A) You are operating a fiber optical network cable from Reykjavik to Egilsstadir (700 km cable length). The transmission speed on the cable is 10 bit/s, and the effective transmission speed of light in that fiber optical cable is 210⁸ m/s. You are sending ping messages over the cable. What is the round-trip-time (RTT) that you can expect to observe (considering only the transmission delay, ignoring any other processing delays)?

B) How long does it take to transfer a 4K HD movie file, 100 byte in size, via the fiber optical network cable, assuming that network headers add 50% overhead to the data size, but apart from that, the available network capacity can be fully utilized?

C) Let's now assume that a single TCP/IP connection is used to transfer the movie from Reykjavik to Egilstadir, and a maxium transmission window of 1 Mbyte is used. Taking these factors into account, what is the actual transfer time to be expected?

D) What could be done to reduce the transmission time you calculated in part (A)? Justify for answer! (The file size and the characteristics of the fiber optical cable cannot be modified!)