Call Forwarding examples for entire line?

I want to move my pstn phone number to a voip provider but I need to get call forwarding working first. Now I can dial a code and Verizon will forward all incoming calls on that line to my cell phone for example. If I move my number to a voip provider, I presume I need Asterisk to perform this function right? I have tried several examples I have Googled but they all seem to deal with forwarding one extension. I even got one example to work but only if I dialed my extension from another inside ext. When I call in from outside, it does not work. Does anyone have examples on how to set this up??

Unless your ITSP explicitly allows you to have simultaneous incoming and outgoing calls, you can’t. On the other hand, most ITSP’s include server-side call forwarding in any package so you won’t lose the functionality. Why set this up yourself?