Free or cheap VoIP solutions might have many advantages over expensive and even hard to use solutions. But if you find a reliable one your costs will be cleared in a time. For example to forward incoming calls and other softphone features I have already tried out an SDK and used its sample program: voip-sip-sdk.com/p_350- forward-incoming-call-voip.html (I don't want to advertise just give an example) and it's still working without problems. But if you use entirely free solutions it's probable that you will find yourself in a very difficult situation. What do you think about it? Please share your ideas about this important topic. Thank you.