I fought with my ata186 until I decided to start dorking with the settings. I found no outbound faxes could be sent (fax handshake never could complete) until I set the "AudioMode 0x00050005". Basically this sets the ATA for fax mode which is documented on: http://www.cisco.com/en/US/products/hw/gatecont/ps514/products_administratio n_guide_chapter09186a00801e0dff.html#wp1012620