[asterisk-users] VoIP over virtualized VPN

[Motiejus Jakštys]

Hi List,
Our company has several small distributed offices we would like to
inter-connect with bridged VPN a single subnet (last example in
http://www.shorewall.net/OPENVPN.html). We have SIP phones in every
office (up to 5) so we can use SIP without any NATing and securely.
Max theoretical simultaneous calls possible ~30, but we have ~5-10 @
regular basis.
OpenVPN server would be in the same datacenter like Asterisk PBX (in
one physical subnet). Asterisk and OpenVPN are virtualized XEN guests.

I wonder about overheads, system loads and other possible gotchas in
this setup. Is there anything I should (re-)consider before
implementing this? Anyone had difficulties running VoIP or VPN traffic
over (virtualized if it makes any difference) VPN?
We use mainly g729 and speex, and very little g711.

Regards
Motiejus