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JP-7855569-B2 - P2MP tree connectivity detection method, device, and system

JP7855569B2JP 7855569 B2JP7855569 B2JP 7855569B2JP-7855569-B2

Inventors

  • ▲謝▼ ▲經▼▲榮▼
  • 耿 雪松
  • 段 方▲紅▼

Assignees

  • 華為技術有限公司

Dates

Publication Date
20260508
Application Date
20210722
Priority Date
20200724

Claims (12)

  1. A point-to-multipoint (P2MP) tree connectivity detection method, wherein the method is applied to a segment routing (SR) domain, the SR domain includes a P2MP tree, the P2MP tree includes a first node, the first node is the root node or intermediate replica node of the P2MP tree, and the method is The first node determines the first next hop node of the first node based on the replication branch information, The first node sends a first request message to the first next-hop node, wherein the first request message includes the segment identifier (SID) of the first next-hop node, and the first request message includes a first identifier, the first identifier indicating that the first request message is for connectivity detection . When the first next-hop node is an intermediate replication node of the P2MP tree, the first next-hop node, in response to receiving the first request message, sends the first request message to the next-hop node of the first next-hop node based on the replication branch information, without sending a response message to the root node. When the first next-hop node is a leaf node of the P2MP tree, the first next-hop node, in response to receiving the first request message, sends a response message to the root node. Methods that include...
  2. A point-to-multipoint (P2MP) tree connectivity detection method, wherein the method is applied to a segment routing (SR) domain, the SR domain includes a P2MP tree, the P2MP tree includes a first node, the first node is the root node or intermediate replica node of the P2MP tree, and the method is The first node determines the first next hop node of the first node based on the replication branch information, The first node sends a first request message to the first next-hop node, wherein the first request message includes the segment identifier (SID) of the first next-hop node, the first request message includes a first identifier, the first identifier indicates that the first request message is for connectivity detection, and the first request message includes a natural number time to live (TTL), the TTL being initialized to an initial value by the root node. When the first next-hop node is an intermediate replication node of the P2MP tree, in response to the first next-hop node receiving the first request message, if the TTL is 1, the first next-hop node sends a response message to the root node; if the TTL is greater than 1, the first next-hop node subtracts 1 from the TTL and, without sending a response message to the root node, sends the first request message to the next-hop node of the first next-hop node based on the replication branch information. When the first next-hop node is a leaf node of the P2MP tree, the first next-hop node, in response to receiving the first request message, sends a response message to the root node. Methods that include...
  3. The first node is the root node of the P2MP tree, the first next hop node is a leaf node of the P2MP tree, and the method is The method according to claim 1 or 2, further comprising the steps of: the first node determining that a path from the first node to the first next hop node is established in response to the first node receiving a first response message transmitted by the first next hop node, wherein the first response message is a response message to the root node in response to a first request message; or the first node determining that a path from the first node to the first next hop node is broken in response to the first node not receiving a response message transmitted to the root node by the first next hop node in response to a first request message.
  4. The first node is the root node of the P2MP tree, the first next-hop node is an intermediate replication node of the P2MP tree, and the method is The method according to claim 1 or 2, further comprising the steps of: determining that the path from the first node to the leaf node is connected in response that the first node has received a second response message transmitted by a leaf node on a path through the first next hop node, wherein the second response message is the response message to the root node in response to the first request message; or determining that the path from the first node to the leaf node is disconnected in response that the first node has not received the response message to the root node transmitted by a leaf node on a path through the first next hop node in response to the first request message.
  5. The replication branch information includes a path from the first node to a downstream node, and the first next-hop node is a node on the path. The step of determining the first next hop node of the first node based on the replication branch information by the first node is: The method according to claim 1 or 2 , further comprising the step of determining the first next hop node based on the path identifier using the first node.
  6. The replication branch information includes the segment identifier SID of the downstream node of the first node, and the SID of the downstream node includes the SID of the next hop node of the first node. The step of determining the first next hop node of the first node based on the replication branch information by the first node is: The method according to claim 1 or 2 , comprising the step of determining the SID of the first next-hop node based on the SID of the downstream node by the first node.
  7. The method according to claim 6, wherein when the SID within the SID is a segment identifier for segment routing over Internet Protocol version 6 IPv6 ( SRv6 SID), the SID of the first next-hop node includes the IPv6 address of the first next-hop node.
  8. The aforementioned method, The first node determines the second next hop node of the first node based on the replication branch information, The method according to claim 1 or 2, further comprising the step of the first node sending a second request message to the second next-hop node, wherein the second request message includes the SID of the second next-hop node and the second request message includes the first identifier.
  9. The method according to claim 1 or 2 , wherein the first request message includes a second identifier, the second identifier being for identifying the P2MP tree.
  10. The method according to claim 9 , wherein the second identifier is one or more of the address of the root node of the P2MP tree, the replication identifier of the replication segment, and the tree identifier of the P2MP tree.
  11. A point-to-multipoint (P2MP) tree connectivity detection system, wherein the system includes a P2MP tree, the P2MP tree is located within a segment routing (SR) domain, and the system comprises a root node, intermediate replication nodes, and leaf nodes of the P2MP tree. The root node is configured to determine, based on first replication branch information, that the next hop node of the root node is the intermediate replication node, to send a first request message to the intermediate replication node, and to determine, in response to receiving a first response message sent by the leaf node, that the path from the root node to the leaf node is connected, wherein the first request message includes the segment identifier (SID) of the intermediate replication node, and the first request message includes a first identifier, the first identifier indicating that the first request message is for connectivity detection, The intermediate replication node is configured to, in response to receiving the first request message, send the first request message to the next hop node based on the second replication branch information, without sending a response message to the root node . The system is configured such that the leaf node, in response to receiving the first request message, sends the first response message to the root node.
  12. A computer-readable storage medium containing a computer program, wherein, when the computer program is executed on the computer, the computer is enabled to perform the method according to any one of claims 1 to 10.

Description

This application claims priority to Chinese Patent Application No. 202010725197.0, titled "Packet Detection Method, Device, and System," filed with the China National Intellectual Property Administration on July 24, 2020, and to Chinese Patent Application No. 202011035873.8, titled "P2MP Tree Connectivity Detection Method, Device, and System," filed with the China National Intellectual Property Administration on September 27, 2020. The aforementioned Chinese patent applications are incorporated herein by reference in their entirety. This application relates to the field of communications, and more specifically, to a point-to-multipoint (P2MP) tree connectivity detection method, device, and system. A Replication Segment provides a building module for P2MP services. For example, a P2MP tree is constructed by concatenating replication segments on nodes within a Segment Routing Domain. The entry node, acting as the root node of the P2MP tree, replicates packets and sends them to the exit node through one or more intermediate replication nodes, so that point-to-multipoint transmission of packets can be performed by the P2MP tree within the SR domain. Unlike traditional Internet Protocol (IP) multicast technology, this technology uses a multicast group address as the destination address of packets and does not require the establishment of multicast forwarding trees and multicast forwarding entries using Protocol Independent Multicast (PIM). Therefore, network load can be reduced and packet forwarding efficiency can be improved. However, currently there is no method to detect the connectivity of P2MP trees within an SR domain, and connectivity detection on P2MP trees and their associated replication segment paths is not possible. This is a schematic diagram illustrating an application scenario for forwarding packets within a P2MP tree, as described in this application.This is a schematic diagram of another application scenario for forwarding packets within a P2MP tree, as described in this application.This is a schematic diagram illustrating the application scenario of P2MP tree connectivity detection as described in this application.This is a schematic flowchart of the P2MP tree connectivity detection method described in this application.This is a schematic diagram of the packet format of the request message according to this application.This is a schematic flowchart of the P2MP tree connectivity detection method described in this application.This is a schematic flowchart of another P2MP tree connectivity detection method according to this application.This is a schematic flowchart of another P2MP tree connectivity detection method according to this application.This is a schematic diagram of the node structure according to this application.This is a schematic diagram of the structure of another node according to this application.This is a schematic diagram of the node hardware structure according to this application.This is a schematic diagram of the hardware structure of another node according to this application.This is a schematic diagram of the structure of the P2MP tree connectivity detection system described in this application. A replication segment provides a way for a node to replicate packets to a group of other nodes within a Segment Routing Domain (SR). In an SR domain, a replication segment is a logical segment that connects a replication node to a group of downstream nodes. A replication segment is a local segment instantiated by a replication node. A replication segment can be configured locally on a node or programmed by a path computation element (PCE). A replication segment is identified using a 2-tuple <Replication Identifier (Replication-ID), Node Identifier (Node-ID)>. The Replication-ID is used to identify the replication segment. For example, the Replication-ID may be a 32-bit integer value or may be extended based on requirements. The Node-ID is the address of the node instantiating the replication segment, and may be, for example, the IPv6 address of the replication node. The content of a replication segment includes the Replication Segment Identifier (Replication SID), Downstream Nodes, and Replication State. The downstream nodes and replication status of a replication segment can change over time. The replication status is a list of replication branches pointing to downstream nodes, and this list can also be called replication branch information. Each replication branch can be abstracted as a <Downstream Node, DownstreamReplication SID>. A Replication SID is a Segment Routing-Multiprotocol Label Switching (SR-MPLS) label or SRv6 SID used to identify a replication segment on the forwarding plane. It will be understood that a replication branch reaching a particular downstream node can be represented by a node SID or a node's neighbor SID. Simply put, downstream nodes may be represented by an SID list (SID-list) or an SR policy. An SR policy specifies an explicit path from the replication