Re: [LARTC] patch: HTB update for ADSL users

[Ed Wildgoose <lists@wildgooses.com>]

>I'm running PPPoEoATM here.  I don't know what my actual PPPoE overhead is, 
>but I guess 10 bytes is reasonably close enough.  PPPoE is handled by my 
>Westell Wirespeed, which doesn't provide any useful cell information.  At the 
>moment I cannot easily obtain a cell count to determine my actual PPP 
>overhead.
>  
>

Try bumping the protocol_overhead up to 16 for PPPoE (from 10).  You 
should also make sure that your MTU is lower than that required by your 
PPPoE provider or else you will get ethernet packet fragmentation and I 
doubt we want to extend the patch to cover those situations anyway.

The patch should actually have most benefit when you are doing transfers 
with smaller packets.  I think with larger constant streams like the one 
you tested, there will be little difference between bumping up the 
interface speed with the patch or leaving it all as it was (at the end 
of the day we are mostly just shifting the calculation of interface 
speed somewhere else).

>Perhaps I need to idle everything and do one of those 'speed tests' to see 
>what my actual upstream is.  Could be it's really around 224, since I'm not 
>guaranteed 256 by my ISP anyway.
>  
>

Your upstream will be 256Kbits of ATM bandwidth.   This consists of 53 
byte packets with 48 bytes of data.  So you already only have 256 * 
48/53 of real bandwidth.  We then have to take off PPP headers and PPPoE 
headers.

We are obviously still a few bytes out with this patch or else you 
should be able to crank up the speed to 250 ish and still see your ping 
speeds stay low.  I will investigate further

Ed W

_______________________________________________
LARTC mailing list / LARTC@mailman.ds9a.nl
http://mailman.ds9a.nl/mailman/listinfo/lartc HOWTO: http://lartc.org/