[asterisk-users] QoS & VPN

[David Backeberg]

On Thu, May 7, 2009 at 3:54 PM, Brent Davidson
<brent at texascountrytitle.com> wrote:
> I've got multiple satellite office all linked back to the main office
> via VPN.  Each office has their own asterisk server which registers back
> to the main office's Asterisk server.  Each office also has a 1Mb
> downstream / 384k - 768k upstream connection.  The branches are using
> Speex for their connections back to the main office.  The issue I'm
> having is that there are times that I need to VNC in to machines at the
> various offices for tech support while the user is also on the phone.
> Unfortunately the VNC connection apparently takes priority and makes it
> impossible for me to understand anything the person on the phone is
> saying, although they can still hear me fine.

VNC is very asymmetric. It doesn't generate much traffic from the
person viewing, and it generates lots of traffic FROM the system being
viewed. This helps explain why the system being viewed side can hear
incoming voice packets, and outbound voice packets that have to
compete with the large amount of outgoing video signal data lose. QoS
may or may not help you here.

If voice quality is important, you should have a separate connection
dedicated to just voice. The obvious workaround is grab your cell
phone and call them with that. You DO have a way to dial directly to
that office without going over the PIX, right, right? How do you call
the remote office when the PIX goes down?

What will help you is getting a bigger line or separating the voice
traffic from the data traffic completely.

If you are good with ssh, you can also do a compressed ssh tunnel to
encrypt and on-the-fly compress the VNC session. But if this is
Windows good luck with that.