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To: altq@csl.sony.co.jp, akorud@polynet.lviv.ua
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Subject: Re: [altq 575] Re[2]: [altq 565] Running ALTQ
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Date: Tue, 05 Sep 2000 13:36:13 +0900
From: Kenjiro Cho <kjc@csl.sony.co.jp>
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Andriy Korud wrote:
> And few more questions:
> 1. What does ALTQ_NOPCC option mean? Will disabling it (using
> processor counters) improve limit resolution?

It requires only one machine cycle to read a processor cycle couner
(timestamp counter for pentium), which is much cheaper than using
microtime().  However, it doesn't affect the kernel timer resolution.

> 2. When CDRN or HFSC are typically used? I saw something about that
> CDRN can limit incoming traffic, is it true? Maybe some references in
> Internet?

CDNR (traffic conditioners) is a set of mechanisms to meter, mark, or
drop incoming traffic.  A good starting point would be RFC2475 (An
Architecture for Differentiated Services).

HFSC (hierachical fair service curve) is a queueing discipline from
CMU.
http://www.cs.cmu.edu/~hzhang/HFSC/main.html

-Kenjiro


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