Tracking development of pjsip, the Open Source SIP, media, and NAT traversal stack/SDK/library for Android, iOS, Windows, Linux, MacOS, RTOS, embedded, and pretty much anything, any device.
Also check PJSIP Documentation site.
It wasn’t that long ago we speculated that pjsip on BlackBerry would be available sooner rather than later.
Well apparently it’s true: Tru has ported pjsip to BlackBerry 10 (a.k.a BB10, snappy though somewhat unimaginative).
So there you go. BB1o has stolen the thunder of us native C developers. Windows Phone 7 (a.k.a WP7), are you scared now?
Here is where we talk about pjsip development in general, and maybe other stuff as well. For the project itself, please go to the main pjsip project website. or pjsip documentation.
PJSIP is backed by Teluu, which provides professional support, additional licensing options, and a network of qualified consultants.
pjsip blog 
One response to “BlackBerry 10 VoIP SIP Client using pjsip”
The advancements in VoIP are just outstanding. With 4g service coming to most areas I think that it’s going to be feesable to place quality voip calls over 4g.