Perhaps I have found an answer for some of my questions below, but most 
of them are still standing.

Here is a snippet I found in an example trace file at:
http://www.cs.odu.edu/~mweigle/research/netsim/intro/tracevar.out

And here is a snip of what that says:

# time srcnode srcport dstnode dstport variable value

0.00000  0  0  -1 -1 cwnd_ 1.000
0.00610  0  0  2  0  cwnd_ 2.000
0.01219  0  0  2  0  cwnd_ 3.000
0.01222  0  0  2  0  cwnd_ 4.000
0.01829  0  0  2  0  cwnd_ 5.000
0.01832  0  0  2  0  cwnd_ 6.000
0.01835  0  0  2  0  cwnd_ 7.000


The headers there is one thing I was looking for.  They make some sense, 
but can anyone verify that they are accurate?  And that doesn't address 
the apparent scale issue I saw with the 'time' value.


Thanks,
Justin



On 03/09/2011 11:45 AM, Justin wrote:
> ...
> I am trying to create graphs for RTT and throughput.
> ...
>
>
> For RTT, I am kind of stuck.  Yes, I have traced 'cwnd_' and 'rtt_' and
> looked at the file.  (Curiously, my RTT trace file (different from my
> cwnd_ trace file) only has one line in it.)
>
> Here is a clip (1st 10 lines) from the file, plus some headers that I am
> guessing at:
>
> Time                    Type    Value
> 0.00000  -1 -1 -1 -1 cwnd_ 1.000
> 1.29029  5  0  1  3  rtt_ 0.050
> 1.29029  5  0  1  3  cwnd_ 2.000
> 1.35309  5  0  1  3  rtt_ 0.070
> 1.35309  5  0  1  3  cwnd_ 3.000
> 1.35986  5  0  1  3  cwnd_ 4.000
> 1.40282  5  0  1  3  rtt_ 0.050
> 1.40282  5  0  1  3  cwnd_ 5.000
> 1.40959  5  0  1  3  cwnd_ 6.000
> 1.41635  5  0  1  3  cwnd_ 7.000
>
>
>
> Here's the corresponding overall out.tr (1st 30 or so lines):
>
> + 0.004717 2 0 tcp 40 ------- 1 2.0 1.0 0 0
> - 0.004717 2 0 tcp 40 ------- 1 2.0 1.0 0 0
> r 0.005749 2 0 tcp 40 ------- 1 2.0 1.0 0 0
> + 0.005749 0 1 tcp 40 ------- 1 2.0 1.0 0 0
> - 0.005749 0 1 tcp 40 ------- 1 2.0 1.0 0 0
> r 0.026206 0 1 tcp 40 ------- 1 2.0 1.0 0 0
> + 0.026206 1 0 ack 40 ------- 1 1.0 2.0 0 1
> - 0.026206 1 0 ack 40 ------- 1 1.0 2.0 0 1
> r 0.046663 1 0 ack 40 ------- 1 1.0 2.0 0 1
> + 0.046663 0 2 ack 40 ------- 1 1.0 2.0 0 1
> - 0.046663 0 2 ack 40 ------- 1 1.0 2.0 0 1
> r 0.047695 0 2 ack 40 ------- 1 1.0 2.0 0 1
> + 0.047695 2 0 tcp 592 ------- 1 2.0 1.0 1 2
> - 0.047695 2 0 tcp 592 ------- 1 2.0 1.0 1 2
> + 0.047695 2 0 tcp 592 ------- 1 2.0 1.0 2 3
> - 0.048169 2 0 tcp 592 ------- 1 2.0 1.0 2 3
> r 0.049169 2 0 tcp 592 ------- 1 2.0 1.0 1 2
> + 0.049169 0 1 tcp 592 ------- 1 2.0 1.0 1 2
> - 0.049169 0 1 tcp 592 ------- 1 2.0 1.0 1 2
> r 0.049643 2 0 tcp 592 ------- 1 2.0 1.0 2 3
> + 0.049643 0 1 tcp 592 ------- 1 2.0 1.0 2 3
> - 0.055935 0 1 tcp 592 ------- 1 2.0 1.0 2 3
> r 0.075935 0 1 tcp 592 ------- 1 2.0 1.0 1 2
> + 0.075935 1 0 ack 40 ------- 1 1.0 2.0 1 4
> - 0.075935 1 0 ack 40 ------- 1 1.0 2.0 1 4
> r 0.0827 0 1 tcp 592 ------- 1 2.0 1.0 2 3
> + 0.0827 1 0 ack 40 ------- 1 1.0 2.0 2 5
>
>
> In the cwnd_ trace file, type = CWND isn't too hard figure out:  that is
> the size of the window at that time.  But what is RTT and how is it
> calculated?  Is it simply for that one packet?  Does it actually
> calculate the return ACK to the sender as part of the RTT (which is what
> we would like, I suppose)?
>
> And why the drastic difference in the time fields?  What units is the
> 'cwnd_' time field in?  It doesn't seem to match up too closely with the
> packets from the full trace file.
>

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