Re: [ns] Flowmon trace format

[Ratul Mahajan <ratul@aciri.org>]

> I need clarification on certain fields of the trace generated by Flow
> Monitor. I make flowmon dump the statistics every 0.1s in a file:
> 
> 1) what is meant by early drops?

The drops as a result of running RED queue. These are drops in the early
detection phase (min_th <= avg_q <= max_th).

 
> 2) Does "arrivals this flow" give the cumulative # of arrivals for a
> particular flow or the arrivals measured between 2 writes (0.1s in my
> case)

Cumulative # of arrivals, unless you "reset" the flowmonitor between
writes.

> Does flowmon make an entry in the trace file only when there are drops in
> a particular flow? I've 80+ flows in my simulation, but just 14 are
> monitored inside the trace file.

No, I _think_ it makes an entry for all the flows which have been
instantiated. Flows get instantiated when they send the first packet. To
verify how many flows get instantiated you could do "$flowmon flows" which
returns the list of flows it is currently monitoring. 
You could read the source file flowmon.cc to verify the above.

Hope that helps.

-ratul