[Fwd: Re: Altq beginner question]

["Greg Thomas" <getbsd_(_at_)_dslextreme_(_dot_)_com>]

Didier Wiroth
> Hi, thanks for answering.
>
>> This is about right.  384/8*0.8=38.4.  What's that mean?  Your
>> advertised rate (384kb) divided by 8 (bits per byte), with about 20%
overhead in the initial TCP packets, gives you a small file download
rate of roughly 38kB/sec.
>>
>> >What speed do you use in the PRIQ parent queue if you are not using
percentages?
>> >
>> >Do you use the actual download rate like?
>> >altq on $ext_if priq bandwidth 37kb queue {xyz}
>> >
>> >
>> no
>
> No???
>
>> >or
>> >Do you use 384kb (which I actually never have)?
>> >altq on $ext_if priq bandwidth 384kb queue {xyz}
>> >
>> >
>> yes
>
> So, because of the "no" above and your "yes" I'm a little bit surprised.
>
> To be sure that I've understand, do I always put the "advertised" rate
in the altq parent queue:
> For example, for my actual tv-cable connection advertised at 384kb (real
download rate 38kb), I put:
> altq on $ext_if priq bandwidth 384Kb queue {xyz}
> and this to for an advertised dsl of 2mb (which will have a download
rate of
> more or less 200kb)
> altq on $ext_if priq bandwidth 2000Mb queue (xyz)
>

I don't know much about altq but I do know you need to be consistent when
talking about bits and bytes.  In your examples above:

b should be bits, B bytes

384 Kb ~ 38 KB
2 Mb = 2048 Kb ~ 204 KB  (2mb is not 2000Mb)

So:

altq on $ext_if priq bandwidth 384Kb queue {xyz}
altq on $ext_if priq bandwidth 2Mb queue (xyz)

Greg