Try MYPhone – myphone.sourceforge.net
I dont know how much it is ,but it works great to my customers Planet VOIP box- in the call section type firstname.lastname@example.org and then press the call button-
You need to have a headset connected to your pc
Martie will answer tell her ” Hi Martie just testing have a nice day!”
Hey dont abuse this call!! Martie is a nice person and deserves respect!