Problem 4 Transmission Delay (31 pts): Consider the figure below, with three links, each with the specified transmission rate and link length. Assume the speed of light propagation delay on each link is v=3108m/sec. A network layer PDU of length P=1000 Bytes is to be transmitted from A to B starting from time 0 . The PDU originates from the network layer at A, and is considered received when being processed by the network layer at B. Between the network and the DLC layers, the communications happen over a shared memory with read/write speed of 1Gbps on all nodes. Other than memory read/write, assume the processing delay is 0ms on all nodes. The DLC layer adds an overhead of 125 Bytes to the PDU, and the physical layer adds no additional overhead. Assume there is no queueing on any link before the transmission. Answer all time-related questions in milliseconds (ms). Note 1: Draw a time figure of the PDU(s) through all layers/links to determine the delays. Note 2: The DLC layer must completely read a packet from shared memory before transmitting it on the bitpipe, similarly the network layer software must completely read a packet from shared memory before forwarding it, and each layer must wait until a packet is completely available in shared memory before starting to read it. F. (4 pts) Assume that from A to B there is another PDU of the same size, which is transmitted back-toback after the first PDU. What is the time T5 when the second PDU is ready to be sent out on link R1R2? Is this before or after when the first PDU leaves R1? Consequently, will the second PDU experience queueing at R1? G. (4 pts) Following E, what is the time T6 when the second PDU is ready to be sent out on link R2-B? Is this before or after when the first PDU leaves R2? Consequently, will the second PDU experience queueing at R2? H. (3 pts) What is the total queueing delay of the second PDU before reaching B? (3 pts) Assume now that there are 7 other transmissions fair sharing Link 2 (R1-R2). What is the bottleneck link bandwidth for the transmission from A to B ? (2 pts) Assume that the links are not perfect. Specifically, Link 1 has a packet loss probability of p1, Link 2 has a packet loss probability of p2, and Link 3 has a packet loss probability of p3. Further assume the links are independent. What is the probability that the second PDU arrives at the destination successfully