Q4. (15 marks) What do the following acronyms and terms represent in connection with reliability for networks? a) MTBF b) MTTRc) Unavailability Your answer should supply definitions for each (6 marks). d) An optical fibre undergoes 0.4 cuts/yr on the average. If the MTTR of the cable is 12 hours, calculate the unavailability in minutes per year. (2 marks) e) i) Explain what the term 1:1 protection means, define all the terms that you use. (2
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