What You Need
In order to use a PRI, your phone system must support PRI. Most phone systems do, but if you don't have a PRI in your phone system now, you will probably need an add-on card to upgrade your system to use a PRI.
Bandwidth Considerations
Keep in mind that you will need adequate bandwidth for any VoIP system. Also keep in mind that you get the best results if you implement VoIP traffic Quality of Service (QoS). This is easly done in most broadband T1 and SDSL routers. We will be glad to help you.