# US 12,003,405 B2 · High latency link determining method, routing advertisement method, and apparatus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,003,405 B2 - Document ID: US12003405B2 - Status: Granted - Kind: B2 - Application number: 17/716,872 - Filed: 2022-04-08 - Published: 2022-07-21 - Granted: 2024-06-04 - Earliest claimed: 2019-10-12 - Assignees: Huawei Technologies Co., Ltd. - Applicants: Huawei Technologies Co., Ltd. - Inventors: Guoliang Liu - Web page: https://patentgrep.com/patent/US12003405B2 ## CPC - H04L 43/16: Threshold monitoring - H04L 45/121: by minimising delays - H04L 43/0852: Delays - H04L 45/123: {Evaluation of link metrics (techniques for monitoring network metrics H04L43/08)} - H04L 45/124: {using a combination of metrics} - H04L 45/125: based on throughput or bandwidth - H04L 45/24: Multipath - H04L 45/66: {Layer 2 routing, e.g. in Ethernet based MAN's} - H04L 12/4641: {Virtual LANs, VLANs, e.g. virtual private networks [VPN] (LAN interconnection over a bridge based backbone H04L12/462; encapsulation techniques H04L12/4633; routing of packets H04L45/00; packet switches H04L49/00; virtual private networks for security H04L63/0272)} - H04L 41/0894: Policy-based network configuration management - H04L 41/122: of virtualised topologies, e.g. software-defined networks [SDN] or network function virtualisation [NFV] - H04L 41/5025: by proactively reacting to service quality change, e.g. by reconfiguration after service quality degradation or upgrade - H04L 43/06: Generation of reports - H04L 43/0894: Packet rate - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract A first provider edge (PE) determines whether a link between the first PE and a second PE is a high latency link, where the second PE is a next hop of the first PE. When determining an actual latency corresponding to the link, the first PE compares the actual latency with a first latency threshold. When the actual latency is greater than or equal to the first latency threshold, it indicates that the actual latency exceeds a latency upper limit corresponding to the link, the first PE determines that the link is a high latency link. In this way, it is not necessary to wait for network management personnel to determine whether the link is a high latency link. After determining the actual latency corresponding to the link, the first PE can determine in time whether the link is a high latency link. ## Claims ### Claim 1 A method performed by a first provider edge (PE) device, comprising: determining an actual latency corresponding to a link between the first PE device and a second PE device, wherein the second PE device is a next hop of the first PE device; and when the actual latency is greater than or equal to a first latency threshold, determining that the link is a high latency link, wherein the first latency threshold is used to indicate a latency upper limit corresponding to the link, wherein the first latency threshold is involved with a received routing message, where the received routing message comprises a community field carrying the first latency threshold. ### Claim 2 (depends on 1) The method according to claim 1, further comprising: when a plurality of actual latencies continuously are all greater than or equal to the first latency threshold, determining that the link is a high latency link. ### Claim 3 (depends on 1) The method according to claim 1, further comprising: sending first data to a first customer edge (CE) device through a second link, wherein the first data is data that is expected to be sent to the first CE device through a first link, wherein the second link and the first link are load sharing links for each other, and wherein the first link is the link between the first PE device and the second PE device. ### Claim 4 (depends on 3) The method according to claim 3, further comprising: obtaining a bandwidth corresponding to each of a plurality of second links; determining, based on the bandwidth corresponding to each second link, a data traffic adjustment proportion corresponding to each second link; and sending the first data to the first CE device through the plurality of second links based on the data traffic adjustment proportion corresponding to each second link. ### Claim 5 (depends on 3) The method according to claim 3, further comprising: sending the first data to the first CE device through one second link. ### Claim 6 (depends on 3) The method according to claim 3, wherein the second link is a non-high latency link. ### Claim 7 (depends on 1) The method according to claim 1, further comprising: when the actual latency is less than or equal to a second latency threshold, determining that the link is a low latency link, wherein the second latency threshold is used to indicate the latency lower limit corresponding to the link between the first PE device and the second PE device. ### Claim 8 (depends on 7) The method according to claim 7, further comprising: when the plurality of actual latencies continuously are all less than or equal to the second latency threshold, determining that the link is a low latency link. ### Claim 9 (depends on 7) The method according to claim 7, further comprising: sending second data to the first CE device through the first link, wherein the second data is data that is expected to be sent to the first CE device through a third link, wherein the third link and the first link are load sharing links for each other, and wherein the first link is the link between the first PE device and the second PE device. ### Claim 10 (depends on 1) The method according to claim 1, where the received routing message is an Ethernet virtual instance auto discovery (EVI-AD) routing message. ### Claim 11 (depends on 10) The method according to claim 10, wherein the EVI-AD routing message comprises an identifier of an Ethernet virtual private network (EVPN) instance, and wherein the link corresponds to the EVPN instance. ### Claim 12 (depends on 10) The method according to claim 10, wherein the EVI-AD routing message comprises a second latency threshold, and wherein the second latency threshold is used to indicate a latency lower limit corresponding to the link. ### Claim 13 An apparatus, comprising a processor, wherein the processor configures the apparatus to: determine an actual latency corresponding to a link between a first provider edge (PE) device and a second PE device, wherein the second PE device is a next hop of the first PE device; and when the actual latency is greater than or equal to a first latency threshold, determine that the link is a high latency link, wherein the first latency threshold is used to indicate a latency upper limit corresponding to the link, wherein the first latency threshold is involved with a received routing message, where the received routing message comprises a community field carrying the first latency threshold. ### Claim 14 (depends on 13) The apparatus according to claim 13, where the processor further configures the apparatus to: send first data to a first customer edge (CE) device through a second link, wherein the first data is data that is expected to be sent to the first CE device through a first link, wherein the second link and the first link are load sharing links for each other, and wherein the first link is the link between the first PE device and the second PE device. ### Claim 15 (depends on 13) The apparatus according to claim 13, where the received routing message is an Ethernet virtual instance auto discovery (EVI-AD) routing message. ### Claim 16 (depends on 15) The apparatus according to claim 15, wherein the EVI-AD routing message further comprises an identifier of an Ethernet virtual private network (EVPN) instance, and wherein the link corresponds to the EVPN instance. ### Claim 17 (depends on 15) The apparatus according to claim 15, wherein the EVI-AD routing message further comprises a second latency threshold, and wherein the second latency threshold is used to indicate a latency lower limit corresponding to the link. ### Claim 18 A non-transitory computer-readable media storing instructions that when executed by a computer configure the computer to perform steps comprising: determining an actual latency corresponding to a link between a first provider edge (PE) device and a second PE device, wherein the second PE device is a next hop of the first PE device; and when the actual latency is greater than or equal to a first latency threshold, determining that the link is a high latency link, wherein the first latency threshold is used to indicate a latency upper limit corresponding to the link, wherein the first latency threshold is involved with a received routing message, where the received routing message comprises a community field carrying the first latency threshold. ### Claim 19 (depends on 18) The computer program product according to claim 18, where the received routing message is an Ethernet virtual instance auto discovery (EVI-AD) routing message. ### Claim 20 (depends on 19) The computer program product according to claim 19, wherein the EVI-AD routing message further comprises an identifier of an Ethernet virtual private network (EVPN) instance, and wherein the link corresponds to the EVPN instance.