In the SDH optical synchronous transmission system, which of the following bytes is used to transmit the quality and usage information of clock sources?
A . G1
B . S1
C . N1
D . M1
Answer: B
In the SDH optical synchronous transmission system, which of the following bytes is used to transmit the quality and usage information of clock sources?
A . G1
B . S1
C . N1
D . M1
Answer: B