ADSL Bandwidth Monitoring

[Joao Barros]

On 9/8/07, Ted Mittelstaedt <tedm at toybox.placo.com> wrote:
>
>
> > -----Original Message-----
> > From: owner-freebsd-questions at freebsd.org
> > [mailto:owner-freebsd-questions at freebsd.org]On Behalf Of Amitabh Kant
> > Sent: Saturday, September 08, 2007 12:25 PM
> > To: Bahman M.
> > Cc: freebsd-questions at freebsd.org
> > Subject: Re: ADSL Bandwidth Monitoring
> >
> >
> > On 9/8/07, Bahman M. <b.movaqar at adempiere.org> wrote:
> > > I tested the connection by downloading 2~3 files simultaneously and used
> > > 'bmon' as Mel suggested in another reply (thanks to him).  As I'd
> > > already guessed the RX don't get bigger than 30~40% of the expected
> > > bandwidth.  I performed the test with some other files and there was no
> > > difference.
> > >
> > > Thanks,
> > >
> > > Bahman
> >
> > The bandwidth being advertised by your ISP would be the maximum
> > thoughput allowed on your DSL lines with multiple DSL users sharing
> > the same bandwidth, something that is generally known as contention
> > ratio.
>
> Rubbish.  I work for an ISP and this is nonsense.  DSL is not a
> shared medium until it gets to the ISP and the ISP should be able
> to handle full rate circuits internally.

>From the customer to the DSLAM it's a copper pair. If the DSLAM is far
from the ISP backbone you have a shared connection. That's where
contention is applied. If for example he has 10mbits downstream
contracted and there are several "power" users hitting the same DSLAM
and the link to the ISP isn't big enough...

> He should be able to get max bandwidth from his home system to his
> ISP's system.  All our customers can. Beyond that, from his ISP to
> the rest of the world
> that is a different story.  But he needs to get the bandwidth correcte
> dbetween himself and his ISP first.

He should be able to get max bandwidth but not every ISP in the world
has link bandwidth allocated for all their customers. Example: you
have 100 customers with 10mbits contracted downstream. Think every ISP
out there will have a 1Gbps link from the DSLAM to the backbone? Most
definitely not. The same happens for mail servers. Do you believe
every ISP has enough storage space to hold the advertised email
storage space to their total number of customers? Most definitely not.

-- 
Joao Barros