Re: traffic shaping and fixed per-packet overhead

[Patrick McHardy <kaber@trash.net>]

Matthias Urlichs schrieb:
> Hi,
> 
> I have an IPIP tunnel through a DSL line (PPPoE) which I need to
> traffic-shape / flow control. Unfortunately, the tunnel has a fixed
> per-packet overhead, which means that small packets overrun the
> bandwidth allowed for the tunnel and get dropped, while (if I set the
> allowed bandwidth to too-small values) the wire will be idle when
> I send large packets.
> 
> (I'm using HTB.)
> 
> I can think of a couple of solutions ...
> - Use bit-banging in the outer filter instead of nice rules on the tunnel.
>   (OK, that's a dumb idea from a useability POV.)
> - Extend the HTB code to allow specifying a per-packet overhead.
> - Hack the kernel to propagate a packet's netfilter MARK.

Totally unrelated to netfilter-devel, but:

# tc qdisc add htb help
...
  mpu      minimum packet size used in rate computations
  overhead per-packet size overhead used in rate computations