Consider Fig. 1, which represents a communication network with some redundant components with variables Sk and Ti shown against the figure indicate the reliability of switch k and trunki, respectively. Ts + To S SA T3 5 SS=0.99, k=1, 2, 3, 4, 5 T=T=0.88, 1, 2, 3, 4, 5, 6, 7 Figure 1: Redundancy in switched telecommunications networks+ There are multiple alternative routes for data transfer between switches 1 and 3 in the network shown in Figure 1. + (a) List all possible routes between switches 1 and 3. (6 marks) + (b) Which of the routes found is the most reliable and why? (c) Compute the percentage of time that switches 1 and 3 can exchange Information. (5 marks) + (d) Compute the availability of the entire network? In order words, what fraction of time is it possible for at least any pair of the switches to exchange data? (6 marks) + (3 marks) +