Thank you guys, I just sorted out the multiple sofia profiles and have FS accepting SIP registrations on our LAN. I plugged a phone into the LAN and it works. Now I'm trying to get this VoIP Plug-In for Microsoft Fax to work, that I downloaded from www.faxback.com. I configured it with a directory number I created, the dialplan seems to work, but it fails when sending the test FAX. The FAX number I'm calling is a POTS line connected to a Fax modem, which is answered by Hylafax. This works and is used everyday. The faxback software is installed on a Windows 7 machine, and configured by putting in a proxy address of 192.168.1.17, a username and password, and address of user@domain. The test call rings the fax modem, it answers, but then after some handshaking, it hangs up and the window says the call was hung up. Hylafax says: "No answer (T.30 T1 timeout)" -- Steve