1. How big window (in number of packets) is required for the channel utilization to be greater than 60% on a cross-country link of 4000 km running at 20 Mbps using 1 kByte packets? Use 2.5*10^8 m/s as the propagation speed.

2. Ethernet V1 access protocol was designed to run at 10 Mbps over 2.5 Km using 1500 byte packets. This same protocol needs to be used at 100 Mbps at the same efficiency. What distance can is cover if the frame size is not changed?