Question 5 Network Communication:

Consider a path consisting of four nodes: A, B, C and D in a store-and-forward packet-switching network. The transmission rate of link (A, B) is S_1 bps, the transmission rate of link (B, C) is S_2 bps, and the transmission rate of link (C, D) is S_3 bps. The propagation delay of each link is d seconds. Assume that the processing delay at each node is zero. Assume that S_3 > S_1 > S_2. The packet size is p bits. Node A sends two packets back-to-back at times t_1 and t_2, respectively, to node D, meaning that t_2 = t_1 + p/S_1. When does node B receive the last bit of the first packet? When does node B receive the last bit of the second packet? When does node C receive the last bit of the second packet? When does node D receive the last bit of the second packet