I have set this up as described on the 3CX website (http: //www.3cx.com/sip-phones/linksys-spa-3102-fax/ no longer available. New link:http://www.3cx.com/sip-phones/). I can make and receive phonecalls. However, outbound faxes do not complete. I get an error report that the number is busy. It is not the provider. They have supported fax through a Linksys SPA9000 for the past four years. Any idea what the problem could be?