单项选择题
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
相关考题
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单项选择题
If node 2 is accepting line timing from node 1, node 2 will send （）to node 1 as its SSM message.
A. ESF
B. PRS
C. DUS
D. SMC
E. B8ZS -
单项选择题
SONET Code Violations (CVs) totals in the PM tables are actually an accumulation of the number of （）.
A. J0 errors detected in a specified interval
B. errors detected in a given Errored Second (ES)
C. errors detected in a given Severely Errored Second (SES)
D. errors the encryption algorithm detects in a specified interval
E. Bit Interleaved Parity (BIP) errors detected in a specified interval -
单项选择题
Scrambling of SONET signals is done to （）.
A. prevent the leakage of external fiber emissions
B. provide the optical network with the highest level of security possible
C. assure an even distribution of 1's and 0's for extended transmitter life
D. assure an adequate number of transitions for clock recovery at the receiver
E. prevent the receiver from assuming AIS inadvertently when all 0's are received
