PTN运行维护篇目录1.1网络故障处理基本思路和方法......................................................................................31.1.1PTN与MSTP告警对比·····································································31.1.2常见告警故障处理方法·······································································51.1.3以太网业务丢包类故障处理方法···························································71.1.4OAM/PING调试法···········································································71.1.5环回逐段定位法···············································································101.2PTN网络例行监控........................................................................................................111.1网络故障处理基本思路和方法PTN的组网、业务配置愈发复杂，需分组厂商网管尽快做好SDH－Like功能。为尽快恢复业务，将检测的故障点最小化，需了解SDH原理、IP网络原理知识、告警信号流及告警产生机理、PTN设备和网管基本操作、常用仪表的基本操作，了解网络拓扑，业务配置，设备运行状态。告警、性能分析法OAM/PING调试法环回法PTN对于Tunnel的故障可用MPLSOAM来检测，MPLSOAM包括CV/FFD、Ping和Traceroute。通过CV（ConnectivityVerification）/FFD（FastFailureDetection）检测可以检测LSP的连通性。CV检测和FFD检测的过程基本一致，其不同在于CV检测发送CV报文的频率固定为1帧/s并且不可设置，而FFD检测发送FFD报文的频率是可以自行定义的。MPLSPing/Traceroute为用户提供了发现LSP错误、并及时定位失效节点的机制。MPLSPing/Traceroute使用MPLSEchoRequest和MPLSEchoReply检测LSP的可用性。MPLSEchoRequest中携带需要检测的FEC（ForwardingEquivalenceClass）信息，和其他属于此FEC的报文一样沿LSP发送，从而实现对LSP的检测。为了更好的理解PTN，我们就把PTN与熟悉的SDH的业务层面告警类比一下，与大家共享。1.1.1PTN与MSTP告警对比对应于业务模型，PTN的告警分为物理层、数据链路层、Tunnel层、PW层、仿真业务层五个层次。对应SDH的物理层、再生段复用段层、服务层、路径层。上层功能的实现依赖于相邻下层提供的服务。低层与高层同时有故障产生时，低层故障的消除是处理高层故障的基础，物理层故障引发的告警屏蔽其它层故障引发的告警。SDH的告警与PTN的最根本的区别在于SDH的告警都是由字节承载上报的，而PTN告警则是由协议控制上报的；但都有其相似之处,如下图：图28PTN网络与MSTP告警对比图业务模型中，PW可类比VC12、Tunnel类比VC4管道，CES即电路仿真业务就是传统的E1；告警可划分为业务类告警，系列类通用类告警，下面表格按业务告警，与SDH进行类比，各业务层告警对比：MSTP告警SDH、PTN类比结果PTN告警业务层（VC12）(ETH/CES/IMA/ATM)TU_AIST_ALOSUP_E1_AISDOWN_E1_AIS等继承了SDHE1、ATM、IMA业务告警的特点PW_DOWNT_ALOSTU_AIS_VC12UP_E1_AISDOWN_E1_AIS等PW&业务层(ETH/CES/IMA/ATM)服务层（VC4）HP_SLMHP_UNEQ继承了服务层SDH告警，新增加了MPLSTunnel类告警MPLS_TUNNEL_LOCVHP_SLMHP_UNEQTunnel层(Tunnel/PW/MPLSAPS)再生段复用段层(开销)B1、B2误码检测告警复用段告警IMA业务告警继承了SHD误码类，复用段类告警(线性)，增加了多协议标签交换(MPLS)告警，LAG类告警B1、B2误码检测线性复用段告警IMA业务告警LAG_DOWNMP_DOWNETH_APS_LOSTETH_APS_PATH_MISMATCHETH_APS_SWITCH_FAILETH_CFM_MISMERGE数据链路层(MLPPP/STM/LAG)物理层(单板/ETH端口/SDH端口/E1口)R_LOSETH_LOST_ALOSLASER_MOD_...
