The dispersion of a non-zero dispersion shifted fiber is 6 ps/nm*km at 1550 nm and 10 ps/nm*km at 1610 nm. 
What is the minimum dispersion compensation required if an L-Band DWDM signal travels through 200 km of fiber and has a dispersion tolerance of 1800 ps/nm？（）

单项选择题Forlaserswithtightlycontrolledwavelengths，approximatelyhowfarapartarethecentersofadjacentwavelengthswhen100GHzspacingisusedinaDWDMsystem？（）

A. 0.4 nanometers
B. 0.6 nanometers
C. 0.8 nanometers
D. 1.2 nanometers
E. 1.6 nanometers

多项选择题Click the Exhibit button. Within an ONS 15454， you are provisioning a circuit on an unprotected SNCP ring. In the exhibit，  which two must you configure？（）

A. revertive
B. circuit size
C. circuit type
D. bidirectional
E. protected drops
F. Switch on PDI-P

多项选择题WhichthreetimingmodesaresupportedontheONS15454shelf？（）

A. line timing
B. loop timing
C. internal timing
D. through timing
E. external timing

单项选择题TheML-seriesEthernetcardontheONS15454providesupto（）activeQ-in-Qinstancespercard.

A. 512
B. 255
C. 1024
D. 4096

单项选择题You are installing a Cisco ONS 15454 SDH in a service provider site. An E3 cable is being connected to a digital cross-connect system.  What is the maximum distance allowed between the two？（）

A. 225 ft
B. 450 ft
C. 655 ft
D. 900 ft