Which of the following statements about the sequence of a signal flow between the SDH interface and the cross-connect unit is correct?
SPI<>RST<>MST<>MSP<>MSA<>HPT
SPI<>RST<>MSA<>MSP<>MST<>HPT
SPI<>MST<>RST<>MSA<>MSP<>HPT
SPT<>MST<>MSA<>RST<>MSP<>HPT
Answer: A