1. Explain the OSI layers.
2. If a person works for 9 hours and takes a 1-hour break and 1 hour for lunch, how much is he productive?
3. What is optical amplifier Types of amplifier What about mux and demux What is dwdm Basic component of dwdm Signal Flow of dwdm What is attnuation and dispersion loss What is crc What is osc How to find recevier sensitivity in fiber otics link