I have a strange FAX issue, where a FAX machine connected to a VG224 can send/receive FAX to any number but is not able to send one outside number a FAX. It can receive FAX's from them fine, just not send. The FAX machines phone or a phone plugged into the FAX phone line can call the # fine so there is not a CSS issue, etc.
The FAX machine is plugged into a VG224 with IOS 12.4(11)T , the VG224 is configured as SCCP (stcapp) and we have tried setting the port capabilty to modem passthrough and not with no change.
The PSTN Gateway is a Cisco 2821 with a PRI, it is MGCP and running IOS 12.4(9)T and has FAX relay disabled.
We have tried 7 different FAX machines of different models and neither are able to call this particular outside FAX machine when going over IPT. When the FAX machines are plugged into a traditional analog circuit there is not a problem and the FAX works fine.