[LARTC] Delay before shaping kicks in

[Andy Furniss]

Steinar Pedersen wrote:
> I am shaping traffic very sucessfully, but I still have one problem that I
> just can't figure out the solution to.
> When my backbone becomes saturated with traffic, I use prio to diffreciate
> between users, so that those who
> need it most, actually gets their service. BUT... when using prio, it
> actually takes a few seconds before the service they
> need is given to them.
> 
> An example:
> 
> One user downloads with 10mbit (full speed of the link)
> Another user with higher priority starts downloading, and for the first few
> seconds only get a fraction of what he really needs, but then suddenly, the
> speed increases, and the low-prio user looses his speed.
> 
> Is there a way to make this "kick in" start faster?
> 
> I checked the net/sched/sch_htb.c and found:
> #define HTB_EWMAC 2     /* rate average over HTB_EWMAC*HTB_HSIZE sec */
> 
> Could decreasing this to like 1 second fix the issue?

It's more likely to be because you are not allowing for overheads and 
have the rate on htb too high for the link so packets get queued elsewhere.

Andy.