[altq 17] Re: When a class is delayed

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

Cbqstat output:

Class_ROOT for Interface pvc0:
        priority: 0 depth: 1 offtime: 1 [us] wrr_allot: 9259 bytes
        nsPerByte: 4000 (2.00 Mbps),    Measured: 0.00 [Kbps]
        pkts: 0         bytes: 0
        overs: 0        overactions: 0
        borrows: 0      delays: 0
        drops: 0        drop_bytes: 0
        QCount: 0       (qmax: 30)
        AvgIdle: 1140 [us],     (maxidle: 1140 minidle: -1148 [us])

Class_DEFAULT for Interface pvc0:
        priority: 1 depth: 0 offtime: 42055 [us] wrr_allot: 14039 bytes
        nsPerByte: 5479 (1.46 Mbps),    Measured: 0.00 [Kbps]
        pkts: 0         bytes: 0
        overs: 0        overactions: 0
        borrows: 0      delays: 0
        drops: 0        drop_bytes: 0
        QCount: 0       (qmax: 30)
        AvgIdle: 1819 [us],     (maxidle: 1819 minidle: -1572 [us])

Class_CONTROL for Interface pvc0:
        priority: 6 depth: 0 offtime: 5573437 [us] wrr_allot: 0 bytes
        nsPerByte: 200000       (40.00 Kbps),   Measured: 0.00 [Kbps]
        pkts: 0         bytes: 0
        overs: 0        overactions: 0
        borrows: 0      delays: 0
        drops: 0        drop_bytes: 0
        QCount: 0       (qmax: 30)
        AvgIdle: 242968 [us],   (maxidle: 242968 minidle: -57375 [us])

Class_0 on Interface pvc0:
        priority: 1 depth: 0 offtime: 341250 [us] wrr_allot: 4807 bytes
        nsPerByte: 16000        (500.00 Kbps),  Measured: 0.00 [Kbps]
        pkts: 0         bytes: 0
        overs: 0        overactions: 0
        borrows: 0      delays: 0
        drops: 0        drop_bytes: 0
        QCount: 0       (qmax: 30)
        AvgIdle: 14875 [us],    (maxidle: 14875 minidle: -4590 [us])

All the parameter are ok.
I've compared them with those computed from the Floyd's papers.
However, (for example class DEFAULT) has an offtime of 42055 but the suspension time is about 130ms (measured with tcpdump).
In fact, the number of ticks is usually between 64 and 70 (more or less) with a kernel timer of 500Hz (2ms).

Hope this helps.

	fulvio

> -----Original Message-----
> From: Kenjiro Cho [mailto:kjc@csl.sony.co.jp]
> Sent: Friday, June 04, 1999 4:35 PM
> To: Fulvio Risso
> Cc: altq@csl.sony.co.jp
> Subject: Re: [altq 15] When a class is delayed
> 
> 
> 
> Fulvio,
> 
> >> Could you explain, maybe with pseudo-code, what is happening in the
> >> function rmc_delay_action (altq_rmclass.c)?
> 
> Please send the output of "cbqstat".  It would be helpful to
> understatnd what's going on.
> 
> -Kenjiro