After configuring 3CX and SPA-3102 according to the guide (http: //www.3cx.com/sip-phones/linksys-spa-3102-fax/ No longer available. New link: http://www.3cx.com/sip-phones/), the extension is registered and a fax from SPA-3102 to 888 works but is distorted. Faxes to external numbers are disrupted and reported failed due to "communication errors". So faxing to 888 "works" but the image is distorted and not readable. See attachment for sample. Any ideas?