Problem
Consider sending a large file of F bits from Host A to Host B, traversing three links with lengths DI, D2, D3 km and transmission rates of R,, Rz, R bps respectively (and two switches) between A and B. Signal propagation speed in the three links is v km/sec. Host A segments the file into segments of S bits each and adds H bits of header to each segment, forming packets of L = H + S bits. Assume R, > R > R3. Find the total time needed from the time that Host A sends the first bit of the file to the time Host B receives the last bit of the file. Ignore processing delay.