I have Call Manager 4.3, Cisco Unified Video Advantage, Gateway 2811 with PRI ISDN and fax on ATA 186.
I have trouble when send fax, sometimes is no problem but frequently is problem: if fax dokument have 2 or more pages - fax send is no complete.
Sometimes fax send document but on other side fax receive nothing.
When fax receive document this is no problem, this working good.
I try to configure ATA 186 and Call Manager like on this site: http://www.cisco.com/en/US/products/hw/gatecont/ps514/products_configuration_example09186a00800d698e.shtml