VoIP Development on BlackBerry 10

Let me be the first to share with you that real-time communications (VoIP) development is not only possible, but the BlackBerry® 10 platform was specifically built from ground up to deliver the best communications experience. There may be plenty of open source stacks out there for VoIP development, but an important one that comes to mind is PJSIP. To provide a brief overview, PJSIP is a free and open source multimedia stack written in C, and it supports audio, video, presence, and instant messaging capabilities. This allows you to develop compelling real-time communication applications, such as VoIP phone.
This may seem like a lot of porting effort but based on my experience in working with our good friends here at Truphone, this was fairly easy to bring over to BlackBerry 10. I want to take this opportunity and share their experience in porting a PJSIP open source multimedia stack over to BlackBerry 10

Check out the interview with Adam from Truphone

Source : Inside BlackBerry Developer