I've gotten closer to figuring out why the softphone cannot receive incoming calls. The following code snippet, from the CCallManager is the cause: private void OnIncomingCall(int sessionId, string number, string info) { IStateMachine call = this[sessionId]; if (call.IsNull) return; sessionId is a 1 for an inbound call, and call is resolved to a NullStateMachine. The code therefore returns immediately instead of calling any associated GUI events. Should the code be creating a state machine for the sessionId instead of returning? Let me know and best regards, Steve -- -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.pjsip.org/pipermail/pjsip_lists.pjsip.org/attachments/20100108/f35c91fc/attachment.html>