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 From:  Dinesh Nair <dinesh at alphaque dot com>
 To:  Justin Ellison <justin at techadvise dot com>
 Cc:  m0n0wall at lists dot m0n0 dot ch
 Subject:  Re: [m0n0wall] Theory behind Magic Shaper?
 Date:  Thu, 02 Dec 2004 15:09:44 +0800
On 02/12/2004 02:13 Justin Ellison said the following:
>>Given high priority up/download are mainly for VPN, so let's assume only
>>catch all and hated are in use: if a queue is completely unused, how is
>>traffic distributed?
>>
>>Default magic shaper config for those is as follows:
>>Upstream weights: catch-all (4), hated (1)
>>Downstream weights: catch-all (40), hated (10)
>>
>>So, am I right in saying that given none of the high-priority queues are in
>>use, for every 4 packets of "ordinary" traffic, one packet of "hated"
>>traffic is allowed? If so, that means that 20% of outgoing traffic should be
>>"hated". Is there any mileage in changing this by reducing the priority of
>>the "high priority" queues in favour of increasing the priority of the
>>general queue?
>>
>>i.e. High priority is redefined as weight=50, general has a weight=49, and
>>hated has a weight=1.
>>If my calculations are correct, that should mean that only 2% of outgoing
>>traffic would be P2P.
> 
> It has been *so* long since I worked with the weights (and to be honest,
> Dinesh had to explain it a few times to me), that I'll let someone else
> answer the above.  Be a good review for me :-)

heheh, well, the weightage system as used in dummynet is more of a ratio 
rather than a true weight in that sense. as you've noticed, if there're no 
packets in any queue other than the catch-all (4) and hated (1), the 
available bandwidth is 80% catch-all and 20% hated, assuming the link is 
being maxed out. however, if there're no catch-all packets, then hated gets 
100% of the link.

-- 
Regards,                           /\_/\   "All dogs go to heaven."
dinesh at alphaque dot com                (0 0)    http://www.alphaque.com/
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