单项选择题

What protection method is used in 4F BLSR networks?（）

A. Each fiber has half of its SONET capacity reserved for protection.
B. Two fibers in the span carry working traffic, while the other two fibers in the span are reserved for protection.
C. The signal is sent simultaneously in both directions around the ring. The receiver determines which fiber to listen to based on signal quality.
D. The signal is sent simultaneously in both directions around the ring. The transmitter determines which fiber has the working bit set for the receiver to acknowledge.

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热门试题

单项选择题Which is a legitimate bandwidth matched pair?（）

A. DS-1; E1
B. DS-1; STM-1
C. OC-3; STM-1
D. STS-1; STM-1
E. OC-192; STM-192

多项选择题SONET Path Terminating Equipment (PTE) requires which three line codes to be supported for DS1 and DS3 circuits?（） (Choose three.)

A.AMI
B.ESF
C.DUS
D.SSM
E.B3ZS
F.B8ZS

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

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