3. Point A needs to send a 50 kb file to point B. Each packet will contain L = 1000 bits of data. The distance between Points A and B is d = 50 km. The propagation velocity is V = 2 x 108 m/sec. The transmit data rate is N = 10 Mbps.

a. How long would it take to transfer the file from point A to point B using Stop-and-Wait flow control?

Time to transmit one frame:

Time to propagate last bit of frame from A to B:

Time to propagate ACK frame from B to A:

Total time to transmit and acknowledge one frame:

Time to transfer file:

b. What is the percent utilization of the link?