SDH Code Violations （CVs） totals in the PM tables are actually an accumulation of the number of（）.

多项选择题Click the Exhibit button. The exhibit shows a 15454 15216 DWDM system and alarm indications.  What are two possible sources of trouble shown in the system？（）

A. fiber failure between Sites A and D
B. EDFA failure at Site A （clockwise direction）
C. EDFA failure at Site C （clockwise direction）
D. 15216 multiplexer at Site A （counter-clockwise direction）
E. OADM pass-through （West "OUT"） failure at site D （clockwise）
F. wavelengths 1 and 3 transmitter failures at Site A （clockwise direction）

多项选择题Whataretwoimportantconsiderationswhenusing2-or4-channel15216OADMs？（）

A. All "Add" channels require uniform power levels.
B. The flexibility of wavelengths per OADM is limited.
C. It is easier to balance "Pass-Through" and "Add" channels.
D. There is lower pass-through loss using multi-channel OADMs.
E. You can extract a single channel without dropping other channels.

单项选择题Click the Exhibit button. What is the maximum allowable loss budget between the ONS 15216 Mux （left side） composite output and the ONS 15216 Demux （right side） composite input，  with the optical values given in the exhibit？ （Assume the worst case loss of 4.5 dB for 15216 200 GHz Mux Demux and ignore power penalties or extra margin.）  （）

A. 15 dB
B. 17 dB
C. 21 dB
D. 26 dB
E. 27 dB

单项选择题A 2.5 Gb s （OC-48 or STM-16） optical signal with a dispersion tolerance of 1200 ps nm goes through fiber with 18ps nm*km of dispersion.  How many 15216-DCU-350 equivalents are needed for enough compensation after traveling 100 km？（）

A. none
B. one
C. two
D. three
E. four

单项选择题The ONS 15216 is a 32-channel system. The ONS 15216 OADMs are capable of adding and dropping one， two， or four channels.  How are the OADMs provisioned to add and drop specific channels？（）

A. The ONS 15216 OADM can be provisioned to add/drop one， two， or four channels via Cisco Transport Manager （CTM）.
B. The ONS 15216 OADM consists only of a four-channel module， and the number of ports utilized determines whether it is a one， two， or four channel OADM.
C. Three separate OADM modules are available for one， two， and four channels. The wavelengths to be dropped and added are programmable via Cisco Transport Manager （CTM）.
D. The ONS 15216 OADM consists only of a single-channel module. Two-channel and four-channel support is available by stacking the single-channel module.
E. The ONS 15216 OADM is available in one， two， four channels.  There are 32 single-channel OADM modules， 16 two-channel OADM modules， and 8 four-channel OADM modules.