I'm running an elastix 2.0 system with a SIP trunk. Inbound calls get a fast busy signal the first time the number is dialed. Wait a few seconds to redial and the call will complete as normal. The IVR or whatever its set to will answer. This works until the system has been idle for a little while then it returns to a fast busy. Outbound calls seem to work normally, and extension to extension calls and all other services work while this is going on. Thanks.