[altq 40] Re: something I cannot understand.

[Fulvio Risso <F.Risso@cs.ucl.ac.uk>]

Hello.
I think it's a problem due to the undertime computation.
In fact, according to me, the suspension time for a specific class is wrong in ALTQ.
Basically, when a class get suspended, the suspension time is more that the correct time, so that a class can not get the assigned bandwidth.

I tried to calculate it in a different way (see, last week, the messages on this topic on the ALTQ mailing list) and in this case a class is able to get the right bandwidth.
We're going to finish a technical report that cover also this point. I think it well be ready next week.

	fulvio



> -----Original Message-----
> From: owner-altq@csl.sony.co.jp [mailto:owner-altq@csl.sony.co.jp]On
> Behalf Of Stefan Stefanov
> Sent: Wednesday, June 16, 1999 1:32 PM
> To: altq@csl.sony.co.jp
> Subject: [altq 39] something I cannot understand.
> 
> 
> Hi all.
> 
> I have something I cannot understand. Here there are two consecutive
> outputs of cbqstat for a given class. Situation is the same with much
> more samples. The class is defined as following:
> 
> class cbq ed1 boza root_class exactbandwidth 192k maxdelay 12000
> 
> It seems that the class cannot reach it's assigned bandwidth. I am very
> sure that there is both available and requested bandwidth from that
> class.
> 
> Am I missing something? The queue has 44 (or 31) packets in it and the
> class is underlimit! Is there some granuality problem?
> 
> ALTQ is 1.0.3 on FreeBSD 2.2.7-RELEASE.
> 
> Class 0 on Interface ed1:
> 	priority: 1 depth: 0 offtime: 189775 [us] wrr_allot: 510 bytes
> 	nsPerByte: 41666	(192.00 Kbps),	Measured: 166.87 [Kbps]
> 	pkts: 9407,	bytes: 4388689
> 	overs: 888,	overactions: 981
> 	borrows: 0,	delays: 887
> 	drops: 0,	drop_bytes: 0
> 	QCount: 44,	(qmax: 191)
> 	AvgIdle: -609 [us],	(maxidle: 8137 minidle: -1954 [us])
> 
> Class 0 on Interface ed1:
> 	priority: 1 depth: 0 offtime: 189775 [us] wrr_allot: 510 bytes
> 	nsPerByte: 41666	(192.00 Kbps),	Measured: 168.00 [Kbps]
> 	pkts: 9625,	bytes: 4494529
> 	overs: 910,	overactions: 1003
> 	borrows: 0,	delays: 909
> 	drops: 0,	drop_bytes: 0
> 	QCount: 31,	(qmax: 191)
> 	AvgIdle: -1898 [us],	(maxidle: 8137 minidle: -1954 [us])
> 
> -- 
> Best Regards,
> 
> Stefan Stefanov
> Orbitel Ltd.