Stephane M wrote:
>
> But I think about companies, which want to install a VoIP system....
> that seems to me not really suitable for companies..

If you do it right, then you are ok.

We don't use any normal phoneline for voice in the office. We use
analogue lines for outbound fax and the PDQ machine, but all voice comms
goes over VoIP.

It works really really well.

But

1) we use a really good ISP
2) All our internal cabling and such is very good
3) We use good quality phones
4) We have a CTX1000 [1]
5) The network is well managed - nobody uses bittorrent, skype or othe
network unfriendly applications.... during working hours.
6) We are near to the phone exchange. We use an AR7 chipset based ADSL
router, which we think are the best at holding up the line. We use
quality faceplate ADSL filters. So our ADSL holds up really well.
7) We use a good quality SIP service provider for our inbound numbers.

We have between 5 and 7 people in the office, using it all the time.
For business phonecalls.

If we didn't use VoIP, then we'd be paying BT for 3 or 4 ISDN2e lines.
Not cheap. Also we would have a different phonenumber - we moved and
took our numbers to VoIP.

> you can't ask people to stop downloading while phoning :-)

You can't.

> So, I can't really see any possibility for professional use... Seems to
> be a bit dodgy !??

Not true.

> I installed in the company an FVX538, thinking that I would be able to
> use VoIP systems...

Maybe not.

> So, the only solution would be the CTX1000 ???

Maybe.

As others have said, you a device on the inbound side of a WAN link does
have limited scope for providing QoS.

But, if you assume that most inbound traffic is TCP. That can be slowed
down by delaying the ACK's, sending ECN or plain dropping packets.

Also, with an ADSL connection the download is in the VoIP's favour.
There is much more download bandwidth than upload. Less chance the
download will be saturated.

Tim