Suppose host a wants to send a large file to host b. the path from host a to host b has three links, of rates r1 = 500 kbps, r2 = 2 mbps, and r3 = 1 mbps. a. assuming no other traffic in the network, what is the throughput for the file transfer? b. suppose the file is 4 million bytes. dividing the file size by the throughput, roughly how long will it take to transfer the file to host b? c. repeat (a) and (b), but now with r2 reduced to 100 kbps

Answer & Explanation:

a)

Throughput means the speed of the slowest link which is bottleneck for the network.

In the above case R1 = 500kbps is the throughput for file transfer.

b) Give file size = 4 million bytes =4 * 1,000,000 * 8 bits = 32,000,000 bits =

Time taken to transfer the file = filesize/throughput = 32,000,000/500,000 = 64 seconds

When R2 reduced to 100kbps

a)  

In this case R2 = 100kbps is the throughput for file transfer.

b) Give file size = 4 million bytes =4 * 1,000,000 * 8 bits = 32,000,000 bits =

Time taken to transfer the file = filesize/throughput = 32,000,000/100,000 = 320 seconds