Voip through vpn

Hi ,

I am using voip in US with one provider. They have asterisk server.

But I want to use it from India .Since ISP"S blocking VOIP in india call is failing.

So I think it would be better to use VPN . But I don’t know the exact way for it. I already have a VPN connection b/w US and India. I can connect my hosts in US.
But the asterisk server is in other location in US. So even though I have a VPN connection between my sites , I think I need to do more since the provider’s asterisk servers in other location. How can I overcome this issue…please help me…

This is my scenario.

VOIP provider

  • internet

_____________ VPN ___________
US SITE < ==========================> SITE IN INDIA