Pls, can anybody explain to me the usage of bandwidth, What am try to say is that if i have a Linux server for web hosting how can i contact or get the bandwidth for my clients.
Is it from the ISP or in what way.
Thanks.

Do you have a control panel running?

All _GOOD_ control panels should show bandwidth usage for each domain.

To add to what wubwob said, your ISP will (should) supply you with overall bandwidth stats using something like MRTG. It's up to you to keep your own stats for comparison.

Thank you very much for the reply, But what i really want is when you contact for web hosting the word (15GB tranfers bandwidth monthly) What does it means, and how can you contact bandwidth for you clients?.

your post is very confusing :(

try rewording it?

What i really need is this (WHEN YOU OFFER 15GB DATA TRAFFIC TRANSFER MONTHLY) WHAT DOES IT MEANS, And how does they acquire this bandwidth, I mean the web hosting Company.¿Does it mean the network line you rent from your ISP or is other thing else am confused?, I can´t understand it.
Thanks.

OK -

You buy webhosting - they allow you 15GB of datatransfer a month.

This means - you are able to download/upload that much of data - the bandwidth is provided by whoever you buy hosting from!

he wants to buy bandwidth......
15gb a month of bandwidth, means you are buying that much data transfer a month....

How old are you?

I think he wants a pipe to feed his server, call your telco and get a t1 if you want to do hosting, or get a ded. server.

And if you want to keep your sanity dont get a t1 from at&t, my 2 new t1's were to be setup last month on the tenth, and Im still waiting for them.