I'm developing a SIP app with both desktop and mobile devices. I've had many headaches dealing with the examples of SIP (mobile mainly).
I was working on a real SIP server but now it's down. I've used Sun and Nokia SIP server emulators but they don't seem to work well.
So do you know a free SIP server (or emulator) easy, simple and robust?
My first goal is to have a dialog between a PC and a cell phone with INVITE.