我来说一下我讨论的结果吧：实际上G.841对protection的lockout有以下两个规定：首先lockout的倒换级别要求很高，仅次于clear，所以下发这个命令以后肯定会优先执行这个命令。第二，Lockout of Protection (LP): Prevents the selector from switching to the protection VC subnetwork connection, by issuing a Lockout of Protection request.也就是下发这个命令后业务会工作到主用上去而防止倒换到备用。第三，The FS-W command is unique only in 1 + 1 non-revertive systems, since the LP command would produce the same effect on a revertive system. 在1+1恢复式保护中，执行lockout业务会倒换到主用去。对于非恢复式，貌似很多厂家也还是这么做的。
