[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[altq 187] Re: CBQ question
Prashant Chandra wrote:
> Kenjiro Cho wrote:
> > > Shouldn't the TCP stream on class4 also be able to use all the
> > > banwidth allocated to class3 (because they are under the same
> > > parent class class1)? I expected to see about 5 Mpbs for TCP in
> > > this case too --- if hierarchical link sharing was working right.
> > The link-sharing mechanism of CBQ is different from that of HFSC.
> > CBQ does not have a clear rule on how the excess bandwidth is
> > distributed. You cannot expect excess bandwidth distribution
> > is proportional to assigned bandwidth.
> > -Kenjiro
> There is excess bandwidth and there is unused bandwidth. I
> think one of the goals of hierarchical link sharing in CBQ,
> is to distribute bandwidth unused by a class to its children
> in the hierarchy. How much of the unused bandwidth each child
> gets may not be clearly defined.
> Still, I find it odd that class3's banwidth is not allocated
> to anybody else. There is about 4 Mbps of unused bandwidth
> that neither of the flows use. Is the CBQ scheduler non
Yes, the CBQ queue is non work-conserving. For more details, see
"cbq-howto.txt" in the "docs" folder of altq distribution.