G.8031/Y.1342 Ethernet Protection Switching学习笔记

This Recommendation specifies linear 1+1 protection switching architecture and linear 1:1 protection switching architecture.
以太网线性保护用于保护一条以太网连接，它是一种专用的端到端保护结构，可以用于不同的网络结构，如网状网，环网等。
G.8031定义了1＋1和1︰1两种保护方式，在1＋1方式中每一个保护资源都对应着一个工作资源，在保护域内，1＋1方式采用双发单收的保护机制；1︰1方式采用保护资源与工作资源彼此切换的机制。

In the linear 1+1 protection switching architecture, a protection transport entity is dedicated to each working transport entity. The normal traffic is copied and fed to both working and protection transport entities with a permanent bridge at the source of the protected domain. The traffic on working and protection transport entities is transmitted simultaneously to the sink of the protected domain, where a selection between the working and protection transport entities is made based on some predetermined criteria, such as server defect indication.
在1＋1结构中，保护连接是每条工作连接专用的，工作连接与保护连接在保护域的源端进行桥接。业务在工作和保护连接上同时发向保护域的宿端，在宿端，基于某种预先确定的准则如缺陷指示来选择接收来自工作或保护连接上的业务。为了避免单点失效，工作连接和保护连接应该走分离的路由。

In the linear 1:1 protection switching architecture, the protection transport entity is dedicated to the working transport entity. However, the normal traffic is transported either on the working transport entity or on the protecti