# How to calculate throughput if there is network traffic

I came across this question in a textbook, but there are no solutions and I'm not sure how to solve this.

The question is: 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=500Kb/s, R2=2Mb/s and R3=1Mb/s. Assuming that there is another busy flow that travels through the same set of links (say from Host C to Host D), what will be the throughput for this file transfer?

I know that the throughput for no traffic would be the min(R1, R2, R3), so would the throughput with traffic be the max(R1, R2, R3)?

• Throughput can never be max(R1, R2, R3). The connection is only as fast as its slowest link. There's also a lot of variables involved, such as how the connections handle multiple requests. Is it on a first-come, first server? Round-Robbin? – CurtisHx May 29 '13 at 20:00
• Question wasn't very specific, so I was assuming that hosts A and C were sending at the same time. – John Li May 29 '13 at 20:17

`````` Speed = min(R1,R2,R3) / number_of_connections