I have been using dummynet(4) to do traffic shaping for simulated WANs for over a decade now and it has been very effective - thanks Luigi.
I am currently looking at migrating the network simulator from 7.1 to
8.2 and have noticed that the statistics reported are now meaningless.
Instead of reporting cumulative statistics, it now appears to reset
them regularly - apparently whenever the pipe is empty.
Sample results from 7.1 (currently inactive):
00224: 2.000 Mbit/s 9 ms 64 KB 1 queues (1 buckets) droptail
mask: 0x00 0x00000000/0x0000 -> 0x00000000/0x0000
BKT Prot ___Source IP/port____ ____Dest. IP/port____ Tot_pkt/bytes Pkt/Byte Drp
0 udp 192.168.224.183/0 192.168.216.179/0 5404902 598099622 0 0
0
Sample results from 8.2 (currently active simulator):
00224: 2.000 Mbit/s 18 ms burst 0
q131296 64 KB 0 flows (1 buckets) sched 65760 weight 0 lmax 0 pri 0 droptail
sched 65760 type FIFO flags 0x0 0 buckets 1 active
0 ip 0.0.0.0/0 0.0.0.0/0 2 1785 0 0 0
(and most of the time, the last line doesn't appear).
I have checked a recent 9.0-BETA1 and it is still broken. Looking at
the dummynet.txt file, I cannot see this mentioned. I have looked
through the source and it does appear that scheduler instances are
marked inactive in serve_sched() once they have no packets queued and
are then garbage-collected via drain_scheduler_cb(). Is this the
intent? If so, how can statistics be collected?
--
Peter Jeremy
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