# US 12,184,541 B2 · Service processing method and network device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,184,541 B2 - Document ID: US12184541B2 - Status: Granted - Kind: B2 - Application number: 18/187,515 - Filed: 2023-03-21 - Published: 2023-09-07 - Granted: 2024-12-31 - Earliest claimed: 2020-09-21 - Assignees: Huawei Technologies Co., Ltd. - Applicants: Huawei Technologies Co., Ltd. - Inventors: Kaiqiang Shen; Sheng Fang; Ruyun Zhang; Ren Tan; Hanlin Li - Web page: https://patentgrep.com/patent/US12184541B2 ## CPC - H04L 45/02: Topology update or discovery - H04L 45/24: Multipath - H04L 45/42: Centralised routing - H04L 45/50: using label swapping, e.g. multi-protocol label switch [MPLS] - H04L 45/64: using an overlay routing layer - H04L 45/741: Routing in networks with a plurality of addressing schemes, e.g. with both IPv4 and IPv6 - H04L 45/34: {Source routing} - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract A service processing method includes that a first network device determines a second network device on a forwarding path of a packet based on a service requirement; the first network device sends a first message to the second network device, to establish a first connection to the second network device; and the first network device sends a second message to the second network device using the first connection, where the second message requests the second network device to assist in determining information related to the forwarding path. when determining the second network device is needed to assist the first network device for information related to the forwarding path of the packet, the first network device actively establishes a connection to the second network device, and requests, using the established connection, the second network device to assist the first network device in determining the information related to the forwarding path. ## Claims ### Claim 1 A first network device, comprising: a memory configured to store computer-executable instructions; and one or more processors coupled to the memory and configured to execute the computer-executable instructions to cause the first network device to: send, to a second network device, a first message for establishing a first connection to the second network device when the second network device is needed to assist the first network device in obtaining information related to computing a forwarding path of a packet, wherein the packet belongs to a service, and wherein the second network device is on the forwarding path of the packet and is associated with a service requirement of the service; and send, to the second network device, a second message using the first connection, wherein the second message requests the second network device to assist in obtaining the information related to the forwarding path, wherein the forwarding path is based on the service requirement, wherein the second network device, based on the forwarding path of the packet, is a stitching node for allocating a stitching label, wherein the second message comprises label stack information, and wherein the second message instructs the second network device to allocate the stitching label corresponding to the label stack information. ### Claim 2 (depends on 1) The first network device of claim 1, wherein the one or more processors are further configured to execute the computer-executable instructions to cause the first network device to receive a third message from the second network device, and wherein the third message comprises the information related to the forwarding path. ### Claim 3 (depends on 2) The first network device of claim 2, wherein the one or more processors are further configured to execute the computer-executable instructions to cause the first network device to determine the second network device on the forwarding path by: determining, based on the service requirement, that the network device cannot obtain the forwarding path of the packet through computation; and determining the second network device based on a network topology for assisting the network device in computing a first path to a destination device. ### Claim 4 (depends on 3) The first network device of claim 3, wherein the second message instructs the second network device to compute the first path to the destination device, and wherein the third message comprises indication information of the first path. ### Claim 5 (depends on 3) The first network device of claim 3, wherein the one or more processors are further configured to execute the computer-executable instructions to cause the first network device to determine that the network device cannot obtain the forwarding path by: determining, based on the service requirement, that the destination device of the packet is not in a first area, wherein the first area is an area in which the network device is located; and determining the second network device based on a network topology of the first area, wherein the second network device is boundary equipment of the first area and a second area, and wherein the destination device is located in the second area or the forwarding path passes through the destination device in the second area. ### Claim 6 (depends on 5) The first network device of claim 5, wherein the computer-executable instructions that when executed by the one or more processors further cause the network device to: establish a second connection to a third network device, wherein the network topology is associated with the third network device, and wherein the third network device is the boundary equipment of the first area and the second area; send a fourth message to the third network device using the second connection, wherein the fourth message is configured to instruct the third network device to compute a second path to the destination device; receive a fifth message from the third network device, wherein the fifth message comprises indication information of the second path; and obtain a part of or all of the forwarding path of the packet based on the third message and the fifth message. ### Claim 7 (depends on 1) The first network device of claim 1, wherein the one or more processors are further configured to execute the computer-executable instructions to cause the first network device to determine the second network device on the forwarding path of the packet by: determining, based on the service requirement, that the network device cannot determine the information related to the forwarding path of the packet; and determining the second network device for assisting in determining the information related to the forwarding path. ### Claim 8 (depends on 1) The first network device of claim 1, wherein the information related to the forwarding path comprises at least one of the stitching label indicating the forwarding path or a path label indicating the forwarding path. ### Claim 9 (depends on 1) The first network device of claim 1, wherein the one or more processors are further configured to execute the computer-executable instructions to cause the first network device to determine the second network device is the stitching node by: determining, based on the forwarding path of the packet, that a quantity of labels that indicate the forwarding path is greater than a maximum quantity of labels that a label stack can carry; and determining the second network device based on the forwarding path, wherein the second network device is on the forwarding path of the packet. ### Claim 10 (depends on 1) The first network device of claim 1, wherein the first connection comprises a Path Computation Element Communication Protocol (PCEP) connection. ### Claim 11 (depends on 1) The first network device of claim 1, wherein the one or more processors are further configured to execute the computer-executable instructions to cause the first network device to: establish a Transmission Control Protocol (TCP) connection to the second network device; and further send the first message to the second network device using the TCP connection for negotiating with the second network device to establish the first connection. ### Claim 12 (depends on 1) The first network device of claim 1, wherein the network device is a head-end node device on the forwarding path of the packet. ### Claim 13 (depends on 12) The first network device of claim 12, wherein the first network device and the second network device are path computation client (PCC) devices on the forwarding path. ### Claim 14 (depends on 1) The first network device of claim 1, wherein the forwarding path of the packet comprises at least one of a segment routing (SR) policy path, a segment routing over Internet Protocol version 4 (SRv4) path, a segment routing over IP version 6 (SRv6) path, a segment routing traffic engineering (SR-TE) path, or a multi-protocol label switching traffic engineering (MPLS-TE) path. ### Claim 15 A service processing method implemented by a first network device, wherein the service processing method comprises: sending, to a second network device, a first message for establishing a first connection to the second network device when the second network device is needed to assist the first network device in obtaining information related to computing a forwarding path of a packet, wherein the packet belongs to a service, and wherein the second network device on the forwarding path of the packet is associated with a service requirement of the service; and sending, to the second network device, a second message using the first connection, wherein the second message requests the second network device to assist in obtaining the information related to the forwarding path, wherein the forwarding path is based on the service requirement, wherein the second network device, based on the forwarding path of the packet, is a stitching node for allocating a stitching label, wherein the second message comprises label stack information, and wherein the second message instructs the second network device to allocate the stitching label corresponding to the label stack information. ### Claim 16 (depends on 15) The service processing method of claim 15, further comprising receiving a third message from the second network device, wherein the third message comprises the information related to the forwarding path. ### Claim 17 (depends on 15) The service processing method of claim 15, wherein determining the second network device on the forwarding path comprises: determining, based on the service requirement, that the first network device cannot determine the information related to the forwarding path of the packet; and determining the second network device for assisting in determining the information related to the forwarding path. ### Claim 18 (depends on 15) The service processing method of claim 15, wherein the information related to the forwarding path comprises at least one of the stitching label indicating the forwarding path or a path label indicating the forwarding path. ### Claim 19 A computer program product comprising computer-executable instructions stored on a non-transitory computer-readable storage medium that when executed by one or more processors, cause a first network device to: send, to a second network device, a first message for establishing a first connection to the second network device when the second network device is needed to assist the first network device in obtaining information related to computing a forwarding path of a packet, wherein the packet belongs to a service, and wherein the second network device on the forwarding path of the packet is associated with a service requirement of the service; and send, to the second network device, a second message using the first connection, wherein the second message requests the second network device to assist in obtaining the information related to the forwarding path, wherein the forwarding path is based on the service requirement, wherein the second network device, based on the forwarding path of the packet, is a stitching node for allocating a stitching label, wherein the second message comprises label stack information, and wherein the second message instructs the second network device to allocate the stitching label corresponding to the label stack information.