Charalampos Alexopoulos wrote: SER is exactly what you want. Although, as Greger says, there are many free providers out there that can provide you with service already (IPtel, IdeaSIP, Gizmo Project, FWD, etc, etc, etc). However, if you're interested in learning about SIP, or you specifically want to set things up yourself for whatever reason, then yes... SER is the way to go. It IS, however, somewhat of a steep learning curve, so be warned. We're in the process of making strides toward having a SER service ready to go with minimal effort, but it's not QUITE there yet. N.