[LARTC] HTB, MPU, and suitable values

[Jason Boxman]

On Monday 17 May 2004 17:23, Ed Wildgoose wrote:
<snip>
> Read the follows to that post as well.  Basically it's only an
> approximation.  The "MPU" is basically pointing out that your ADSL
> stream is encapsulated in an ATM stream.  ATM uses fixed size 64 byte
> packets.  You need at least 2 of these, hence the 108 figure for MPU.
> Now you also need to estimate overhead which is going to be the size of
> the header on those ATM packets.

Now I'm confused.  Is it 53 bytes or 64 bytes?

http://www.faqs.org/docs/Linux-HOWTO/ADSL-Bandwidth-Management-HOWTO.html

> However, that still leaves the "wasted space" on the end of small
> packets (eg those that take up 2.5 ATM cells, how much does the 0.5 take
> up).
>
> I suggested a crude way to tweak that patch (easy to see how it works if
> you look at the relevant lines in the orig file). However, I dont even
> have a working QOS system so I haven't even compiled it!  Look up the
> specs for ATM though and you should be able to tweak that suggested line
> change and get something.

So the patch is supposed to increase the cost of dequeuing packets, then, 
provided you know what numbers to use?

> I for one would be really interested to hear if it solves the problem!
>
> Ed W