intelligent load balancing

[Marco Berizzi]

I'm doing simple load balancing with two cheap adsl lines using
nth to SNAT packets:

-m nth -every 2 -packet 1 -SNAT adslA
-m nth -every 2 -packet 2 -SNAT adslB

This is working quite good, but I would like to do an intelligent
load bal. Here is how it is currently working:

1° socket -->> SNAT adslA --- 3k gif file
2° socket -->> SNAT adslB --- 700m iso Slackware 1° cd image
3° socket -->> SNAT adslA --- 5k html text only page
4° socket -->> SNAT adslB --- 700m iso Slackware 2° cd image
5° socket -->> SNAT adslA --- 2k png file
6° socket -->> SNAT adslB --- 40m tar.gz linux source file

As you can see adslB line is full and adslA line is empty.
Is there anyway to optimize this?