> Stef, > > thanks for your answer. I've read your FAQ and other sections of > www.docum.org. I've also been perusing Martin's original HTB > documentation now for a couple of days and doing graphing experiments > aimed at gaining better understanding of HTB's bursting behavior but > some questions remain. ;) > > From what you write, I would still say that burst and quantum do have > something in common, namely that they both somewhat determine how much > data is a class permitted to send where it's its turn to send. In your > example, it seems to me that setting burst kind of overrides for a > moment the behavior otherwise determined by quantum. But I agree this > connection between quantum and burst may be seen as too weak or abstract > so I won't push this point any further. > > Important notes to take: > > - you use bytes *per second* to specify burst - do you mean it, or is > that a typo? From docs I understand that burst is specified in bytes. Indeed, it's in bytes. > - more importantly, it follows from my measurements that setting burst > (not cburst, that's a different story) *won't* let a class go above > its ceil - if you are interested, go to http://kostra.uh.cz/htb-bursting/ > (ignore the Czech text ;) and see the section under header "Experiment > 1". Check out the complete config script and graphs of all three classes > below. 1:78 has a bit fat burst set, still it cannot break its ceil. > (However, it *does* make its parent class to break its ceil.) Did I mess > up the config? No. I did some tests my self witb burst and cburst. The problem is that it's very difficult to measuer and explain it. You have to believe Devik that it works :) And burst is not made for big bursts like you did. It also helps if you disable HTB_HYSTERESIS in the htb qdisc. See faq page for more info. > - back to your example - I'd even dare to say that the class you > described wouldn't profit from setting burst at all *unless* there's > another class competing for the bandwidth. (If there is a contention, > the burst setting will matter.) Can you confirm this? No. If you have a 10kbyte/s link and you have a class with ceil = rate = 5kbyte/s and a big burst/cburst (100.000byte or so), you can measure the burst. The first 100.000 byte will be sended by the burst so it will be sended in 10 second. I have some very detailed information about how the burst and cburst from parent and child classes are interacting, but I still have to create a page for it. It also explains how burst and cburst can exists and how the tokens and ctokens are changing when you are using the burst. Maybe something I can do tonight. I will keep you informed. Stef -- stef.coene@docum.org "Using Linux as bandwidth manager" http://www.docum.org/ #lartc @ irc.oftc.net
