A.STM-1幀 B.STM-4幀 C.VC4 D.VC12
A.+4dBr或-4dBr B.-7dBr或-4dBr C.+4dBr或-7dBr D.0dBr或-4dBr
A.64Kbps B.32Kbps C.2Mbps D.8Mbps