One of my clients changed carriers recently. The new carrier is a SIP provider. A call was attempted from a copper line from Verizon to the SIP provider. The caller hears "All Circuits are busy". Same caller uses cell phone and gets in no problem. I called from my Comcast line and get to SIP service no problem. I call with Cell and Comcast and Broadview at the same time and get in with no problem. It seems that calls from Verizon to SIP provider are not making it. Tried with 1 and no 1 prefix. Tried 10 times from Verizon line - same recording. Is it possible that the Verizon database is not populated with the phone number from new carrier. The phone number is 50 years old. The receiving PBX is Asterisk Free PBX.