Thanks for tip.
As you can see, I am a newbie in these fields, linux, iptables and so on… but slowly learning stuffs.
What I wanted to do is MLPPP to bond two DSL lines into one single double speeded line, however stupid one month notice for cancelling policy in my previous ISP prevent me from applying MLPPP for whole last month so I just played around with Net balancer feature which caused me mysterious uploading timeout problems till now.
Jae