In the OSNR model for EDFA amplifiers， SNR OUT = 1/（1/SNR IN + FhvB/P IN ）， what does SNR IN represent？（）

If node 2 is accepting line timing from node 1， node 2 will send （） to node 1 as its SSM messge.

What is the difference between the transmitted power and the sensitivity of the receiver？ （）

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？（）

If the dispersion of a given fiber is 17ps/nm*km at 1550 nm and zero at 1310 nm， then what is the accumulated dispersion of an ITU wavelength after it travels 200 km？ （）

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？（）

Which is a legitimate bandwidth matched pair？（）

If the power is 0 dBm， what is the power in mW？（）

How is SNCP and MS-SPRing traffic rerouted during a protection switch when a complete fiber cable cut occurs？（）

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？（）