Incorrect formula for round trip time

[arciszewski]

INGInious-open/q-rel-delay1/run

Line 32 in 04eec31

rtt=1000*(dlen/(bw*1000000)+0.0001+clen/(bw*1000000)+2*prop)

Formula is:
rtt=1000*(dlen/(bw*1000000)+0.0001+clen/(bw*1000000)+2*prop)

1. dlen/(bw*1000000) - amount of time to send frame in seconds
2. 0.0001 its 0.1 ms, not 1 ms
3. clen/(bw*1000000) - amount of time to send frame in seconds
4. 2*prop - this time is in milliseconds
5. 1000*(... - factor that supposedly should transform milliseconds into seconds

Consider the example I had:
Distance between hosts is 550 km. The transmission I calculated is delay is 2.75 ms, which matches the expected result. The Bandwidth I have is 16 Mbps. What I calculated is:

1. 1000/16e6 = 0.0000625 s = 0.0625 ms = 62.5 μs - time to send data frame
2. 2.75 ms = 0.00275 s - time to transport signal from host1 to host2
3. 1 ms = 0.001 s - host2 processing time
4. 40/16e6 = 0.0000025 s = 0.0025 ms = 2.5 μs - time to send ack frame
5. 2.75 ms = 0.00275 s - same time to travel back
   0.0000625 s + 0.00275 s + 0.001 s + 0.0000025 s + 0.00275 s = 0.006565 s = 6.565 ms

The formula gives
rtt = 1000*(1000/(16*1000000)+0.0001+40/(16*1000000)+2*2.75) = 5500.165 s ~= 91 min ~= 1.5 hr

Overall there are three problems:

1. Multiplication by 1000 should be removed as the result is already in seconds
2. host2 response time in formula must be 0.001
3. 2*prop should be divided by 1000 to convert milliseconds into seconds