Which timing mode is appropriate for a SONET NE that is adjacent to a SONET NE using BITS－1 timing source?()
题目内容(请给出正确答案)
Which timing mode is appropriate for a SONET NE that is adjacent to a SONET NE using BITS－1 timing source?()
A.DUS
B.line timing
C.loop timing
D.internal timing
E.through timing
