Re: WFQ: Rounded packet size

Petr and all,
the formula for active flow from the IEWB below is:
newSN = previousSN + W * PacketSize

This is very different from the formula in "CCIE Practical Studies
Volume II" chapter "Chapter 6:
newSN = previousSN + W

They are profoundly different because the latter doesn't account for
packet size.

So which is the correct one?
Thanks,
bit.

On Mon, 2008-12-15 at 15:56 +0300, Petr Lapukhov wrote:
> Hi,
>
>
> Most likely, the book refers to the "round number" which is the size
> of the last packet sent by the scheduler. This value is used to
> initialize every new flow queue byte counter. You can read a detailed
> description of WFQ algorithm (explaning how this round number is used
> btw) here:
>
>
> http://www.internetworkexpert.com/downloads/IEWB-RS-VOL-I-V5.Section.10.QoS.teaser.pdf
>
>
> The second task in dedicated to WFQ. Understanding the internal
> working of WFQ is very important since the same scheduling procedure
> is used by CBWFQ.
>
>
> HTH,
>
>
> --
> Petr Lapukhov, CCIE #16379 (R&S/Security/SP/Voice)
> petr_at_internetworkexpert.com
>
> Internetwork Expert, Inc.
> http://www.InternetworkExpert.com
> Toll Free: 877-224-8987
> Outside US: 775-826-4344
>
>
>
> 2008/12/14 Bit Gossip <bit.gossip_at_chello.nl>
> Experts,
> any idea on how these value are calculated for the WFQ min-max
> algorithm?
> In "CCIE Practical Studies Volume II" chapter "Chapter 6. QoS
> b Rate
> Limiting and Queuing Traffic" there is an example where 60 and
> 700 are
> used. But how are these value determined?
> "During the WFQ process, packet size is noted when new packets
> arrive.
> If the IP flow that they belong to is new, a rounded packet
> size is also
> used."
> Tnx,
> bit
>
>
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Received on Mon Apr 26 2010 - 21:49:37 ART