I was looking for a free Voip application in order to test my SIP Server. So I installed Fring and Whistle. Both Programs allow you to selected a Private SIP. So I put in the proper server Public IP address and the USER/Password. The funny thing with Whistle, that it looks for numbers in the USA Numbring plan. So If I dila 9+XXX-YYYY it will reject it. If I dial 9-03-XXX-YYYY it will consider it as if I intended to dial area cod 903 and reject it. But if I dial 4 digit number ( Our Internal Phone system at work) it works OK. Couldn't find a place or setup to tell it to forget thr USA Numbering plan. But anyway - It works great (free) on our PBAX. Fring works fine also for out dialing like dialing 9-xxx-yyyy. So who said the iPAD is not a phone ?????