ITU-T G.8032/ERPS协议介绍（中英文）

G.8032/ERPS标准概述

Overview of the G.8032/ERPS Standard

G.8032/ERPS（以太网环路保护切换）是由国际电信联盟电信标准化部门 (ITU-T) 制定的标准化协议，旨在为二层以太网环路拓扑提供快速可靠的保护切换机制。当链路或节点发生故障时，ERPS 可确保在 50 毫秒内无缝切换到备份路径，从而保持数据传输不间断，确保网络服务持续可用。

ERPS 利用 R-APS（环路自动保护切换）协议持续监控网络状态并管理切换过程。RPL（环路保护链路）机制的集成可有效防止网络环路和广播风暴，从而增强网络整体稳定性。此设计可在需要时快速切换到备份路径，从而确保数据传输的顺畅。

G.8032/ERPS 的运行由对网络节点和链路状态的持续监控驱动。一旦检测到主链路故障，系统会立即激活预定义的备份路径，确保数据流不中断。虽然恢复时间可能因网络规模和 R-APS 数据包处理量等因素而异，但典型的切换时间在 50 毫秒以内，标准范围为 10 至 500 毫秒。

对于要求高可用性和实时恢复的应用，例如工业自动化、智能交通和企业骨干网，G.8032/ERPS 提供了一种高效、经济且易于部署的环形网络冗余解决方案。

G.8032/ERPS (Ethernet Ring Protection Switching) is a standardized protocol developed by the International Telecommunication Union Telecommunication Standardization Sector (ITU-T), designed to provide a fast and reliable protection switching mechanism for Layer 2 Ethernet ring topologies. In the event of a link or node failure, ERPS ensures seamless failover to a backup path within 50 milliseconds, maintaining uninterrupted data transmission and ensuring continuous network service availability.

ERPS utilizes the R-APS (Ring Automatic Protection Switching) protocol to continuously monitor the status of the network and manage the switching process. The integration of the RPL (Ring Protection Link) mechanism effectively prevents network loops and broadcast storms, thus enhancing overall network stability. This design guarantees smooth data transmission by enabling rapid failover to a backup path whenever required.

The operation of G.8032/ERPS is driven by continuous monitoring of both network nodes and link status. Upon detecting a failure in the primary link, the system immediately activates a predefined backup path, ensuring that data flow remains uninterrupted. While recovery time may vary depending on factors such as network size and R-APS packet processing volume, the typical switching time is under 50 milliseconds, with a standard range of 10 to 500 milliseconds.

For applications demanding high availability and real-time recovery, such as industrial automation, smart transportation, and enterprise backbone networks, G.8032/ERPS delivers an efficient, cost-effective, and easily deployable ring network redundancy solution.

技术概念和拓扑架构

Technical Concepts and Topology Architecture

ERPS的设计基于环网拓扑的高可用性和快速恢复能力。其运行机制基于 ITU-T G.8032 标准，利用协议消息交换和拓扑控制策略实现实时故障检测和自动网络恢复。此外，ERPS 支持多种环网架构，为复杂的网络设计提供灵活的解决方案。

The design of ERPS is built on high availability and rapid recovery capabilities within a ring network topology. Its operational mechanism is based on the ITU-T G.8032 standard, leveraging protocol message exchange and topology control strategies to enable real-time fault detection and automatic network recovery. Additionally, ERPS supports a variety of ring network architectures, offering flexible solutions for complex network designs.

1. 协议与机制

Protocol and Mechanism

ERPS 使用专用协议消息（R-APS）进行实时网络状态通信，包括信号故障 (SF)、无请求 (NR) 和 RPL 阻塞 (RB) 等消息类型。当环网中任何一条链路发生故障时，ERPS 会立即将该链路标记为故障，并激活 RPL（环保护链路）端口（默认设置为阻塞状态）完成流量重路由。故障清除后，系统会根据配置的模式（可恢复或不可恢复）决定是否恢复到原始路径。

在正常运行条件下，RPL 所在节点的端口被设置为阻塞状态，以防止环路拓扑中出现环路和广播风暴。此阻塞机制不会影响正常的数据传输，并且仅在必要时激活备份路径，从而确保最佳的网络性能和稳定性。

ERPS utilizes a dedicated protocol message (R-APS) for real-time network status communication, including message types such as Signal Fail (SF), No Request (NR), and RPL Blocked (RB). When any link within the ring network experiences a failure, ERPS immediately marks the link as faulty and activates the RPL (Ring Protection Link) port, which is set to a blocked state by default, to complete traffic rerouting. Once the fault is cleared, the system can decide whether to revert to the original path based on the configured mode (Revertive or Non-Revertive).
Under normal operating conditions, the port on the node where the RPL resides is set to the blocked state to prevent loops and broadcast storms within the ring topology. This blocking mechanism does not affect regular data transmission and only activates the backup path when necessary, ensuring optimal network performance and stability.

2. 应用与拓扑

Application and Topology

ERPS 支持多种环网拓扑结构。其核心拓扑类型包括主环、子环和互联环，高级应用模型可扩展到多环和负载均衡。

• 主环作为网络的核心骨干，连接多个节点，并将 RPL 配置为主备份路径。它非常适合需要传输大量关键流量、对稳定性和恢复时间要求较高的场景。

• 子环嵌套在主环内，通过虚拟通道互联，提供独立的保护功能。它适用于区域或分支网络部署，增强网络模块化和管理效率。

• 互联环由多个 ERPS 环通过互联节点连接而成。不同的实例和 VLAN 用于隔离控制报文，防止报文干扰。此拓扑结构适用于大规模或多层网络架构。

ERPS supports a variety of ring network topologies. Its core topology types include Major Ring, Sub-Ring, and Interconnected Ring, with advanced application models extending to multiple rings and load balancing.

• Major Ring serves as the core backbone of the network, connecting multiple nodes and configuring RPL as the primary backup path. It is ideal for scenarios requiring the transmission of large volumes of critical traffic, with high demands for stability and recovery time.

• Sub-Ring is nested within the Major Ring, interconnected via virtual channels, providing independent protection capabilities. It is suited for regional or branch network deployments, enhancing network modularity and management efficiency.

• Interconnected Ring consists of multiple ERPS rings connected through interwoven nodes. Different instances and VLANs are used to separate control messages, preventing message interference. This topology is suitable for large-scale or multi-layered network architectures.

此外，ERPS 还支持多种高级拓扑设计：

• 单环拓扑：最基本的 ERPS 架构，适用于小型企业或数据中心。

• 多环拓扑：支持多个独立环共存，增强冗余性和灵活性，非常适合大型工业设施或智能交通系统等应用。

• 负载均衡环拓扑：实施流量分配机制，实现链路负载均衡，从而提高性能和可用性。

In addition, ERPS supports various advanced topology designs:

• Single Ring Topology: The most basic ERPS architecture, suitable for small enterprises or data centers.

• Multiple Ring Topology: Enables the coexistence of multiple independent rings, enhancing redundancy and flexibility—ideal for applications such as large-scale industrial facilities or intelligent transportation systems.

• Load-Balanced Ring Topology: Implements traffic distribution mechanisms to achieve link load balancing, thereby improving performance and availability.

这些拓扑设计可以根据实际部署需求灵活组合，提供高可靠、可扩展、高效的网络冗余解决方案。

These topology designs can be flexibly combined based on actual deployment requirements, offering a highly reliable, scalable, and efficient network redundancy solution.

3. 特性与优势

Features and Advantages

ERPS 的设计融合了高性能和标准化协议机制，具有以下关键技术优势：

• 快速恢复与收敛

ERPS 采用 R-APS 协议进行实时监控和自动切换。检测到链路或节点故障后，可在 50 毫秒内重新路由流量，从而最大限度地减少数据包丢失并降低服务中断的风险。

• 环路保护与稳定传输

为了防止环形拓扑中的环路和广播风暴，ERPS 使用环路保护链路 (RPL) 机制阻塞特定端口。它还利用基于 VLAN 的流量隔离来确保稳定安全的数据传输。

• 标准化与互操作性

ERPS 支持不同品牌交换机之间的互操作性，从而降低部署和集成成本。这使您的网络部署能够适应多供应商交换机设备的使用。

• 灵活的拓扑支持

ERPS 支持多种环形拓扑结构，具有多实例和 VLAN 隔离功能，可实现流量隔离和独立运行。G.8032 v2 增加了对多环和阶梯形拓扑结构的支持，增强了部署灵活性。

ERPS is designed with a combination of high performance and standardized protocol mechanisms, offering the following key technical benefits:

• Fast-Recovery and Convergence
ERPS utilizes the R-APS protocol for real-time monitoring and automatic switching. Upon detecting a link or node failure, traffic can be rerouted within 50 milliseconds, minimizing packet loss and reducing the risk of service disruption.

• Loop-Protection and Stable-Transmission
To prevent loops and broadcast storms in ring topologies, ERPS blocks specific ports using the Ring Protection Link (RPL) mechanism. It also leverages VLAN-based traffic isolation to ensure stable and secure data transmission.

• Standardization and Interoperability
ERPS supports interoperability between switches of different brands, thus reducing deployment and integration costs. This enables your network deployment to adapt to the use of multi-vendor switch equipment.

• Flexible Topology Support
ERPS supports diverse ring topologies with multi-instance and VLAN separation, enabling traffic isolation and independent operation. G.8032 v2 adds support for multi-ring and ladder topologies, enhancing deployment flexibility.

ERPS 与 RSTP 比较

ERPS vs. RSTP

ERPS 在收敛速度、拓扑灵活性、恢复模式和管理功能方面均具有明显优势，是现代高可用性网络的首选。

ERPS offers clear advantages in convergence speed, topology flexibility, recovery modes, and management capabilities, making it a preferred choice for modern, high-availability networks.

应用场景与部署

Application Scenarios and Deployment

ERPS 广泛应用于对网络稳定性和快速恢复能力要求较高的环境，包括：

• 智慧城市：部署于交通信号灯、监控摄像头、智能路灯和环境传感器等场景。主环路连接主要道路，子环路连接交叉路口设备，确保即使在链路故障时数据流也能不间断。

• 工业自动化：以弹性环形拓扑连接 PLC、传感器和控制系统，并支持自动故障切换到备份路径，确保生产运行稳定。

• 智能交通：主环路沿高速公路或铁路铺设，连接收费站、监控点和交通检测器。虚拟通道支持跨环通信，从而提高可用性和管理性。

• 数据中心：采用单环或子环拓扑结构，确保高速数据交换和快速恢复。

• 智能电网：采用多环和负载均衡拓扑结构，保障电力系统的实时监控和安全控制。

ERPS is widely adopted in environments requiring high network stability and rapid recovery, including:

• Smart Cities: Deployed in traffic signals, surveillance cameras, smart streetlights, and environmental sensors. Main rings follow major roads, while sub-rings connect intersection devices, ensuring uninterrupted data flow even during link failures.

• Industrial Automation: Connects PLCs, sensors, and control systems in a resilient ring topology. Enables automatic failover to backup paths, ensuring stable production operations.

• Intelligent Transportation: Main rings run along highways or railways, linking toll stations, monitoring points, and traffic detectors. Virtual channels enable cross-ring communication for improved availability and management.

• Data Centers: Uses single or sub-ring topologies to ensure high-speed data exchange and fast recovery.

• Smart Grids: Employs multi-ring and load-balanced topologies to guarantee real-time monitoring and secure control of power systems.

EtherWAN 工业级网管型以太网交换机，支持 ERPS 环网保护交换

EtherWAN Industrial Managed Ethernet Switch with ERPS Support

EtherWAN 的工业级网管型以太网交换机支持 ERPS（以太网环网保护交换），可实现无缝数据传输和快速链路恢复。EtherWAN 的 ERPS 解决方案专为智能工厂、工业自动化和交通监控等高可用性应用而设计，具有快速恢复、灵活部署和强大的互操作性，是关键任务网络的理想选择。

EtherWAN’s industrial-grade managed Ethernet switches support ERPS (Ethernet Ring Protection Switching), enabling seamless data transmission and rapid link recovery. Designed for high-availability applications such as smart factories, industrial automation, and traffic surveillance, EtherWAN’s ERPS solution delivers fast recovery, flexible deployment, and robust interoperability—making it an ideal choice for mission-critical networks.

主要特点：

Key Features:

• 符合 ITU-T G.8032 ERPS v2 标准，支持单环、主环、子环和互联环等多种拓扑结构。

• 支持可恢复和非可恢复模式，以及手动切换功能，实现灵活的管理和故障模拟测试。

• 通过智能端口阻塞机制，防止环形拓扑中的网络环路和广播风暴。

• 实现低于 50 毫秒的网络恢复，最大限度地减少链路或节点故障期间的数据包丢失。

• 可与多厂商设备互操作，实现跨异构网络环境的 ERPS 无缝运行。

• Compliant with ITU-T G.8032 ERPS v2, supporting various topologies including single ring, major ring, sub-ring, and interconnected ring structures.

• Supports Revertive and Non-Revertive modes, along with manual switching for flexible management and fault simulation testing.

• Prevents network loops and broadcast storms in ring topologies through intelligent port blocking mechanisms.

• Enables sub-50ms network recovery, minimizing packet loss during link or node failures.

• Interoperable with multi-vendor devices, allowing seamless ERPS operation across heterogeneous network environments.