cwnd and sstresh monitor

[Alin-Adrian Anton]

Alin-Adrian Anton wrote:
> 
> I used it now, and with a small patch it shows exactly what I need (seq, 
> ack, timestamp, cwnd and ssthresh). I just added my knob to trpt.c .
> 
> I also modified the iptime() function to provide microsecond resolution 
> instead of miliseconds, because most of the packets have the same 
> timestamp attached. Still, a decent number of packets have the same 
> timestamp. I'm looking at them only on one side of the connection (the 
> transmitter), I wonder if there is any better solution then timestamping 
> them on both sides - and mixing the values.
> 
> Thanks guys for the precious information, it helped a lot!
> 

Actually the method above had issues, packets not being logged in the 
debug buffer (which is limited and gets discarded quickly).

Using trpt -f did solve this problem, at the cost of duplicate entries.

So what finally did the job was a small "patch" of tcp_debug.c to print 
on console and print only what is needed (FreeBSD 6.0 won't allow 
"options TCPCONSDEBUG"), and /var/log/messages was parsed to extract the 
values.

Cheers,
-- 
Alin-Adrian Anton
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