Hello Im Sourish, I'm a asterisk, vicidial and linux expert. I have installed more than 50 voip servers in last 3 years.
I can do this for you within 3 - 4 hour. Please let me know the device that you are having and the voip provider that you would be using. This job is just a walk on the cake for me and I'm confidant enough. You can try it with me and if you are satisfied then you can pay me. Please do let me know if i can be a part of this project and i would eagerly wait for your response.