05-07-2010 05:59 AM
there are a large SIP voip that works with Blackberry as : Truphone, Gizmo5, tuitalk ,....
This a list of top voip softphone that works with Blackberry
11-09-2010 03:32 AM
There is a true BlackBerry SIP VoIP client for Bold/Curve. It's still in Beta testing phase but works pretty good. You can use it with any standards based SIP capable PBX including Asterisk and most SIP providers.
You can check it out here: