# US 2013/0155874 A1 · Method, apparatus, and system for detecting multi-protocol label switching ring network > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2013/0155874 A1 - Document ID: US20130155874A1 - Status: Published application - Kind: A1 - Application number: 13/681,205 - Filed: 2012-11-19 - Published: 2013-06-20 - Earliest claimed: 2011-11-17 - Assignees: Huawei Technologies Co., Ltd. - Inventors: Li SHA; Ling BAN; Jinyong REN; Huisheng LI - Web page: https://patentgrep.com/patent/US20130155874A1 ## CPC - H04L 43/0811: by checking connectivity - H04L 12/42: Loop networks - H04L 45/50: using label swapping, e.g. multi-protocol label switch [MPLS] - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract Embodiments of the present invention disclose a method, an apparatus, and a system for detecting a multi-protocol label switching ring network. The method includes: initiating, by a ring ingress node, a detection request packet; determining a ring label switched path LSP forwarding equivalence class FEC corresponding to the detection request packet, and encapsulating the ring LSP FEC into the detection request packet; sending the detection request packet after encapsulation to a ring egress node; and determining whether a detection reply packet sent by the ring egress node is received; if yes, determining that the ring LSP is connected; otherwise, determining that the ring LSP is not connected. Therefore, the embodiments of the present invention are able to directly detect connectivity of a ring LSP, solving the problem in the prior art where an interference exists during detection of the ring LSP connectivity. ## Claims ### Claim 1 A method for detecting a multi-protocol label switching ring network, comprising: initiating, by a ring ingress node, a detection request packet; determining a ring label switched path (LSP) forwarding equivalence class (FEC) corresponding to the detection request packet, and encapsulating the ring LSP FEC into the detection request packet; sending the detection request packet after encapsulation to a ring egress node; and determining whether a detection reply packet sent by the ring egress node is received; if the detection reply packet sent by the ring egress node is received, determining that a ring LSP corresponding to the ring LSP FEC is connected; if the detection reply packet sent by the ring egress node is not received, determining that the ring LSP is not connected. ### Claim 2 (depends on 1) The method according to claim 1, wherein before the initiating, by the ring ingress node, the detection request packet, the method further comprises: receiving, by the ring ingress node, a detection command, wherein the detection command comprises a ring identity, a ring direction, and a ring egress node address. ### Claim 3 (depends on 2) The method according to claim 2, wherein the determining the ring label LSP FEC corresponding to the detection request packet comprises: according to a ring ingress node address, the ring identity and the ring egress node address comprised in the detection command, determining the ring LSP FEC corresponding to the detection request packet, wherein the ring LSP FEC comprises the ring ingress node address, the ring egress node address, and ring identity. ### Claim 4 (depends on 1) The method according to claim 1, wherein before the sending the detection request packet after the encapsulation to the ring egress node, the method comprises: querying label mapping information corresponding to the ring LSP, acquiring an outgoing label along the ring direction on the ring ingress node, and pressing the outgoing label into the detection request packet. ### Claim 5 (depends on 1) The method according to claim 1, wherein the sending the detection request packet after the encapsulation to the ring egress node comprises: sending the detection request packet after the encapsulation along the ring direction to the ring egress node. ### Claim 6 A method for detecting a multi-protocol label switching ring network, comprising: initiating, by a ring ingress node, a fault detection request packet with incremental time to live (TTL); determining a ring label switched path (LSP) forwarding equivalence class (FEC) corresponding to the fault detection request packet, and encapsulating the ring LSP FEC into the fault detection request packet; respectively sending the fault detection request packet after encapsulation with the incremental TTL to downstream nodes, wherein the downstream nodes comprise all intermediate nodes between the ring ingress node and the ring egress node; and if no fault detection reply packet returned by a downstream node is received, determining that the downstream node is a faulty node. ### Claim 7 (depends on 6) The method according to claim 6, wherein before the initiating, by the ring ingress node, the fault detection request packet with the incremental TTL, the method further comprises: receiving, by the ring ingress node, a fault detection command, wherein the fault detection command comprises a ring identity, a ring direction, and the ring egress node address. ### Claim 8 (depends on 7) The method according to claim 7, wherein the determining the ring LSP FEC corresponding to the fault detection request packet comprises: according to a ring ingress node address, the ring identity and the ring egress node address comprised in the fault detection command, determining the ring LSP FEC corresponding to the fault detection request packet, wherein the ring LSP FEC comprises the ring ingress node address, the ring egress node address, and the ring identity. ### Claim 9 (depends on 6) The method according to claim 6, wherein before the respectively sending the fault detection request packet after the encapsulation with the incremental TTL to the downstream nodes, the method comprises: querying label mapping information corresponding to a ring LSP corresponding to the ring LSP FEC, acquiring an outgoing label along the ring direction on the ring ingress node, and pressing the outgoing label into the fault detection request packet. ### Claim 10 (depends on 6) The method according to claim 6, wherein the respectively sending the fault detection request packet after the encapsulation with the incremental TTL to the downstream nodes, wherein the downstream nodes comprise all the intermediate nodes between the ring ingress node and the ring egress node, and the ring egress node, comprises: respectively sending the fault detection request packet after the encapsulation with the incremental TTL, along the ring direction to the downstream nodes, wherein the downstream nodes comprise all the intermediate nodes along the ring direction between the ring ingress node and the ring egress node. ### Claim 11 An apparatus for detecting a multi-protocol label switching ring network, comprising: an initiating module, configured to initiate a detection request packet; a encapsulating module, configured to determine a ring label switched path (LSP) forwarding equivalence class (FEC) corresponding to the detection request packet, and encapsulate the ring LSP FEC into the detection request packet; a sending module, configured to send the detection request packet after encapsulation to a ring egress node; and a detecting module, configured to determine whether a detection reply packet sent by the ring egress node is received; if the detection reply packet sent by the ring egress node is received, determine that the ring LSP is connected; if the detection reply packet sent by the ring egress node is not received, determine that a ring LSP corresponding to the ring LSP FEC is not connected. ### Claim 12 (depends on 11) The apparatus according to claim 11, further comprising: a receiving module, configured to receive a detection command, wherein the detection command comprises a ring identity, a ring direction, and a ring egress node address. ### Claim 13 (depends on 11) The apparatus according to claim 11 further comprising: a label acquiring module, configured to query label mapping information corresponding to the ring LSP, acquire an outgoing label along the ring direction on a ring ingress node, and press the outgoing label into the detection request packet. ### Claim 14 An apparatus for detecting a multi-protocol label switching ring network, comprising: an initiating module, configured to initiate a fault detection request packet with incremental time to live (TTL); an encapsulating module, configured to determine a ring label switched path (LSP) forwarding equivalence class (FEC) corresponding to the fault detection request packet, and encapsulate the ring LSP FEC into the fault detection request packet; a sending module, configured to respectively send the fault detection request packet after the encapsulation with the incremental TTL to downstream nodes, wherein the downstream nodes comprise all intermediate nodes between a ring ingress node and a ring egress node; and a detecting module, configured to: if no fault detection reply packet returned by a downstream node is received, determine that the downstream node is a faulty node. ### Claim 15 (depends on 14) The apparatus according to claim 14, further comprising: a receiving module, configured to receive a fault detection command, wherein the fault detection command comprises a ring identity, a ring direction, and a ring egress node address. ### Claim 16 (depends on 14) The apparatus according to claim 14, further comprising: a label acquiring module, configured to query label mapping information corresponding to the ring LSP, acquire an outgoing label along the ring direction on the ring ingress node, and press the outgoing label into the fault detection request packet. ### Claim 17 A system for detecting a multi-protocol label switching ring network, comprising: a ring ingress node, and a ring egress node that communicates with the ring ingress node; wherein, the ring ingress node comprises an apparatus for detecting the multi-protocol label switching ring network, the apparatus comprises: an initiating module, configured to initiate a detection request packet; an encapsulating module, configured to determine a ring label switched path (LSP) forwarding equivalence class (FEC) corresponding to the detection request packet, and encapsulate the ring LSP FEC into the detection request packet; a sending module, configured to send the detection request packet after encapsulation to a ring egress node; and a detecting module, configured to determine whether a detection reply packet sent by the ring egress node is received; if the detection reply packet sent by the ring egress node is received, determine that a ring LSP corresponding to the ring LSP FEC is connected; if the detection reply packet sent by the ring egress node is not received, determine that the ring LSP is not connected; and the ring egress node is configured to: receive a detection request packet after the encapsulation sent by the ring ingress node, and determine, according to a ring identity comprised in the ring LSP FEC, whether a ring LSP along a ring direction between the ring ingress node and the ring egress node corresponds to the ring identity; if the ring LSP along the ring direction between the ring ingress node and the ring egress node corresponds to the ring identity, further determine, according to a ring egress node address comprised in the ring LSP FEC, whether the ring egress node corresponds to the ring egress node address; if the ring egress node corresponds to the ring egress node address, encapsulate the ring LSP FEC into a detection reply packet, and send the detection reply packet after the encapsulation to the ring ingress node. ### Claim 18 A system for detecting a multi-protocol label switching ring network, comprising: a ring ingress node, a ring egress node that communicates with the ring ingress node, and all intermediate nodes along a ring direction between the ring ingress node and the ring egress node; wherein, the ring ingress node comprises an apparatus for detecting the multi-protocol label switching ring network, the apparatus comprises: an initiating module, configured to initiate a fault detection request packet with incremental time to live (TTL); an encapsulating module, configured to determine a ring label switched path (LSP) forwarding equivalence class (FEC) corresponding to the fault detection request packet, and encapsulate the ring LSP FEC into the fault detection request packet; a sending module, configured to respectively send the fault detection request packet after the encapsulation with the incremental TTL to downstream nodes, wherein the downstream nodes comprise all intermediate nodes between a ring ingress node and a ring egress node; and a detecting module, configured to: if no fault detection reply packet returned by a downstream node is received, determine that the downstream node is a faulty node ; the intermediate nodes are configured to: receive a fault detection request packet after the encapsulation with the incremental TTL sent by the ring ingress node, and determine, according to a ring identity comprised in the ring LSP FEC, whether a ring LSP along a ring direction between the ring ingress node and the ring egress node corresponds to the ring identity; if the ring LSP along the ring direction between the ring ingress node and the ring egress node corresponds to the ring identity, encapsulate the ring LSP FEC and downstream node information of the intermediate nodes into a fault detection reply packet, and send the fault detection reply packet after the encapsulation to the ring ingress node; and the ring egress node is configured to: receive the fault detection request packet after the encapsulation sent by the ring ingress node, and determine, according to the ring identity comprised in the ring LSP FEC, whether the ring LSP along the ring direction between the ring ingress node and the ring egress node corresponds to the ring identity; if the ring LSP along the ring direction between the ring ingress node and the ring egress node corresponds to the ring identity, further determine, according to a ring egress node address comprised in the ring LSP FEC, whether the ring egress node corresponds to the ring egress node address; if the ring egress node corresponds to the ring egress node address, encapsulate the ring LSP FEC into the fault detection reply packet, and send the fault detection reply packet after the encapsulation to the ring ingress node.