3. Consider distributing a file of F bits held on a server to N peers using a P2P architecture. Let half of the peers have upload and download rates un dhe that are 10 times higher than the upload and download rates Hlow - diow of the other half of the peers. Let u, denote the upload rate of the server, and let us be 10 times higher than un. For the server, assume a fluid model where the server can simultaneously transmit to multiple peers, transmitting to each peer at different rates, as long as the combined rate does not exceed us. Each peer can transmit to only one other peer at a time. Ignore propagation delay. Assume that the server and peers know the upload and download rates of each other. Specify a distribution scheme to efficiently distribute the file. Approximately how much time does it take to distribute the file to all peers? Is your scheme better or worse for some numbers of peers than others? 4. Hosts R and Seach send a packet to port 5140 of Host T. (a) If the hosts use UDP as the transport protocol, then do the two packets go through the same socket of Host T? (b) If the hosts use TCP as the transport protocol, then do the two packets go through the same socket of Host T? (c) Explain why your answers to (a) and (b) are the same or are different. 5. In a selective repeat (SR) protocol, if a receiver gets a duplicate copy of a packet that it has earlier acknowledged and this packet has a sequence number in a range below its current window base, then the receiver sends a new ACK. (Details quoted below.) Explain why it is necessary for the receiver to reacknowledge this packet. From Figure 3.25 (SR receiver events and actions), Step 2: "Packet with sequence number in [rev_base-N, rcv_base-1 ) is correctly received. In this case, an ACK must be generated, even though this is a packet that the receiver has previously acknowledged