"Stephane M" <> wrote in message
news:dbi74s$mgl$1$...
> Hello,
>
> I have a slow ADSL... (512kb/s) however, I can see that if I make a VoIP
> phone call AND if I download a file at the same time, I have some trouble
> with my communication. (Not really suprising ... 
>
> - Do you think that this desappear with quicker broadband ?
No. Given more bandwidth, your download will be faster but will probably
still swamp out the VoIP call.
> - Or is there a trick to keep a good communication when somebody else is
> downloading at the same time on the network ??
>
Maybe.
The issue is that VoIP requires a certain bandwidth but without anything
stopping it, other things such as downloads grab all the badnwidth leaving
the VoIP call starved. You can reconfigure your network (if its not
already) like this...
Internet--- ADSL --- VoIP ATA --- Router/Switch/Hub -- Computer
|
+-- phone
However, this is still not 100% safe since this will protect the route up
from ATA to internet and might not help with the downstream. However its
possible that the ATA may also slow the downlink by acknowledging TCP
packets more slowly than it would otherwise - I'm no TCP algorithm expert
though.
For "real" VoIP installations, people create VoIP backbones with proper
Quality of Service (QoS) set up to protect the voice from the data. You can
do the same by stopping downloads whilst your on the phone.
Of course this all assumes that the ISP doesn't swamp your VoIP data
either - and you have no control on this.
Paul DS