单项选择题
In order to avoid misconnections due to a failed node in an MS-SPRing， Alarm Indication Signals （AISs） are sent on every channel normally terminating in that node. What is the name of this process？（）
A. bridging B. switching C. squelching D. nodal bypass E. node failure insertion
单项选择题 WhichtimingmodeisappropriateforanSDHNEthatisadjacenttoanSDHNEBits-1timing？（）
多项选择题 WhichtwocanbetransportedinoneAU-4？（）
单项选择题 HowisSNCPandMS-SPRingtrafficreroutedduringaprotectionswitchwhenacompletefibercablecutoccurs？（）
