Re: more info. on qmonitors.

[kfall@ee.lbl.gov]

>
> From:  kpoduri@BayNetworks.COM (Kedarnath Poduri)
> To:    kfall@ee.lbl.gov
> Subject: more info. on qmonitors.
> Date:  Sun, 23 Nov 1997 20:22:57 PST
>
> Hi kevin,
> 
> 	Few days back I had asked a question regarding qmonitors and you wanted
> some more information. I had done some debugging and I found few things. Q 
> monitors by themselves work correctly. But if I have a flowmonitor 
> (Qmonitor/ED/FlOW) and a Qmonitor on the same link then the Q monitor does no
t
> work correctly. To be precise, the Q monitor counts only the overflow pkt dro
ps
> as pkt drops excluding the early pkt drops. Also, with a flow monitor on the 
> same link, Qmontior does not give correct values for average Qsize. However t
he 
> flowmonitor works correctly and is consistent.
> 
> 	Why is there a problem when I use both of them simultaneously?? I had 
> observed that get-bytes-integrator (bytesInt_) which is required for calculat
ing 
> average qsizes etc is not supported for flowmonitors. Can I obtain instantane
ous 
> and average qsizes at regular intervals with flowmonitors alone?
> 	
> Thank you
> kedar

One thing you should notice is that FlowMonitors are a subclass of
EDQueueMonitor, so you should not, in general, need both a flowmon and
a queue-mon (because a flowmon includes all the stuff a q-mon has).
So, install the flowmon, and where you need to, treat it as a qmon.
If you want to monitor early drops w/out a flow-monitor, you will
need an EDQueueMonitor (subclass of QueueMonitor).  QueueMonitors themselves
do not understand early drops.

hope this helps,
- K