iptables match bits per second

Hi list,

I am searching for an iptables target/match to account/measure the bits per second on two different lines.

I've got 2 WAN connections with traffic shaping. Now I need to differentiate how much the network load is on line a, so i can switch to line b if it is above xx/mbit/s.

I've got kernel 2.6.14.4 with iptables 1.2.11.

I found "iptables connbyte", but it is only for 2.4 kernels.
I found "iptables connrate", which is exactly what I need, but it is only designed for kernel <= 2.6.5? (I got rejects in ip_conntrack_standalone.c). It seems like the code in kernel 2.6.14 and in the diff is on an absolutly different base.

Does anybody have got an idea how I could measure the bytes ?

Thanks