set.
  • the selection module performs the optimal intra-domain path selection according to the sub-PCE to select an optimal cross-domain path, including:
  • the selecting module associates the intra-domain path in which the sub-PCE calculation is successful with an abstract link, and the intra-domain path metric target is set as an abstract link metric target, and the abstract link corresponding to the intra-domain path in which the calculation fails is deleted;
  • the inter-domain link is used to construct the cross-domain path calculation topology, and according to the inter-domain routing policy, all the inter-domain paths arranged according to the path metric target value are calculated; and the current optimal cross-domain path is selected.
  • the requesting module may be further configured to: when the selected cross-domain path fails to reserve resources, select the next optimal cross-domain path according to the path metric target value, and request the sub-PCE to perform parallel computing. Reserve resources in the intra-domain path segment of the cross-domain path.
  • scheduling module in the calculated sequence of the domain, scheduling the sub-PCE to calculate all the intra-domain path routes in parallel comprises:
  • the scheduling module traverses the inter-domain links of each domain and the upstream and downstream domains according to the calculated sequence of the domain sequence, and determines the inbound boundary node group and the outbound boundary node group of each sub-domain respectively; creating the inbound boundary node and the outbound boundary node Interval m*n intra-area path calculation request, m is the number of inbound boundary nodes, n is the number of outbound boundary nodes, the first domain inbound boundary node group only contains the source node, and the tail domain outbound boundary node group only contains the sink nodes; Each sub-PCE sends the intra-domain path computation request.
  • FIG. 1 In the illustrated 4-domain MPLS-TE/GMPLS network, an optimal cross-domain path from the source node (also referred to as the head node) N11 to the sink node N32 is requested to be calculated.
  • the source node also referred to as the head node
  • the sink node N32 In the illustrated 4-domain MPLS-TE/GMPLS network, an optimal cross-domain path from the source node (also referred to as the head node) N11 to the sink node N32 is requested to be calculated.
  • Embodiment 1 The path calculation and resource reservation in the sub-PCE domain are successful.
  • the parent PCE controls the calculation of the inter-domain path process, and the scheduling sub-PCE calculates the cross-domain path and the path resource in the specified domain in parallel.
  • the cross-domain path calculation process is described by the change of the topology between the parent PCE domains:
  • the parent PCE receives the calculation cross-domain path request message forwarded by the first domain sub-PCE, and determines the optimal domain sequence according to the inter-domain routing policy: domain 1, domain 2, and domain 3, as shown in FIG. 8(a);
  • Inbound node group Outbound node group Domain 1 (PCE1) ⁇ N11 ⁇ ⁇ N12, N13 ⁇ Domain 2 (PCE2) ⁇ N21, N25 ⁇ ⁇ N22, N23, N24 ⁇ Domain 3 (PCE3) ⁇ N31, N33, N34 ⁇ ⁇ N32 ⁇
  • the parent PCE traverses the inbound and outbound node pairs of each subdomain, constructs and sends all inbound path calculation requests from the inbound node to the outbound node to each sub PCE, specifically: requesting PCE1 to calculate N11 to N12, N11 to N13 two intra-domain path calculations, request PCE2 to calculate N21 to N22, N21 to N23, N24 to N22, N25 to N22, N25 to N23, N25 to N24 six intra-domain paths, request PCE3 to calculate N31 to N32, N33 to N32, N34 to N32 three intra-domain paths;
  • PCE1, PCE2, and PCE3 calculate the optimal intra-domain path of multi-point to multi-point (MP2MP) in parallel.
  • MP2MP path can be calculated on the same topological resource and decomposed into multiple point-to-multipoints.
  • P2MP optimal path parallel computing such as: PCE2 decomposes MP2MP calculation from 2 to 3 points into 2 P2MP parallel calculations, and calculates the optimal route of 6 intra-domain paths, including only passing nodes and chains. Route routing information, no reserved nodes and link resources.
  • the sub-PCE generates a Path-Key that calculates the path in the successful domain according to the RFC5220 protocol, and returns the parent PCE through the ERO of the PCEP PcRep message.
  • the path-key is described by "jj-PKxxyy". Path: jj represents the domain serial number, xx represents the serial number in the source node domain, and yy represents the serial number in the sink node domain;
  • the parent PCE After receiving the intra-domain path calculation response of all the sub-PCEs, the parent PCE calculates the successful intra-domain path as an abstract link (for example, the paths N11 to N12 in the domain 1 are the abstract path 1-PK12, and the paths N21 to N23 in the domain 2 are taken as The abstract path 2-PK13, etc., assigns the path metric target value (Metric object) in the domain to the abstract link in the domain, along the domain sequence, the cross-domain path constructed by the inter-domain link and the abstract link calculates the topology as shown in the figure
  • the embodiment of the present invention adopts the KSP algorithm, but is not limited to such an algorithm, and calculates all cross-domain paths sorted according to the path metric target value:
  • the third advantage N11, 1-PK12, N12, N21, 2-PK14, N24, N33, 3-PK32, N32;
  • the parent PCE selects the current optimal cross-domain path: N11, 1-PK12, N12, N21, 2-PK13, N23, N34, 3-PK42, N32, as shown in Figure 8(d), at this time, 1 -PK12, 2-PK13, 3-PK42 are connected by dashed lines, indicating that the path resources in the domain have not been reserved;
  • the parent PCE requests PCE1, PCE2, and PCE3 to reserve the path 1-PK12, 2-PK13, and 3-PK42 resources in the specified domain;
  • PCE1, PCE2, PCE3 complete the link resource reservation of the path 1-PK12, 2-PK13, 3-PK42 in the domain in parallel, and return the result to the parent PCE;
  • the parent PCE After receiving the message that the resources are reserved for the PCE1, PCE2, and PCE3, the parent PCE returns the cross-domain path calculation result to PCE1, PCE2, PCE3, and PCE4. At this time, the intra-domain path resource has been reserved, 1-PK12, 2-PK13. , 3-PK42 solid line connection, as shown in Figure 8 (e), the parent PCE ends the calculation.
  • the sub-PCE receives the cross-domain path calculation result, and each sub-PCE searches for the intra-domain path in the ERO information of the cross-domain path, and releases the in-domain path data that is not found, and PCE1, PCE2, and PCE3 release 1-PK12 and 2-PK13, respectively.
  • Intra-domain path data other than 3-PK42, PCE4 does not need to release any intra-domain path data;
  • PCE1 is the first domain sub-PCE, and returns the cross-domain path calculation result to the first node N11, and the sub-PCE ends the calculation.
  • Embodiment 2 Failure of Path Calculation in Sub-PCE Partial Domain
  • the path of the two domains N21 to N22 and N21 to N23 in the domain 2 of the PCE2 fails to be calculated, and the path calculation in the other domain is successful, and the cross-domain path calculation topology of the parent PCE is as shown in FIG. 9(a).
  • the topology does not contain two abstract links N21 to N22 and N21 to N23.
  • the optimal cross-domain path calculated and selected by the parent PCE in this embodiment is: N11, 1-PK12, N12, N25, 2-PK52, N22. N31, 3-PK12, N32, as shown in Figure 9(b), at this time, 1-PK12, 2-PK52, 3-PK12 are connected by dashed lines, indicating that the intra-domain path resource has not been reserved; accordingly, the parent PCE specifies PCE1. , PCE2, PCE3 reserved the intra-domain path 1-PK12, 2-PK52, 3-PK12 resources successfully, as shown in Figure 9 (c), and then continue to complete cross-domain path calculation.
  • Embodiment 3 Failure of path calculation in all domains of sub-PCE
  • the parent PCE After receiving the cross-domain path calculation request, the parent PCE calculates the domain sequence domain 1, domain 2, and domain 3, and requests PCE1, PCE2, and PCE3 to calculate the path segment in each domain. For the part, refer to steps 1) to 4 of the first embodiment. ).
  • PCE2 calculates that all the intra-domain paths of domain 2 fail.
  • the parent PCE performs fault domain backtracking calculation, sets domain 2 as the fault domain, and calculates a new domain sequence domain 1, domain 4 , domain 3, as shown in Figure 10 (b); according to the sequence of the parent PCE to determine the entry and exit boundary node group of each domain, as shown in Figure 10 (c).
  • the primary PCE requests PCE1, PCE4, and PCE3 to cooperate to complete the cross-domain path calculation.
  • the subsequent steps may refer to the first embodiment.
  • the cross-domain path calculation topology constructed by the inter-domain link and the abstract link in this embodiment is as shown in FIG. 10(d); the parent PCE calculates and selects
  • the optimal cross-domain paths are: N11, 1-PK13, N13, N41, 4-PK12, N42, N31, 3-PK12, N32, as shown in Figure 10(e).
  • PCE4 if all the intra-domain paths of PCE4 fail to be calculated on the new domain sequence domain 1, domain 4, and domain 3, the parent PCE continues to set domain 4 as the fault domain, and recalculates the domain sequence. After domain 2 and domain 4, domain 1 to domain 3 are unreachable, and the calculation of the return cross-domain path fails.
  • the fault domain backtracking method of the present example is used to calculate the domain sequence from the best to the poor in the whole network until the optimal cross-domain path is successfully calculated, or the calculation fails.
  • Embodiment 4 The case where the sub-PCE fails to reserve the path resource in the specified domain
  • the example calculation of the cross-domain path process is the same as steps 1) to 5) of the first embodiment, and also obtains the topology as shown in FIG. 8(c);
  • the parent PCE selects the current optimal cross-domain path: N11, 1-PK12, N12, N21, 2-PK13, N23, N34, 3-PK42, N32. As shown in Figure 8(d), specify PCE1, PCE2, and PCE3 respectively. Reserve 1-PK12, 2-PK13, 3-PK42 intra-domain path resources;
  • the parent PCE receives the path resource response in the calculation domain: PCE1 returns 1-PK12 to reserve the resource successfully, PCE2 returns 2-PK13 to reserve the resource, PCE3 returns 3-PK42 to reserve the resource successfully, and the parent PCE records the intra-domain path.
  • 1-PK12, 2-PK13, 3-PK42 resource reservation results select the next optimal cross-domain path: N11, 1-PK12, N12, N25, 2-PK52, N22, N31, 3-PK12, N32, as shown in the figure 9(b); the intra-domain path 1-PK12 has reserved the intra-domain path resource, and the parent PCE only requests PCE2 and PCE3 to reserve the 2-PK52 and 3-PK12 intra-domain path resources.
  • the parent PCE receives the path resource failure response message in the sub-PCE reserved domain, and selects the next optimal cross-domain path, and requests the sub-PCE to reserve the intra-domain path resource that is not reserved in the inter-domain path.
  • all or part of the steps of the above embodiments may also be implemented by using an integrated circuit. These steps may be separately fabricated into individual integrated circuit modules, or multiple modules or steps may be fabricated into a single integrated circuit module. achieve.
  • the devices/function modules/functional units in the above embodiments may be implemented by a general-purpose computing device, which may be centralized on a single computing device or distributed over a network of multiple computing devices.
  • each device/function module/functional unit in the above embodiment When each device/function module/functional unit in the above embodiment is implemented in the form of a software function module and sold or used as a stand-alone product, it can be stored in a computer readable storage medium.
  • the above mentioned computer readable storage medium may be a read only memory, a magnetic disk or an optical disk or the like.
  • the above technical solution reduces the calculation range of the domain and the calculation of the path resource in the reserved domain, improves the calculation efficiency, and can better satisfy the network application.
  • the above technical solution ensures that the cross-domain path is calculated in the whole network, and the calculation success rate is improved.

Abstract

一种跨域路径的计算方法及装置；方法包括：父PCE按照域间路由策略计算最优的域序列；在所计算出的所述域序列上，所述父PCE调度子PCE并行计算全部域内路径路由；所述父PCE根据所述子PCE计算成功的域内路径选择最优的跨域路径；所述父PCE请求所述子PCE并行计算所选择的跨域路径的域内路径段预留资源；全部子PCE预留路径资源成功后，所述父PCE返回所选择的跨域路径作为跨域路径计算结果。上述技术方案能够在保证跨域路径计算成功率的同时，进一步提高了计算效率。

Description

一种跨域路径的计算方法及装置 技术领域
本文涉及但不限于通信领域的路径计算技术，具体说，是一种跨域路径的计算方法及装置。
背景技术
MPLS-TE(多协议标签交换-流量工程)/GMPLS(通用多协议标签交换)网络应用中，需要快速计算出基于流量工程的最优端到端标签交换路径TE-LSP(流量工程-标签交换路径)，达到业务快速建立、恢复和优化网络的目的。IETF(互联网工程任务组)组织提出的基于RFC4655协议的路径计算单元(PCE)架构实现了这一功能，PCE管理网络流量数据，具有端到端TE-LSP路径计算能力。
基于网络安全、性能、管理等因素，将MPLS/GMPLS网络中属于共同地址管理范围或遵循相同路径计算规则的节点集划分到一个域(DOMAIN)，大规模网络由域间链路连接的多个域组成，每个域拥有至少一个PCE，管理本域内及域间流量数据，和计算端到端TE-LSP路径。图1是一个4域MPLS-TE/GMPLS网络拓扑图，环形虚线上的节点表示域边界节点(包括域1的节点N11、N12、N13、N14，域2的节点N21、N22、N23、N24、N25，域3的节点N31、N32、N33、N34，域4的节点N41、N42、N43、N44)，PCE1、PCE2、PCE3、PCE4分别是域1、域2、域3、域4的一台域PCE服务器，均连接到主PCE，维护流量数据库和负责本域节点请求的路径计算。
多域网络中，每个域PCE管理的域内流量数据相互保密，单域子PCE无法获取其它域的域内信息，不能计算其它域的域内路径，因此，任何单域PCE无法独立完成跨域端到端TE-LSP路径计算，需要多域PCE协作，将每域PCE计算出的本域域内路径段，拼接成完整的跨域路径。PCE之间按照RFC5440协议定义的PCEP(路径计算单元通信协议)消息进行交互，目前有三种多PCE协作计算跨域路径方法。
方法1、基于RFC5152协议的多PCE逐域计算跨域路径方法。
首域PCE收到计算跨域路径请求，计算出域间路径路由并返回源节点，域间路由节点按照RSVP-TE(资源预留协议-流量工程)协议建立跨域路径，沿着域间路由传递PATH信令，计算域间路径预留资源，源节点和域入边界节点收到域间PATH信令后，请求本域PCE计算出域内路径路由，沿着域内路由传递PATH信令，计算域内路径预留资源，目的节点收到PATH信令后，沿着域间、域内路由逆向返回RESV信令，在每个节点分配路径资源，完成跨域路径建立。
如图2所示，首节点SRC收到建立首节点SRC到目的节点DST的跨域路径请求，向PCE1请求计算跨域路径，PCE1在域间拓扑上，按照域间路由策略计算出最优域间路径路由为：SRC、节点BN_EX1、节点BN_EN2、节点BN_EX2、节点BN_EN3、DST，计算结果返回SRC，消息流(1)，沿着域间路由传递PATH信令，SRC、BN_EN2、BN_EN3收到域间PATH信令后，分别请求PCE1、PCE2、PCE3计算出域1、域2、域3的域内路径路由，见消息流(2)、(5)、(8)，域内PATH信令沿着域内路径预留域1、域2、域3内路径资源，见消息流(3)、(6)、(9)，目的节点DST收到PATH消息后，沿着跨域路径路由逆向返回RESV信令，分配域间域内路径资源，见消息流(10)，首节点SRC收到RESV信令，完成跨域路径建立。
本方法路径计算包含在路径建立过程中，将首域PCE计算出的跨域路径分成域内路径段，沿着域间路径PATH信令方向，逐域PCE计算域内路径路由，沿着域内路径PATH信令每个节点计算预留路径资源。这种方法一次仅能计算出一条跨域路径，虽然计算时间较少，但计算成功率低，任一域内路径计算失败都会导致跨域路径计算失败，失败回溯重算实现复杂，并且计算出的跨域路径不一定全网最优。
方法二、基于RFC5441协议的逆向递归路径计算(BRPC)方法。
首域PCE收到计算跨域路径请求，按照域间路由策略计算出最优域序列，从首域PCE开始向下游域PCE发送BRPC路径计算请求消息，直到尾域PCE收到BRPC路径计算请求消息，尾域PCE计算出从尾域入边界节点到目的节点的最短路径树(VSPT)，将域VSPT返回上游域PCE，上游域PCE计算 出本域入边界节点经过下游域VSPT到达目的节点的VSPT，继续将VSPT计算结果返回上游域PCE，只到首域PCE收到下游域VSPT，计算出源节点到目的节点的最短路径作为跨域路径计算结果。
如图3所示，PCE1收到计算节点N11到节点N32的跨域路径请求，计算出最优域序列域1、域2、域3，PCE1向PCE2发送BRPC计算请求，PCE2向PCE3发送BRPC计算请求，PCE3计算出VSPT(域3)，返回给PCE2，PCE2计算出VSPT(域2)，返回给PCE1，PCE1计算出VSPT(域1)，即N11到N32的最优跨域路径。
本方法在指定域序列上，遍历计算全部跨域路径，选择最优跨域路径结果，计算成功率较高，但计算效率较差，需要每个域PCE顺序计算全部域内路径段。
方法三、基于RFC6805协议的等级PCE架构跨域路径计算方法。
路径计算单元分成父子PCE两级，子PCE维护域内拓扑信息，向父PCE洪泛域间拓扑信息，父PCE维护域间拓扑信息，减少了域间拓扑信息洪泛规模，提高了拓扑收敛和路径计算速度。父子PCE协作计算跨域路径，父PCE在域间拓扑上计算出跨域路径的全部域间路径路由，按照域间路由调度子PCE并行计算出全部域内路径段，父PCE从计算成功的域内路径段中，拼接并选出最优跨域路径。
如图4所示，PCE1、PCE2、PCE3、PCE4分别是四个子域PCE，父PCE收到来自PCE1的N11到N32的跨域路径计算请求后，在域间拓扑上，计算出全部4条跨域路径域间路由：一是N11、N13、N25、N22、N31、N32，二是N11、N13、N25、N24、N33、N32，三是N11、N13、N41、N43、N33、N32，四是N11、N14、N44、N43、N33、N32，父PCE请求子PCE计算全部域内路径段：PCE1计算域1内N11到N13、N11到N14的两条域内路径，PCE2计算域2内N25到N22、N25到N24的两条域内路径，PCE3计算域3内N31到N32、N33到N32的两条域内路径，PCE4计算域4内N41到N43、N44到N43的两条域内路径，全部子PCE将域内路径计算结果返回父PCE，父PCE选择计算成功的最优跨域路径。
本方法在全网范围内，每个域子PCE并行计算全部域内路径段，父PCE 拼接并选出最优跨域路径，计算效率较高，但是，这种方法仅适用于简单域间拓扑网络，当域间拓扑复杂时，需要计算的域内路径段增多，计算效率降低。为了提高计算效率，通过限制父PCE一次计算的域间路径路由数目，减少子PCE计算的域内路径数量，但可能由于父PCE没有命中最优跨域路径路由，降低了计算成功率。
上述三种多PCE协作跨域路径计算方法，在计算成功率和计算效率上存在较大的冲突。
发明内容
以下是对本文详细描述的主题的概述。本概述并非是为了限制权利要求的保护范围。
本发明实施例提供一种新的跨域路径计算方案，以解决在保证跨域路径计算成功率的同时，进一步提高计算效率的技术问题。
本发明实施例提供了一种跨域路径的计算方法，包括：
父路径计算单元PCE按照域间路由策略计算最优的域序列；
在所计算出的所述域序列上，所述父PCE调度子PCE并行计算全部域内路径路由；
所述父PCE根据所述子PCE计算成功的域内路径选择最优的跨域路径；
所述父PCE请求所述子PCE并行计算所选择的跨域路径的域内路径段预留资源；
全部子PCE预留路径资源成功后，所述父PCE返回所选择的跨域路径作为跨域路径计算结果。
可选地，所述的方法还包括：
当存在全部域内路径计算失败的域时：
当该域为所述域序列的中间域时，所述父PCE设置该域为故障域；当该域为所述域序列的尾域且所述域序列中的域的个数大于2时，所述父PCE设置该域的上游域为故障域；当该域为所述域序列的首域且所述域序列中的域 的个数大于2时，所述父PCE设置该域的下游域为故障域；所述父PCE排除所设置的所述故障域后重新计算最优的域序列并进行后续操作；
当该域为所述域序列的首域且所述域序列中只存在两个域时，或该域为所述域序列的尾域且所述域序列中只存在两个域时，所述父PCE返回跨域路径计算结果为失败。
可选地，所述父PCE根据所述子PCE计算成功的域内路径选择最优的跨域路径包括：
所述父PCE将所述子PCE计算成功的域内路径与抽象链路关联，域内路径度量目标设置成抽象链路度量目标，删除计算失败的域内路径对应的抽象链路；
所述父PCE用所述抽象链路和域间链路构造跨域路径计算拓扑，按照域间路由策略，计算出按照所述路径度量目标值顺序排列的全部跨域路径；
所述父PCE选择当前最优的跨域路径。
可选地，所述的方法还包括：
当所选择的跨域路径预留资源失败时，按照所述路径度量目标值选择出下一优的跨域路径请求所述子PCE并行计算所选择的跨域路径的域内路径段预留资源。
可选地，所述在所计算出的所述域序列上，父PCE调度子PCE并行计算全部域内路径路由包括：
所述父PCE按照所计算出的域序列顺序，遍历每域与上下游域的域间链路，分别确定每个子域的入边界节点组和出边界节点组；创建入边界节点和出边界节点间的m*n条域内路径计算请求，m为入边界节点个数，n为出边界节点个数，首域入边界节点组仅包含源节点，尾域出边界节点组仅包含宿节点；
所述父PCE向每个子PCE发送所述域内路径计算请求。
本发明实施例还提供了一种跨域路径的计算装置，设置于父路径计算单元PCE中；所述装置包括：
域序列计算模块，设置为按照域间路由策略计算最优的域序列；
调度模块，设置为在所计算出的所述域序列上调度子PCE并行计算全部域内路径路由；
选择模块，设置为根据所述子PCE计算成功的域内路径选择最优的跨域路径；
请求模块，设置为请求所述子PCE并行计算所选择的跨域路径的域内路径段预留资源；
结果返回模块，设置为当全部子PCE预留路径资源成功后，返回所选择的跨域路径作为跨域路径计算结果。
可选地，所述的装置还包括：
故障域设置模块，设置为当存在全部域内路径计算失败的域时，如果该域为所述域序列的中间域，则设置该域为故障域；如果该域为所述域序列的尾域且所述域序列中的域的个数大于2，则设置该域的上游域为故障域；如果该域为所述域序列的首域且所述域序列中的域的个数大于2，则设置该域的下游域为故障域；如果该域为所述域序列的首域且所述域序列中只存在两个域，或该域为所述域序列的尾域且所述域序列中只存在两个域，则指示所述结果返回模块返回跨域路径计算结果为失败；
故障域排除模块，设置为排除所设置的所述故障域后重新启动所述域序列计算模块计算最优的域序列。
可选地，所述选择模块是设置为通过如下方式实现根据所述子PCE计算成功的域内路径选择最优的跨域路径：
将所述子PCE计算成功的域内路径与抽象链路关联，域内路径度量目标设置成抽象链路度量目标，删除计算失败的域内路径对应的抽象链路；用所述抽象链路和域间链路构造跨域路径计算拓扑，按照域间路由策略，计算出按照路径度量目标值顺序排列的全部跨域路径；选择当前最优的跨域路径。
可选地，所述请求模块还设置为当所选择的跨域路径预留资源失败时，按照所述路径度量目标值选择出下一优的跨域路径请求所述子PCE并行计算所选择的跨域路径的域内路径段预留资源。
可选地，所述调度模块是设置为通过如下方式实现在所计算出的所述域序列上调度子PCE并行计算全部域内路径路由：
按照所计算出的域序列顺序，遍历每域与上下游域的域间链路，分别确定每个子域的入边界节点组和出边界节点组；创建入边界节点和出边界节点间的m*n条域内路径计算请求，m为入边界节点个数，n为出边界节点个数，首域入边界节点组仅包含源节点，尾域出边界节点组仅包含宿节点；向每个子PCE发送所述域内路径计算请求。
本发明实施例提供了一种计算机存储介质，所述计算机存储介质中存储有计算机可执行指令，所述计算机可执行指令用于执行上述的方法。
与相关技术相比较，本发明实施例提出的跨域路径计算方案，基于等级PCE架构，在最优域序列上，子PCE并行计算组成跨域路径的域内路径段，将域内路径路由和资源预留计算分开，减少了域的计算范围和预留域内路径资源计算量，提高了计算效率，能够更好地满足网络应用。另外，本发明实施例引入故障域回溯算法，保证在全网计算跨域路径，提高了计算成功率。
在阅读并理解了附图和详细描述后，可以明白其他方面。
附图概述
图1是MPLS-TE/GMPLS网络拓扑示例图；
图2是多PCE逐域计算跨域路径示意图；
图3是BRPC方法计算跨域路径示意图；
图4是等级PCE架构计算跨域路径示意图；
图5是本发明实施例一种跨域路径的计算方法的流程示意图；
图6是本发明实施例一个例子中父子PCE协作计算跨域路径方法的流程图；
图7是本发明实施例中设置于父路径计算单元PCE中的一种跨域路径的计算装置示意图；
图8(a)是本发明实施例中域序列的示意图之一；
图8(b)是本发明实施例中域边界节点组的示意图之一；
图8(c)是本发明实施例中的跨域路径计算拓扑示意图之一；
图8(d)是本发明实施例中所选择的跨域路径示意图之一；
图8(e)是本发明实施例中资源分配完成的跨域路径示意图之一；
图9(a)是本发明实施例中的跨域路径计算拓扑示意图之二；
图9(b)是本发明实施例中所选择的跨域路径示意图之二；
图9(c)是本发明实施例中资源分配完成的跨域路径示意图之二；
图10(a)是本发明实施例中的跨域路径计算拓扑示意图之三；
图10(b)是本发明实施例一中域序列的示意图之二；
图10(c)是本发明实施例中域边界节点组的示意图之二；
图10(d)是本发明实施例中的路径拓扑意图之三；
图10(e)是本发明实施例中所选择的跨域路径示意图之三；
图10(f)是本发明实施例中资源分配完成的跨域路径示意图之三。
本发明的较佳实施方式
下面将结合附图及实施例对本发明的技术方案进行更详细的说明。
需要说明的是，如果不冲突，本发明实施例以及实施例中的各个特征可以相互结合，均在本发明的保护范围之内。另外，虽然在流程图中示出了逻辑顺序，但是在某些情况下，可以以不同于此处的顺序执行所示出或描述的步骤。
一种跨域路径的计算方法，如图5所示，包括：
父路径计算单元PCE按照域间路由策略计算最优的域序列；
在所计算出的所述域序列上，所述父PCE调度子PCE并行计算全部域内路径路由；
所述父PCE根据所述子PCE计算成功的域内路径选择最优的跨域路径；
所述父PCE请求所述子PCE并行计算所选择的跨域路径的域内路径段预留资源；
全部子PCE预留路径资源成功后，所述父PCE返回所选择的跨域路径作为跨域路径计算结果。
本发明实施例基于等级PCE架构，从最优域序列开始，在该域序列上遍历计算全部跨域路径路由，多个子PCE并行计算域内路径段路由和预留指定跨域路径资源，减少子PCE串行计算和预留多余域内路径资源时间，提高了计算效率。
所述方法还可以包括：
当存在全部域内路径计算失败的域时：
当该域为所述域序列的中间域时，所述父PCE设置该域为故障域；当该域为所述域序列的尾域且所述域序列中的域的个数大于2时，所述父PCE设置该域的上游域为故障域；当该域为所述域序列的首域且所述域序列中的域的个数大于2时，所述父PCE设置该域的下游域为故障域；所述父PCE排除所设置的所述故障域后重新计算最优的域序列并进行后续操作；
当该域为所述域序列的首域且所述域序列中只存在两个域时，或该域为所述域序列的尾域且所述域序列中只存在两个域时，所述父PCE返回跨域路径计算结果为失败。
这样通过故障域回溯算法，重算域序列，全网计算跨域路径，保证计算成功率。
所述父PCE根据所述子PCE计算成功的域内路径选择最优的跨域路径包括：
所述父PCE将所述子PCE计算成功的域内路径与抽象链路关联，域内路径度量目标设置成抽象链路度量目标，删除计算失败的域内路径对应的抽象链路；
所述父PCE用所述抽象链路和域间链路构造跨域路径计算拓扑，按照域间路由策略，计算出按照路径度量目标值顺序排列的全部跨域路径；
所述父PCE选择当前最优的跨域路径。
所述域间路由策略可以事先指定或根据相关技术选定。
可选地，所述方法还可以包括：如果所选择的跨域路径预留资源失败，则按照路径度量目标值选择出下一优的跨域路径请求所述子PCE并行计算所选择的跨域路径的域内路径段预留资源。
所述在所计算出的所述域序列上，父PCE调度子PCE并行计算全部域内路径路由可以包括：
所述父PCE按照所计算出的域序列顺序，遍历每域与上下游域的域间链路，分别确定每个子域的入边界节点组和出边界节点组；创建入边界节点和出边界节点间的m*n条域内路径计算请求，m为入边界节点个数，n为出边界节点个数，首域入边界节点组仅包含源节点，尾域出边界节点组仅包含宿节点；
所述父PCE向每个子PCE发送所述域内路径计算请求。
图6中是本发明实施例一个例子中，父子PCE协作计算跨域路径流程，图中只描述了一个子PCE的计算流程，以及父子PCE协作消息流。父子PCE之间协作消息采用RFC5440协议PCEP消息格式，父子PCE协作消息如下：
消息1：InterPath_REQ，首域子PCE发送给父PCE的跨域路径计算请求消息，PCReq消息类型；
消息2：IntraPath_REQ，父PCE发送给子PCE的多条域内路径计算请求消息，PCReq消息类型；
消息3：IntraPath_RSP，子PCE返回给父PCE的多条域内路径计算结果消息，PCRep消息类型；
消息4：IntraAlloc_REQ，父PCE发送给子PCE的预留指定域内路径资源请求消息，PCNtf消息类型；
消息5：IntraAlloc_RSP：子PCE返回给父PCE的预留指定域内路径资源结果消息，PCNtf消息类型；
消息6：InterPath_RSP，父PCE返回给子PCE跨域路径计算结果消息，PCRep消息类型。
父PCE计算过程如下：
步骤101：父PCE收到首域子PCE跨域路径计算请求InterPath_REQ消息，或者计算出新的故障域，排除故障域，按照域间路由策略计算最优的域序列；
步骤102：如果域序列计算失败，执行步骤115，返回跨域路径计算失败，如果成功，执行步骤103；
步骤103：所述父PCE按照所计算出的域序列顺序，遍历每域与上下游域的域间链路，确定入出边界节点组，第i个子域入出边界节点组描述如下：
{BN_en(i,1),…,BN_en(i,m)}:域i的m个入边界节点，首域m＝1；
{BN_ex(i,1),…,BN_ex(i,n)}:域i的n个出边界节点,尾域n＝1；
首域入边界节点组仅包含源节点，尾域出边界节点组仅包含宿节点，创建入出边界节点间的域内路径计算请求，域内路径成为构建跨域路径的域间抽象链路，创建上面描述的第i个子域m*n条域内路径计算请求；
步骤104：所述父PCE请求每个子PCE计算域内路径路由，向域序列上所有域的子PCE发送IntraPath_REQ消息；
步骤105：所述父PCE收到子PCE返回的域内路径响应IntraPath_RSP消息，如果全部域内路径计算失败，执行步骤106，如果域序列的每个子PCE都能计算成功至少一条域内路径执行步骤108；
步骤106：所述父PCE采用故障域回溯算法，判定全部域内路径计算失败子域在域序列中的位置后，执行如下处理：
1)位置在首域：如果下游域是尾域，跨域路径计算失败，执行步骤115，如果下游域不是尾域，设置下游域为故障域，执行步骤107；
2)位置在中间域：设置该域为故障域，执行步骤107；
3)位置在尾域：如果上游域是首域，跨域路径计算失败，执行步骤115，如果不是首域，设置上游域为故障域，执行步骤107；
步骤107：所述父PCE将失败域增加到故障域序列，返回执行步骤101，即：回溯重算出新的域序列，计算跨域路径；
步骤108：遵循域内数据保密原则，按照RFC5220协议，父PCE收到的IntraPath_RSP消息，消息中计算成功域内路径的ERO采用Path-Key格式，所述父PCE将计算成功的域内路径Path-Key与对应的抽象链路关联，域内路径度量目标(metric object)设置成抽象链路度量目标，删除计算失败的域内路径对应的抽象链路；
步骤109：所述父PCE判定是否收到域序列上全部域的子PCE的IntraPath_RSP消息，如果没有，继续执行步骤109，等待接收域子PCE计算响应，如果全部收到，执行步骤110；
步骤110：用跨域抽象链路和域间链路构造跨域路径计算拓扑，按照域间路由策略，采用合适的路径算法，计算出按照路径度量目标值顺序排列的全部跨域路径；
步骤111：选择当前最优的跨域路径，判定是否成功，如果失败，执行步骤115，返回跨域路径计算失败，如果成功，执行步骤112；
步骤112：请求子PCE计算所选择的最优的跨域路径的域内路径预留资源，向子PCE发送IntraAlloc_REQ消息；
步骤113：收到子PCE预留资源响应IntraAlloc_RSP消息，判定子PCE预留域内路径资源是否成功，如果失败，将该跨域路径删除或标定为不可用后执行步骤111，即：选择下一优的跨域路径计算预留资源，如果成功，执行步骤114；
步骤114：判定所选择的跨域路径是否完成预留域内路径段资源，如果没有完成，执行步骤113，等待子PCE预留资源响应消息，如果完成，执行步骤115返回跨域路径计算成功；
步骤115：向所有域的子PCE返回跨域路径计算结果InterPath_RSP消息，结束父PCE计算过程。
子PCE的计算过程如下：
步骤201：首域子PCE收到源节点的跨域路径计算请求，向父PCE发送跨域路径计算请求InterPath_REQ消息，从而触发所述步骤101；
步骤202：子PCE收到所述父PCE发送的m*n条域内路径计算请求 IntraPath_REQ消息，选择合适的路径算法，计算m*n条域内最优路径的路由，采用Path-Key格式生成计算成功域内路径的ERO信息，向父PCE发送IntraPath_RSP消息；
步骤203：子PCE收到所述父PCE发送的预留指定域内路径资源请求IntraAlloc_REQ消息，调用预留资源算法计算域内路径节点和链路预留资源，向父PCE返回预留域内路径资源结果IntraAlloc_RSP消息；
步骤204：子PCE收到所述父PCE发送的跨域路径计算结果InterPath_RSP消息，释放本域未被选中的域内路径数据；
步骤205：判定本子PCE是否为跨域路径的首域子PCE，如果不是，结束子PCE计算过程，如果是，执行步骤206；
步骤206：将跨域路径计算结果返回源节点，结束子PCE计算过程。
本发明实施例提供了一种计算机存储介质，所述计算机存储介质中存储有计算机可执行指令，所述计算机可执行指令用于执行上述的方法。
图7所示，一种跨域路径的计算装置，设置于父路径计算单元PCE中；所述装置包括：
域序列计算模块，设置为按照域间路由策略计算最优的域序列；
调度模块，设置为在所计算出的所述域序列上调度子PCE并行计算全部域内路径路由；
选择模块，设置为根据所述子PCE计算成功的域内路径选择最优的跨域路径；
请求模块，设置为请求所述子PCE并行计算所选择的跨域路径的域内路径段预留资源；
结果返回模块，设置为当全部子PCE预留路径资源成功后，返回所选择的跨域路径作为跨域路径计算结果。
所述的装置还可以包括：
故障域设置模块，设置为当存在全部域内路径计算失败的域时，如果该域为所述域序列的中间域，则设置该域为故障域；如果该域为所述域序列的尾域且所述域序列中的域的个数大于2，则设置该域的上游域为故障域；如果该域为所述域序列的首域且所述域序列中的域的个数大于2，则设置该域的下游域为故障域；如果该域为所述域序列的首域且所述域序列中只存在两个域，或该域为所述域序列的尾域且所述域序列中只存在两个域，则指示所述结果返回模块返回跨域路径计算结果为失败；
故障域排除模块，设置为排除所设置的所述故障域后重新启动所述域序列计算模块计算最优的域序列。
其中，所述选择模块根据所述子PCE计算成功的域内路径选择最优的跨域路径包括：
所述选择模块将所述子PCE计算成功的域内路径与抽象链路关联，域内路径度量目标设置成抽象链路度量目标，删除计算失败的域内路径对应的抽象链路；用所述抽象链路和域间链路构造跨域路径计算拓扑，按照域间路由策略，计算出按照路径度量目标值顺序排列的全部跨域路径；选择当前最优的跨域路径。
可选地，所述请求模块还可以设置为当所选择的跨域路径预留资源失败时，按照所述路径度量目标值选择出下一优的跨域路径请求所述子PCE并行计算所选择的跨域路径的域内路径段预留资源。
可选地，所述调度模块在所计算出的所述域序列上调度子PCE并行计算全部域内路径路由包括：
所述调度模块按照所计算出的域序列顺序，遍历每域与上下游域的域间链路，分别确定每个子域的入边界节点组和出边界节点组；创建入边界节点和出边界节点间的m*n条域内路径计算请求，m为入边界节点个数，n为出边界节点个数，首域入边界节点组仅包含源节点，尾域出边界节点组仅包含宿节点；向每个子PCE发送所述域内路径计算请求。
为方便理解，通过几个实施例说明本发明在多域网络中的应用。在图1 所示的4域MPLS-TE/GMPLS网络中，请求计算源节点(也称为首节点)N11到宿节点N32的最优跨域路径。
实施例一：子PCE域内路径计算和资源预留成功的情形
父PCE控制计算跨域路径流程，调度子PCE并行计算跨域路径路由和预留指定域内路径资源，本实施例通过父PCE域间计算拓扑的变化，描述了跨域路径计算过程：
1)父PCE收到首域子PCE转发的计算跨域路径请求消息，按照域间路由策略，确定最优域序列：域1、域2、域3，见图8(a)；
2)按照域1、域2、域3顺序，父PCE确定每个域的入出边界节点组，见图8(b)：
  入边界节点组 出边界节点组
域1(PCE1) {N11} {N12，N13}
域2(PCE2) {N21，N25} {N22，N23，N24}
域3(PCE3) {N31，N33，N34} {N32}
3)父PCE遍历每个子域的入出边界节点对组合，构造并发送所有入边界节点到出边界节点的域内路径计算请求给每个子PCE，具体而言就是：请求PCE1计算N11到N12、N11到N13两条域内路径计算，请求PCE2计算N21到N22、N21到N23、N24到N22、N25到N22、N25到N23、N25到N24六条域内路径，请求PCE3计算N31到N32、N33到N32、N34到N32三条域内路径；
4)PCE1、PCE2、PCE3并行计算多点到多点(MP2MP)的最优域内路径，为进一步提高路径计算效率，可以将MP2MP路径计算在相同的拓扑资源上，分解成多个点到多点(P2MP)的最优路径并行计算，如：PCE2将2点到3点的MP2MP计算分解成2个P2MP并行计算，同时计算出最优的6条域内路径的路由，只包含经过的节点和链路路由信息，没有预留节点和链路资源。
子PCE按照RFC5220协议，生成计算成功域内路径的Path-Key，通过PCEP的PcRep消息的ERO返回父PCE，比如用“jj-PKxxyy”描述Path-Key 路径：jj表示域序号，xx表示源端节点域内序号，yy表示宿端节点域内序号；
5)父PCE收到全部子PCE的域内路径计算响应后，将计算成功的域内路径作为抽象链路(比如域1内路径N11到N12作为抽象路径1-PK12，域2内路径N21到N23作为抽象路径2-PK13等)，将域内的路径度量目标值(Metric object)赋值给域内的抽象链路，沿着域序列，由域间链路和抽象链路构造的跨域路径计算拓扑如图8(c)所示，本发明实施例采用KSP算法，但并不限制于这种算法，计算出按照路径度量目标值排序的全部跨域路径：
第1优：N11、1-PK12、N12、N21、2-PK13、N23、N34、3-PK42、N32；
第2优：N11、1-PK12、N12、N25、2-PK52、N22、N31、3-PK12、N32；
第3优：N11、1-PK12、N12、N21、2-PK14、N24、N33、3-PK32、N32；
……；
6)父PCE选择当前最优的跨域路径：N11、1-PK12、N12、N21、2-PK13、N23、N34、3-PK42、N32，如图8(d)所示，此时，1-PK12、2-PK13、3-PK42虚线连接，表示还没有预留域内路径资源；
7)父PCE请求PCE1、PCE2、PCE3预留指定域内路径1-PK12、2-PK13、3-PK42资源；
8)PCE1、PCE2、PCE3并行完成域内路径1-PK12、2-PK13、3-PK42节点的链路资源预留，将结果返回父PCE；
9)父PCE收到PCE1、PCE2、PCE3预留资源成功的消息后，向PCE1、PCE2、PCE3、PCE4返回跨域路径计算结果，此时已经预留域内路径资源，1-PK12、2-PK13、3-PK42实线连接，如图8(e)所示，父PCE结束计算。
10)子PCE收到跨域路径计算结果，每个子PCE在返回跨域路径的ERO信息查找域内路径，释放没有查找到的域内路径数据，PCE1、PCE2、PCE3分别释放1-PK12、2-PK13、3-PK42之外的域内路径数据，PCE4不需要释放任何域内路径数据；
11)PCE1是首域子PCE，向首节点N11返回跨域路径计算结果，子PCE结束计算。
实施例二：子PCE部分域内路径计算失败的情形
前面的过程和实施例一的步骤1)到4)相同。
不同的是，本实施例中，PCE2计算域2内N21到N22、N21到N23两条域内路径失败，其它域内路径计算成功，父PCE生成跨域路径计算拓扑如图9(a)所示，拓扑不包含N21到N22和N21到N23两条抽象链路。
后继步骤可参考实施例一，与实施例一不同的是，本实施例中父PCE计算并选择出的最优跨域路径为：N11、1-PK12、N12、N25、2-PK52、N22、N31、3-PK12、N32，如图9(b)所示，此时，1-PK12、2-PK52、3-PK12虚线连接，表示还没有预留域内路径资源；相应地，父PCE指定PCE1、PCE2、PCE3预留域内路径1-PK12、2-PK52、3-PK12资源成功，如图9(c)所示，然后继续完成跨域路径计算。
实施例三：子PCE全部域内路径计算失败的情形
父PCE收到跨域路径计算请求后，计算出域序列域1、域2、域3，请求PCE1、PCE2、PCE3计算每个域内路径段；这部分可参见实施例一的步骤1)到4)。
本实施例中，PCE2计算域2的域内路径全部失败，如图10(a)所示，父PCE执行故障域回溯计算，设置域2为故障域，计算出新的域序列域1、域4、域3，如图10(b)所示；按照该序列父PCE确定每个域的入出边界节点组，见图10(c)所示。
主PCE请求PCE1、PCE4和PCE3协同完成跨域路径计算。后继步骤可参考实施例一，与实施例一不同的是，本实施例中由域间链路和抽象链路构造的跨域路径计算拓扑如图10(d)所示；父PCE计算并选择出的最优跨域路径为：N11、1-PK13、N13、N41、4-PK12、N42、N31、3-PK12、N32，如图10(e)所示，此时，1-PK13、4-PK12、3-PK12虚线连接，表示还没有预留域内路径资源；相应地，父PCE指定PCE1、PCE4、PCE3预留域内路径1-PK13、4-PK12、3-PK12资源成功，如图10(f)所示，然后继续完成跨域路径计算。
可选的，如果在新的域序列域1、域4、域3上，PCE4的全部域内路径也计算失败，父PCE继续将域4设置成故障域，重新计算域序列，图1网络排除域2和域4后，域1到域3不可达，返回跨域路径计算失败。
采用本实例这种故障域回溯的方法，在全网由优到劣计算域序列，直到成功计算出最优跨域路径，或返回计算失败为止。
实施例四：子PCE预留指定域内路径资源失败的情形
该实例计算计算跨域路径过程前面和实施例一的步骤1)到5)相同，也是得到如图8(c)所示的拓扑；
父PCE选择当前最优跨域路径：N11、1-PK12、N12、N21、2-PK13、N23、N34、3-PK42、N32，如图8(d)所示，指定PCE1、PCE2、PCE3分别预留1-PK12、2-PK13、3-PK42域内路径资源；
本实施例中，父PCE收到计算域内路径资源响应：PCE1返回1-PK12预留资源成功，PCE2返回2-PK13预留资源失败，PCE3返回3-PK42预留资源成功，父PCE记录域内路径1-PK12、2-PK13、3-PK42资源预留结果，选择下一优跨域路径：N11、1-PK12、N12、N25、2-PK52、N22、N31、3-PK12、N32，如图9(b)所示；域内路径1-PK12已经预留域内路径资源，父PCE仅请求PCE2、PCE3预留2-PK52、3-PK12域内路径资源，成功后如图9(c)所示，继续完成跨域路径计算过程。以此类推，父PCE收到子PCE预留域内路径资源失败响应消息，就选择下一优跨域路径，请求子PCE预留选中跨域路径中未预留的域内路径资源。
当然，本发明还可有其他多种实施例，在不背离本发明精神及其实质的情况下，熟悉本领域的技术人员当可根据本发明作出各种相应的改变和变形，但这些相应的改变和变形都应属于本发明的权利要求的保护范围。
本领域普通技术人员可以理解上述实施例的全部或部分步骤可以使用计算机程序流程来实现，所述计算机程序可以存储于一计算机可读存储介质中， 所述计算机程序在相应的硬件平台上(如系统、设备、装置、器件等)执行，在执行时，包括方法实施例的步骤之一或其组合。
可选地，上述实施例的全部或部分步骤也可以使用集成电路来实现，这些步骤可以被分别制作成一个个集成电路模块，或者将它们中的多个模块或步骤制作成单个集成电路模块来实现。
上述实施例中的各装置/功能模块/功能单元可以采用通用的计算装置来实现，它们可以集中在单个的计算装置上，也可以分布在多个计算装置所组成的网络上。
上述实施例中的各装置/功能模块/功能单元以软件功能模块的形式实现并作为独立的产品销售或使用时，可以存储在一个计算机可读取存储介质中。上述提到的计算机可读取存储介质可以是只读存储器，磁盘或光盘等。
工业实用性
上述技术方案减少了域的计算范围和预留域内路径资源计算量，提高了计算效率，能够更好地满足网络应用。另外，上述技术方案保证在全网计算跨域路径，提高了计算成功率。

Claims (11)

  1. 一种跨域路径的计算方法，包括：
    父路径计算单元PCE按照域间路由策略计算最优的域序列；
    在所计算出的所述域序列上，所述父PCE调度子PCE并行计算全部域内路径路由；
    所述父PCE根据所述子PCE计算成功的域内路径选择最优的跨域路径；
    所述父PCE请求所述子PCE并行计算所选择的跨域路径的域内路径段预留资源；
    全部子PCE预留路径资源成功后，所述父PCE返回所选择的跨域路径作为跨域路径计算结果。
  2. 如权利要求1所述的方法，还包括：
    当存在全部域内路径计算失败的域时：
    当该域为所述域序列的中间域时，所述父PCE设置该域为故障域；当该域为所述域序列的尾域且所述域序列中的域的个数大于2时，所述父PCE设置该域的上游域为故障域；当该域为所述域序列的首域且所述域序列中的域的个数大于2时，所述父PCE设置该域的下游域为故障域；所述父PCE排除所设置的所述故障域后重新计算最优的域序列并进行后续操作；
    当该域为所述域序列的首域且所述域序列中只存在两个域时，或该域为所述域序列的尾域且所述域序列中只存在两个域时，所述父PCE返回跨域路径计算结果为失败。
  3. 如权利要求1所述的方法，其中，所述父PCE根据所述子PCE计算成功的域内路径选择最优的跨域路径包括：
    所述父PCE将所述子PCE计算成功的域内路径与抽象链路关联，域内路径度量目标设置成抽象链路度量目标，删除计算失败的域内路径对应的抽象链路；
    所述父PCE用所述抽象链路和域间链路构造跨域路径计算拓扑，按照域 间路由策略，计算出按照所述路径度量目标值顺序排列的全部跨域路径；
    所述父PCE选择当前最优的跨域路径。
  4. 如权利要求3所述的方法，还包括：
    当所选择的跨域路径预留资源失败时，按照所述路径度量目标值选择出下一优的跨域路径请求所述子PCE并行计算所选择的跨域路径的域内路径段预留资源。
  5. 如权利要求1所述的方法，其中，所述在所计算出的所述域序列上，父PCE调度子PCE并行计算全部域内路径路由包括：
    所述父PCE按照所计算出的域序列顺序，遍历每域与上下游域的域间链路，分别确定每个子域的入边界节点组和出边界节点组；创建入边界节点和出边界节点间的m*n条域内路径计算请求，m为入边界节点个数，n为出边界节点个数，首域入边界节点组仅包含源节点，尾域出边界节点组仅包含宿节点；
    所述父PCE向每个子PCE发送所述域内路径计算请求。
  6. 一种设置于父路径计算单元PCE中的跨域路径的计算装置，所述装置包括：
    域序列计算模块，设置为按照域间路由策略计算最优的域序列；
    调度模块，设置为在所计算出的所述域序列上调度子PCE并行计算全部域内路径路由；
    选择模块，设置为根据所述子PCE计算成功的域内路径选择最优的跨域路径；
    请求模块，设置为请求所述子PCE并行计算所选择的跨域路径的域内路径段预留资源；
    结果返回模块，设置为当全部子PCE预留路径资源成功后，返回所选择的跨域路径作为跨域路径计算结果。
  7. 如权利要求6所述的装置，还包括：
    故障域设置模块，设置为当存在全部域内路径计算失败的域时，如果该域为所述域序列的中间域，则设置该域为故障域；如果该域为所述域序列的尾域且所述域序列中的域的个数大于2，则设置该域的上游域为故障域；如果该域为所述域序列的首域且所述域序列中的域的个数大于2，则设置该域的下游域为故障域；如果该域为所述域序列的首域且所述域序列中只存在两个域，或该域为所述域序列的尾域且所述域序列中只存在两个域，则指示所述结果返回模块返回跨域路径计算结果为失败；
    故障域排除模块，设置为排除所设置的所述故障域后重新启动所述域序列计算模块计算最优的域序列。
  8. 如权利要求1所述的装置，其中，所述选择模块是设置为通过如下方式实现根据所述子PCE计算成功的域内路径选择最优的跨域路径：
    将所述子PCE计算成功的域内路径与抽象链路关联，域内路径度量目标设置成抽象链路度量目标，删除计算失败的域内路径对应的抽象链路；用所述抽象链路和域间链路构造跨域路径计算拓扑，按照域间路由策略，计算出按照路径度量目标值顺序排列的全部跨域路径；选择当前最优的跨域路径。
  9. 如权利要求8所述的装置，
    所述请求模块，还设置为当所选择的跨域路径预留资源失败时，按照所述路径度量目标值选择出下一优的跨域路径请求所述子PCE并行计算所选择的跨域路径的域内路径段预留资源。
  10. 如权利要求9所述的装置，其中，所述调度模块是设置为通过如下方式实现在所计算出的所述域序列上调度子PCE并行计算全部域内路径路由：
    按照所计算出的域序列顺序，遍历每域与上下游域的域间链路，分别确定每个子域的入边界节点组和出边界节点组；创建入边界节点和出边界节点间的m*n条域内路径计算请求，m为入边界节点个数，n为出边界节点个数，首域入边界节点组仅包含源节点，尾域出边界节点组仅包含宿节点；向每个子PCE发送所述域内路径计算请求。
  11. 一种计算机存储介质，所述计算机存储介质中存储有计算机可执行 指令，所述计算机可执行指令用于执行权利要求1～5任一项所述的方法。
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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US11968120B2 (en) 2021-08-03 2024-04-23 Cisco Technology, Inc. Adaptive hierarchical service path selection in dynamic edge computing environments

Families Citing this family (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106161233A (zh) * 2016-06-28 2016-11-23 杭州华三通信技术有限公司 一种报文转发方法及装置
US10728098B2 (en) 2016-07-06 2020-07-28 Futurewei Technologies, Inc. Connections and accesses for hierarchical path computation element (PCE)
CN106850435A (zh) * 2016-12-16 2017-06-13 北京格林伟迪科技股份有限公司 一种跨域端到端标签交换路径建立方法和系统
CN107220024B (zh) * 2017-05-19 2021-08-31 郑州云海信息技术有限公司 一种基于fpga的数据处理方法、装置及系统
CN107332768B (zh) * 2017-06-06 2020-04-21 烽火通信科技股份有限公司 一种多域控制器的跨域路径计算方法
CN109587061B (zh) * 2018-11-08 2022-04-22 华为技术有限公司 一种路由处理的方法、装置及设备
CN110086710B (zh) * 2019-03-26 2021-06-11 中国人民武装警察部队工程大学 一种基于n人非合作博弈的多域光网络组播路由恢复方法
CN110099002B (zh) * 2019-04-12 2021-06-04 烽火通信科技股份有限公司 一种路径计算方法及装置
CN113449205B (zh) * 2021-08-30 2021-11-09 四川省人工智能研究院(宜宾) 一种基于元数据增强的推荐方法及系统

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102195869A (zh) * 2010-03-01 2011-09-21 中兴通讯股份有限公司 双向回溯路径计算方法及装置
CN102238443A (zh) * 2011-06-01 2011-11-09 电子科技大学 一种满足波长连续性约束条件的跨域路径建路方法
CN103688497A (zh) * 2013-09-26 2014-03-26 华为技术有限公司 跨域路径的建立方法及设备

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101854291B (zh) * 2009-03-31 2013-10-09 华为技术有限公司 一种通告跨域链路信息及计算跨域路径的方法、装置和系统

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102195869A (zh) * 2010-03-01 2011-09-21 中兴通讯股份有限公司 双向回溯路径计算方法及装置
CN102238443A (zh) * 2011-06-01 2011-11-09 电子科技大学 一种满足波长连续性约束条件的跨域路径建路方法
CN103688497A (zh) * 2013-09-26 2014-03-26 华为技术有限公司 跨域路径的建立方法及设备

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US11968120B2 (en) 2021-08-03 2024-04-23 Cisco Technology, Inc. Adaptive hierarchical service path selection in dynamic edge computing environments

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