ADSL Bandwidth Monitoring

[Bahman M.]

Hi all,

I have an ADSL connection at home.

When I'm _uploading_ files the whole upload bandwidth is consumed; so 
far so good.

But when _downloading_ no more than 30~40% of download bandwidth is 
consumed.

The guys in the ISP say they've granted me the requested bandwidth but 
this is not what I see in action.

How may I know the real bandwidth limits of my connection?  Any tool or 
trick?  Or maybe I'm misunderstanding something about ADSL bandwidth?

TIA,

Bahman