Recall that in go-back-N protocol, the transmitting window size is N and the receiver window size is 1. Consider a pipelined, reliable transport protocol that uses go-back-N with cumulative acknowledgment. Assume that the timeouts trigger retransmissions (but note that duplicate acknowledgments do not). Further assume that the receiver does not maintain any receive buffer, the one-way delay between the sender and receiver is 50ms, and every packet is 10,000 bits long. Suppose that the sender must be able to send at a steady rate of 1Gb/s (gigabit per second) under ideal conditions. (a) What should be the window size to allow the steady rate mentioned above? (b) Suppose that the expected number of packets lost per 100,000 packets is 1. If the sender uses a timeout of 500ms and a window size of 20,000 packets, calculate the expected gap between two timeouts, when (i) The bottleneck link rate is 1Gb/s. (ii) The bottleneck link rate is 2Gb/s.