Question : VoIP with VPN

I have a leased line between the headquarters and another office. I already have VoIP on this line. I want to setup a vpn between these two locations and want to setup VoIP on this vpn just to make a second connection incase my leased line is down. Is this possible and if yes how can I do this ? Thanks.

Answer : VoIP with VPN

Hi burcayaroglu,
You're probably best asking in the Networking TA about how to set up a VPN.
Doing fail-over routing through a VPN could get a bit tricky, so you'd need to post a fair bit about your infrastructure setup.

Assuming that you've got that set up, you can indeed run VoIP between your sites over the VPN.
Exactly how you'd do this will depend on what VoIP equipment/software you're using.  

Assuming that you have a VoIP phone system at each office, you would configure them to communicate with each other using the internal IP addresses that would be accessible through the VPN.

Bear in mind that VoIP traffic is very fussy about packet loss, high latency and jitter.  If you're transmitting this data over the Internet (albeit through a VPN), you will need to consider the Quality of Service (QoS) issues.  Take a look at http://www.voip-info.org/wiki-QoS for more info.